Effects of Two Kinds of Thawing Methods on the Quality of Freshwater Fish

In order to study the effects of two kinds of thawing methods on the quality change of freshwater fish at 4℃ low temperature thawing and 25℃ water bath thawing. These frozen channel catfish,perch and mandarin fish were used as research objects by 4℃ low temperature thawing and 25℃ water bath thawing in this paper,the effects of two thawing methods on the thawing loss rate,pressure loss rate,cooking loss rate,pH,whiteness,toughness,microstructure and water distribution of the three freshwater fish were studied. The results for the same species freshwater fish showed that after thawing at 4℃,the thawing loss rate,pressure loss rate,cooking loss rate and whiteness value of the same freshwater fish were lower than that of the 25℃ water bath thawing group. The same species of freshwater fish 4℃ low temperature thawing method pH,toughness higher than 25℃ water bath thaw. In terms of microstructure,the cell gap was increased in the 25℃ water bath thawing compared to the 4℃ low temperature thawing method. Low-field NMR analysis showed that the low temperature thawing at 4℃ was higher than the non-movable water content in the 25℃ water bath thawing method,and its free water content was low,so the 4℃ low temperature thawing method was better than the 25℃ water bath thawing method. The comprehensive consideration that 4℃ low temperature thawing method would be more conducive to maintaining the good quality of freshwater fish.