Effect of the non-covalent and covalent interactions between proteins and mono- or di-glucoside anthocyanins on β-lactoglobulin-digestibility

The present study aims to affect the nature of the interaction between β-lactoglobulin (β-Lg) and cyanidin 3-glucoside (C3G) or cyanidin 3-rutinoside (C3R) on the digestibility, and antioxidant capacity. C3R and C3G were-conjugated with β-Lg by means of covalent and non-covalently interaction, and their binding ability, degree of hydrolysis, solvable proteins SDS-PAGE-bands, secondary structure, morphological clicks, and particles size were determined. Results disclosed that C3R and C3G improved the in vitro digestibility of β-Lg by amending the degree of hydrolysis, solvable peptides-parts, and declining its agglomeration. It was also found that C3R displayed better digestion-promoting effects than C3G, in which covalent interaction was more productive than the non-covalent one. Furthermore, C3G/R improved the antioxidant capacity of the digested peptides. Most notably, it was noted that C3G/R could partly unfold the β-Lg-structure via shifting their α-helix and β-sheet components. Furthermore, the binding of β-Lg-C3R/G was accountable for the modifications in the β-Lg subordinate structure. It was assumed that the partly unfolding in β-Lg-structure that was stimulated by β-Lg-C3R/G gathering might expand the availability of peptide bonds to the digestive enzymes and accelerate the ' digestibility of proteins. [Display omitted] •C3G and C3R aided the digestion of β-Lg proteins.•C3G and C3R partially unfolded the secondary structure of β-Lg proteins.•The covalent binding seems to be more efficient than the noncovalent one.