三种生物防腐剂联合处理对龙眼汁抑菌效果的研究

目的研究纳他霉素、乳酸链球菌素和溶菌酶三种生物防腐剂对龙眼汁抑菌效果的影响。方法设计两两复配和响应面实验,以菌落总数为指标,观察贮藏期间内的抑菌率变化,得出最优抑菌组,并测定最优组的一些理化指标。结果由两两复配实验得出,当添加总浓度为200 mg/kg,纳他霉素:溶菌酶=3:7、Nisin:溶菌酶=5:5、Nisin:纳他霉素=9:1时的抑菌效果明显;响应面实验结果显示三种生物防腐剂浓度均为225mg/kg时的抑菌效果最好,最大抑菌率为84.2%。结论三种生物防腐剂复配后添加于龙眼汁中,能显著提高抑菌率,延长保存期,同时可在一定程度减缓Vc含量、总酸含量和色差的变化。

Antimicrobial effects of combined treatments of 3 kinds of biological pre-servatives on Longan juice

Objective To research the inhibitory effect of natamycin, Nisin and lysozyme on Longan juice. Methods Through compound experiments and response surface experiments, with the total number of colonies as index, the optimal antimicrobial group was obtained based on the inhibition rate observed in the duration of storage. Some related physicochemical quotas of the optimal antimicrobial group were determined as well. Results Among the results of compound experiments, with the total concentration of 200 mg/kg, the antibacterial effect was obvious when Natamycin: lysozyme = 3: 7, Nisin: lysozyme = 5: 5 or Nisin: Natamycin = 9: 1. Response surface experimental results showed that the inhibitory effect was best when the concentration of three kinds of biological preservative are all 225 mg/kg,and the inhibitory rate was 84.2%. Conclusion The combined use of three kinds of biological preservative can significantly improve the inhibitory rate, prolong the shelf life, and also slow down the change of Vc content, total acid content and the chromatic aberration in some degree.