改性对柿子渣不溶性膳食纤维的理化特性和结构的影响

Effects of modification on physicochemical properties and structure of insoluble dietary fiber from persimmon pomace

该研究采用复合酶法和碱性过氧化氢法来对柿子渣不溶性膳食纤维(insoluble dietary fiber,IDF)进行改性处理,并分析比较改性前后IDF的理化特性和微观结构的变化。结果表明,2种改性方法均能提高IDF的持水力、膨胀力、亚硝酸盐吸附力和阳离子交换能力,其中,碱性过氧化氢法改性的IDF的持水力能达到6.84 g/g,阳离子交换力达到了0.36 mmol/g。改性后IDF表面结构疏松,裂缝增多,通过X射线衍射发现改性前后IDF的晶体构型没有改变,仍保持典型的纤维素结构。红外图谱结果显示,改性前后主要官能团未发生明显变化,特征吸收峰的整体峰型和位置不变,但改性后吸收峰强度有所减弱。总体来看,碱性过氧化氢法的改性处理较复合酶法效果更好,可作为改性柿子渣IDF的一种优良方法,从而提高柿子渣的综合利用率,在食品工业中开发新的产品。

In this study,the modification of persimmon pomace insoluble dietary fiber(IDF)was carried out by the compound enzyme method and alkaline hydrogen peroxide method,and the physicochemical properties and microstructure of IDF were compared before and after modification.Results showed that the two modification methods could improve the water-holding capacity,swelling capacity,nitrite adsorption,and cation exchange capacity of IDF.Among them,the water holding capacity of IDF modified by the alkaline hydrogen peroxide method could reach 6.84 g/g and the cation exchange capacity could reach 0.36 mmol/g.The modified IDF had a loose structure and increasing cracks.XRD results showed that the modification did not change the crystal configuration of IDF,which still retained the typical cellulose structure.FT-IR results showed that the main functional groups did not change significantly before and after modification.The characteristic absorption peak and position did not change,but the intensity decreased.In general,the modification effect of the alkaline hydrogen peroxide method was better than the compound enzyme method,which could be used as an excellent method to modify the insoluble dietary fiber of persimmon pomace,so as to improve the comprehensive utilization rate of persimmon pomace and develop new products in the food industry.