摘要： 食物及饮用水中亚硝酸盐的污染将危害人类健康。因此控制亚硝酸盐含量、降低亚硝酸盐的方法成为了食品安全的重中之重。目前国内外有很多方法降解亚硝酸盐，本课题选用乳酸菌和植物提取液来降解亚硝酸盐。乳酸菌生长16h时最好，且乳酸菌的培养过程是不断产酸的过程。之后再用固定化细胞技术对乳酸菌进行固定化，以提高微生物细胞的稳定性，尽量减少酶活性的流失。通过单因素试验对乳酸菌海藻酸钙凝胶小球的制备条件进行优化，确定包埋量的最优值为90mg/mL，此时的降解率为81.01%。在此基础上进行海藻酸钠－壳聚糖－海藻酸钠(ACA)液芯微囊的制备，在最优条件下测定其降解亚硝酸盐的能力。实验证明微囊对亚硝酸盐的降解能力比凝胶小球更好。含有维生素C和维生素V的植物提取液对亚硝酸盐的降解率达到99.66%。62120

毕业论文关键词： 乳酸菌；亚硝酸盐；固定化细胞；海藻酸钠－壳聚糖－海藻酸钠(ACA)液芯微囊

Study on the technology of reducing nitrite content

Abstract:Nitrite in food and drinking water has been a threat to human health.Therefore,methods to control and reduce the content of nitrite has become a top priority to food security.At present, there are many methods to degrade nitrite in domestic and overseas, this paper uses lactic acid bacteria and plant extracts to degrade nitrite.Lactic acid bacteria grow best when 16h, and the culture of lactic acid bacteria is the process of continuous production of acid.Then immobilized cell technology was used to fix the lactic acid bacteria, in order to improve the stability of the microbial cells, to minimize the loss of enzyme activity.The optimum preparation conditions of lactobacillus calcium alginate gel beads were determined through single factor experiment:concentration of bacteria 90 mg/mL.The degradation of this rate was 81.01%.The preparation of alginate chitosan alginate (ACA) liquid core microcapsules was carried out, and the ability to degrade nitrite was determined under the optimum conditions.The experimental results show that the degradation ability of the microcapsules is better than that of the gel beads.The degradation rate of the plant extracts containing vitamin C and vitamin V reached 99.66%.

Key words: lactic acid bacteria; nitrite; immobilized cells; sodium alginate chitosan alginate (ACA) liquid core microcapsules

1.绪论 1

1.1 课题研究的目的和意义 1

1.2 亚硝酸盐的重要用途 1

1.3 亚硝酸盐的主要来源 1

1.3.1 饮用水 1

1.3.2 蔬菜 1

1.3.3 肉制品 2

1.4 亚硝酸盐的危害和预防措施 2

1.4.1 亚硝酸盐的危害 2

1.4.2 预防措施 3

1.5 目前国内外对于亚硝酸盐的降解方法 3

1.5.1 红曲色素降低亚硝酸盐 3

1.5.2 亚硝基血红蛋白降低亚硝酸盐 3

1.5.3 深红酵母降解亚硝酸盐 3

1.5.4 生物降解亚硝酸盐 4

1.5.5 酶法处理降解亚硝酸盐 4

1.5.6 绿茶和茶多酚降解亚硝酸盐 4

1.5.7 其它天然物质降解亚硝酸盐 4

1.6 乳酸菌简介 5