【作者】 刘俊霞；

【导师】 陈永福；

【作者基本信息】 内蒙古农业大学 ， 农业硕士（专业学位）， 2022， 硕士

【摘要】 瑞士乳杆菌H11(Lactobacillus helveticus H11)是一株从新疆地区伊犁州酸马奶中分离的具有我国自主知识产权的益生菌,其发酵乳饮料具有较高的ACE(血管紧张素转换酶)抑制活性和ACE抑制肽(VPP和IPP)。首先将L.helveticus H11进行单菌株发酵,接菌量分别为(2×10~6、5×10~6、1×10~7CFU/m L),然后将0.003%的商业发酵剂Mild1.0进行发酵并与上述接菌量为(2×10~6、5×10~6、1×10~7CFU/m L)的L.helveticus H11分别进行复配发酵。本研究通过对发酵乳的发酵特性、流变学特性、质构特性、感官评价、挥发性风味物质、ACE抑制活性和ACE抑制肽(VPP和IPP)含量进行分析,综合评价L.helveticus H11在发酵乳中的应用潜力。结果表明:(1)L.helveticus H11与商业发酵剂复配可显著降低发酵时间,其中M+H11(5×10~6CFU/m L)复配时发酵时间最短为(6.04±0.05h)。贮藏期间,L.helveticus H11复配发酵乳酸度适宜、组织细腻、粘弹性好、感官得分高、活菌数存活率较高。贮藏结束时,复配发酵乳L.helveticus H11的活菌数高于10~8CFU/m L,能够保证益生活性。(2)贮藏期间,添加L.helveticus H11的发酵乳具有较高的ACE抑制活性,其中M+H11(5×10~6CFU/m L)复配发酵乳在贮藏14d时ACE抑制活性最高(75.08±0.33%),同时ACE抑制肽VPP和IPP的含量分别为(1.7±0.12μmol/L)和(1.48±0.12μmol/L)。(3)在贮藏期间共检测出57种挥发性风味物质,包括酸类化合物20种、酮类化合物21种、酯类化合物9种、醛类化合物4种、烷烃类化合物3种,添加L.helveticus H11的发酵乳中挥发性风味物质种类更丰富,尤其在贮藏14d时复配发酵乳的风味特征最为突出,与感官评价结果保持一致。研究表明,L.helveticus H11以(5×10~6CFU/m L)接菌量与商业发酵剂复配发酵,能够提高发酵乳的发酵特性、贮藏稳定性、ACE抑制活性和感官品质。本研究为L.helveticus H11的产业化推广应用提供理论数据支持,为功能性乳制品的开发提供新的研究思路。更多还原

【Abstract】 Lactobacillus helveticus H11 is a probiotic with independent intellectual property rights in my country isolated from yogurt in Ili Prefecture,Xinjiang.Its fermented milk beverage has high ACE inhibition activity and ACE inhibitory peptides(VPP and IPP).First,L.helveticus H11 was fermented with a single strain,and the viable counts were(2×10~6、5×10~6、1×10~7 CFU/m L),and then 0.003%of the commercial starter Mild1.0,L.helveticus H11 with bacterial counts(2×10~6、5×10~6、1×10~7CFU/m L)were fermented separately.In this study,L.helveticus H11 and commercial starter Mild1.0 strains were fermented in bovine milk in single strain and compound mode.Sexual flavor substances,ACE inhibition rate and content of ACE inhibitory peptides(VPP and IPP)were analyzed to comprehensively evaluate the application potential of L.helveticus H11 in fermented milk.The results showed that:(1)The combination of L.helveticus H11 and commercial starter significantly reduced the fermentation time,among which the fermentation time of M+H11(5×10~6CFU/m L)was the shortest(6.04±0.05h).During storage,L.helveticus H11 compound fermentation had suitable lactic acid degree,fine texture,good viscoelasticity,high sensory score and stable viable count.At the end of storage,the viable count of compound fermented milk L.helveticus H11 was higher than 10~8CFU/m L,which could ensure probiotic activity.(2)During storage,L.helveticus H11-added fermented milk had higher ACE inhibitory activity,among which M+H11(5×10~6CFU/m L)compound fermented milk had the highest ACE inhibition activity(75.08±0.33%)at 14d storage.),while the contents of VPP and IPP were(1.7±0.12μmol/L)and(1.48±0.12μmol/L)respectively.(3)A total of 57 volatile flavor compounds were detected during storage,including 20acid compounds,There are 21 kinds of ketone compounds,9 kinds of ester compounds,4kinds of aldehyde compounds,and 3 kinds of alkane compounds.The fermented milk added with L.helveticus H11 has more kinds of volatile flavor substances,especially when it is stored for 14 days.The most prominent flavor characteristics were consistent with the sensory evaluation results.The research showed that the fermentation characteristics,storage stability,ACE inhibitory activity and sensory quality of fermented milk could be improved by using L.helveticus H11 with 5×10~6 CFU/m L inoculum and commercial starter.This study provides theoretical data support for the industrialization and application of L.helveticus H11,and provides new research ideas for the development of functional dairy products.更多还原