Magnesium chelation of low molecular weight peptides from protein-rich industrial wastes: Production and properties

Magnesium chelating is considered a promising method to increase Mg uptake, thus fight against the prevalent case of Mg deficiency. In this study, hydrolysates and peptide fractions from spent brewer's yeast (SBY) and soybean meal (SBM) were evaluated for the magnesium chelating ability. Despite the similar amino acid profile and protein concentration, SBY hydrolysate showed superior chelating yield than that of SBM. Cross flow filtration was shown to have facilitated the chelating process, with the specific chelating yield peaked at 94.44 mg/g protein for the 3 kDa peptide fraction of SBY hydrolysate. It was also demonstrated that at optimum conditions (pH 2 to 4 and Mg loaded 5 mM to 25 mM), the ≤ 3 kDa peptide fraction of SBY exhibited the highest magnesium chelating yield of more than 98 %. Physical and biochemistry properties of spray dried peptide chelate were also scrutinized. The FTIR spectra confirmed the chelating sites of peptide were amino and carboxyl groups; and the particle size distribution of Mg chelated peptides was identified in the range of 1000 nm. Our findings concerning the in-vitro gastrointestinal stability and cytotoxicity have confirmed the suitability of magnesium chelated SBY for animal and human consumption.