Preliminary Study on the Influence of the Polyphenols of Different Groups on the Digestibility of Wheat Starch, Measured by the Content of Resistant Starch

Abstract

The scientific goals of this research were to examine the impact of various polyphenols from different groups on resistant starch development. Wheat starch was tested, and the polyphenols were added to starch after its pasting in the amount suggested in the literature as optimal—10 mg, and at twice and half the optimal, i.e., 20 mg and 5 mg. The most frequently consumed and most frequently occurring compounds in food products were selected for the proposed research: (1) phenolic acids—p-coumaric acid, ferulic acid; (2) flavanones—hesperidin, naringenin; (3) flavanols—(+)catechin, epigallocatechin gallate; (4) flavonols—quercetin, kaempferol; (5) anthocyanins—cyanidin-3-O-glucoside, delphinidin-3-O-glucoside. As a result, either the dose or the kind of polyphenolic compound had a statistically significant influence on the wheat starch digestibility (p < 0.05). However the observed impact was dose-dependent, and interestingly, higher amounts of RS were found in the case of the lowest dose applied (5 mg—4.76% of starch gel; mean = 2.94 ± 1.23 g·100 g−1 dm) as compared to the other doses: 10 mg—9.09% of starch gel (mean = 1.58 g·100 g−1 dm) and 20 mg—16.66% of starch gel (mean = 1.51 ± 0.90 g·100 g−1 dm). Among all tested polyphenols added to wheat starch gels in an amount of 10 mg and 20 mg, epigallocatechin gallate was found to be the most effective compound (p < 0.05), while (+)catechin was most efficient in the dose of 5 mg (p < 0.05).