不同方法提取苜蓿草渣膳食纤维的效果比较

选用正交试验设计,分别采用碱结合木瓜蛋白酶水解法和化学法对苜蓿草渣膳食纤维的提取工艺进行了研究,并对两种方法的效果进行了比较.结果表明:1)用蛋白酶水解法提取膳食纤维的最佳条件为:NaOH浓度5%,碱浸温度60℃,碱浸时间50 min,蛋白酶用量0.3%.成品气味较淡,膳食纤维含量81.54%,膨胀力高达8.00 mL/g,持水力8.97 g/g.2)用化学法提取膳食纤维的最佳条件为:碱浸温度80℃,碱浸时间70 min,酸浸温度50℃,酸浸时间4 h.成品气味较差,膳食纤维含量76.09%,膨胀力3.05 mL/g,持水力5.48 g/g.用蛋白酶水解法提取膳食纤维效果明显好于化学法.

Comparison of the effectiveness of two extracting methods of dietary fiber from alfalfa dregs

Orthogonal experiment was designed to study the optimal techniques on extracting of dietary fiber(DF) from alfalfa dregs.In the experiment,papain hydrolysis and chemical process were used and their effectiveness were compared.The results showed as follow:1)The optimal conditions for extracting DF with papain were soda concentration 5 %,soda-soaking temperature 60 ℃,soda-soaking time 50 min and the amount of used papain 0.3 %.Under the above conditions,the extraction had a mild taste,with fiber content around 81.54 %.Its expansion capacity was 8.00 mL/g and water holding capacity was 897 %.2)The optimal conditions for extracting DF with soda and acid were:soda-soaking temperature 80 ℃,soda-soaking time 70 min,acid-soaking temperature 50 ℃,and acid-soaking time 4 h.Under the above conditions,the extraction had a disagreeable odor,with fiber content around 76.09 %.Its expansion capacity was 3.05 mL/g and water holding capacity was 548 %.The method of papain hydrolysis was apparently better than that of chemical process.