Effects of high hydrostatic pressure treatment on the antigenicity, structural and digestive properties of whey protein

The effects of high hydrostatic pressure (HHP) treatment and in vitro simulated infant digestion on the antigenicity of whey protein concentrate (WPC) were investigated. The results revealed that the greatest decline in allergenicity was observed at 500 MPa for 10 min, which was 76.19% ± 1.45%. HHP treatment (500 MPa/10 min) contributed to WPC structure stretched as β-sheet content increased from 18.45% ± 0.32%–20.93% ± 0.59% (p < 0.05). Fluorescence spectroscopy indicated the fluorescence intensity increased from 4.649 × 106 to 5.205 × 106 with the increased HHP time (0–15 min). There was a 1.39-fold increase in hydrophobicity of HHP-modified WPC which was the equilibrium result of protein unfolding and intermolecular aggregation. HHP treatment (500 MPa/10 min) facilitated the conformational changes of WPC that were needed to increase the effectiveness of in vitro simulated infant digestion, and increased the content of peptides with molecular weights below 10,000 Da in digestion products by 9.99%. HHP pretreatment prior to in vitro simulated infant digestion reduced the retention of WPC antigenicity to the lowest level, which was 38.96%. Overall, this study suggests that appropriate HHP treatment could be a promising technique to improve the digestibility of milk proteins and reduce their antigenicity.