Frequently Asked Questions

  • What is the main use of the Distell Fish Fatmeter?
    Its main use is to measure the Fat / Oil Content of FISH & FISH PRODUCTS eg. Salmon, Tuna, Trout, Herring Mackerel, Sardines, Smoked Salmon, and many other species of fish.
  • Do normal laboratory tests still need to be carried out?
    YES… BUT NOT SO MANY, because the Distell Fish Fatmeter is designed to allow many measurements to be taken to routinely screen the product. Occasional laboratory tests should be used can be used to confirm the Fatmeter measurements.
  • Can samples be used after testing?
    YES… because the Distell Fatmeter is NON-DESTRUCTIVE, you can measure the same sample many times if necessary without affecting the quality of the fish.
  • Can it be used on LIVE Fish?
    YES… because it is NON-INVASIVE and harmless, it can be used to monitor individual fish and how they respond to various diets.
  • How fast is the Measurement?
    Approximately TWO minutes to take EIGHT MEASUREMENTS from a large Salmon. Much faster than any other methods for which sample preparation and measurement can be anything from 15 minutes to several hours.
  • Can the MEASUREMENT DATA be electronically stored for later use?
    YES… The Distell Fatmeter has a memory facility which will store up to 1,000 sets of measurements. These reading can be downloaded into your computer at any time, using our Data Management Software. This Software is supplied as standard, when you purchase a Fatmeter.
  • Is it really portable?
    YES… unlike other methods, it is a HAND-HELD instrument powered by rechargeable batteries. The Fatmeter will operate for up to eight hours continuously.
  • Is it Waterproof?
    YES… to IP65 standards. This allows the Fatmeter to be used in very wet environments such as fish farms.
  • How accurate is the Fatmeter?
    For individual salmon, an accuracy level of +/- 1% can be achieved. For Herring the accuracy for a batch of EIGHT fish can be similar.
  • What precautions should I take when comparing Fish Fatmeter results with laboratory Analysis?
    This is a very important question, and great care should be taken to ensure rigorous attention to detail… . Where you know that the measurements made by the Fatmeter are going to be compared to some form of Laboratory Analysis, always ensure a rigorous preparation procedure. Otherwise you may get a different result from the laboratory, and this will create confusion and doubt.

    The preparation instructions are clearly described in the Fatmeter Handbook, but for the avoidance of doubt we have given a brief description here, as follows…

    Switch ON the Fatmeter and allow it to warm up and stabilise for 10 minutes. Then select the correct calibration, from the menu. You can confirm that it is the correct calibration by pressing the ‘RESET’ button on the Fatmeter… the selection will be displayed briefly on the LCD display.

    You are now ready to take measurements… The Fatmeter will request a series of EIGHT readings. Please ensure that the readings are taken from around the sample… at recommended measurement sites, fully described in your handbook.

    Place the sensor head fully in contact with the sample, being careful to exclude any air cavities. Press and hold the ‘READ’ button until the reading has stabilised, then release the button, whilst sensor is still firmly in contact with the sample.

    Take all eight readings from various positions on the sample ( see chart supplied ). After the eight readings the Fatmeter will automatically display the Average Fat Content of the sample. The result should give accurate Fat Content, representing the Fat / Oil Content of the sample.

    For the avoidance of doubt… Calibrations have been created to represent different portions of the fish. For instance… The following THREE Calibrations represent different portions of a Salmon…

    SALMON-1 Measurements taken along the length of the fish, BOTH sides. After 8 readings the readout shows the average fat / oil content representing Fat Content of… TWO x TRIMMED FILLETS of this one fish (subject to ‘Standard trimming techniques’ that is…excluding head, tail, fins, skin, belly cavity, and fat deposits at Dorsal and Anal Fins)
    SALMON-2 Measurements taken on the ‘Mowi Section’ of the fish. After 8 readings the readout shows the average fat / oil content representing the ‘Mowi Section’ of this one fish (subject to ‘Mowi Standard trimming techniques’… please see appendix section for further details).
    SALMON-3 Measurements taken on the ‘NQC Section’ of the fish. After 8 readings the readout shows the average fat / oil content representing fat Content of the ‘NQC Section’ of this one fish (subject to ‘NQC Standard trimming techniques’… please see appendix for further details.

    Having measured the sample with the Fatmeter, duly prepared samples should now be sent to the Laboratory for analysis, if you wish to confirm the performance of the Fatmeter. Remember, the laboratory only use between 9 – 25 gms of the fish sample for the analysis process, so you must ensure that the laboratory do in fact blend ALL of the fish sample… prior to taking their sample for analysis.

    In addition, the laboratory must do triplicate analysis, taking a 2nd & 3rd sample from the blended sample. This ensures that we have a check on the uniformity of the blended product.

    The Fatmeter can be compared with any recognised Lab Method. However, the Fatmeter has been calibrated against Foss-Let Chemical Method… an AOAC recognised Laboratory based Chemical Extraction Method. This will give the best comparative accuracy. There can be significant variances in Laboratory results depending on the method used, and we recommend that the method of comparison is taken into account. If you have followed carefully the instructions above, the Fatmeter results should compare favourably with laboratory results, and should be within the performance range quoted in Operators Manual.

  • Does temperature affect the performance or results achieved using the Fatmeter?
    Provided that the Fish or Fish Fillets being measured are not frozen, and no ice crystals present in the sample, temperature should have no significant effect. Where the Fish or Fish Fillets are frozen, or contain ice crystals, the Fatmeter will tend to over-read the Fat Content level… this is due to the Microwave system being unable to measure the water in the frozen state, thus interpreting a lower quantity of water in the fish… than is actually the case.

    • We have found that Fish and Fish Fillets down to –2°C normally do not contain ice crystals… and can be measured as normal.
    • We have also found that Fish or Fish Fillets, stored at or above 10°C, can suffer moisture loss, and create a variance from the Fatmeters’ Natural Fish Calibration.

    For consistent, wholly accurate results, the operator should ensure that the Fish or Fish Fillets are measured at the same ambient temperature on a daily basis… within a temperature range of 0 – 10°C.

  • Can we use the Fatmeter to measure processed Fish, even although the Fatmeter is not specifically calibrated for that product?
    Yes, you can… let us explain… there are TWO categories of fish calibrations…

    Calibrations for… Fish in the natural state…
    The natural fish species calibrations are universal, and do not change significantly around the world. The one set of calibrations per species is sufficient.

    Calibrations for… Processed Fish…
    Artificially changed from the natural state, eg. Mateus Herring, Smoked Salmon, Salted Fish, Cooked Fish, etc.

    The processed fish are different. Everyone has their own individual recipes, with varying amount of salts, spices, drying, smoking, or cooking processes. Therefore it is not possible to produce a universal calibration for each type of processed fish product. All we can do is create a Graph / Chart by taking an average of manufacturers samples, and combining the data. The accuracy achieved using the Fatmeter will vary between individual companies, depending on the quality control aspects of the process, and the quantity of food additives, smoking, brining, drying or cooking time.

    Distell can, of course, carry out a specific product calibration for a specific recipe, and thus monitor accurately the fat content variances encountered. However, when you consider that any one processor may have up to 300 different recipes, then it becomes uneconomic to carry out individual recipe calibrations… especially when each special calibration costs upwards of… £ 750.

    The answer is simply to use a Graph / Chart… for the process. The operator can then log all of the results achieved using the Fatmeter on that particular fish product for perhaps the first 1-2 weeks, then carry out a series of laboratory analysis on the samples. This will allow the creation of a graphed “Table-of-Error”, such as the charts shown below. This will allow the company / operator to monitor the specification of the product, by allowing for this “error factor”.

    Of course, it is necessary to compile a reasonable number of data samples, preferably reflecting the extremes normally encountered for that product in the process… from the very low fat content, to the very high fat content levels. This will ensure a good spread, and allow a clear picture of trends.

    Thereafter, the Fatmeter can be used to accurately monitor the day-to-day quality and uniformity of that product, and allow rapid reaction, where product variances are encountered. This procedure can be adopted for most of the companies processed products.

    The clear message is…

    • The Fatmeter does not necessarily have to contain a dedicated calibration for each and every processed product. Simply build up a library of ” Error Tables” for each product, and apply the error factor accordingly.
    • The Fatmeter is a quality monitoring tool, giving the operator the ability to check one days’ production against the next day. If the results are the same… day-to-day, then the specification is correct… if there is a variance from one day to the next, then this will be clearly highlighted and allow for investigation at an early stage.
    • Where there is a requirement for a dedicated, truly accurate calibration for a processed product, Distell can prepare an accurate calibration for that product.
  • Some advice on using the Fish Fatmeter where you do not have a specific fish calibration available…
    The Fatmeter does not necessarily require to have a dedicated product specific calibration. It is easy to create your own “ERROR TABLE” without going to the expense of a dedicated calibration.

    The Fatmeter is portable, and its advantage lies in its’ ability to monitor large numbers of samples rapidly and non-destructively. Thus checking Specification, Sample homogeneity, Product uniformity… day-to-day, hour-to-hour, if need be.

    How to create the Error Table…
    The enclosed example illustrates the results using the Fatmeter and then comparing with traditional laboratory method. We have prepared graphs of the data. The graphs allow you to see, at a glance… FOUR important factors… And allows the operator or quality control department the ability to monitor the following…

    • Product uniformity… hour-to-hour, day-to-day.
    • Sample variability from batch-to-batch, sample-to-sample.
    • Product is within specification requirement
    • Screen the production process at various points in the factory
      • The trend lines on the graphed results allow you to assess the value of the variance between your existing lab method and a chosen calibration setting on your Fatmeter. We have shown below TWO examples of different types of Fish, measured using the Fish Fatmeter on existing standard calibration settings. The samples were then sent to the laboratory for analysis, and the results of the Fatmeter were compared to the Fosslet Laboratory results.

        By charting the results of the two methods ( it means that you can compare the Fatmeter results with any system currently in use within your facilities), the operator can readily prepare an “Error Table” and thus continue to use the Fatmeter for monitoring and measurement of any of their processed products… without going to the expense of a dedicated calibration.