Trypsin Inhibition Activity and Functionality of Whiteleg Shrimp (Litopenaeus Vannamei) Head Protein Hydrolysate

Trypsin inhibition activity (TIA) of whiteleg shrimp (Litopenaeus vannamei) head (WLSH) protein hydrolysate was investigated. Alcalase hydrolysis was performed under a determined condition, including a 1:7 (w/v) WLSH powder to water ratio, an enzyme to substrate (E:S) ratio of 30 U/g protein, and a 3 h of hydrolysis, to produce a hydrolysate demonstrating the TIA of 1190.0 ± 25.8 trypsin inhibition units (TIU)/mg protein. Beyond 50% of this activity was retained after the hydrolysate was treated at pH range of 3 to 8 or heated for 90 min at 100°C. Regarding functional features, within the pH range from 3 to 8, the WLSH hydrolysate expressed notable solubility, heat stability, foaming and emulsifying properties. Moreover, average capacities of holding water and oil of the hydrolysate were ascertained. Besides, the hydrolysate could be served as an amino acid (AA) supplement which provided at least 8 essential AAs with the proportion of 44.59% of the hydrolysate’s total AAs. Furthermore, membrane ultrafiltration further enhanced the TIA of the hydrolysate, with its 1-3 kDa peptide fraction exhibiting the TIA of 1614.40 ± 32.20 TIU/mg protein. These findings would benefit the development of natural trypsin inhibition products from the WLSH, which could be employed in different areas.