外源表没食子儿茶素没食子酸酯添加对荞麦粉理化特性和碗托食用品质的影响

Influence of Exogenous Epigallocatechin Gallate Addition on Physicochemical Properties of Buckwheat Flour and Eating Quality of Buckwheat Wantuo

本文旨在利用外源多酚添加方法改善中华传统淀粉基凝胶食品—荞麦碗托的食用品质。通过向荞麦粉中加入不同比例的表没食子儿茶素没食子酸酯(Epigallocatechin gallate,EGCG)制备混合粉(Buckwheat polyphenol flour,BPF),利用多种表征手段分析多酚添加对混合粉色泽、水合、糊化和凝胶质构等特性及其碗托制品有序结构、质构、抗氧化和消化等特性和感官评定的影响。结果表明,EGCG添加量的增加使得混合粉颜色变红暗,水溶性指数增加,回生值降低,凝胶截面孔洞数目明显增多,尺寸变小;碗托制品有序结构减少,相对结晶度减少,粘聚性、回复性下降,总酚含量和抗氧化能力上升,淀粉消化速率显著降低,对感官评定分数中的质构和色泽影响不大而对食味有一定影响。其中,当EGCG添加量为1%时,混合粉的回生值降低16.30%;碗托样品的总酚含量增加至534.04 mg GAE/100 g,快消化淀粉降低了14.40%,pGI降低至61.72,此时感官评定分数最高为78.00分。上述结果表明EGCG的添加会影响混合粉加工特性,有效改善碗托制品的抗氧化和消化特性。

This research aims to ameliorate the eating quality of Chinese traditional starch-based food:buckwheat Wantuo via the addition of exogenous polyphenol.The mixed flour(MF)was prepared by adding various amount of Epigallocatechin gallate(EGCG)to common buckwheat flour.The influence of addition amount on physicochemical properties(like color,hydration and pasting)of MF and eating quality(like total phenol content,antioxidant activity and digestibility)of buckwheat Wantuo(BWT)were investigated.The results clearly showed that the color of MF turned dark red while the water solubility index and setback value were increased and decreased with increasing EGCG concentration,respectively.Meanwhile,the number of pores in MF gel section was significantly increased,whereas the pore size was decreased.The ordered structure and relative crystallinity as well as the cohesiveness and resilience of BWT samples were decreased gradually,while the total phenols content and antioxidant activity of BWT samples were significantly increased.Remarkably,the starch digestibility was significantly decreased.Sensory attributes of texture and color were insignificant with the addition of EGCG,whereas the taste score was affected.When the addition amount of EGCG was 1%,setback value of MF was decreased about 16.30%;rapidly digestible starch of BWT was decreased about 14.4%,while total phenolic compound content and pGI value of BWT were increased and decreased to 534.04 mg GAE/100 g and 61.72,respectively.At this point,the sensory score was 78.00 which was the highest in BWT samples.The results above indicated that the addition of EGCG can significantly influence the physicochemical properties of MF and can help ameliorate the antioxidant activity and digestibility of BWT.