沙棘水溶性膳食纤维固体发酵法制备的研究

发布时间：2018-02-10 18:53

  本文关键词： 沙棘粕 固体发酵 沙棘水溶性膳食纤维 脱色 特性研究　出处：《东北农业大学》2011年硕士论文　论文类型：学位论文

【摘要】：水溶性膳食纤维(soluble dietary fiber,SDF)是指不能被人体消化道分泌的消化酶所消化,但可溶于热水,且其水溶液能被四倍乙醇沉淀的那部分膳食纤维。水溶性膳食纤维以其重要的生理功能,越来越被国内外学者及民众所认识和关注。本实验以里氏木霉发酵法发酵沙棘粕,提高沙棘水溶性膳食纤维的提取率,并对发酵后提取的沙棘水溶性膳食纤维进行脱色处理,并对获得的沙棘水溶性膳食纤维的特性进行了测定与分析。 本试验通过对三种发酵菌株的筛选,发现里氏木霉菌株适合作为沙棘粕固体发酵菌株。通过单因素试验和正交试验可知,影响发酵法制备沙棘水溶性膳食纤维的因素大小依次为接菌量发酵时间发酵温度水分含量。最佳工艺条件为:接种量5 mL·100 mg~(-1),发酵温度28℃,发酵时间6 d,水分加入量2 mL·g~(-1),沙棘水溶性膳食纤维的提取率可达9.65 %。 通过对脱色剂的选择试验,发现粉末状活性炭适合作为发酵制备的沙棘水溶性膳食纤维的脱色。单因素试验和正交试验可知,沙棘水溶性膳食纤维脱色最佳工艺条件为:脱色液pH值为5,活性炭加入量0.5 %,脱色温度为40℃。脱色后的沙棘水溶性膳食纤维为淡黄色。 通过对沙棘水溶性膳食纤维特性研究发现,沙棘水溶性膳食纤维为典型的多糖类物质,单糖的摩尔比为,鼠李糖:阿拉伯糖:木糖:甘露糖:葡萄糖:半乳糖= 2.93:4.06:4.58:6.13:6.63:28.06。发酵作用能提高沙棘水溶性膳食纤维的持水力(6.4 g/g)和膨胀力(5.3 mL/g)。沙棘SDF溶液粘度研究发现,随着沙棘SDF浓度的增加粘度直线增大,随温度的升高降低,且受pH值影响较大。此外,沙棘SDF溶液粘度受食盐浓度影响较小,但受蔗糖浓度的影响较大。沙棘SDF对O~(2-)和·OH具有一定的清除作用,对DPPH(1,1-二苯基-2-三硝基苯肼)清除作用较小。
[Abstract]:Soluble dietary fiber is the portion of dietary fiber that can not be digested by digestive enzymes secreted by human digestive tract, but soluble in hot water, and its aqueous solution can be precipitated by four times ethanol. More and more scholars and people at home and abroad have paid more and more attention to the fermentation of seabuckthorn meal by Trichoderma leucovskii in order to improve the extraction rate of water-soluble dietary fiber of Hippophae rhamnoides and decolorize the water-soluble dietary fiber extracted from Hippophae rhamnoides after fermentation. The characteristics of water-soluble dietary fiber obtained from seabuckthorn were determined and analyzed. Through the screening of three fermentation strains, Trichoderma Richalii strain was found to be suitable for the solid fermentation of seabuckthorn meal. The factors affecting the preparation of water-soluble dietary fiber from Hippophae rhamnoides were inoculated at 5 mL 路100 mg / L and fermentation temperature at 28 鈩，

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