Influence of spontaneous and inoculated fermentation of açai on simulated digestion, antioxidant capacity and cytotoxic activity

[Display omitted] •The first report demonstrating the effects of different types of fermentation on the in vitro bioaccessibility of açai anthocyanins.•Spontaneous fermentation of açai increases the bioaccessibility in vitro of cyanidin-3-glucoside.•Alcoholic fermentation of açai reduces reactive oxygen species generated by H2O2 in the HCT8 cell line.•Alcoholic fermentation of açai reduces chromosomal aberrations in A549 cells. This work describes the kinetic study of different types (spontaneous, lactic and alcoholic) of açai fermentation in terms of total phenolics and total anthocyanins, as well as antioxidant capacity, before and after simulated digestion (SD). Cytotoxicity (A549, HCT8 and IMR90 cells) and formation of reactive oxygen species (A549 cells) were also evaluated. The results revealed that spontaneous fermentation (SF) for 24 h, followed by SD, generated a product with greater bioaccessibility of phenolics (52.68%) and cyanidin-3-glucoside (27.01%) than unfermented açai. Likewise, lactic fermentation (LF) for 72 h improved the bioavailability of phenolics (64.49%) and cyanidin-3-rutinoside (20.00%). On the other hand, alcoholic fermentation (AF) decreased the bioaccessibility of phenolic compounds and anthocyanins after SD. The SF 24 h (10.16 ± 1.25 μmol Trolox /g) and LF 72 h (15.90 ± 0.51 μmol Trolox /g) significantly increased the antioxidant capacity after SD, when compared to unfermented açai (SF 0 h, 4.00 ± 0.09 μmol Trolox /g; LF 0 h, 10.57 ± 0.91 μmol Trolox /g). It was concluded that the samples did not show cytotoxicity in the cell lines tested and, in addition, AF 24 h showed antioxidant and antimutagenic effects in vitro, reducing about 40% of chromosomal aberrations. The results obtained provide important information that can be used to produce foods with greater bioaccessibility of bioactive compounds.