米糖膳食纤维的微粉—酶法改性及其理化功能性质的变化研究
发布时间：2018-10-12 14:00
【摘要】：本实验针对脱脂米糠膳食纤维(defatted rice bran dietary fibre,DRBDF)中可溶性膳食纤维(soluble dietary fibre,SDF)含量低、功能性质差的问题进行了改性处理。SDF含量是衡量膳食纤维(dietary fibre,DF)品质的重要指标。因此,本实验以脱脂米糠(defatted rice bran,DRB)为原料,提取DRBDF,对DRBDF进行微粉-酶法改性的研究,目的是提高DRBDF中SDF含量和DF的功能性质。脱脂米糠中的淀粉和蛋白质先后分别用高温α-淀粉酶和碱性蛋白酶酶解除去,得到DRBDF。然后对DRBDF进行超微粉碎,再用纤维素酶和木聚糖酶的复合酶水解DRBDF,并采用单因素试验和响应曲面试验确定了酶解的最佳条件为:纤维素酶加酶量63.1 EGU/g、木聚糖酶加酶量30.6 FXU/g、酶解时间4.1 h、粉碎的样品粒径范围100～150μm、pH4.5、酶解温度55℃,在此条件下,SDF得率为8.32%。酶解得到的 TDF(total dietary fibre)和 IDF(insoluble dietary fibre),持水力分别达到5.19g/g和5.47g/g,持油力分别达到5.26g/g和5.39g/g。相比DRBDF,TDF的持水力增大了 1.32倍,持油力增大了 2.21倍;IDF的持水力增大了 1.40倍,持油力增大了 2.26倍。酶解后DF的溶胀力有所下降,TDF和IDF的溶胀力分别为DRBDF的78.6%和87.1%,而阳离子交换能力稍有增强。通过红外光谱分析改性后DF的理化特性发现:各DF均有典型的糖类吸收峰,SDF中出现酚类苯环的特征吸收峰。分析改性前后DF的功能性质发现..酶解得到的SDF和TDF对葡萄糖的吸附能力相比DRBDF均显著(p0.05)增强,其中SDF最高,达到134.19mg/g。SDF和TDF在pH 7.0时对胆固醇的吸附量分别达到30.86mg/g和24.37mg/g,比DRBDF分别提高了 45%和14.5%,IDF对胆固醇的吸附能力有所降低。酶解后SDF对N02-的清除能力相比DRBDF来说显著增强,而IDF则基本与DRBDF持平。酶解后,各DF中可提取酚类物含量显著增加。SDF和TDF的总酚含量分别达到20.03 mg没食子酸当量/g和4.52 mg没食子酸当量/g,分别为DRBDF的9.36倍和2.11倍。SDF和TDF的总抗氧化能力分别是37.16μmol Trolox当量/g和16.22μmol Trolox当量/g,分别是 DRBDF的4.97倍和2.17倍。IDF的总酚含量和总抗氧化能力也比DRBDF略有提升。改性后,各DF清除氧化自由基的能力增强。将酶解制得的SDF作为添加剂制作米糠纤维酸乳,最佳发酵条件为:米糠SDF液添加量5%,蔗糖5g/100mL、接种量4mL/100mL、发酵温度42℃、发酵时间5h。
[Abstract]:In this experiment, the content of soluble dietary fiber (soluble dietary fibre,SDF) in defatted rice bran dietary fiber (defatted rice bran dietary fibre,DRBDF) was treated with low content of soluble dietary fiber (soluble dietary fibre,SDF) and poor functional properties. SDF content is an important index to evaluate the quality of dietary fiber (dietary fibre,DF). Therefore, in this experiment, DRBDF, was extracted from defatted rice bran (defatted rice bran,DRB) to modify DRBDF by micro-powder and enzymatic method, in order to improve the content of SDF in DRBDF and the functional properties of DF. The starch and protein in defatted rice bran were digested with high temperature 伪 -amylase and alkaline protease respectively, and DRBDF. was obtained. And then the DRBDF is ground up, After hydrolysis of DRBDF, with cellulase and xylanase complex enzyme, the optimum conditions of enzymatic hydrolysis were determined by single factor test and response surface test. The optimum conditions were as follows: cellulase addition amount 63.1 EGU/g, xylanase amount 30.6 FXU/g, hydrolysis time 4.1 h, powder hydrolysis time 4.1 h. The particle size of the sample was 100 渭 m ~ 150 渭 m ~ (-1), pH was 4.5, and the enzymatic hydrolysis temperature was 55 鈩，
本文编号：2266384
[Abstract]:In this experiment, the content of soluble dietary fiber (soluble dietary fibre,SDF) in defatted rice bran dietary fiber (defatted rice bran dietary fibre,DRBDF) was treated with low content of soluble dietary fiber (soluble dietary fibre,SDF) and poor functional properties. SDF content is an important index to evaluate the quality of dietary fiber (dietary fibre,DF). Therefore, in this experiment, DRBDF, was extracted from defatted rice bran (defatted rice bran,DRB) to modify DRBDF by micro-powder and enzymatic method, in order to improve the content of SDF in DRBDF and the functional properties of DF. The starch and protein in defatted rice bran were digested with high temperature 伪 -amylase and alkaline protease respectively, and DRBDF. was obtained. And then the DRBDF is ground up, After hydrolysis of DRBDF, with cellulase and xylanase complex enzyme, the optimum conditions of enzymatic hydrolysis were determined by single factor test and response surface test. The optimum conditions were as follows: cellulase addition amount 63.1 EGU/g, xylanase amount 30.6 FXU/g, hydrolysis time 4.1 h, powder hydrolysis time 4.1 h. The particle size of the sample was 100 渭 m ~ 150 渭 m ~ (-1), pH was 4.5, and the enzymatic hydrolysis temperature was 55 鈩，
本文编号：2266384
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