乳酸菌抑制N-亚硝胺形成的机理探究及应用效果

Inhibition Mechanism and Application of Lactic Acid Bacteria on N-Nitrosamine Formation

将前期实验筛选得到的能够有效抑制红肠中N-亚硝胺形成的乳酸菌发酵剂PRO-MIX5(木糖葡萄球菌+清酒乳杆菌+类植物乳杆菌)分别用肉糜培养基和MRS培养基培养,在亚硝酸盐降解体系和N-二甲基亚硝胺(N-nitrosodimethylamine,NDMA)形成体系中逐步筛选,分别排除代谢产物、胞内酶、菌体的作用,得到的菌体碎片具有抑制NDMA形成的效果后,进一步筛选MRS培养基中添加的诱导剂种类,测定菌体碎片添加量对NDMA抑制效果的影响,最后将最优培养方式得到的菌体碎片分别以湿质量的0.05%、0.25%、0.5%比例应用于红肠和培根的制作中,以验证其在产品中对N-亚硝胺形成的抑制作用。结果表明,PRO-MIX5抑制N-亚硝胺的形成主要是其菌体碎片的作用,且使用含有质量浓度0.04μg/mL的9种N-亚硝胺的MRS肉汤培养基扩增培养PRO-MIX5,得到的菌体碎片对N-亚硝胺形成的抑制作用效果较好,应用于3个湿质1量比例的红肠和培根中,均为0.05%比例抑制9种N-亚硝胺形成的效果最佳,在2种产品中的抑制率分别达到41.04%和13.83%,应用效果良好。

This study aimed to explore the inhibition mechanism of Lactobacillus starter culture PRO-MIX5(containing Staphylococcus xylosus+Lactobacillus sake+Lactobacillus paraplantarum),which had been obtained in our previous study and found to effectively inhibit the formation of N-nitrosamines in Harbin red sausage,on the formation of N-nitrosamines.PRO-MIX5 was cultured in both minced meat medium and MRS medium for stepwise screening using nitrite degradation system and N-nitrosodimethylamine(NDMA)generation system.As a result,we found that the cell debris but not the metabolites,intracellular enzymes or whole cells could inhibit NDMA formation.Furthermore,the effect of the type of inducer added to MRS medium and the amount of cell debris added on the inhibition of NDMA formation was investigated.Finally,confirmation experiments were conducted by adding the cell debris obtained under optimized conditions at levels of 0.05%,0.25%and 0.5%(on a wet mass basis)to Harbin red sausage and bacon.The results showed that the cell debris of PRO-MIX5 inhibited NDMA formation.A good inhibition effect was observed by culturing PRO-MIX5 in MRS medium containing 9 N-nitrosamines at a concentration of 0.04μg/mL.Among the three addition levels,the cell debris at 0.05%showed the highest inhibition effect on the formation of the N-nitrosamines in both Harbin red sausage and bacon with inhibition percentages of 41.04%and 13.83%,respectively,and therefore its application could give good results.