Influence of flour extraction rate on static in vitro gastrointestinal digestion characteristics of wheat protein during conventional milling

Abstract

The flour extraction rate determines the components of wheat flour. However, the correlation between variations in components resulting from flour extraction rate and the protein digestion characteristics remains to be clarified. In this study, digestion characteristic of wheat flour protein influenced by flour extraction rates was investigated. The results indicated that the degree of protein hydrolysis, the number of peptides at the intestinal stage and the digestive rate constant (k) at the gastric stage exhibited a significant increase as the flour extraction rate increased (35%–85%). Moreover, wheat flour with 85% extraction rate presented the highest protein hydrolysis degree (25.85%), the most peptides (n = 79) and the maximum intestinal digestion rate constant (k = 0.0285). Therefore, increasing the flour extraction rate from 75% to 85% can improve the wheat flour protein digestibility in conventional milling, thereby establishing a fundamental basis for nutritional control of flour products.