2008 Volume 2 Issue 1 Pages 145-152
The digestibility of nonpressurized bovine whey protein isolate (WPI) and pressure-induced WPI gel and the effect of different pressures (200-600MPa) on digestibility were evaluated by measuring digestive rate in simulated astrointestinal digestion system and SDS-PAGE. The results showed that the digestibility of high pressure induced WPI gel significantly increased compared with that of untreated WPI after digesting by pepsin and trypsin, which were 72.59% and 61.02% respectively. When the pressure was over 400MPa, the digestibility of high pressure-induced WPI gel showed no significant change(ANOVA, p<0.05). Although the b-lactoglobulin(β-Lg) from untreated WPI sample was not easy to be digested by pepsin, β-Lg from the high pressure-induced gel (400MPa) was digested partly. Furthermore, when the pressure was up to 600MPa, β-Lg from the high pressure-induced gel was digested almost completely. In addition, the peptides with molecular masses of 3500-6500 Da were formed after pepsin digestion.