Abstract: In this study, the production of polysaccharides by kefir grains during milk fermentation was optimized with respect to the amount of nutrients added to the fermentation medium (sterilized milk) employing one-factor-at-a-time and orthogonal array design methods. The results showed that the optimal carbon sources added to sterilized milk were 3% maltose, 4% sucrose and 4% glucose, resulting in a maximum yield of polysaccharides of 1.92 g/L, the optimal nitrogen sources were 0.2% yeast extract, 1% peptone and 0.004% L-tyrosine, resulting in a maximum yield of polysaccharides of 2.07 g/L, and the optimal inorganic salts were 0.4% KH2PO4, 0.08% MgSO4·7H2O, 0.02% CaCO3 and 0.25% NaCl, resulting in a maximum yield of polysaccharides of 2.01 g/L.

Key words: kefir; nutrient; fermentation; polysaccharide

摘要： 开菲尔是一种由开菲尔粒发酵的功能性酒精性的乳制品.在开菲尔粒发酵培养期间,对外加营养元素进行单因素与正交试验,以研究其对开菲尔多糖产量的影响.结果表明:在无菌灭菌乳中添加3％麦芽糖、4％蔗糖、4％葡萄糖时,开菲尔多糖的产量最高,达到1.92 g/L;在无菌灭菌乳中添加酵母膏0.2％、蛋白胨1％、L-酪氨酸0.004％时,开菲尔多糖的产量最高,达到2.07 g/L;在无菌灭菌乳中添加0.4％ KH2PO4、0.08％ MgSO4·7H2O、0.02％CaCO3、0.25％NaC1时,开菲尔多糖的产量最高,达到2.01 g/L.

关键词: 开菲尔；营养元素；发酵；多糖