Exploring the metabolic fate of antioxidant and hypoglycemic compounds from Pistacia vera shells through in vitro simulated digestion and untargeted metabolomics

Pistacia vera L. shells (PS) are a sustainable source of health-promoting ingredients. The metabolic fate of a PS extract with antioxidant/antiradical and hypoglycemic properties prepared by microwave-assisted extraction (MAE) was investigated through in vitro gastrointestinal digestion to consider its potential value as nutraceutical ingredient. The results revealed significant changes in the phytochemical profile, bioactivity, and bioaccessibility of the extract during digestion. According to LC-ESI-LTQ-Orbitrap-MS analysis, compounds were mainly preserved in the oral (40.48 μg/mg DW) and gastric (73.67 μg/mg DW) phases, and less in the intestinal phase (13.24 μg/mg DW). α-Amylase inhibitory properties of PS extract remained consistent during digestion, whereas α-glucosidase inhibition and antioxidant/antiradical effects gradually decreased. Multivariate data analysis confirmed the interdependency between phytochemical composition and bioactivity of undigested extract and its digests. This study represents a step forward for developing PS-based functional foods, providing unique insights into the metabolism of PS bioactive constituents under simulated gastrointestinal conditions.