嗜酸乳杆菌发酵制备苜蓿叶蛋白的研究

摘要

In the present work,we investigated the growth regularity of Lactobacillus acidophilus,screened out a high yield acid-producing strain and used the strain to ferment water extract from the young stems and leaves of Medicago sativa（alfalfa） cv.Zhaodong to precipitate alfalfa leaf protein by produced acids.The precipitation of alfalfa leaf protein from water extract from the young stems and leaves of Medicago sativa（alfalfa） cv.Zhaodong was studied by adjusting its pH.The effects of fermentation time,inoculum size,material/liquid ratio in raw material extraction on alfalfa leaf protein yield were explored.pH 3.0—3.7 proved optimal for precipitating alfalfa leaf protein.The optimal conditions for preparing alfalfa leaf protein were extraction material/liquid ratio of 1：20,fermentation time of 11 h,and inoculum amount of 107 cells/mL.Under the optimal extraction conditions,the extraction yield of alfalfa leaf protein was up to 45.08%.%以＂肇东＂紫花苜蓿干草为实验材料,利用嗜酸乳杆菌发酵沉降提取苜蓿叶蛋白,研究嗜酸乳杆菌的生长规律、并筛选高产酸嗜酸乳杆菌,确定苜蓿叶蛋白的等电点;研究发酵时间、接种量、料液比3个因素对叶蛋白得率的影响,确定发酵法提取苜蓿叶蛋白的最佳工艺。结果表明：pH3.0～3.7为苜蓿叶蛋白的最佳沉降范围;最佳发酵条件参数为：发酵时间11h、料液比1：20、接种量为107个/mL;在该条件下,制备的苜蓿叶蛋白粗蛋白含量为45.08%。