The Effect of Gel Microstructure on Simulated Gastric Digestion of Protein Gels

The objective of this study was to analyse the impact of the gel structure obtained by different heat-induced temperatures on the in vitro gastric digestibility at pH 2. To achieve this, gels were prepared from soy protein, pea protein, albumin from chicken egg white and whey protein isolate at varying temperatures (90, 120 and 140 °C) for 30 min. Gels were characterised prior to digestion via microstructure and SDS-PAGE analysis. Subsequently, the gastric digestion process was followed via the protein hydrolysis and HPSEC analysis up to 180 min. Peptides of different sizes (<5 kDa) were gradually formed during the digestion. Our results showed that gels induced at 140 °C were digested faster. The protein source and gelation temperature had great influence on the in vitro gastric protein digestibility.