Changes in the Quality and Freshness of Silurus meridionalis Chen under Partial Freezing and Frozen Conditions

In order to obatin the effects of three storage temperatures on the quality change of Silurus meridionalis Chen,the changes of total number of colonies,pH,total volatile basic nitrogen(TVB-N),K value,color value,elasticity and hardness of Silurus meridionalis Chen in partial freezing storage(-3℃)and frozen storage(-18,-25℃)were studied respectively. And combined with sensory evaluation,the freshness of Silurus meridionalis Chen was analyzed. The results showed that the changes rate of each index reduced with the decrease of the storage temperature. With the extension of the storage time,the sensory scores,brightness value L^*,elasticity and hardness index decreased continuously under three kinds of storage temperature,and the total number of colonies,TVB-N,K value and yellow-blue value b^* were on the rise,while the pH was firstly decreased and then increased which showed an V-type change. According to the experimental results of indicators,the shelf life of Silurus meridionalis Chen was 18 days at-3℃,while the frozen storage group did not show spoilage at the end of experiment(60 d). What's more,compared with the partial freezing storage,the frozen storage could significantly prolong the storage period of the Silurus meridionalis Chen.