植物乳杆菌对提高发酵牛乳中共轭亚油酸含量的研究

Increasing conjugated linoleic acid concentration in fermentedmilk by using Lactobacillus plantarum LT2-6

利用植物乳杆菌(Lactobacillusplantarum)LT2-6发酵添加亚油酸(LA)的脱脂牛乳,转化LA生成共轭亚油酸(CLA),以期提高发酵牛乳中的CLA含量。结果表明:LA诱导可提高发酵牛乳中的CLA产量,发酵温度37℃,CLA生成量和LA转化率为最高。加入葡萄糖、酪蛋白酶水解物,有助于植物乳杆菌LT2-6的生长和提高CLA的生成量。添加0.075%的LA,发酵24h,43%的LA转化为CLA,发酵后牛乳中的CLA含量达到320μg/mL,为普通发酵牛乳的5～6倍。经脂肪酸萃取和甲酯化,气相色谱检测显示生成的CLA主要为:cis-9,trans-11-CLA。

Skim milk with linoleic acid (LA) added was fermented by Lactobacillus plantarum LT2-6. This research is expected to increase conjugated linoleic acid (CLA) concentration in fermented milk, converting LA into CLA. The results showed that inducer of LA could enhance CLA concentration in fermented skim milk. At 37°C, CLA concentration and LA conversion ratio reached the highest level. Adding glucose or casein hydrolysates in skim milk proved to be useful for the growth of Lactobacillus plantarum LT2-6 and increasing CLA concentration. 43% of LA was converted into CLA, with adding 0.075% LA and fermenting 24 h, CLA concentration reached 320 μg/mL, which was 5-6 times higher than that of market yoghourt. Then fatty acid was extracted, methylated and determined by gas chromatography analysis, cis-9, trans-11 CLA was proved to be the majority of CLA.