虾酱酶法模拟加工过程中的细菌学分析

Bacteriological Analysis in Mimic Enzymatic Processing of Shrimp Sauce

对虾酱酶法加工过程中各工序的细菌总数、大肠菌群数、副溶血性弧菌和沙门氏菌进行检验。结果表明:鲜虾原料的细菌总数为3.4×104CFU/g,冰水清洗后明显降低为3.0×103CFU/g,50℃酶解3h后的细菌总数显著增加至3.7×104CFU/g,加入食盐能抑制细菌的生长;采用100℃杀菌30min,能有效杀死虾酱中的细菌,成品虾酱的细菌总数为2.6×104CFU/g。鲜虾原料的大肠菌群数为15MPN/g,冰水清洗后明显降低至3.6MPN/g,酶解作用对大肠菌群的生长影响不大,加盐、保温、杀菌能明显消除大肠菌群的污染,成品虾酱的大肠菌群数小于3.0MPN/g。虾酱加工过程中均未检出副溶血性弧菌和沙门氏菌。由此可见,冰水清洗、加盐、杀菌等工艺条件是虾酱酶法加工过程中控制细菌总数和大肠菌群数的关键工序。

Total viable bacteria,coliforms,Vibrio parahaemolyticus and Salmonella were counted at various stages of enzymatic processing of shrimp sauce.The results indicated that the total bacterial count in fresh shrimps was 3.4×104 CFU/g,and a lower value of 3.0×103 CFU/g was observed after washing with ice water.However,the number of total bacteria in shrimps after enzymatic hydrolysis at 50 ℃ for 3 h was increased to 3.7×104 CFU/g.Salt addition could obviously inhibit bacterial growth.Sterilization at 100 ℃ for 30 min could effectively kill bacteria in shrimp sauce and the sterilized shrimp sauce showed a total bacterial count of 2.6×104 CFU/g.Washing with ice water could cause the coliform count in fresh shrimps to obviously decline from 15 to 3.6 MPN/g.However,enzymatic hydrolysis did not affect coliform count.Salt addition,constant temperature and sterilization could significantly decrease the pollution from coliforms and coliforms in shrimp sauce products were counted to be less than 3.0 MPN/g.Neither Vibrio parahaemolyticus nor Salmonella were detected during the processing of shrimp sauce.Therefore,ice water washing,salt addition and sterilization are critical for the control of total bacteria and coliform counts.