Influence of in vitro gastrointestinal digestion and probiotic fermentation on the bioaccessibility of gallic acid and on the antioxidant potential of Brazilian fruit residues
Julianna Karla Santana Andrade, Romy Gleyse Chagas Barros, Nayjara Carvalho Gualberto, Christean Santos de Oliveira, Saravanan Shanmugam, Narendra Narain
Abstract
This study aims to investigate the fruit residues of cashew apple and soursop regarding their chemical composition (sugars, carotenoids and organic acids by HPLC-DAD/RID), total phenolics, flavonoids, antioxidant capacities (ABTS, DPPH, FRAP and ORAC), inhibition of α-amylase enzyme, cytotoxicity by cell viability of fibroblast cells lines (L929). The aqueous and ethanolic extracts were submitted to simulated in vitro gastrointestinal digestion and probiotic fermentation (Lactobacillus delbrueckii, Lactobacillus jhonsoni, Lactobacillus rhamnosus and Bifidobacterium longum). The bioaccessibility of individual phenolic compounds was evaluated by UFLC-DAD system. The results revealed high bioaccessibility index for total phenolics (74.91 ± 1.10 to 475.25 ± 2.92%), flavonoids (27.86 ± 0.61 to 111.65 ± 0.94%), antioxidant capacity ORAC (131.40 ± 1.92 to 813.32 ± 21.13%). β-Carotene, citric acid, gallic acid, catechin, pyrocatechol, vanillin, quercetin, protocatechuic acid and propyl gallate were the most important compounds. The extracts showed good inhibition of α-amylase, cell viability and high bioaccessibility of gallic acid compound (960.74 ± 0.00 to 1347.28 ± 51.75%). This study suggests that gastrointestinal digestion and probiotic fermentation of fruit residues increase the bioaccessibility of phenolic compounds with highly promising antioxidant potential for human health benefits.