Abstract: In this study, the effect of pH (5.0–6.5) on flavor characteristics of Maillard reaction products from enzmatic hydrolysates of beef (EBH-MRP) was studied. Results showed that as the pH increased, the sensory properties of EBHMRP were mainly changed from meaty, salty to roast, and bitter flavor. The umami taste intensity of model blank chicken soup was enhanced more weakly, but the kokumi taste intensity was improved steadily. A significant positive correlation was observed between roast aroma and bitterness taste intensity. Excessive roast aroma implied the formation of bitter compounds, which not only could mask the meaty aroma of EBH-MRP but also inhibit its umami, kokumi taste and umamienhancing intensity. Quantitative analysis of flavor compounds demonstrated that meaty aroma intensity was neither correlated with the amount of the important precursor cysteine (Cys), nor with the contents of the key aroma substances. These findings demonstrated that meaty aroma was regulated by the interaction of various odorant compounds, which were generated by an extremely complex mechanism. In addition, a significantly positive correlation existed between the total content of nitrogen-containing heterocyclic odorants and roast aroma intensity. The high molecular weight EBH-MRP (> 3 000 D) was the major contributor to the bitterness taste. The increase of kokumi taste was associated with appropriate degradation of peptides.

Key words: enzymatic hydrolysate of beef, Maillard reaction, flavor, pH value, correlation