Yeasts from fermented Brazilian fruits as biotechnological tools for increasing phenolics bioaccessibility and improving the volatile profile in derived pulps

Caatinga Biome fruits have been scarcely explored as a source of biotechnological yeasts. This study isolated yeasts from naturally fermented Caatinga fruits and evaluated Hanseniaspora opuntiae 125, Issatchenkia terri-cola 129, and Hanseniaspora opuntiae 148 on fermentation of soursop and umbu-caj ' a pulps. All strains were able to ferment the pulps (72 h), increasing (p < 0.05) acetic acid, phenolics concentration and bioaccessibility, and maintaining counts above 7 log CFU/mL after fermentation and/or in vitro digestion. H. opuntiae 125 showed the highest counts (8.43-8.76 log CFU/mL; p < 0.05) in pulps and, higher organic acids production, increased survival to digestion, and higher bioaccessibility of various phenolics (p < 0.05) in the umbu-caj ' a pulp. I. ter-ricola 129 and H. opuntiae 148 showed higher metabolic activity, concentration and bioaccessibility of specific phenolics in umbu-caj ' a and soursop pulps, respectively (p < 0.05). Volatiles varied (p < 0.05) with the yeast strain. Generally, the yeast biotechnological performance for pulp fermentation was better on its fruit source.

Automated summary

This study explored the yeasts isolated from fermented Caatinga fruits and evaluated their fermentation performance on soursop and umbu-caj 'a pulps. All strains were able to ferment the pulps effectively, increasing acetic acid, phenolics concentration, and bioaccessibility. H. opuntiae 125 showed the highest fermentation performance, while I. ter-ricola 129 and H. opuntiae 148 displayed higher metabolic activity and bioaccessibility of specific phenolics in umbu-caj 'a and soursop pulps, respectively. Volatile compounds varied with different yeast strains.