發(fā)布時(shí)間：2018-10-12 14:00

【摘要】：本實(shí)驗(yàn)針對脫脂米糠膳食纖維(defatted rice bran dietary fibre,DRBDF)中可溶性膳食纖維(soluble dietary fibre,SDF)含量低、功能性質(zhì)差的問題進(jìn)行了改性處理。SDF含量是衡量膳食纖維(dietary fibre,DF)品質(zhì)的重要指標(biāo)。因此,本實(shí)驗(yàn)以脫脂米糠(defatted rice bran,DRB)為原料,提取DRBDF,對DRBDF進(jìn)行微粉-酶法改性的研究,目的是提高DRBDF中SDF含量和DF的功能性質(zhì)。脫脂米糠中的淀粉和蛋白質(zhì)先后分別用高溫α-淀粉酶和堿性蛋白酶酶解除去,得到DRBDF。然后對DRBDF進(jìn)行超微粉碎,再用纖維素酶和木聚糖酶的復(fù)合酶水解DRBDF,并采用單因素試驗(yàn)和響應(yīng)曲面試驗(yàn)確定了酶解的最佳條件為:纖維素酶加酶量63.1 EGU/g、木聚糖酶加酶量30.6 FXU/g、酶解時(shí)間4.1 h、粉碎的樣品粒徑范圍100～150μm、pH4.5、酶解溫度55℃,在此條件下,SDF得率為8.32%。酶解得到的 TDF(total dietary fibre)和 IDF(insoluble dietary fibre),持水力分別達(dá)到5.19g/g和5.47g/g,持油力分別達(dá)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的溶脹力有所下降,TDF和IDF的溶脹力分別為DRBDF的78.6%和87.1%,而陽離子交換能力稍有增強(qiáng)。通過紅外光譜分析改性后DF的理化特性發(fā)現(xiàn):各DF均有典型的糖類吸收峰,SDF中出現(xiàn)酚類苯環(huán)的特征吸收峰。分析改性前后DF的功能性質(zhì)發(fā)現(xiàn)..酶解得到的SDF和TDF對葡萄糖的吸附能力相比DRBDF均顯著(p0.05)增強(qiáng),其中SDF最高,達(dá)到134.19mg/g。SDF和TDF在pH 7.0時(shí)對膽固醇的吸附量分別達(dá)到30.86mg/g和24.37mg/g,比DRBDF分別提高了 45%和14.5%,IDF對膽固醇的吸附能力有所降低。酶解后SDF對N02-的清除能力相比DRBDF來說顯著增強(qiáng),而IDF則基本與DRBDF持平。酶解后,各DF中可提取酚類物含量顯著增加。SDF和TDF的總酚含量分別達(dá)到20.03 mg沒食子酸當(dāng)量/g和4.52 mg沒食子酸當(dāng)量/g,分別為DRBDF的9.36倍和2.11倍。SDF和TDF的總抗氧化能力分別是37.16μmol Trolox當(dāng)量/g和16.22μmol Trolox當(dāng)量/g,分別是 DRBDF的4.97倍和2.17倍。IDF的總酚含量和總抗氧化能力也比DRBDF略有提升。改性后,各DF清除氧化自由基的能力增強(qiáng)。將酶解制得的SDF作為添加劑制作米糠纖維酸乳,最佳發(fā)酵條件為:米糠SDF液添加量5%,蔗糖5g/100mL、接種量4mL/100mL、發(fā)酵溫度42℃、發(fā)酵時(shí)間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 偽 -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，

本文編號：2266384