Identification of peptides from defatted wheat germ proteins with dual functionality: Emulsifying activity and anti-adhesive activity against Helicobacter pylori

Abstract

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 μm, 1.163 ± 0.010 μm, and 1.159 ± 0.257 μm, respectively. Compared to Tween 80, only VNQAIYLLTTGAR maintained good emulsifying stability at different pHs, ionic strengths, and heating. The anti-adhesive 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.