摘要
为提高发酵牛乳共轭亚油酸(CLA)含量,以植物乳杆菌(Lactobacillus plantarum LT2-6)发酵添加亚油酸的脱脂牛乳,并对其生成CLA的过程进行了研究。结果表明,接种后6h CLA开始生成,24h CLA生成量达到最高,再延长发酵时间后CLA生成量缓慢下降。接种3～12h,牛乳滴定酸度快速增加,12h后滴定酸度增加缓慢。发酵18h时CLA的生成速率最大;24h时,牛乳pH降到4.0,CLA生成基本停止。牛乳发酵过程中,pH下降是影响植物乳杆菌LT2-6转化LA生成CLA的主要因素。脱脂牛乳中加入LA,经植物乳杆菌LT2-6发酵、脂肪酸萃取和甲酯化,并用气相色谱检测,结果显示:生成的CLA主要为cis9、trans11/trans9和cis11-CLA。
In order to increase conjugated linoleic acid(CLA)concentration in fermentation milk,skim milk added linoleic acid(LA)was fermented by Lactobacillus plantarum LT2-6,and the CLA formation process was studied. The results showed that CLA could be measured after inoculation 6 h,and CLA concentration reached the highest level at 24 h. However,CLA concentration decreased slowly with the increase of time. Titratable acidity of skim milk increased rapidly in 3～12 h,subsequently increased slowly. CLA formation rate reached the highest level at 18 h,however,as pH decreased to 4.0 at 24 h,CLA concentration was not increased. pH decrease was a main factor which influenced the bioconversion of LA into CLA. Then fatty acid was extracted,methylated and determined by gas chromatography. The result showed that the cis9,trans11/trans9,cis11-CLA was the majority of CLA.
出处
《中国食品学报》
EI
CAS
CSCD
2005年第2期12-16,共5页
Journal of Chinese Institute Of Food Science and Technology
基金
国家自然科学基金资助(No.20376084)
