Rapid discovery of three umami crab peptides from Eriocheir sinensis by virtual hydrolysis and LC–MS/MS

Traditionally, Eriocheir sinensis elicits wide distribution, easy accessibility, and unique taste, but the low comprehensive utilization restricts its application. The present study aimed to extract and identify peptides from the defective E. sinensis and analyze the umami mechanism of crab peptides. Virtual hydrolysis showed that protein hydrolysate prepared by the dual enzyme combination (papain and alkaline protease) had high hydrolysis degrees and umami fragments, which was consistent with the actual hydrolysis results. The three strong-flavoring crab peptides (AADESERM, SDEERMDAL, and EERAESGES) were screened by umami prediction and amino acid sequence analysis, and the umami profiles with thresholds ranged 0.0625–0.250 mg/mL determined by sensory evaluation and electronic tongue. The AADESERM had the highest umami enhancement effect. Besides, molecular docking and molecular dynamics simulation revealed that all the three crab peptides bound stably to the active cavity of T1R1. Asp147, His71, Ala302, Cys106, and Lys379 were the crucial binding sites for umami presentation. This study was accurately identifying umami crab peptides from defective E. sinensis based on pre-virtual hydrolysis. It will reduce the wastage of crab resources and further provide support for the high-value utilization.