No abstract

In this study, the effects of H 2 O 2 , 2,2 0 -Azobis(2-amidinopropane) dihydrochloride (AAPH) and metal ion Fe 3+ on β-lactoglobulin (BLG) glyco-oxidation were investigated. The results demonstrated all the three inducers caused BLG morphology change and higher molecular weight BLG-glucose (BLG-Glu) adducts formation. H 2 O 2 and AAPH significantly accelerated BLG oxidation by increasing carbonyl content and decreasing freesulphydryls (P < 0.05). However, Fe 3+ showed little influence on carbonyl and free sulphydryls contents. All the three inducers promoted fluorescent-advanced glycation end products (fl-AGEs) and carboxymethyl-lysine (CML) formation. Fe 3+ and H 2 O 2 (0.5% and 1%) could increase methylglyoxal (MGO) level and caused less time to reach its peak concentration than control group. Compared with the control group, new glycation sites were determined in H 2 O 2 , AAPH and Fe 3+ treatments, indicating the inductive effect of those free radicals or metal ion on BLG glycation. The results will provide important information for the control of protein-based products glyco-oxidation during food processing and storage.