A kliinatyzacja - Vasiennictwo, 1960, 4, 595 l 6 Ermakow, A. J.. Bielki w pron?;vshlennosti i sielskonz I-hoziaistwie, Ahad. N a u k SSSR, AT1oskwa, 1052 l 6 Kretovich, V. I,., B i d . Infovm. centv. L a b . Quantitative aspects of the extraction fi-om fresh and cold-stored cod flcsh of myosin as free as possible of actomyosin have been examined. -1 method for extraction of a large proportion of reasonably pure myosin has been standardised and used t o study the changes in extractability of this protein during cold-storage of cod flesh. It appears that 70-800/, of the niyosin becomes non-extractable a t a rate similar t o that a t which the total myofibrillar protein of the flesh becomes non-exti-actable. The remainder becomes non-extractable at a very much slower rate. The implications of these findings in the mechanism of cold-storage deterioration in texture are discussed. of frozen storage a t -14' that produce marked diminution in the extractability of the total myofibrillar protein. Loss of the enzymic activity of myosin coulcl be demonstrated2 during storage of cod flesh a t -14' and -z 0 , indicating that this protein was being truly denatured, but the rate of loss of activity was slower than that of the extractability of the whole myofibrillar protein.An attempt has now been made to follow the changes in extractability of the myosin alone during frozen storage a t -14', to provide further information on the behaviour of the individual myofibrillar proteins. ExperimentalMaterials the year, were used.Xorth Sea cod (Gadus callarias L.), not more than 30 in. in length and caught throughoutOtherwise the fish were Lire specimens were taken from a shore tank.

No abstract

The eating quality of cod kept for different periods in melting ice before being frozen and stored at three different temperatures has been evaluated by a taste panel using a new score sheet. Objective measurements of both initial freshness before freezing and deterioration during frozen storage were carried out on the same samples. Correlations were obtained between the objective measurements and various aspects of eating quality. The relative contributions of the various aspects of eating quality to the final overall acceptability were obtained, and the value of the objective measurements in predicting overall acceptability assessed.

Actin has been prepared from fresh cod flesh and from cod flesh which has been stored a t -14' for u p to 127 weeks. The properties of these actin preparations have been compared with respect t o ability to polymerise and to combine with cod myosin. It is concluded that up to the time (30 weeks) when the actomyosin portion of the salt-soluble protein of the flesh becomes completely insoluble, there is only a very small change in the properties of the actin.

Fresh cod muscle treated with formaldehyde at concentrations approximating to those attained during frozen storage, is rendered partially inextractable in solutions of sodium dodecyl sulphate. This finding throws doubt on the role of formaldehyde as a methylene crosslinking agent acting during frozen storage of cod and similar species.