IN VITRO BIOACESSIBILITY OF BIOACTIVE COMPOUNDS IN MIXED TROPICAL FRUIT BARS

Fruit bars are products of the combination of fruit pulps and hydrocolloids, an alternative to healthy food of practical consumption. The objective of this study was to evaluate the influence of hydrocolloids on bioaccessibility of polyphenols and antioxidant activity of mixed tropical fruit bars. The samples were made with 50% of each of the pulps: mango with caja (MCa), mango with cashew (MCu) and mango with acerola (MAc), and agar-agar (Sosa®), gellan gum low acyl-LA and high acyl-HA (CP Kelco®), in the LA:HA ratios of 100:0, 75:25 and 50:50 (w/w), in a total concentration of 0.75%. The pulps with hydrocolloid were heated (88øC/60s) in Termomix, poured into silicone molds and refrigerated at 5øC/12h. Gastrointestinal digestion was performed in vitro (DGI) with pepsin-HCl, and bile-pancreatin-NaHCO3. The polyphenols and the antioxidant capacity were analyzed by the methods of Folin-Ciocalteu and ABTS radical. Before DGI, the polyphenol values of the pulps were 259.06 (MCa), 258.08 (MCu) and 745.72 (Mac) mg gallic acid/100g sample, and antioxidant activity was 7.42 (MCa), 9.07 (MCu) and 24.80 (MAc) μM Trolox/g sample. The bioaccessibility of polyphenols ranged from 24.58(pulp) to 29.45%(agar) in MCa samples, from 34.72(pulp) to 46.35% (LA:HA 75:25) and from 59.79 (pulp) to 75.50% (LA:HA 75:25) at Mac. There is no significant difference between mixed and pulp samples except LA:HA 75:25 (MCu). The bioaccessible values of antioxidant capacity among samples were similar, ranging from 21.10 (LA:HA 75:25) to 35.21% (pulp) in the MCa samples, 36.57 (LA:HA 100:0) at 50,08% (LA:HA 75:25) in MCu, and 40.01 (agar) at 51.05% (LA:HA 75:25) in Mac. The hydrocolloids used have similar capabilities in retention of bioactive compounds and maintain bioaccessibility values close to that of in natura pulps even after the process. Therefore, fruit bars are promising products for preserving polyphenols and antioxidant activity, exhibiting high bioaccessibility of these components.