Impacts of in vitro gastrointestinal digestion on phenolic compounds bioaccessibility and biological activities of uvaia (Eugenia pyriformis Cambess) fractions

Abstract

Uvaia (Eugenia pyriformis Cambess) is a species native to the Atlantic Rainforest (Brazil) that has a great potential for technological applications, but which remains unexplored in relation to its biological potential. Hereby, we evaluated the effect of in vitro gastrointestinal digestion on phenolic compounds bioaccessibility, antioxidant capacity, α-amylase, α-glucosidase inhibition and antiglycation activity of two uvaia portions: edible fraction and seed. The phenolic characterization, antioxidant capacity and antidiabetic potential of the aqueous phenolic extract of both uvaia fractions were also evaluated. UHPLC-MS/MS analysis in the aqueous extract showed that quinic acid was the main organic acid present in uvaia seed (171.91 mg/100 g), whereas quercitrin was found mainly in the edible fraction (16.00 mg/100 g). Uvaia seed had the greatest antioxidant capacity (9951 – 37500 µmol Trolox equivalent (TE)/100 g) compared with edible fraction (1900 – 9123 µmol TE/100 g). Edible fraction showed higher α-amylase inhibitory potential (IC50 = 5.72 mg/mL), while there was no difference between both evaluated fractions for α- glucosidase inhibition (IC50 = 5.24–5.26 mg/mL). Uvaia seed showed higher antiglycation potential (IC50 = 1.09 mg/mL) compared with the edible fraction (IC50 = 8.46 mg/mL). Regarding the phenolics bioaccessibility, rutin and epicatechin significantly decreased after gastrointestinal digestion for both fractions. However, p-coumaric acid and quercitrin significantly increased after digestion for edible fraction (7 and 3-fold, respectively). In general, the antidiabetic potential of both uvaia fractions increased after gastrointestinal digestion. These results could encourage the development of new formulations with functional claims using different parts of uvaia.