Impact of methylglyoxal modification of chicken sarcoplasmic protein emulsions on emulsifying properties, rheological behavior and advanced glycation end products.

BACKGROUND: Protein modification is used to improve emulsion properties. However, there are limited reports on the effect of methylglyoxal (MGO) modification on emulsifying properties and on the production of advanced glycation end-products (AGEs) in chicken sarcoplasmic protein emulsion (SPE). In this study, MGO solution was dispersed into prepared emulsion (17 mg mL-1 sarcoplasmic-soybean oil (v/v 5:1)) at 0, 0.5, 5, 10, 30 and 50 mmol L-1 concentrations. Emulsifying activity index (EAI), emulsifying stability index (ESI), Z-average diameter, polydispersity index (PDI), zeta potential, rheological behavior (thermal condensation characteristics and fluidity) and AGEs in different concentrations of MGO SPE were measured. In addition, the effect of MGO on the levels of AGEs, lipid and protein oxidation of the emulsion as well as their relationship has also been analyzed. RESULTS: Our findings showed that ESI had the lowest value when MGO was added at a concentration of 10 mmol L-1 , while Z-average, PDI, carbonyl and AGEs had the highest value at the same concentration. Also, 10 mmol L-1 MGO played an important role in affecting the rheology of the emulsion. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results showed that the presence of myofibrillar proteins (MPs) in SPE was the main reason for the crosslinking of polymers which could be damaged by high concentration of MGO (>10 mmol L-1 ). CONCLUSION: Different concentration of MGO showed varying effects on emulsion properties and on the formation of AGEs in chicken SPE. Pearson's correlation analysis concluded that protein oxidation played a significant positive role during MGO modification. © 2020 Society of Chemical Industry.