茶树菇膳食纤维改性及理化性质研究

以茶树菇膳食纤维（DF）为原料，比较改性前后可溶性膳食纤维（SDF）得率以及理化性质，采用纤维素酶和高温高压对膳食纤维改性。在单因素基础上进行正交试验优化，得到两种最佳改性工艺条件。结果表明，纤维素酶改性茶树菇DF的最佳工艺条件为:料液比1:30，纤维素酶用量1.5%，酶解时间2.0 h。在最佳改性条件下，茶树菇SDF得率为4.9%。高温高压改性茶树菇DF的最佳工艺条件:料液比1:30，改性温度125℃，改性时间50 min。在最佳改性条件下，茶树菇SDF得率为6.8%。纤维素酶改性和高温高压改性均能改善膳食纤维的理化性质；高温高压法处理的膳食纤维在持水力、膨胀力、阳离子交换力、葡萄糖吸收力上要优于纤维素酶法。扫描电镜分析表明，两种改性方法使膳食纤维结构表面积明显增大且表面疏松多孔，与理化分析的结果一致。

Modification and Physicochemical Properties of Agrocybe aegerita Dietary Fiber

Dietary fiber(DF)of Agrocybe aegerita was modified with cellulase and high temperature-high pressure treatment,the yield and physicochemical properties of soluble dietary fiber(SDF)before and after modification were compared.Two optimum modification conditions were obtained by orthogonal experiment on the basis of single factor.The results showed that the optimum conditions for cellulose treatment were determined as follows:The material to liquid ratio was 1∶30,cellulase dosage was 1.5%,and the enzymatic hydrolysis time was 2.0 h.Under these optimal conditions,the yield of SDF was 4.9%.The optimal conditions for high temperature-high pressure treatment were determined as material to liquid ratio of 1∶30,temperature of 125℃,and time of 50 min,giving an SDF yield of as high as 6.8%.Both cellulase and high temperature-high pressure modification can improve the physicochemical properties of DF.The DF treated by high temperature-high pressure was superior to cellulase in water holding capacity,swelling capacity,cation exchange capacity and glucose absorption capacity.SEM analysis showed that the surface area and surface pores of the modified DF increased significantly,which was consistent with the results of physical and chemical analysis.