Chemical Characterization and Emulsifying Properties of Grass Carp Myofibrillar Protein Glycated with Glucose

Glucose was used as a glycosyl donor to glycosylate the grass carp myofibrillar protein to investigate the physicochemical properties and emulsifying properties of glycosylation production. The reaction products of grass carp myofibrillar protein and glucose mixture (1:2, w/w) were prepared by dry-heating at 50℃ and 44% relative humidity, and the content of furosine, free amino group, fluorescence intensity and secondary structure, and emulsifying property and emulsifying stability of the conjugates were further analyzed. Results showed that, as dry-heating time was prolonged, the content of furosine and the fluorescence intensity firstly increased and then decreased;and the total colour difference (ΔE) increased (p<0.05), and for 48 h of dry-heating, the content of furosine reached the maximum ((4.09±0.07) mg/100 mg). Structural analyses suggested that glycosylation had little effects on the secondary structure of myofibrillar protein. Moreover, the glycation significantly improved the emulsifying activity (EAI) and emulsifying stability (ESI) of grass carp myofibrillar protein (p<0.05), and the conjugates prepared from 48 h of dry-heating showed the highest ability of EAI and ESI, which was 1.32 and 1.53 times of original grass carp myofibrillar protein, respectively. Furthermore, the extent of glycation clearly affected the ability of EAI and ESI of grass carp myofibrillar protein based on the correlation analysis.