γ-Glutamyl dipeptides (γ-GGDPs) have been implicated be generated by enzymatic action on γ‑glutamyl groups, modulate kokumi sensation of fermented foods via activating calcium-sensing receptors (CaSR). However, their variation and potential formation mechanism in Jinhua ham remain unclear. 10 γ-GGDPs (γ-EA, γ-ED, γ-EE, γ-EL, γ-EM, γ-EG, γ-EF, γ-EY, γ-EI, γ-EW) in Jinhua ham were quantified by UHPLC-Q-TOF-MS and accumulating significantly during processing (P < 0.05), with final contents ranging from 0.78 ± 0.01 μg/g (γ-EW) to 24.75 ± 0.33 μg/g (γ-EA). Sensory evaluation confirmed these γ-GGDPs enhanced the kokumi, saltiness, and umami of Jinhua ham during the post-ripening periods. Mechanistic investigation indicated that γ-glutamyl transpeptidase (GGT) transfer and hydrolytic activities increased progressively to 9.11 ± 0.17 U/mg and 12.19 ± 0.40 U/mg, respectively, which corroborated GGT's role in driving γ-GGDPs formation by catalyzing the transfer of γ-glutamyl groups to free amino acids (FAAs) generated by endogenous enzymes in Jinhua ham. Further validation via a ternary reaction system (comprising FAAs, γ-glutamyl donors, and GGT extracted from Jinhua ham) confirmed this GGT-catalyzed transfer reaction for γ-GGDPs biosynthesis. This study provides a theoretical foundation for the potential formation mechanisms of γ-GGDPs in Jinhua ham and regulation of Kokumi sensation in fermented foods.
扫码关注我们
求助内容:
应助结果提醒方式:
