In vitro study on digestion of pumpkin oil cake protein hydrolysate: Evaluation of impact on bioactive properties.

摘要

A simulated gastrointestinal digestion of pumpkin oil cake protein hydrolysate prepared by alcalase (AH; subtilisin) was studied, to evaluate the impact of the main gastrointestinal proteinases on its antiradical and angiotensin I-converting enzyme (ACE) inhibitory activity. In vitro digestion was performed in a model system under optimised reaction conditions, 1st by pepsin and then with alpha-chymotrypsin and trypsin, simultaneously. Treatment with the gastrointestinal proteinases led to a significant increase in the degree of hydrolysis, up to 55.95 +or- 3.1% in the final digest. After digestion, the 2,2-azinobis3-ethylbenzo-thiazoline-6-sulfonic acid radical cation activity of AH increased from 7.59 +or- 0.1 to 10.25 +or- 0.3mM Trolox equivalent antioxidant coeff./mg (p < 0.05), while ACE inhibitory activity was not affected, being 74.29 +or- 1.25% (IC₅₀ = 0.404 +or- 0.014 mg/ml; p > 0.05) in the final digest. These results showed an advantage of AH in increasing antiradical activity whilst leaving ACE inhibitory activity unafffected during digestionof pumpkin oil cake protein hydrolysate by the main gastrointestinal proteinases, thus making it a promising bioactive food ingredient.