The evaluation of the three edible tissues of dead adult Chinese mitten crabs (Eriocheir sinensis) freshness in harvest season based on the analysis of TVBN and biogenic amine

摘要

This study was carried out to evaluate the quality of the three edible tissues (muscles, hepatopancreas and gonads) of the male and female Chinese mitten crab (Eriocheir sinensis) in natural harvest season, based on total volatile base nitrogen test (TVBN) and biogenic amines analysis at intervals time of 3 h extended for 24 h during 30 °C storage (a mean ambient temperature in harvest season). In addition, the relationship between the value of TVBN and storage time or main biogenic amine was evaluated. Results showed that TVBN level of female gonad reached the recommended limit (30 mg/100 g) at 3 h, and the times of reaching the recommended limit were 15 h in both sexes muscles, while in male and female hepatopancreas reached the recommended limit at times of over 24 and 24 h respectively. Moreover, putrescine was highest in amount in all biogenic amines analyzed. We suggested that TVBN value could be as a good indicator for Chinese mitten crab freshness. According to analysis for biogenic amine accumulated in edible tissues of crab, it was possible that dead crab poisoning may be caused by putrescine. Dead Chinese mitten crabs for over 24 h, should be not recommended for eating or processing.