不同脱糖方式下荔枝果渣膳食纤维的理化特性比较

Comparison of the Physicochemical Properties of Dietary Fiber from Lychee Pomace Treated with Different Desugarization Methods

该研究探讨了三种不同预处理(醇洗、水洗和酵母发酵)对荔枝果渣的脱糖效果及其膳食纤维理化特性的影响。结果表明:荔枝果渣中的总糖含量达到11.13%,果糖和葡萄糖的含量分别为4.89%和4.33%(m/m);三种脱糖方式均可有效脱除荔枝果渣的还原糖,其中,醇洗组和水洗组的荔枝果渣损失率超过60%,进而降低了可溶性膳食纤维(SDF)和不溶性膳食纤维(IDF)的得率,当酵母发酵组脱糖率达到91.24%时,其果渣损失率仅为36.07%,IDF得率下降了3.34%,SDF得率略有增加但差异不显著(p>0.05);与未脱糖相比,醇洗组总膳食纤维(TDF)的持水力、结合水力和膨胀性分别提高了1.53 g/g、1.19 g/g和0.70 g/g,水洗组和发酵组的水合性质则有所下降(p>0.05);三种脱糖方式均显著提高了TDF的压缩指数和阳离子交换能力(CEC),其中发酵组TDF的CEC最高,为0.67 mmoL/g。综上所述,酵母发酵法可以作为荔枝果渣膳食纤维提取前的合适脱糖方式。

This study investigated the effects of three different pretreatments(alcohol wash,water wash and fermentation with yeast)on the desugarization of lychee pomace and the physicochemical properties of dietary fiber.The results showed that the contents of total sugar,fructose,and glucose in the lychee pomace were 11.13%,4.89%and 4.33%(m/m),respectively.All the three desugarization methods could effectively remove the reducing sugar from the lychee pomace.Among them,the loss rate of lychee pomace in the alcohol-washing group and water-washing group exceeded 60%,which in turn decreased the yields of soluble dietary fiber(SDF)and insoluble dietary fiber(IDF).When the desugarization rate of lychee pomace of the yeast-fermentation group reached 91.24%,with the loss rate of lychee pomace being only 36.07%,the IDF yield decreasing by 3.34%,and the SDF yield increasing slightly(the difference was insignificant,p>0.05).Compared with the undesugarized,the water-holding capacity,water-binding capacity and swelling capacity of the total dietary fiber(TDF)in the alcohol-washing group increased by 1.53 g/g,1.19 g/g and 0.70 g/g,respectively,whilst the hydration properties of the water-washing group and yeast-fermentation group decreased(p>0.05).The three desugarization methods all significantly improved the compression index and cation exchange capacity(CEC)of TDF,and the CEC of the TDF in the yeast-fermentation was the highest(0.67 mmoL/g).In summary,the fermentation with yeast can be used as a suitable desugarization method used before the extraction of dietary fiber from lychee pomace.