Effect of the Maillard reaction with xylose on the emulsifying properties of a shrimp hydrolysate (Pandalus borealis)

The emulsifying properties of native shrimp hydrolysate (SH) and its sugar-conjugate (GSH) were studied at two concentrations (0.5% (w/w) or 1.5% (w/w)). GSH was obtained through the Maillard reaction in mild conditions (xylose; 65 °C; pH = 6.5; 4 h). Size exclusion chromatography of GSH demonstrated the occurrence of new fractions with higher molecular weights, resulting from the Maillard reaction. GSH showed a loss of ~ 30% of available amino groups expressed in terms of lysyl residues. Emulsions containing GSH significantly retarded and decreased creaming at both concentrations more than SH, and they had the highest consistency index values (K in mPa sn) and apparent viscosities (ηapp in mPa s). Finally, increasing SH and GSH concentrations in emulsions decreased their flow index values (n dimensionless) by 32% and 16% respectively. From these results, the Maillard reaction may be a useful approach for improving emulsifying properties of SH.