Quality of frozen mackerel during storage as processed by different freezing methods

The fresh mackerel was frozen using four different quick-freezing methods, such as refrigerator freezing, quick freezer spiral tunnel freezing and plate freezing. Water retention, color, texture, electrical conductivity, total volatile base nitrogen (TVB-N), K value, malondialdehyde (MDA), sulfhydryl group protein secondary structure were used physicochemical indicators to evaluate the changes in fish quality, water migration observed by low field NMR. results showed that treated with method closest samples, best retention capacity during slow decrease hardness elasticity, rate of increase conductivity values, TVB-N content, MDA content more stable structure. This indicated fat oxidation lowest degradation least, which effectively maintained moisture freshness samples most favorable treatment maintain quality compared other groups.