Identification and characterization of flavor precursor peptide from beef enzymatic hydrolysate by Maillard reaction.

In this study, beef enzymatic hydrolysate was fractionated by sequential UF/GFC/RP-HPLC. RP-HPLC fractions were subjected to Maillard reaction with xylose. The FD/TD factors of the MRPs were prominent. Sensory evaluation showed that F-3 exhibited intense meaty taste; the kokumi intensity, umami-enhancing capacity in F-4; the umami-enhancing capacity in F-5; the umami intensity and umami-enhancing capacity in F-6. All these were strong in F-7 and F-8. The RP-HPLC fractions were subsequently analyzed by ESI-Q-TOF MS/MS. Of the 21 peptides identified, Leu(Ile)-X, Val-X, Phe-X, and Cys-containing peptides were the major ones. Six peptides (Leu-Cys, Glu-Cys-Gly, Cys-Gly-Val, Val-Met, Phe-Glu, and Phe-Gln) were synthesized and included in the Maillard reaction with xylose. FD factors of MRPs of all these synthesized peptides were significantly greater than those of fraction F-7. The stronger Maillard reactivity demonstrated by the synthesized peptides proves that this work is correct.