Functional Properties of Campomanesia xanthocarpa Infusions: Phenolic Profile, Digestive Stability, Enzyme Inhibition, and Glycemic Effects

This study explored the functional potential of C. xanthocarpa infusions through phytochemical profiling, simulated gastrointestinal digestion, enzymatic inhibition assays, and an in vivo assessment of glycemic markers. Leaf infusions contained 32 phenolic compounds and exhibited higher total phenolic content (TPC; up to 204.2 mg GAE/g) and antioxidant capacity (TAC; up to 3028 µmol Trolox/g) compared to fruit infusions (21 compounds; 129.9 mg GAE/g and 1316.7 µmol Trolox/g). After digestion, leaf extracts showed greater stability, with TPC reductions of 13.8% (gastric) and 24.8% (intestinal), while fruit extracts decreased by 32.6% and 35.6%. Bioaccessibility indices were notable for compounds such as benzoic acid (93.7%) and quercetin-3-glucoside (up to 33.9%). In vitro assays revealed strong inhibition of salivary α‑amylase (99.7–99.9%) and β‑glucosidase (52.9–99.3%) by leaf extracts, whereas fruit extracts showed minimal activity against β‑glucosidase. In a 32‑day in vivo trial, dogs fed biscuits enriched with leaf infusion experienced no change in fasting glucose or serum amylase, but exhibited a significant treatment × time interaction for serum fructosamine (p = 0.05), indicating a delayed modulation of glycemic control possibly related to antioxidant or antiglycation effects. The combined findings suggest that C. xanthocarpa leaf infusion is a promising functional ingredient for food formulations aimed at glycemic regulation and metabolic health.