抗胃肠道胁迫益生菌的筛选及产品开发

发布时间：2018-05-06 13:31

  本文选题：益生菌 + 益生特性　； 参考：《东北农业大学》2012年硕士论文

【摘要】：嗜酸乳杆菌和双歧杆菌是人体肠道重要的益生菌群,其在肠道内的数目是评价机体健康程度的重要指标,它们具备多种保健功能,如酸和胆汁盐耐受性,粘附人体上皮细胞,定植肠道产生细菌素,改善乳糖不耐症,降低胆固醇、氨和其他毒性物质,产生B族维生素,使遭受抗生素破坏的紊乱肠道菌群恢复正常,刺激免疫反应等。目前我国益生菌产品面临的关键问题是工业、胃肠道胁迫对菌株的各种破坏,如产品的制造、贮存、销售、食用过程。双歧杆菌、嗜酸乳杆菌等益生菌,多为厌氧菌或兼性厌氧菌,生长过程中不形成芽孢,抗性较差,生命活动中还会产生一些危机自身繁殖的乳酸和乙酸等代谢物,故在液体条件下难以长期保存；另外益生菌产品的贮存和运输均要求冷链,货架期较短。本课题针对以上各种弊端,研究将益生菌以干物质状态应用,实现益生菌的随时膳食补充。 本研究首先利用细菌生态学、生理学和16S rDNA基因序列分析,筛选出性能较佳的5株益生菌作为研究对象,研究其益生特性；其次优化设计确定5株益生菌的最佳冻干保护剂组合,研究每株益生菌菌粉的保存稳定性；再次对5株益生菌进行小中试发酵,从pH、滴定酸度、质构物性和流变学特性来分析比较5种发酵乳,以及利用HPLC进行主体代谢产物的含量测定；最后确定吸管和瓶盖的应用方式。 益生特性试验表明：嗜酸乳杆菌和动物双歧杆菌都有很好的酸和胆汁盐耐受性,动物双歧杆菌的耐酸性较强于嗜酸乳杆菌的；5株益生菌对致病菌大肠杆菌、沙门氏菌和金黄色葡萄球菌均有抑制作用,嗜酸乳杆菌的抑菌性较强于动物双歧杆菌的；五株益生菌均不具有耐药性,对抗生素青霉素、链霉素和乙酰螺旋霉素均敏感。保存稳定性试验表明：在冻干保护剂脱脂乳、蔗糖、海藻糖和Vc钠盐的最佳组合下,5株益生菌的冻干存活率均在85.00%以上,5株益生菌菌粉在4℃和25℃下保存12个月,菌粉活菌数都在1.0×108cfu/g以上,达到了FAO/WHO建议食品益生菌活菌数应在106-107cfu/ml以上的要求,4℃保存的菌粉稳定性高于25℃的。小中试发酵试验表明：嗜酸乳杆菌KLDSAD2发酵乳的组织状态粘弹性最好。主体代谢产物试验表明：嗜酸乳杆菌代谢产乳酸量较大,而动物双歧杆菌代谢产乙酸量较大。应用试验表明：成功设计菌粉吸管,可随时放入经常喝的各种饮料中,如矿泉水、果汁、营养快线、以及盒装牛奶等。 本研究筛选出具有抗胃肠道胁迫的益生菌,研究其以干物质状态的应用方式,克服了益生菌在液体环境中的各种弊端,使菌粉饮料在保存1年后,活菌数仍在1.0×108cfu/g以上,使人体摄入的益生菌活菌数达到FAO/WHO的要求,为健康造福。
[Abstract]:Lactobacillus acidophilus and bifidobacterium are important probiotics in the human gut. Their number in the intestine is an important index to evaluate the health of the body. They have a variety of health care functions, such as acid and bile salt tolerance, adhesion to human epithelial cells, The colonized intestine produces bacteriocin, improves lactose intolerance, reduces cholesterol, ammonia and other toxic substances, produces B vitamins, returns to normal intestinal flora damaged by antibiotics, and stimulates immune response. At present, the key problem of probiotic products in China is the damage caused by gastrointestinal stress, such as manufacture, storage, sale and edible process. Bifidobacterium, Lactobacillus acidophilus and other probiotics, mostly anaerobes or facultative anaerobes, do not form spores during growth, so they have poor resistance, and some metabolites such as lactic acid and acetic acid, which are in danger of propagating themselves, are produced in life activities. The storage and transportation of probiotic products require cold chain and the shelf life is short. In view of the above disadvantages, this paper studies the application of probiotics as dry matter to realize the dietary supplement of probiotics at any time. In this study, five probiotics strains with better performance were selected by using bacterial ecology, physiology and 16s rDNA gene sequence analysis to study their probiotic characteristics. Secondly, the optimal freeze-dried protectant combination of five probiotics was optimized to study the preservation stability of each probiotic powder, and then to ferment the five probiotics in a small scale, from pH, titration acidity, The properties of texture and rheology were used to analyze and compare five kinds of fermented milk and to determine the content of main metabolites by HPLC. Finally the application mode of straw and bottle cap was determined. The probiotics test showed that both Lactobacillus acidophilus and Bifidobacterium animal had good tolerance to acid and bile salt, and the acid tolerance of animal bifidobacterium was stronger than that of 5 strains of probiotics of Lactobacillus acidophilus to Escherichia coli. Salmonella and Staphylococcus aureus had inhibitory effect, Lactobacillus acidophilus was stronger than bifidobacterium in animal, and the five probiotics were not resistant to penicillin, streptomycin and acetylspiramycin, and were sensitive to antibiotics penicillin, streptomycin and acetylspiramycin. The preservation stability test showed that the survival rate of 5 probiotics was 85.00%, 5 probiotics powder were stored at 4 鈩，

本文编号：1852507