Kombucha and kefir fermentation dynamics on cashew nut beverage (Anacardium occidentale L.)

Plant-based beverages are often poor in nutrients, and fermentation can be a tool to solve this issue. This work aimed to study the fermentation kinetics and symbiotic potential of kefir and kombucha in cashew nut beverages (CNB). Three samples were formulated with CNB, and each sample received a different inoculum: 100% kefir, 50/50% kefir, kombucha, and 100% kombucha. They fermented for 72 h at 28 °C, and aliquots were analyzed at different times. The mixed cultures did not influence the production of glucuronic acid, but it was more efficient in consuming oligosaccharides. No acute toxicity was reported with zebrafish, but open camp assay pointed to lower locomotor action in mixed and 100% kombucha samples, which suggests probiotic activity. The sugar contents got lower with time within the 50/50% sample. Fermented cashew nut-based beverages can be a healthy alternative to bring new flavors and textures to cashew nut based beverages, which can be explored in cooking and in the creation of new recipes. •Kombucha and kefir together enhanced oligosaccharide hydrolysis in cashew nut milk.•Mixed cultures did not optimize functional acids production.•Zebrafish open field assay had changes in motricity, suggesting probiotic activity.•Higher results in open field tests are related to higher sugar content.