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Developmemt of reliable methods of differentiating unfrozen from frozen-thawed flesh foods - AN0625

There is a need for reliable methods of distinguishing unfrozen flesh foods to enable legislation on labelling of foods to be enforced. To date, no satisfactory method is available. Most of the methods which have been proposed are based on the princilpe that freezing and thawing of muscle tissue results in the release of enzymes from cellular organelles such as mitochondria or lysosomes. The released enzymes can then be assayed for activity in extracts of muscle tissue or by specific staining of electrophoretograms. Thpical mitochondrial enzymes are citrate synthetase and b-hydroxyocyl-CoA-dehydrogenase )HADH); typical lysosomal enzymes are b-N-acetylglucosamidase, alpha-glucosidase and cathepsin D. All methods suffer from a major disadvantage that the enzyme released as a result of rupture of membranes on freezing are eventually released as the tissue breaks down on autolysis, making for uncertainty in differentiating fresh frozen-thawed material from unfrozen but spoiled tisse. As none of the proposed methods is generally applicable to flesh foods, am evaluation would have to be made for each species of interest.
To develop reliable methods of differentiating unfrozen from thawed-frozen foods to enable enforcement of legislation on labelling of foods.
Time-Scale and Cost
From: 1992

To: 1995

Cost: £204,118
Contractor / Funded Organisations
Central Science Laboratory