Effect of Fermentation pH on Protein Bioaccessibility of Soymilk Curd with Added Tea Polyphenols As Assessed by in Vitro Gastrointestinal Digestion

• Published in: Journal of agricultural and food chemistry 2017-12, Vol.65 (50), p.11125-11132
• Main Authors: Xing, Guangliang, Rui, Xin, Wang, Dan, Liu, Mei, Chen, Xiaohong, Dong, Mingsheng
• Format: Article
• Language: English
• Subjects: Camellia sinensis - chemistry; Digestion; Fermentation; Food Additives - chemistry; Food Additives - metabolism; Food Handling; Gastrointestinal Tract - metabolism; Hydrogen-Ion Concentration; Models, Biological; Plant Extracts - chemistry; Plant Extracts - metabolism; Polyphenols - chemistry; Polyphenols - metabolism; Soy Milk - chemistry; Soy Milk - metabolism; Soybean Proteins - chemistry; Soybean Proteins - metabolism
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.7b04456

The aim of this study was to compare the effect of fermentation pH on protein bioaccessibility of four soymilk curds enriched with tea polyphenols (TP). The curds were generated by fermentation with Weissella hellenica D1501 and the fermentation terminated at different pH values, namely at pH 5.7, 5.4, 5.1, and 4.8 (SMTP-5.7, SMTP-5.4, SMTP-5.1, SMTP-4.8). Particle-size distribution, soluble protein content, gel electrophoresis, and peptides content were monitored at oral, gastric, and intestinal levels. Results showed that SMTP-4.8 was the matrix most resistant to protein digestion in the gastric phase according to the soluble protein content. Similar particle size distribution and protein degradation patterns were observed for these curds in gastric and intestinal phase. However, there was a significant difference (P < 0.05) in the content of small peptides (