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USER MANUAL DISTELL FISH FRESHNESS

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1. Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 15 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 11 12 5 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 8 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 8 10 B yeasty odours Lactic acid sour milk Trace of off flavours 5 7 13 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 5 bate Uy Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 3 4 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 3 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 Bs gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish store
2. Chisawasawa normal handling Ladyfish normal handling Sea bream dentex spp normal handling Sea bream pagellus spp normal handling Spanish mackerel normal handling Tilapia normal handling Guidance for angling club competitions scsssescsesseessseesseeeeseseessseessseueseseneessseesssseeesseeeeseoeeens 53 Contact details icc sccivscecadescdscesecedescciceiaced wate bevacedaietacadaledocsiededeusdsieiacedaSetaxatateteredetecomscdsoncesdeueesesdouee sd 54 Freshness Meter User Manual Page 4 DISTCLL com gt the art of distell ing Introduction Freshness of fish and its measurement Fish is a highly perishable commodity When newly caught it has pleasant sweet flavours that are highly acceptable On storage these flavours are progressively lost and though the fish is acceptable it is not of such high quality Further storage produces off flavours and ultimately these become so strong that the fish is unfit to eat Fish is generally stored and transported in ice and under these conditions species from arctic or temperate waters will reach the unfit state within about two weeks Tropical fish can be held somewhat longer Spoilage is much faster if the fish is not held at chill temperatures It is therefore important for anyone concerned with quality of fish to be able to measure its freshness i e the amount of deterioration that has occurred since it was caught Traditionally fresh
3. Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 49 DISTECLL com gt the art of distell ing Sea bream pagellus spp normal handling Species Sea bream Pagellus coupei Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for sea bream Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 3 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 12 3 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 11 8 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 11 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 9 15 B yeasty odours Lactic acid sour milk Trace of off flavours 5 8 19 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 7 22 Not graded slightly sweet fruity or sourness and bitter
4. Applies to Boxed fish Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for plaice landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 13 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 11 7 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 11 210 B yeasty odours Lactic acid sour milk Trace of off flavours 5 10 11 13 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 10 16 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 9 10 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 8 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 lt 6 gt 18 Not graded eggs hydrogen sulphide Putrid Ined
5. CHOICES MENU Y DOWNLOAD N Downloading Download Complete Erase N If Yes then data is erased from If No then data is retained in the meter s memory the meter s memory When the data has been successfully downloaded it will appear in the DMS in a spreadsheet grid form With the data in the DMS you can now Print the data Add extra columns of information e Save the data in native form as an FMD file Export the data as a Comma Separated Value CSV file for exporting into other applications such as Excel Access etc Real Time Data Download You can use this function to download data in real time sample by sample each time that an average reading is created by the meter The real time data will appear on screen line by line as you use the meter Freshness Meter User Manual Page 21 DISTECLL com gt the art of distell ing The purpose of the real time facility is to allow the user to see sample data instantaneously as the readings are taken Each time that an average reading is generated by the meter it downloads the sample data via the USB communications port There is no specific process in the meter to download data in real time the samples are automatically sent to the PC as they are taken Enabling real time data download Connect the meter to the PC and start the DMS as described in steps 1 and 2 of Historical Data Download above then select Real time d
6. boxed unhandled Species Herring Clupea harengus Applies to Boxed unhandled approx 20 fat content Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for herring landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 14 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 H 3 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 4 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 5 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 6 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 F Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 8 Not graded byre like odours Strong ammonia bad
7. messages will be displayed In these circumstances this menu option can be used to erase the samples and avoid the MEMORY FULL message being displayed CHOICES MENU Y CLEAR N Freshness Meter User Manual Page 15 DISTECLL com gt the art of distell ing Usage recommendations Using the meter in quality control Sampling The Fish Freshness Meter was designed with the needs of the quality controller in mind The term quality controller is meant to include officials responsible for public health inspection or enforcement of mandatory regulations concerning quality as well as persons concerned with quality control in industry and commerce In a typical situation a controller is required to test batches of fish that are being inspected sold or processed as a unit and for this a suitable sample must be taken The meter simplifies this process of assessing a batch by sampling If the freshness of individual fish within a batch is measured with the meter it will be found to vary This fish to fish variation in meter readings is caused by two factors a Variation in intrinsic freshness among individual fish b Variation of meter readings among fish of the same freshness Both are expressions of the variability of biological organisms A batch of fish caught at the same time and handled and stored identically will spoil at slightly different rates because of variations in chemical constitution and bacterial activit
8. meter Always fit dust moisture cap in place before commencing work especially in wet environments Note Use only this Distell power unit for battery charging or meter power Do not use excessive force when plugging the power unit into the meter socket Freshness Meter User Manual Page 9 DISTECLL com gt the art of distell ing Getting started Verify that battery has been charged Switch on Switch on the Meter and allow the meter to cycle through its start up procedure Part of the start up procedure is to show how many readings are currently stored in the meter You may wish to download and erase any stored readings before taking new measurements You can find out about the download procedure in the Data Management System section After around 15 seconds the meter is ready for use The display will show the last calibration setting used and will look something like the example below Calibration Setting TORRY 1 Y SN 3 N Yes Number of samples used No to calculate average Measuring product samples Have a copy of the organoleptic charts at hand For best accuracy always follow the measurement recommendations in this manual Before starting we recommend you carry out some checks 1 Check that you have set the correct number of samples from 1 to 16 from the Samples menu 2 Check that you have selected the correct calibration setting on the meter for the fish being sampled
9. B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 12 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 14 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 zl Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 19 Not graded byre like odours Strong ammonia bad Inedible ul 5 Di Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 21 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 47 DISTECLL com gt the art of distell ing Ladyfish normal handling Species Ladyfish Otolithus senegalensis Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for ladyfish Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 14 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavo
10. Distell website If you need to return the unit for repair please contact your supplier for advice on how to do so The meter should be carefully packed together with an explanatory note as to the nature of the fault Should you have difficulty in returning your Freshness Meter to your supplier for servicing you can always contact Distell directly using the information in the Contact Details section Please quote the date of purchase and give a full description of the fault Freshness Meter User Manual Page 19 DISTECLL com gt the art of distell ing Data Management System Installation Requirements The Data Management System referred to as the DMS requires a PC running Windows XP or later and a free USB socket for data downloads Installing the DMS This section tells you how to install the program on your system and how to run the program It is best to close all programs before installing the software You should have at least 5 Mb of hard disk space available for the installation Insert the CD in the computer e Find the Installation files folder on the CD then open the Data Management Software DMS folder Run the DMSInstaller exe file and follow the prompts to complete the installation Running the DMS Click the Windows Start button on your desktop select programs select Distell then locate the DMS icon from the files listed there You can use the program straight away after i
11. EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 13 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 12 4 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 11 8 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 12 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 9 a Ti B yeasty odours Lactic acid sour milk Trace of off flavours 5 8 gi B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 7 26 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 ST gt 26 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt T gt 26 Not graded byre like odours Strong ammonia bad Inedible 1 lt 7 gt 26 Not graded eggs hydrogen sulphide Putrid Inedible 0 zI gt 26 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 52
12. batch of fish rather than one individual sample An appropriate number of fish are taken the fish evaluated separately and the average of the batch calculated The recording and calculation required though simple are inconvenient to carry out at the market or in the factory There is therefore a requirement for a rapid and objective method for measuring fish freshness in a wide range of conditions The method should be accessible to untrained staff and non destructive in use Preferably it should also allow batch grading with a minimum of computation and record keeping The Fish Freshness Meter or Torrymeter has been developed to meet these requirements Freshness Meter benefits The Fish Freshness Meter when used with organoleptic charts eliminates the uncertainty delay and cost previously incurred by sending fish samples to a test laboratory It can be used out of the box on known calibrated fish species and after a simple calibration procedure for new species The following sections of the manual explain fully how to use the meter and organoleptic charts Before these it will be useful to have an introduction to their underlying concepts Freshness Meter User Manual Page 5 DISTECLL com gt the art of distell ing For known species one for which an organoleptic chart exists the procedure is simple Take a meter reading from a sample of your required species the result measured on the Torry Freshness Scale
13. care of the meter It is a measurement instrument and should be handled carefully The meter should be cleaned and stored in its case after use Meter unit Data power socket The 7 way socket on the side of the meter LCD Display serves three functions Data download socket for transferring data to PC using cable supplied Reset No button Read Yes button Allows the meter to run on external power Used for charging internal batteries 7 Data power socket Sensor The sensor has two outer carbon electrodes for measuring freshness and two inner metal electrodes for sensing contact with the skin of the fish It is a good idea to wipe the sensor clean between readings since it is easy for fish scales to stick to the sensor and affect readings Sensor Read button Yes Press and hold this button to take a reading e Press to answer Yes to any Yes No question on the display Reset button No e Press to reset the measurement routine or to abort an incomplete series of readings Press to answer No to any Yes No question on the display Data cable Always use the data cable supplied for downloading to computer Connect the 7 way plug to outlet on meter and the other end directly into a USB port on your computer Freshness Meter User Manual Page 8 DISTCLL com the art of distell ing CD ROM The CD contains the user manuals Data Management System calibration c
14. flavours but reduced in intensity Slightly musty mousy Neutral 7 10 5 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 8 7 B yeasty odours Lactic acid sour milk Trace of off flavours 5 6 10 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 4 k F Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 2 14 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 2 gt 16 Not graded byre like odours Strong ammonia bad Inedible ai lt 2 gt 16 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 2 gt 16 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 51 DISTECLL com gt the art of distell ing Tilapia normal handling Species Tilapia Oreochromis lidole Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for Tilapia Raw odour description Cooked flavour Taste Freshness Days
15. is accessed using the RESEARCH 1 calibration which offers a range of 0 1 to above 99 9 By taking a second set of readings using this higher resolution you will be able to obtain a set of meaningfully differentiated readings over the narrow range of the 12 8 example above Having obtained a reference dataset of such readings over the period from fresh to putrid you can a Simply continue using this dataset as a reference for future measurements of the same species or b Load the data into a spreadsheet for further analysis or reference or c Generate an Analysis Dataset of equal daily decrements from 18 to 1 and use this within the Data Management System to scale the Reference Dataset readings The scaled output dataset becomes the new custom calibration for the new species it can be stored in the meter and entered into a new Organoleptic Chart You can refer to the Freshness Meter Technical Manual on the CD ROM and on the Distell website for more information on custom calibrations General description This latest model of the Fish Freshness Meter is compact robust fully portable and suitable for any normal application within fish processing industry markets processing factories or quality control laboratories It provides rapid measurements and is simple to use The freshness of the fish is indicated on the LCD display The meter can be set to measure from 1 16 fish The menu driven software will sum the readings of all
16. like odours Ammonia strong 2 lt 3 10 Not graded byre like odours Strong ammonia bad Inedible 1 lt 3 Ti Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 12 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 46 DISTTECLL com gt the art of distell ing Chisawasawa normal handling Species Chisawasawa Lethrinops praeorbitalis Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for chisawasawa Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 14 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral i ial 7 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 9
17. meter reading decreases with spoilage The current passed through the fish is approximately 1 milliamp and so cannot harm the operator or affect the fish Between the measuring electrodes are two auxiliary electrodes These electrodes in conjunction with one of the carbon electrodes sense whether there is proper contact with the fish The fish sensing device prevents readings being taken under inappropriate conditions e g in air or in ice Since the phase angle depends on temperature as well as freshness the reading displayed by the instrument must be corrected to the value it would show at a reference temperature of 0 C The meter is powered by rechargeable batteries within the instrument They have sufficient capacity to allow a full working day s operation Technical data This User Manual does not cover the technical side of the Freshness Meter in great depth You can find a copy of our Technical Manual on the CD ROM that is supplied with the meter or you can download a copy from our website This will help you explore the technical aspects of the Freshness Meter s operation as well as how to create custom calibrations Freshness Meter User Manual Page 7 DISTECLL com gt the art of distell ing Step by step guide The Freshness Meter kit Your Freshness Meter kit comprises the following items Meter unit e Power supply charger USB data cable e CD ROM User manual Carry case Please take good
18. milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 4 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 5 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 6 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 6 9 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 5 10 Not graded byre like odours Strong ammonia bad Inedible 1 lt 4 gt 10 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 12 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 37 DISTECLL com gt the art of distell ing Herring 15 fat boxed unhandled Species Herring Clupea harengus Applies to Boxed unhandled approx 15 fat content Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for herring landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter sco
19. recommend that the unit be immersed in water or any other fluid Anyone tampering with the unit opening the seals etc will immediately invalidate the warranty The meter is encased in impact resistant ABS plastic with the sensing probes made from stainless steel and carbon materials It may be cleaned with a damp cloth using a mild solution of soap or detergent in water Be aware that some household cleaners may contain chemicals which could seriously damage the plastic housing Avoid the use of any petroleum based solvent cleaners Do not let slime dry out on the electrode surfaces Do not attempt to clean the electrode surfaces with abrasives The unit should be charged regularly and the meter retained within its case when not in use for safekeeping The Freshness Meter is a precision instrument Ensure that the unit is stored securely in transit Do not drop or otherwise misuse the equipment as this may invalidate the warranty Before calling for service If you have reason to believe that a fault has occurred please first of all check the following Is the unit switched on e Has the battery pack been charged If no obvious fault is apparent please telephone our Help Desk for advice and to report the fault Warranty and service Your Torrymeter is fully warranted against manufacturing defect for a period of 12 months The warranty and terms amp conditions are explained in our Technical Manual available on the CD ROM or from the
20. samples then the individual sample values will not be reported as they are taken i e the sampling is done blind These individual readings are stored in the meter and can be seen when downloaded to the Data Management System CHOICES MENU Y SAMPLES N Download menu The Download menu allows you to send any stored sample data to a connected PC running the Data Management System The DMS is documented later in this guide and the download procedure is covered there CHOICES MENU Y DOWNLOAD N If no data has If data is ready been recorded for download Freshness Meter User Manual Page 13 DISTECLL com gt the art of distell ing Add Product option Using this menu provides the ability to programme the meter with additional calibrations This facility is especially useful for those who wish to refine existing meter calibrations or create a new calibration setting based on their own data Full instructions on how to use this facility are in the Technical Manual available on the CD ROM and from the Distell website CHOICES MENU Y ADD PRODUCT N Waiting data Date amp Time menu You should check the date and time when you first receive the meter and update it if necessary Each sample that is recorded by the meter has a date and time stamp so it is recommended that the date and time be kept accurate This will then ensure that all downloads reflect the correct date and time Note t
21. should be between 16 for fresh and 1 for spoiled Then refer to the relevant organoleptic chart for an interpretation of the meter reading and its implication for the freshness of your sample For example if you wish to sample cod which is boxed between catch and port refer to the first chart in Organoleptic charts This chart shows that a meter reading of 16 represents a fish of less than 2 days old A reading of 8 would indicate that the fish was 10 days old and a reading of below 3 would indicate that the fish was more than 18 days old and spoiled If the species is not known and has no organoleptic chart you can perform a custom calibration exercise in which you generate a chart for future reference To do this take a set of readings for the fish as it decays from fresh to spoiled This may give a reasonable set of readings from somewhere near 16 fresh to 3 or below when spoiled If this is in fact the case the readings can be used to write into an organoleptic chart which becomes the reference for the new species Alternatively however you may find that the range of readings as the fish decays from fresh to putrid is too narrow for useful interpretation For example you may see an initial reading of 12 when fresh and 8 when spoiled The answer is to use the full internal range of the meter which has much more resolution available than the scales available with the TORRY 1 0 1 to 18 5 or TORRY STD 1 to 18 scales The internal range
22. 3 Check to ensure that you have prepared or have been supplied with an organoleptic chart suitable for this fish species 4 Select the fish samples at random from the batch Where you are taking fish samples from a varied batch the samples should be grouped according to size length weight 5 Check that temperature of the fish to be measured is between O and 10 C with no ice crystals present in the samples The measurement procedure is outlined as follows 1 Ensure that the sensor is placed firmly against the skin of the fish thus ensuring that there are no air pockets between the sensor and the sample to be measured Press the Read Yes button the Meter will confirm contact with the fish take the measurement display and store the value 2 Ifyou see No Contact displayed on the meter then check that the sensor is making good contact with the skin of the fish The meter will not take any readings until it detects good skin contact 3 For best results be consistent Always place the sensor on the same part of each fish This will ensure that you achieve optimum comparable results It is normal to experience variability in the individual readings when taken at different parts of the fish Note also that different parts of the fish will spoil at different rates depending upon the level of bacteriological activity present within the fish 4 One set of readings should be taken from each fish at the recommended measurement sit
23. Bread malt beer Insipid no flavours 6 10 9 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 10 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 12 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 14 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 4 5 16 Not graded byre like odours Strong ammonia bad Inedible 1 lt 3 gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 30 DISTECLL com gt the art of distell ing Saithe normal handling Species Saithe Pollachius virens Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for saithe landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 15 lt 2
24. DISTCLL com gt the art of distell ing Guidance for angling club competitions The Fish Freshness Meter is used around the world as an objective measurement of freshness of fish caught at various angling competitions With ever increasing prize money at stake many competitors try to beat the system by having a suitable fish caught and stored in ice or frozen outside the competition window The fish is then presented as having been caught within the competition and the prize money claimed The Freshness Meter allows an objective method of assessing the relative freshness of the competition fish simply and easily Also the meter is exceptionally useful for identifying fish that have been previously frozen such fish will yield a freshness score of 4 or less even though the fish looks very fresh and wholesome We suggest that before the competition date you should have an organoleptic chart for the fish species that you intend to fish If the fish species is not already specified in this manual then you need to prepare a new chart You can prepare a new organoleptic chart by using the Freshness Meter to measure one or two fish over a period of 1 to 2 weeks as follows Procure one or two fish from the competition water Immediately store the fish in ice and maintain at or just above 0 C Do not allow the fish to become frozen as this destroys the cellular structure The meter will display a value of 4 or less where f
25. E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 313 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 11 12 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 8 7 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 Fd 9 B yeasty odours Lactic acid sour milk Trace of off flavours 5 6 10 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 4 a2 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 lt D 14 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 3 gt 16 Not graded byre like odours Strong ammonia bad Inedible 1 23 gt 16 Not graded eggs hydrogen sulphide Putrid Inedible 0 EAE gt 16 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 31 DISTELL com gt the art of distell ing Plaice boxed Species Plaice Pleuronectes platessa
26. Inedible 4 5 10 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 10 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 39 DISTECLL com gt the art of distell ing Herring 25 fat boxed unhandled Species Herring Clupea harengus Applies to Boxed unhandled approx 25 fat content Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for herring landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 14 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 11 3 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 4 B yeasty odours Lactic acid sour milk Trace of off flavou
27. JIS Tetll com gt USER MANUAL DISTELL FISH FRESHNESS METER Model Torrymeter CE DISTELL Com June 2011 Version 2 9 for use with v3 firmware distell ing pres part verb 1 to distell 2 to rapidly analyse fat content of food products using microwave technology DISTTCLL com the art of distell ing Contents Introduction 5052252052 clan ath neg oh oe Lica a A E E 5 Freshness of fish and its measurement Freshness Meter benefits General description Principle of operation Technical data DH N Step by step guide The Freshness Meter kit Meter unit Data power socket Read button Yes Reset button No Data cable Carry case Power supply charger Charging the meter Getting started Switch on Measuring product samples Comparing the meter with laboratory analysis Menu structure Product menu Research menu Samples menu Download menu Add Product option Date amp Time menu Rental Key option Send Ref option Clear option lo amp amp amp 0 0 amp 00 Usage recommendations isssscisccssssscicsnsesessnetcvscevessnctssetincsssctsestvnetvestsertenctcvestsetenstssececessousesecencssancesie Using the meter in quality control Sampling Freshness Meter performance The relationship between meter readings and other measures of freshness Effects of handling and processing E
28. age water Strong bitter flavours 3 4 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 3 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 lt 3 gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 63 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 26 DISTCLL com gt the art of distell ing Cod fillets bone side Species Cod Gadus morhua Applies to Fillets bone side Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for cod landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 8 9 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 6 2 4 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 3 5 6 A odours flavours but reduced in intensity Slightly musty mo
29. al Page 28 DISTECLL com gt the art of distell ing Haddock amp Whiting normal handling Species Haddock amp Whiting Melanogrammus aeglefinus Merlangius merlangus Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for haddock amp whiting landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 15 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 11 12 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 8 7 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 yi 310 B yeasty odours Lactic acid sour milk Trace of off flavours 5 3 4 13 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 23 IS Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 lt 3 18 Not graded Nearly turnip sour s
30. are based on the scales used at Torry Research Station and have been described in their publications These scales were interpreted as follows Perfectly fresh fish is given a score of 10 Good quality fish has a score of 6 or more Below a score of 4 the fish are considered unfit to eat These freshness scores are only a rough guide Users are strongly advised to obtain equivalent levels from scores given by their own trained panel as the scores may be based upon different criteria or obtained under different conditions from those obtained by Torry Research Station and Distell For comparison the approximate number of days of storage in ice which would cause the fish to reach a given freshness score is also included in the charts An explanation of the different columns of meter readings is given in the next section The examples given are typical demersal fish The situation with fish of high and variable fat content is rather more complex and the relationships between the meter readings and sensory scores are not always well defined However extensive work carried out by the staff of Torry Research Station with herring has established that the manner in which meter readings vary with time of storage in ice is very dependent on a The fat content of the fish b Whether or not it is iced immediately after catching G The extent to which it is subjected to handling The organoleptic charts show the approximate age in ice corr
31. d longer than 2 days in ice Freshness Meter User Manual Page 35 DISTECLL com gt the art of distell ing Herring 5 fat boxed unhandled Species Herring Clupea harengus Applies to Boxed unhandled approx 5 fat content Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for herring landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 14 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 lt 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 11 3 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 9 6 B yeasty odours Lactic acid sour milk Trace of off flavours 5 8 8 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 7 9 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 6 10 Not graded Nearly turnip sour
32. d to be of interest to most users so they are not documented here You can however read more about them in our Technical Manual which is available on the CD ROM or can be downloaded from the Distell website Freshness Meter User Manual Page 22 DISTCLL com gt the art of distell ing Organoleptic charts The following pages show organoleptic charts for a range of commercial fish species This is not meant to be an exhaustive list and users of the Fish Freshness Meter are encouraged to create their own organoleptic charts to cover the different species and handling storage methods that are of interest This user manual is included on the CD ROM that is part of the Freshness Meter Kit You may wish to print out individual charts for your convenience Freshness Meter User Manual Page 23 DISTECLL com gt the art of distell ing Cod boxed Species Cod Gadus morhua Applies to Boxed Fish Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for cod landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC Grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sw
33. e The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 42 DISTECLL com the art of distell ing Mackerel 13 fat boxed unhandled Species Mackerel Scomber scrombus Applies to Boxed unhandled approx 13 fat content Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for mackerel landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 14 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 11 2 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 3 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 5 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 6 Not graded slightly swee
34. e Choices menu screen will appear in the order shown below There are six options Cycle through the options by pressing Reset No until the correct one is displayed then press Read Yes TORRY STD Y SN 3 N Sf aes pence seme Us RESEARCH DOWNLOAD RENTAL KEY SEND REF Only one of the SET TIME and RENTAL KEY options will be available Product menu In the Product menu you can choose which of the product calibration settings you wish to use Simply choose the calibration that corresponds with the type of measurement you wish to use CHOICES MENU Y PRODUCT N Freshness Meter User Manual Page 12 DISTTCLL com the art of distell ing Research menu In the Research menu you can choose which of the research calibration settings you wish to use The Fatmeter is normally supplied with the RESEARCH 1 setting but additional calibrations can be added to the research block via the Custom Calibration process Full details are available in our Technical Guide which is available on the CD ROM and from our website CHOICES MENU Y RESEARCH N RESEARCH 1 Samples menu For greatest accuracy you should use eight samples per fish and measure eight fish from a batch For single fish we recommend that the Freshness Meter be set up for three samples per fish In both cases all the measurements should be taken at the same site on the fish You can choose between 1 and 16 samples here Note if you choose 16
35. eet meaty creamy 9 14 2 4 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 13 5 6 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 11 8 9 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 41 B yeasty odours Lactic acid sour milk Trace of off flavours 5 8 ge B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 7 16 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 5 718 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 zg gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 z3 gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 E gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 24 DISTTECLL com gt the art of distell ing Cod normal handling Species Cod Gadus morhua Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate time
36. es The results will be stored in the Freshness Meter for later downloading Freshness Meter User Manual Page 10 DISTCLL com gt the art of distell ing 5 Place the base of the meter firmly on the fish so that it lies flat against the surface and parallel to the lateral line at a thick fleshy part of the fish The best position is at the shoulder area within the first third of the fish in the region of the lateral line as shown in the illustration below Avoid the head and belly cavity regions 6 If this is the first reading after the meter has been in a warm place hold the probe head against the fish for 10 20 seconds to allow the sensor to cool down before pressing the Read Yes button 7 To measure individual fish set the Freshness Meter to read 3 samples see the Menu Structure section for details place the meter at the recommended measurement site and take measurements three times The individual values and the average value will be stored in the meter for downloading When the average value is shown on the display press Read Yes to take more readings on a different fish or press Reset No to finish 8 Avoid pressing the READ button when the meter is not in contact with a fish If there is a thick layer of slime on the probe head it may conduct enough current to act as if the electrodes were in contact with a fish and a measurement will be made 9 Switch the meter off after use to retain the charge
37. esponding to given meter readings for boxed herring of various fat contents The age in ice is valid only for fish which has been boxed and iced immediately after catching Delayed icing always gives rise to lower meter readings during subsequent storage in ice compared with those shown in the chart Freshness Meter User Manual Page 17 DISTECLL com gt the art of distell ing The extent of the effect varies with fat content and temperature during storage before icing For example lean fish held for 8 hours at a temperature of about 5 C before icing will generally show meter readings about one unit lower than the appropriate organoleptic chart would suggest With fatty fish the effect can be up to twice as great for the same time and temperature before icing There is evidence to show that the higher initial temperatures can easily double this effect Mackerel generally behave in much the same way as do herring although detailed information is not at present available The organoleptic charts for mackerel pages 42 and 43 give some idea of readings to be expected from carefully handled fish boxed and iced Although less is known of the relationship between objective sensory scores and meter readings than for white fish it is believed that meter readings give a fair indication of the intrinsic quality of unhandled boxed fatty fish irrespective of fat content The charts on pages 47 to 52 show relationships between the Fish Fresh
38. ff flavours 4 T 16 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 6 gt 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 6 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 lt 6 gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 6 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 33 DISTECLL com gt the art of distell ing Redfish boxed Species Applies to Redfish Boxed fish Sebastes spp Relationship between objective sensory scores for freshness freshness Meter readings and approximate times of storage in ice for redfish landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 16 22 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 2 E loss of fresh sea green plant weediness characteristics No odours ne
39. ffects of freezing and brining Meter care and service Cleaning and general care Before calling for service Warranty and service Data Management System arrana aa aN rN EEES EE 20 Installation Requirements Installing the DMS Running the DMS Historical Data Download Step 1 Connecting the Meter Step 2 Configure the DMS Freshness Meter User Manual Page 3 DISTECLL com gt the art of distell ing Step 3 Initiate the download from the meter er xi Real Time Data Download 000 Enabling real time data download Annotating the data DMS data files Printing data Exporting data Data Management software Help Advanced topics Organoleptic charts Cod boxed Cod normal handling Cod fillets skin on skin side Cod fillets bone side Haddock amp Whiting boxed Haddock amp Whiting normal handling Saithe boxed irissen Saithe normal handling Plaice boxed Place normal handling Redfish boxed Redfish normal handling Herring 5 fat boxed unhandled Herring 10 fat boxed unhandled Herring 15 fat boxed unhandled Herring 20 fat boxed unhandled Herring 25 fat boxed unhandled Herring 30 fat boxed unhandled Mackerel 8 fat boxed unhandled Mackerel 13 fat boxed unhandled Salmon normal handling Blue whiting boxed Blue whiting normal handling
40. harts and other useful information User manual A hard copy of the user manual and the calibration certificate is included Carry case The Freshness Meter kit is supplied in a robust carry case and comes complete with two keys for security of your Freshness Meter Power supply charger Only the unit supplied with your kit should be used to charge the battery pack or power the meter This is connected to the 7 way outlet on the meter The charger supply unit simply plugs into the mains socket accepting input mains voltage from 110v 240v AC 50 60 Hz The charger unit comes complete with various plug configurations for use around the world A red LED will illuminate when charger power supply is switched on The battery pack should be fully charged after a period of 12 hours When charging is complete first disconnect the charger from the mains and then from the meter The power supply charger can also be used to power the meter during use while also charging the internal batteries at a reduced rate Charging the meter Notes on charging the Meter Insert power unit connector plug carefully into meter socket to insert turn plug gently until the plug slides into the connector Meter should be charged for a full 12 hours before use if possible e Always ensure that meter is switched OFF before charging e When charging is complete first disconnect the power unit from the mains and then from the
41. hat is all there is in the batch If the controller or inspector wants greater confidence in the batch average more than one set of eight fish can be sampled and a grand average of the results calculated Note that the precision of an averaged result increases only as the square root of the sample size An average of 64 readings is only twice as precise as an average of 8 readings Freshness Meter performance The relationship between meter readings and other measures of freshness There are many ways of expressing the freshness of fish Perhaps the simplest for fish held in ice is to quote the storage time However as is well known the initial quality of many species of fish varies with the seasons of the year due to such factors as the spawning cycle and the availability of food These factors also affect the rate of spoilage so that the time in ice is not necessarily a good measure of Freshness Meter User Manual Page 16 DISTCLL com gt the art of distell ing freshness unless related to the time of the year It has been found that a better way of expressing freshness is to construct a system of numerical scales based upon methods of objective sensory assessment by a trained taste panel Such a system is better because it is directly related to eating quality rather than depending on knowledge of the storage conditions Often the fish is allocated to one of a few quality grades based on definitions in sensory terms An exam
42. hat if a meter is configured as a rental meter then this option will not be available CHOICES MENU SET TIME Y N Year Rental Key option If your meter has been supplied as part of a rental agreement then the Rental Key menu option will be available This allows you to enter a sequence of eight numbers and letters that is specific to your meter and is used to change your rental settings e g change the rental expiry date You can read more about rental keys at http www distell com downloads rentalkey pdf CHOICES MENU RENTAL KEY Y Freshness Meter User Manual Page 14 DISTCLL com gt the art of distell ing Send Ref option This option is used by the Custom Calibration process to copy the meter s built in RESEARCH 1 calibration setting to the Data Management System This data is used as a reference to construct a custom calibration You can read more about this in the Technical Manual available on the CD or on the Distell website CHOICES MENU SEND REF Y Clear option This menu option allows the user to clear any stored readings from the meter Normally this is not required because stored readings can be cleared after being downloaded to the Data Management System Some users however may use the meter purely for instant measurements without ever downloading the samples and in time the Fatmeter s storage capacity will fill up and MEMORY FULL
43. ible 0 lt 6 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 32 DISTCLL com D the art of distell ing Place normal handling Species Plaice Pleuronectes platessa Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for plaice landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 11 12 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 7 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 8 10 B yeasty odours Lactic acid sour milk Trace of off flavours 5 7 8 13 B or oily odours some sourness but no bitterness Grass old boots Some o
44. in the battery Normally three readings are recommended We have found that this gives the best balance between accuracy and speed You can change the number of readings that the meter will take before averaging by using the Samples menu option See the Menu Structure section for more details The Freshness Meter can store up to 1000 sets of readings These can be downloaded to a PC running the Data Management System See the Data Management System section for more information on how to do this There is also an option to download the data in real time i e as the readings are taken and this is covered in the same section Comparing the meter with laboratory analysis If you wish to compare the results achieved using the Freshness Meter with a laboratory procedure it is important that the entire fish carcass sample is packaged and sent to the laboratory for the analysis The sample should be stored in a sealed polythene bag immediately after measurement and the temperature of the sample should be maintained as close to 0 C as possible This will ensure that spoilage of the sample is reduced as far as possible Important Do not allow the sample to freeze The whole carcass of the fish fillet should be received at the laboratory properly packed and sealed and the current age from death of the sample should be ascertained using standard laboratory methods e g TVBN etc If the results from the Laboratory do not c
45. ink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 3 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 lt 3 gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 s3 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 29 DISTECLL com gt the art of distell ing Saithe boxed Species Saithe Pollachius virens Applies to Boxed fish Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for saithe landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 2 3 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 13 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 lal 7 A Decrease in milky or caprylic garlic freshness peppery
46. ip between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for sea bream Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 15 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 13 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral i 12 4 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 11 8 B yeasty odours Lactic acid sour milk Trace of off flavours 5 10 13 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 9 17 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 5 a7 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 3 gt 17 Not graded byre like odours Strong ammonia bad Inedible ai lt 3 gt 17 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 17 Not graded Putrid sulphides
47. ish have been allowed to freeze Measure the fish as recommended in this manual ensuring that you measure consistently at the same position on the fish each time Measure the fish twice per day in the morning and in the evening and keep a note of the readings Continue the process until the fish is spoiled Use this information to prepare an organoleptic chart like the samples in this manual If possible have your new chart checked by an experienced fisherman or fish expert who can help validate your results Whether using an existing chart or a new chart of your own making arrange that all fish caught during the competition are measured using the Freshness Meter Use the organoleptic chart to assess the age of the fish Any fish that show a significant difference in freshness value from the average should be further investigated Freshness Meter User Manual Page 53 DISTECLL com gt the art of distell ing Contact details The DISTELL FISH FRESHNESS METER is manufactured in the UK by DISTELL COM UNIT 5 OLD LEVENSEAT FAULDHOUSE WEST LOTHIAN EH47 9AD SCOTLAND TELEPHONE 44 0 1501 770124 FAX 44 0 1501 772424 WEBSITE www distell com EMAIL info distell com Freshness Meter User Manual Page 54
48. lavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 15 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 3 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 5 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 8 7 B yeasty odours Lactic acid sour milk Trace of off flavours 5 6 9 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 4 i Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 lt 3 gt 12 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 3 gt 12 Not graded byre like odours Strong ammonia bad Inedible 1 lt 3 gt 12 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 12 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter U
49. may develop Shellfish odours and Sweet meaty creamy 9 13 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 H 3 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 4 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 6 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 8 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 10 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 gt 10 Not graded byre like odours Strong ammonia bad Inedible 1 5 gt 10 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 10 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 41 DISTECLL com gt the art of distell ing Mackerel 8 fat boxed unhandled Species Mackerel Scomber scrombus Applies to Boxed unhandled approx 8 fat content Relationship between objective
50. ness chloroform like odours Stale cabbage water Strong bitter flavours 3 6 26 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 5 29 Not graded byre like odours Strong ammonia bad Inedible 1 lt 4 gt 29 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 29 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 50 DISTTECLL com gt the art of distell ing Spanish mackerel normal handling Species Spanish mackerel Scomber colias Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for Spanish mackerel Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 15 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours
51. ness Meter readings and time of storage in ice for a few species of African fish The data has been supplied by the Tropical Products Institute London Effects of handling and processing The Fish Freshness Meter measures certain properties of fish muscle and skin that change in a systematic way during storage in the wet state Any other process that affects the structure of the muscle at the cellular level will also affect the measurements almost invariably to lower them Handling is an important factor A common method of handling fish in Europe is to store it mixed with ice in bulk aboard the vessel then unload it onto the quayside and sort the fish into containers The pressure it is subjected to in the hold the handling during discharge and the sorting process tend to lower the meter readings when compared with fish that have been stowed carefully in boxes with ice and kept undisturbed until measured The difference is indicated in the charts in the Organoleptic charts section The meter can also be used to grade fillets For skin on fillets make the measurements on the skin side in the usual way The meter measures properties of both skin and muscle but it can still be used with skin off fillets In this case the meter should be applied to the bone side of the fillet The readings though are much lower than for whole fish or skin on fillets of equivalent freshness Also discrimination in fish material with a freshness score belo
52. ness has been assessed by sensory methods using the human senses of sight smell and touch This approach gives an immediate appraisal of quality without damage to the fish However there are some difficulties Trained and experienced staff is required and this training takes a long time It is not easy to make sensory assessment quantitative The changes occurring during spoilage can be described and codified but individuals may interpret these descriptions somewhat differently Though a single judge may be consistent within himself different judges will vary among themselves This makes it difficult to establish standards that can be applied in different locations and by different assessors There is therefore a need for objective methods for measuring freshness that do not depend on the subjective opinion of human judges Several chemical procedures are in use for this purpose but all suffer from common disadvantages in respect to quality control within the industrial environment in that they are somewhat slow to carry out whereas quality controllers and inspectors usually require an immediate answer The analysis requires laboratory facilities and appropriately qualified staff a feature which renders the methods unsuitable for field work and expensive for factory use The methods are destructive and the damaged fish samples are no longer fit for processing Generally a quality controller or inspector needs to evaluate the freshness of a
53. nstallation The program enables you to download print save and export data quickly and efficiently The DMS also allows you to create and upload your own custom calibrations to the Freshness Meter see the Technical Manual on the CD ROM and on the Distell website All program functions are accessed using the menu and toolbar options There is a comprehensive on line help facility which is available by clicking on the Help menu option Historical Data Download This function enables you to download readings that are stored in the Freshness Meter The data includes the date and time of the sample the calibration setting that was used the number and values of the individual samples taken and the average value of the samples To illustrate the procedure we ll assume that you have taken some sample readings with the Freshness Meter and are ready to download them to your PC Step 1 Connecting the Meter Connect the meter to a USB port on your PC using the data cable supplied with the meter then turn the meter on When the cable is connected the USB driver software installed on the PC will create two virtual serial ports Normally these are COM3 and COM4 but this may change if you have other USB virtual serial devices installed Your computer will normally reserve COM1 and COM2 for built in hardware or for legacy purposes Step 2 Configure the DMS Start the DMS then use the Preferences option under the Edit menu to select the COM p
54. ompare favourably with your meter check the meter s use as follows Is the operator proficient in the use of the Fish Freshness Meter e Is the fish species the same as that quoted on your Organoleptic Chart Freshness Meter User Manual Page 11 DISTECLL com gt the art of distell ing Check the product for species identification measurement technique size and preparation Check the laboratory procedure as follows e Verify the analytical method being used Check that the sample preparation was OK This is just a short check list on how to use and compare the Freshness Meter with other methods Remember that the primary purpose in using the Freshness Meter is to screen a lot of product for uniformity specification and shelf life and to identify fish that has been frozen or irradiated During the measurement process finite accuracy is not the objective The object is to try and ensure that the bulk of the day s raw materials and processed production meets with your specifications time after time If after these checks there is still a significant difference please contact Distell for advice and help Note that the Distell website has a comprehensive Frequently Asked Questions section as well as technical information on the Freshness Meter Menu structure When the standard measurement display is shown see the example at the start of this chapter you can access the menu by pressing the Reset No button Th
55. ort to use If the USB driver created COM3 and COM4 then you would choose COM4 here In general you should always select the virtual COM port with the higher number If you see an error message when you select the COM port then ensure that the meter is connected properly and turned on If it is try selecting a different COM port Freshness Meter User Manual Page 20 DISTCLL com gt the art of distell ing Once you have connected the meter and selected the correct communication port select Download Historical Data from the Download menu The DMS will now monitor the COM port for incoming data from the meter Step 3 Initiate the download from the meter Once the DMS is ready and waiting for data the meter needs to be told to begin the download Find the Download option in the choices menu see Menu Structure At the Standard D L option press the Read Yes button then look for the data arriving at the DMS If no data is seen at the DMS then you may have selected the wrong COM port Go back to step 2 and try an alternative port Once the data has been safely downloaded then you can if you wish erase the data from the meter You can alternatively allow data to build up in the meter up to the maximum 1000 readings If you wish to clear the data from the meter at a later stage then you can go through the download process but without connecting the meter to the PC then reply Yes to the Erase question
56. ownload from the Download menu Data will now appear in the DMS once the average reading has been recorded in the meter Annotating the data The DMS presents the data in a grid with one row for each set of samples You can add extra columns to the grid using the Add a new column option of the Edit menu and use that column to add notes about any given sample Extra columns can also be deleted using the Delete column option of the Edit menu DMS data files Like most applications the DMS can save data to a file on disk and load it back in again Data is stored in a proprietary format in files with a FMD extension The Open and Save options under the File menu are used to load and save these data files Printing data The DMS can print a report of the data for audit purposes The Print option is under the File menu Exporting data The DMS was never intended to be an analysis tool Instead you can export the data to a Comma Separated Value file CSV for use within a spreadsheet or database To export the data select Save As under the File menu then select CSV files CSV in the Save as type option Data Management software Help The DMS program provides an On Line Help Facility This can be accessed at any time when using the software program Advanced topics The DMS has the capability to create custom calibrations and to upload those calibrations to the meter These are areas that are not expecte
57. ple of this is the European Economic Community s system of grading fish for marketing purposes An extreme form of this type is the public health inspector s grading into fit and unfit A quality controller may not even consciously put a score or a grade to a batch but must accept or reject it for the purpose in mind In practice the quality controller in industry adopts the most convenient system for his purpose but an official inspector will have to use whatever is laid down in the regulations It is quite possible to define grades boundaries or acceptance rejection ranges of freshness for various outlets etc in terms of meter readings and indeed this is a good way of using the instrument However until the user is familiar with the instrument it is best to employ it in parallel with the accustomed method of assessing freshness After some experience the relationship between the quality levels the user is familiar with and the meter readings can be established Nevertheless the meter can be used by an unskilled operator after very little instruction As a guide to the values that can be expected from some species of interest to European Fish Processors average readings for different levels of freshness are shown in the set of organoleptic charts in the Organoleptic charts section These results were obtained by Torry Research Station at their laboratories in Aberdeen and Hull and at various fishing ports in the UK The sensory scores
58. re onice spoilage score Fresh sea weedy Watery metallic 10 14 22 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 ala 3 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 4 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 5 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 6 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 i 7 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 9 Not graded byre like odours Strong ammonia bad Inedible 1 5 10 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 10 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 38 DISTCULL com gt the art of distell ing Herring 20 fat
59. roduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 25 DISTECLL com gt the art of distell ing Cod fillets skin on skin side Species Cod Gadus morhua Applies to Skin on fillets skin side Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for cod landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 15 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 2 4 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 5 6 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 8 9 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 9 ae B yeasty odours Lactic acid sour milk Trace of off flavours 5 7 said B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 6 16 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabb
60. rs 5 9 5 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 7 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 8 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 9 Not graded byre like odours Strong ammonia bad Inedible 1 5 10 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 10 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 40 DISTCULL com gt the art of distell ing Herring 30 fat boxed unhandled Species Herring Clupea harengus Applies to Boxed unhandled approx 30 fat content Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for herring landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 14 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness
61. s of storage in ice for Cod landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 15 16 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 2 4 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 11 12 5 6 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 8 9 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 8 ait B yeasty odours Lactic acid sour milk Trace of off flavours 5 7i 14 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 5 16 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 3 4 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 3 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 lt lt gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 ce gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness int
62. sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for mackerel landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 14 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 22 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 3 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 11 4 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 5 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 6 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 Fi Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 g Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 gt 10 Not graded byre like odours Strong ammonia bad Inedible 1 5 gt 10 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 10 Not graded Putrid sulphides Not
63. ser Manual Page 45 DISTECLL com gt the art of distell ing Blue whiting normal handling Species Blue whiting Micromesistius poutassou Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for blue whiting landed at European ports Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 15 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 14 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 10 3 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 8 4 B yeasty odours Lactic acid sour milk Trace of off flavours 5 6 6 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 4 7 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 lt 3 9 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene
64. sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 5 ag Fi Not graded byre like odours Strong ammonia bad Inedible 1 lt 4 gt 14 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 14 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 36 DISTTECLL com gt the art of distell ing Herring 10 fat boxed unhandled Species Herring Clupea harengus Applies to Boxed unhandled approx 10 fat content Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for herring landed at European ports Raw odour description Cooked flavour Taste Freshness Days on EC grade State of description panel Meter score ice spoilage score Fresh sea weedy Watery metallic 10 14 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 2 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 H 3 A Decrease in
65. t fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 8 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 10 Not graded byre like odours Strong ammonia bad Inedible 1 5 gt 10 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 10 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 43 DISTECLL com gt the art of distell ing Salmon normal handling Species Salmon Salmo Oncohynchus Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for salmon Raw odour description Cooked flavour Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 14 lt 2 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 12 3 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 10 5 A odours flavo
66. the samples and then display their average value The meter is most accurate in this mode Generally the measurements can be taken without disturbing the fish in their containers and the testing does not damage or mark the samples in any way Principle of operation The original research leading to the development of the Fish Freshness Meter was carried out at Torry Research Station in Aberdeen Scotland Freshness Meter User Manual Page 6 DISTCLL com gt the art of distell ing It was found that certain dielectric properties of the fish skin and muscle alter in a systematic way during spoilage as tissue components degrade These alterations occurring at microscopic level are strongly associated with the gross changes in appearance odour texture and flavour which take place during spoilage and which are normally used to judge freshness Hence determination of the appropriate dielectric properties gives a measurement of the freshness of the fish The base of the instrument sensing head has two pairs of concentrically arranged electrodes This sensing head is applied directly on to the skin of the fish An alternating current is passed through the fish between the outer pairs of electrodes and the resulting voltage sensed by the inner pair The phase angle between the current and voltage is measured and converted electronically to allow digital display on a convenient scale in the range O 18 The phase angle and hence the
67. ur Taste Freshness Days EC grade State of description panel Meter score onice spoilage score Fresh sea weedy Watery metallic 10 16 lt 1 E Very fresh odours starchy Initially no sweetness but meaty flavours with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 15 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 13 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 11 7 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 10 B yeasty odours Lactic acid sour milk Trace of off flavours 5 8 13 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 6 7 15 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 5 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 23 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 33 gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 3 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manu
68. urs but reduced in intensity Slightly musty mousy Neutral 7 9 8 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 8 yi B yeasty odours Lactic acid sour milk Trace of off flavours 5 7 14 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 6 16 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 5 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 5 gt 18 Not graded byre like odours Strong ammonia bad Inedible 1 g gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 5 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 44 DISTTECGLL com gt the art of distell ing Blue whiting boxed Species Blue whiting Micromesistius poutassou Applies to Boxed fish Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for blue whiting landed at European ports Raw odour description Cooked f
69. urs with slight sweetness may develop Shellfish odours and Sweet meaty creamy 9 13 lt 2 E loss of fresh sea green plant weediness characteristics No odours neutral Sweet and characteristic 8 12 4 A odours flavours but reduced in intensity Slightly musty mousy Neutral 7 akl 7 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 10 11 B yeasty odours Lactic acid sour milk Trace of off flavours 5 9 13 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 8 18 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 7 22 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 6 25 Not graded byre like odours Strong ammonia bad Inedible 1 5 28 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 4 gt 28 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 48 DISTTECLL com gt the art of distell ing Sea bream dentex spp normal handling Species Sea bream Dentex canariensis Applies to Normal handling Relationsh
70. usy Neutral 7 a 8 9 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 il oe B yeasty odours Lactic acid sour milk Trace of off flavours 5 14 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 16 Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong Z gt 18 Not graded byre like odours Strong ammonia bad Inedible T gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 27 DISTECLL com gt the art of distell ing Haddock amp Whiting boxed Species Haddock amp Whiting Melanogrammus aeglefinus Merlangius merlangus Applies to Boxed fish Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for haddock amp whiting landed at European ports Raw odour description Cooked flavo
71. utral Sweet and characteristic 8 13 5 A odours flavours but reduced in intensity Slightly musty mousy Neutral F 12 8 A Decrease in milky or caprylic garlic freshness peppery Bread malt beer Insipid no flavours 6 11 10 B yeasty odours Lactic acid sour milk Trace of off flavours 5 10 713 B or oily odours some sourness but no bitterness Grass old boots Some off flavours 4 9 S Not graded slightly sweet fruity or sourness and bitterness chloroform like odours Stale cabbage water Strong bitter flavours 3 8 18 Not graded Nearly turnip sour sink wet rubber sulphide like spoiled matches phosphene like odours Ammonia strong 2 lt 6 gt 18 Not graded byre like odours Strong ammonia bad Inedible T lt 4 gt 18 Not graded eggs hydrogen sulphide Putrid Inedible 0 lt 3 gt 18 Not graded Putrid sulphides Note The influence of seasonal factors on freshness introduces a range of variation of 2 days in ice in the estimated values for fish stored longer than 2 days in ice Freshness Meter User Manual Page 34 DISTCLL com gt the art of distell ing Redfish normal handling Species Redfish Sebastes spp Applies to Normal handling Relationship between objective sensory scores for freshness Freshness Meter readings and approximate times of storage in ice for redfish landed at European ports
72. w 6 is not possible Typical values for cod are shown in the charts beginning on page 24 The quality of herring and mackerel is most sensitive to handling and in each case this is reflected by the readings obtained with the meter Even careful handling of the fish can lower the instrument readings by 1 or 2 units Normal commercial handling reduces the readings still further Effects of freezing and brining Freezing has a drastic effect on the cellular constituents of muscle It is not possible to determine the original freshness of thawed fish since meter readings are invariably in the range of 0 3 whatever the quality before freezing In fact this property can be used in many cases to determine whether fish has been frozen at some time in its history If the sample judging by odour appearance and flavour appears to be fresh i e should have a high meter score but in fact gives a low reading then there are grounds for suspecting it has been frozen at some time Once again judgment should not be based on one fish only several fish should be examined Brining also lowers the reading though not quite as much as freezing It is therefore not possible to check the freshness of brined fish Freshness Meter User Manual Page 18 DISTCLL com gt the art of distell ing Meter care and service Cleaning and general care The Freshness Meter is a sealed unit and is waterproofed prior to leaving the factory However we do not
73. y Hence the individual fish in the batch will have a range of freshness a range that will tend to increase as spoilage increases The meter readings themselves are not direct measures of freshness as defined in sensory terms but are strongly associated with it The relationship between meter readings and freshness as measured by a sensory panel will once again be different for each individual fish For this reason it is not recommended that the meter be used to assess the freshness of single fish except within rather wide limits These deviations from average behaviour tend to cancel out when the means of samples from batches are taken and the bigger the sample the better the correlation between the mean meter reading and freshness score It follows from sampling theory that the number of fish which ought to be sampled from a batch depends mainly on the desired precision of the mean score It also follows that provided the batch is large enough the required sample size does not depend on the size of the batch From observations made it has been decided to use a sample size of eight fish as the basis for the averaging in the Fish Freshness Meter In most marketing and distribution systems the fish are held in containers with a capacity of 50Kg Several containers constitute a batch In this situation fish from as many containers as possible should be sampled i e one from each container if the batch has eight or more four from each container if t

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