The accelerated freeze-drying (AFD) method of food preservation / a report on some work of the Research Establishment and Experimental Factory of the Ministry of Agriculture, Fisheries and Food, Aberdeen, Scotland, between 1955 and 1960.

  • Great Britain. Ministry of Agriculture, Fisheries and Food.
Date:
1961
Catalogue details

Licence: Public Domain Mark

Credit: The accelerated freeze-drying (AFD) method of food preservation / a report on some work of the Research Establishment and Experimental Factory of the Ministry of Agriculture, Fisheries and Food, Aberdeen, Scotland, between 1955 and 1960. Source: Wellcome Collection.

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    sufficient information about the material under test. Therefore with the guidance of the statistician score sheets were devised appropriate to the com- modity and the form of the experiment. (As the range of foods under investi- gation was large so also was the range of score sheets.) The general principle was one of devising a set of descriptions of the range of characteristics found, under the headings of ‘flavour’, ‘texture’, ‘odour’, etc., for each commodity, with sometimes the addition of a quantitative record of intensity or frequency of such qualities. Table 16 is a specimen copy of the score sheet used for samples of carrot coming from the processing line, the numbers having no mathematical sig- nificance, but merely acting as codes for a verbal description. Table 17 is the score sheet for samples of carrot from storage tests, and indicates the forms of deterioration to be expected. Table 18 is a score sheet for dehydrated meat devised at the Low Temperature Research Station, Cambridge, and Table 15 one for fish. These latter two incorporate a quantitative numerical score. It was found very difficult to devise a suitable scoring system for the various fruits and some of the vegetables, and the crude system of scoring was used for these items. 4 — excellent 3 — good 2 — fair 1 — poor 0 — very poor Presentation of Samples: The taste-panel room contained six individual and entirely separate cubicles entered from a common corridor. Each cubicle was furnished with a shelf, a cuspidor flushed by a hot water tap, a set of various coloured lights and a sliding panel enabling the kitchen staff to pass samples to the taster. The coloured lights were used extensively in order to eliminate any prejudice caused by the appearance of the food. Panels were held daily, at set times. All members were aware of the times at which they were liable for tasting but were reminded 15 min beforehand when they would actually be required. It was considered that the tasters gave more accurate results and were more consistent in the mornings although it was never statistically proved. On presenting themselves for a panel each member was allocated a cubicle, given ascore sheet and marking sheet and all the samples under test at the one time. The sliding panel was then closed. The tasters now assessed the samples entirely free from surrounding influences. Some form of palate cleanser was always given. The three used in Aberdeen were—orange juice for fish and hot meat; hot tea when tasting cold meat minces, to ensure that all fat was removed from the palate; and soda water at vegetable and fruit panels. (As these commodities were sometimes treated with sulphite it was felt that the sulphite present in orange juice might be misleading.) On completion of the assessment of flavour and texture the coloured lights were changed to a mixture of incandescent white and fluorescent day-light for colour assessment. It was found that this mixed light gave a more natural appearance to the foodstuff than either on its own. This type of taste panel was the one used most extensively at Aberdeen as being most suitable to the work there. However, the triangular test or the two-out-of-five test was occasionally used when a direct comparison of samples