Protein denaturation in frozen fish. V.—Development of the cell fragility method for measuring cold‐storage changes in the muscle

A new technique is described for following the deteriorative changes that occur when cod muscle is cold‐stored. It is based on the observation that, after being thawed, the individual muscle cells become progressively more difficult to rupture with a homogeniser as storage time increases. Measurement of the cold‐storage change is carried out by submitting weighed muscle samples to a standard homogenisation procedure in dilute formaldehyde solution, arid then measuring the optical density of the homogenate in a colorimeter. The resulting figure is related to the proportion of muscle cells destroyed, and so to the extent of protein denaturation. The experimental conditions were varied, and the effects on the results were noted in order to establish the optimum procedure. The method is more sensitive and reliable than either the soluble protein method or a taste panel, besides being much quicker to carry out.