Study on the biogenic amines and quality changes of crucian carp(Carassius cuvieri) stored at chill temperature(4 ℃) and ice(0 ℃)

Crucian carp(Carassius cuvieri)is a widely distributed freshwater fish species in China and used as raw material for food production.A considerable amount of crucian carp spoiled due to endogenous enzymes and microbial action each year.Chilled storage,usually refers to store fish at 0-4 ℃,is a common way of preservation of fish,but this method can keep the freshness of fish only one week.Iced storage can maintain lower temperature and prolong the shelf life of fish.However,few reports could be found about crucian carp stored in ice.The aim of this study was to investigate the quality changes of crucian carp stored at chill temperature(4 ℃) and in ice(0 ℃).The fish after death were immediately scaled,gutted,washed and divided into two groups.One stored at chill temperature,the other in ice.During the whole storage,the changes in sensory assessment,K value,total volatile basic nitrogen w(TVB-N),total bacterial count and eight biogenic amines(tryptamine,2-phenylethylamine,putrescine,cadaverine,histamine,tyramine,spermidine and spermine) were monitored every two days.The results showed that:K value,w(TVB-N) and total bacterial count increased with time,and fish stored in ice changed more slowly than that at 4 ℃.K value increased very quickly in the beginning and got to 61.77% at 4 ℃ and 34.21% in ice after 6 days.There were no significant difference(P0.05) between chilled storage and iced storage in w(TVB-N) within 6 days.Throughout the period,w(TVB-N) stayed below 20.00 mg/100 g.The peak value of w(TVB-N) at chill temperature and in ice were 17.49 mg/100 g(on the 12th day) and 18.53 mg/100 g(on the 16th day) respectively.The initial value of total bacterial count was 3.78 log CFU/g,and the value reached to 7.42 log CFU/g and 5.54 log CFU/g respectively after 10 days storage at chill temperature and in ice.During the storage,the content of tryptamine and putrescine changed with time evidently,so they could be used as referential indicators of crucian carp.The preservation life of crucian carp at chill temperature(4 ℃) and in ice(0 ℃) was 8 days and 10 days respectively.Iced storage could prolong the preservation life effectively compared to chilled storage.