Characterization and application of indigenous microbial strains in mixed-culture fermentation of cashew apple juice

Abstract

This study evaluated the technological and functional potential of indigenous yeasts, lactic acid bacteria (LAB), and acetic acid bacteria (AAB) isolated from fermented cashew apple products to develop a mixed-culture low-alcoholic beverage. Fifty-two isolates (34 yeasts, 14 LAB, and 4 AAB) were identified by 16S and ITS genomic regions DNA sequencing. Growth and metabolite production kinetics were monitored in clarified cashew juice using microplate assays and high-performance liquid chromatography to select the high-performing microbial strains. The predominant yeast species yeast genera were Hanseniaspora opuntiae, Pichia kudriavzevii , and Saccharomyces cerevisiae , while Lactiplantibacillus plantarum and Acetobacter pasteurianus were the most represented bacterial species. The most interesting isolated strains exhibited distinct and complementary techno-functional profiles: S. cerevisiae (Sac11) showed ethanol yield (40 g L⁻¹) and rapid growth; P. kudriavzevii (Pik4a) and H. opuntiae (Hao71) produced esters with fruity and floral (isoamyl acetate, ethyl decanoate); whereas isolated Lp. plantarum (Lap21) and A. pasteurianus (AAB36) were selected to ensure acidification and oxidative stability. Different consortium combinations and fermentation conditions were screened using a 2² factorial design. Desirability analysis of yielded beverages satisfying a balanced acidity (pH 3.5–3.8), moderate sweetness (8–10 °Brix), and ethanol below 20 g.L⁻¹, with pleasant, fruity, slightly sparkling sensory attributes. Check-All-That-Apply (CATA) and hedonic tests revealed that the consortium (Lap21 + AAB36 + Sac11) produced the most appreciated beverages. These findings highlight the technological relevance of West African indigenous strains to contribute to the sustainable biotransformation of tropical fruits.