蒙古族传统酸马奶中嗜酸乳杆菌发酵特性研究

Study on the Fermentable Properties of Lb. acidophilus Isolated from Traditional Koumiss of Mongolia

从蒙古乌兰巴托周边牧民家庭采集的5个酸马奶样品中,分离并鉴定出30株嗜酸乳杆菌,从中筛选出4株具有潜在益生特性的进行发酵特性研究.结果表明:37℃发酵24h,嗜酸乳杆菌发酵乳平均产酸为147.40T,pH值在3.69～3.53之间,粘度在366.3～384.3cP之间,12%TCA可溶性氮为6.262L～9.241mmol/L;4℃冷藏过程中,发酵乳pH降低缓慢,乳糖含量呈降低趋势,且仍有较高活菌数;4℃冷藏4周时,MG1-5、MG2-1、MG4-2和MG1-12的存活率分别为96.86%、90.39%、89.73%和89.39%,乳糖分解率分别为39.52%、58.2%、46.57%和40.22%;4株菌表现出不同的发酵特性,MG2-1有较强产酸能力、蛋白水解能力和乳糖分解能力(P＜0.05),MG1-5则具有更高存活率,MG1-12表现出更强产粘能力.

Some fermentable properties of four strains of Lb. Acidophilus isolated from the samples collected from koumiss in Mongolia were studied, and the result was that the average acidity of yogurt inoculated Lb. acidophilus was 147.4^0T, the correspondingly pH changed among 3.69-3.53, the concentration of 12% TCA-soluble nitrogen was 6.262-9.241 mmol/L, the viscosity varied from 366.3 to 384.3 cP, the content of lactose was 23.77-33.44 mg/mL during the fermentation at 4℃, the decrease of pH was slow, and the content of lactose decreased slightly all the same, Lb. acidophilus kept relatively high viability until the 4th week. At the end of 4th week, the livability of MG1-5, MG2-1, MG4-2 and MG1-12 was 96.86%, 90.39%, 89.73% and 89.39%; correspondingly the percent of decomposed lactose was 39.52%, 58.2%, 46.57% and 40.22%. The four stains had shown different properties. MG2-1 had a higher ability of acid production, proteolysis and utilizing of lactose（p〈0.05）, MG1-5 had a better viability, and MG1-12 had a higher ability of viscosity production.