Physicochemical Stability, Sensory Acceptance, and Biological Impact of Green Tea Kombucha Flavored with Native Cerrado Fruits (Spondias mombin L. and Anacardium occidentale L.)

Kombucha is a functional beverage produced through the fermentation of Camellia sinensis by a symbiotic culture of bacteria and yeast (SCOBY). Incorporating cashew (Anacardium occidentale L.) and Cajá (Spondias mombin L.) pulps represents a value-addition strategy to mitigate the post-harvest perishability of native Cerrado fruits. This study evaluated physicochemical kinetics, 21-day refrigerated shelf life, consumer acceptance, and biological effects in Caenorhabditis elegans of flavored kombuchas. During a 9-day primary fermentation, the pH decreased to 2.95 while total acidity reached 5.38%. Following flavoring (10% v/v pulp/juice), cashew kombucha exhibited the highest total phenolic content (4.19 mg GAE/mL) and ferric reducing power (FRAP), whereas Cajá kombucha showed superior DPPH scavenging activity (1236 µM TroloxE/mL). Refrigerated storage (4 °C) maintained high counts of viable microorganisms (>105 CFU/mL), though active residual fermentation induced ongoing sugar cleavage and a transient yeast proliferation peak on day 7 (8.15 log CFU/mL in Cajá kombucha). Toxicity assays using C. elegans revealed the initial mortality (31.5–62.5%); however, adjusting the pH to near-neutrality restored high organism viability (<10% mortality), confirming that mortality was acidity-driven. In pH-adjusted media, cashew kombucha promoted a modest extension of nematode lifespan, whereas Cajá kombucha reduced lipid accumulation. Sensory testing revealed moderate consumer acceptance, with cashew kombucha achieving a higher Acceptance Index (72.92%) than Cajá (67.26%). Overall, fruit supplementation enriches the bioactive potential of green tea kombucha, provided that post-fermentation acidity is appropriately managed.