Changes in the adenosinetriphophatase activity and sulphydryl groups of cod flesh during frozen storage

The adenosinetriphophatase (ATP‐ase) activity, “easily‐reactable” and total sulphydryl groups of cod flesh have been determined during frozen storage for up to 170 weeks at — 14°, —22° and —29°. At —29° no change in enzyme activity could be detected, but at —22° and —14° definite loss of activity occurred. The rate of loss of activity at these two latter temperatures was very much less than the rate of development either of insolubility of the enzyme, or of toughness of the flesh. No change in either ‘easily‐reactable’ or total sulphydryl groups was detected at any storage temperature.