摘要
开菲尔基质(kefiran)是发酵乳开菲尔(kefir)中乳酸菌产生的胞外多糖,为水溶性多糖,分子量在1000kD以上。本文采用水提醇沉的方法,对发酵乳体系中kefir胞外多糖kefiran、荚膜kefiran的提取分离因素进行了研究。经过试验确定开菲尔基质的优化分离条件为:发酵液中添加2%氯化钠电解质溶液;三氯乙酸添加量15%(以上清液质量为基准)进一步除残余蛋白质;醇沉pH为7。Kefiran提取方法经过优化后其得率为基本方法的3.06倍,优化效果显著。荚膜多糖的最佳提取方法是超声波法。
Kefiran is a water soluble exopolysaccharide produced by lactic acid bacteria in kefir. The molecular weight is more than 1000 kD. Water extraction and alcohol precipitation arc used to isolate the kefiran from kefir. Factors influencing the extraction and the separation of extracellular kefiran and capsular kefiran in the fermented milk system are studied. The optimum separation conditions are： the fermented milk by adding 2% NaCl solution; 15% trichloroacetic acid （ based on the mass of the supernatant） to eliminate remnant protein; and alcohol for precipitation at pH 7.0. The kefiran yield is increased from 139.66mg/L to 427.33mg/L after optimization. And the optimum method to extract capsular kefiran is by sonication at 50W for 3min at 4℃.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2006年第3期130-133,共4页
Food Science
