酸法和酶法制备不同分子质量的麦麸阿拉伯木聚糖  

Preparation of Arabinoxylans Extracted from Wheat Bran with Different Molecular Weight by Acid and Enzymatic Degradation

作　　者：刘丽娅[1] 张梅红[1] 钟葵[1] 佟立涛[1] 赵梦丽[1] 周素梅[1] 

机构地区：[1]中国农业科学院农产品加工研究所/农业部农产品加工综合性重点实验室,北京100193

出　　处：《中国食品学报》2013年第12期52-58,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(31271852);国家国际科技合作专项(2012DFA31400);国家科技支撑计划课题(2012BAD34B01);科研院所技术开发研究专项(2013EG134235)

摘　　要：采用酶法(戊聚糖酶)和酸法(盐酸、乙酸、柠檬酸)对碱提取阿拉伯木聚糖(简称AX)进行分子质量分级,并用凝胶渗透色谱-多角度激光光散射技术(HPSEC-MALLS)研究降解产物分子质量及分布规律。试验结果表明:AX经戊聚糖酶降解,再经80%乙醇沉淀,分子质量大幅降低,主要组分Mw集中在5.227×104u;而低于80%乙醇沉淀,分级效果不佳。盐酸和柠檬酸可有效降低AX分子质量,主要组分的分子质量可降至103数量级,但乙酸降解AX作用不理想。在95℃下处理2 h,经盐酸降解的AX主要组分Mw为7.501×103u,峰面积百分比达84.10%,分子质量呈宽分布现象(Mw/Mn=11.88)。AX的柠檬酸降解产物主要组分Mw为8.997×103u,峰面积百分比达56.70%,样品均一性好(Mw/Mn=1.673)。本研究结果揭示柠檬酸作为一种弱酸,可有效降低AX分子质量,与盐酸降解和生物酶法降解相比,具有明显优势。This paper introduced the degradation of alkaline extraction of arabinoxylan（AX） through enzymatic and acid hydrolysis,meanwhile,the molecular weight（Mw） and distribution of the degradation product was studied though High Performance Size Exclusion Chromatography-Multiangle Laser Light Scattering（HPSEC-MALLS）.The Result showed that the enzymatic hydrolyzed AX samples were successively fractionated with different concentration ethanol.Among these the average Mw of 80% ethanol treatmentis declined to 5.277 ×10^4u and lower than 80% ethanol treatment resulted in poorer fractionation.While among acid hydrolyzed AX samples,both hydrochloric acid and citric acid can effectively re-duced the Mw of AX and the Mw of the main component can be reduced to 10^3orders of magnitude,instead,the effect of acetic acid hydrolysis AX is very weak.In the condition of 95 ℃ for 2 hours,the Mw of HCl treatment AX is 7.501× 10^3u with peak area percentage of 84.10%,but the distribution is board（Mw/Mn =11.88）;the Mw of citric acid degrada-tion product is 8.997×10^3u with peak area percentage of 56.70%,and the samples has good homogeneity（Mw/Mn =1.673）.This study revealed that citric acid,as a weak acid,has its obviously advantage on effectively reducing the AX molecu-lar weight,compared to the hydrochloric acid and enzymatic degradation.

关 键 词：麦麸 阿拉伯木聚糖 降解 分子质量 

分 类 号：TS201.2[轻工技术与工程—食品科学]