酶法改性对小米糠膳食纤维体外胆固醇吸附活性的影响  

Effect of Enzymatic Treatment on Cholesterol-Binding Capacity of Dietary Fiber from Millet Bran

作　　者：朱玉[1] 郭利娜[1] 楚佳希 吕凤霞[1] 陆兆新[1] 别小妹[1] 张充[1] 赵海珍[1] 

机构地区：[1]南京农业大学食品科技学院,江苏南京210095

出　　处：《食品科学》2015年第19期211-216,共6页Food Science

摘　　要：以小米糠为原材料,采用AOAC 985.29《食物中总膳食纤维酶-质量法》制备小米糠总膳食纤维(total dietary fiber,TDF)。利用纤维素酶对TDF进行酶法改性,以提高其体外胆固醇吸附活性。通过单因素试验和正交试验,最终确定TDF的酶法改性条件为:酶解pH 3.8、酶添加量140 U/g、酶解温度55℃、酶解时间3 h,所得纤维素酶改性膳食纤维(cellulase-modified dietary fiber,CMF)的体外胆固醇吸附效果最佳,吸附量达到14.21 mg/g,比TDF的胆固醇吸附量(5.91 mg/g)提高了1.40倍。对TDF和CMF的单糖组成、红外光谱以及超微结构等物化特性分析发现,纤维素酶的作用改变了TDF的单糖组成,形成了更多纤维二糖,产生了较多憎水基团,结构粗糙,这些组成及微观结构的改变可能与CMF胆固醇吸附活性显著提高有着密切的关系。Total dietary fiber（TDF） was prepared from millet bran by enzymatic-gravimetric method.In order to improve its in vitro cholesterol-binding capacity,TDF was modified with cellulase.Based on single factor experiments,an L93~4orthogonal array design was employed to optimize four parameters for enzymatic modification.The optimal enzymatic treatment conditions that provided a 2.40-fold increase in cholesterol-binding capacity compared with the original TDF（14.21 versus 5.91 mg/g） were determined as 3.8,140 U/g,55 ℃ and 3 h for initial pH,cellulase amount,hydrolysis temperature and time,respectively.Comparative studies between the native and modified TDF showed the cellulase treatment changed the monosaccharide composition of TDF and resulted in formation of more cellobioses in the cellulase-modified dietary fiber（CMF）.Compared with TDF,CMF was rougher and had more hydrophobic groups.These physicochemical changes may be closely related to high cholesterol-binding capacity of CMF in vitro.

关 键 词：小米糠 总膳食纤维 纤维素酶 胆固醇吸附活性 物理化学分析 

分 类 号：TS209[轻工技术与工程—食品科学]