The objective of this study was to identify peptides derived from defatted wheat germ proteins with both emulsifying property and anti-adhesive activity against H. pylori. The emulsifying property was predicted by calculating the amphiphilic scores and secondary structures in silico. Six top-ranking peptides were synthesized for validation of their emulsifying and anti-adhesive activities. Three peptides (HLNLDFQLQEGGR, VNQAIYLLTTGAR, and ESLLNALTEHVK) showed high emulsifying activity by forming smaller oil droplet sizes of 1.396 +/- 0.015 mu m, 1.163 +/- 0.010 mu m, and 1.159 +/- 0.257 mu m, respectively. Compared to Tween 80, only VNQAIYLLTTGAR maintained good emulsifying stability at different pHs, ionic strengths, and heating. The antiadhesive activity ranged from 36.3 +/- 2.0% (VNQAIYLLTTGAR) to 5.5 +/- 7.0% (AINDIRDQLER) at 10 mg/mL, which is attributable to binding of the peptides and H. pylori adhesins through hydrogen bonding and hydrophobic interactions. In conclusion, VNQAIYLLTTGAR showed both biological and techno-functional properties, thus making it a strong candidate for further development as a dual functional food ingredient.

Corn gluten meal (CGM) is a promising alternative protein source for human consumption, yet it remains under utilized due to its low protein digestibility and poor functionality. Thermal processing techniques have been demonstrated to effectively improve digestibility of plant proteins. The presence of other components such as starch also play a vital role in protein digestibility. However, the impact of starch removal and various thermal processing methods (such as microwaving, extrusion, heating, and baking) on the in vitro protein digestibility of CGM, as well as the underlying mechanisms, remains unexplored. This study demonstrated that the applied thermal processing did not significantly enhance CGM protein digestibility, while starch removal using alpha-amylase significantly improved protein digestibility by 26.3%-37.8% (P < 0.05). The elevated protein digestibility resulting from starch removal could possibly be attributed to the improved water absorption capacity and zeta potential, reduced disulfide bond content and particle size, and changes in secondary structures from ordered beta-sheet to disordered random coils. The altered surface morphology with more pores and lower aggregation, as evidenced by SEM and CLSM images, also contributed to the increased digestibility after starch removal. This study presented novel evidence supporting the potential applications of CGM with removed starch as a sustainable protein source with enhanced digestibility and has unraveled its underlying chemistry mechanism.

Approximately 50-80% of the world population are infected with H. pylori, which is categorized as a class I carcinogen. Antiadhesive therapy is emerging as a promising alternative to antibiotics against bacterial infection. This study demonstrated that defatted wheat germ protein hydrolysates (DWGPH) effectively inhibited H. pylori adhesion to gastric epithelial cells. DWGPH prepared by pronase possessed the best activity where its inhibitory percentage at 10 mg/mL was 51.7 +/- 6.8% and the minimum antiadhesive concentration was 0.31 mg/mL. The antiadhesive activity is attributable to peptides acting as receptor analogs in binding to H. pylori. Peptides with potential H. pylori-binding ability (n = 267) were identified, and their structural characteristics were comprehensively analyzed, including net charge, Boman index, instability index, aliphatic index, molecular weight, isoelectric point, hydrophobicity, and Hmoment (alpha-helix and beta-sheet). This work provided an array of peptide sequences for further exploration as putative ligands of H. pylori adhesins and for elucidating molecular mechanisms.