新型益生菌发酵竹笋膳食纤维酸奶的菌种筛选及通便功能研究

Study on Strains Screening and Laxative Function of Bamboo Shoot Dietary Fiber Yogurt Fermented by New Probiotics

针对目前我国功能性乳制品研发基础薄弱,发酵膳食纤维酸奶大多采用传统酸奶菌的现状,采用全因子试验研究料水比和均质时间对竹笋膳食纤维汁pH值和稳定性的影响。以自行分离选育出的10株新型益生乳酸菌为试验菌株,以保加利亚乳杆菌Lb-DR、嗜热链球菌St-LDY为对照菌株,研究菌株在竹笋膳食纤维汁中的生长活力、产酸特性,对菌株进行初筛。分析初筛菌株发酵的竹笋膳食纤维牛乳培养基的感官品质,对菌株进行复筛。研究复筛菌株发酵竹笋膳食纤维酸奶的通便功能。结果表明:竹笋膳食纤维与水的比例1∶10,均质时间15 min,调配的竹笋膳食纤维汁均一、稳定,pH值为6.34,适合乳酸菌生长繁殖。经初筛和复筛,获得3株益生乳酸菌,即:植物乳杆菌07-191、鼠李糖乳杆菌05-28、干酪乳杆菌05-21。将其分别在竹笋膳食纤维汁中37℃发酵12 h,活菌数分别是1.77×10^(9),2.76×10^(9),1.59×10^(9) CFU/mL,pH值分别是4.51,4.68,4.75,滴定酸度分别是53.2,56.2,54.6°T。其分别发酵的竹笋膳食纤维牛乳培养基的风味优于其它菌株,适宜发酵竹笋膳食纤维酸奶。复筛益生菌发酵的竹笋膳食纤维酸奶能够促进小鼠小肠推进,缩短排便时间,增加排便粒数和排便量,即竹笋膳食纤维酸奶具有通便功能。

In view of the current weak research and development foundation of functional dairy products in China,the status of traditional yogurt bacteria yoghurt are mostly used in fermented dietary fiber yoghurt.In this paper,the effects of ratio of material to water and homogenization time on the pH value and stability of bamboo shoot dietary fiber juice were studied by full factorial central composite design.With 10 newly self-selected probiotics used as test strains,Lactobacillus bulgaricus and Streptococcus thermophilus as control strains,the strains were screened for the first time by studying the growth activity and acidogenic properties of the strain in the dietary fiber juice of bamboo shoots.The strains were rescreened by analyzing the sensory quality of the initial screening strains fermented preliminary bamboo shoot dietary fiber milk medium.The laxative function of bamboo shoot dietary fiber yoghurt fermented by rescreening strains was studied.The results show that having obtained a dietary fiber juice of bamboo shoots of uniform,stable,pH value of 6.34,which is fit for the growth and reproduction of lactic acid bacteria,through the ratio of bamboo shoot dietary fiber to water of 1∶10 and homogeneous 15 min.After preliminary screening and rescreening,3 strains of probiotic lactic acid bacteria:Lactobacillus plantarum 07-191,Lactobacillus rhamnosus 05-28,and Lactobacillus casei 05-21 were obtained;When they were respectively fermented in bamboo shoot dietary fiber juice for 12 h at 37℃,the viable counts were 1.77×10^(9),2.76×10^(9) and 1.59×10^(9) CFU/mL,the pH values were 4.51,4.68 and 4.75,the titratable acidity were 53.2,56.2 and 54.6°T,respectively,and the flavor of the fermented preliminary bamboo shoot dietary fiber milk medium were better than other strains.So the two probiotics are suitable for fermenting bamboo shoot dietary fiber yogurt.The bamboo shoot dietary fiber yoghurt product fermented by rescreening probiotics can promote the experimented mice intestinal propulsion,shorten the defecation time,increase the number and amount of defecation.That is,the bamboo shoot dietary fiber yoghurt has a laxative function.This study provides a feasible basis for the further development and industrial production of probiotic lactic acid bacteria fermented bamboo fiber dietary functional yoghurt products,thereby increasing the utilization and value of bamboo shoots,opening up new ways to utilize bamboo shoot resources,and also provides reference guide for the research and development of other dietary fiber functional products fermented by probiotics.