魚肉の調理・加工におけるタンパク質の変化 ＩＩＩ かすづけ処理におけるサワラ肉タンパク質の変化

Abstract

Kasuzuke is a processing where fish meat and vegetables are cured in lees of sake (Japanese rice wine) for the purpose of preservation. In kasuzuke the fish meat cured in sake lees acquires a peculiar texture. Changes in muscle proteins were examined in relation with the texture changes. Spanish mackerel fillets were cured in sake lees after salting and were stored at 4°C for 1, 7, 14, 21 and 28 days. The fillets were submitted to the tests and measurements for firmness (after being cooked), extractability of proteins, viscosity and natural fluorescence of actomyosin solutions and the analysis of proteins by SDS-PAGE after various periods. For control, fillets were stored with the addition of 2% NaC1 or without any treatment. Firmness of the texturometer test increased after a day and 7 days, then decreased after 14 days and 21 days. Extractability of actomyosin and water soluble proteins did not change appreciably for 28 days. The changes in reduced viscosity and relative fluorescence intensity suggested that the conformations of actomyosin of muscle cured in sake lees have changed. SDS-PAGE patterns showed that the proteins of muscle cured in lees were decomposed during storage into fragments with smaller molecular weights. The decomposition of proteins were attributed to the effect of the acid proteinases in the sake lees. The texture changes during the curing in lees were suggested to come from the changes of proteins.