AVALIAÇÃO DO POTENCIAL IMUNOMODULADOR, ANTIOXIDANTE E ANTIBACTERIANO DE BEBIDAS MISTAS PROBIÓTICAS ELABORADAS COM BABAÇU E BURITI OU CAJU

Abstract

Fermented beverages of plant origin have been gaining recognition as functional foods due to their acceptability and potential health benefits, particularly for individuals who do not consume milk and dairy products. In this context, the selected plant matrix and the strain used for fermentation can enhance the production of bioactive compounds with immunomodulatory, antioxidant, and antibacterial properties through distinct mechanisms. The objective of this study was to evaluate whether the fermentation process by the probiotic microorganism Lacticaseibacillus casei could contribute to the functional potential of two mixed beverages: Babassu and Buriti, and Babassu and Cashew. This dissertation is structured into two chapters. Chapter I presents an integrative review of the existing literature, titled “Antioxidant and Antimicrobial Properties of Probiotics: Insights from In Vitro Assays.” The study discusses the main mechanisms of action and analytical methods employed, based on selected publications from the MEDLINE (PubMed), Web of Science, Scopus, Science Direct, and Embase databases. The review highlights variations in the content of bioactive compounds such as phenolics and flavonoids following fermentation, as well as improvements in their bioaccessibility, in addition to antioxidant and antimicrobial activity observed in both fermented products and probiotics in in vitro studies. Chapter II, titled “Mixed Probiotic Beverages with Babassu: Immunomodulatory, Antioxidant, and Antibacterial Activity of Combinations with Buriti or Cashew,” evaluates factors related to the functional properties of fermented beverages, such as probiotic bacterial survival, acidity, phenolic and flavonoid content, cytotoxicity, and immunomodulatory, antioxidant, and antibacterial activity in fermented and non-fermented mixed beverages. The Babassu and Buriti, and Babassu and Cashew mixed beverages supported the growth and viability of probiotics (>8 Log CFU). Acid content increased after fermentation, leading to a corresponding decrease in pH. Total phenolic content (BBnF: 12±0.02, BBF: 8.4±0.02, BCnF: 14±0.03, BCF: 8.8±0.02 mg GAE g⁻¹) and flavonoid content (BBnF: 0.216±0.005, BBF: 0.152±0.003, BCnF: 0.268±0.003, BCF: 0.152±0.005 mg QE g⁻¹) decreased after fermentation; however, this did not significantly affect the antioxidant activity of the fermented beverages, which was maintained or, in some cases, even improved after probiotic fermentation (DPPH – BBnF>BBF at 1:8 and 1:16, BCnF<BCF at 1:32 /PL – BBnF>BBF at 1:4 and 1:8, BBnF<BBF at 1:32, BCnF<BCF at 1:32). Non-fermented beverages exhibited good cell viability across all tested concentrations, while fermented beverages displayed toxicity at a 1:2 dilution factor. In the minimum inhibitory concentration assay, none of the tested concentrations (1:2, 1:4, 1:8, 1:16, 1:32) exhibited antibacterial activity. Nitric oxide quantification in the supernatant of macrophage cultures revealed that the non-fermented beverages were able to reduce NO production at all pre-treatment times and across different concentrations (1:4, 1:8, and 1:16), whereas the fermented beverages exhibited this effect only after 24 hours of pre-exposure and exclusively at the highest concentration (1:4). Additionally, an increase in NO production was observed at lower concentrations (1:8, 1:16, and 1:32). The data indicate that fermentation induced changes in the mixed beverages of babassu with buriti or cashew, maintaining or enhancing their antioxidant activity; however, it did not confer antibacterial activity. Moreover, the non-fermented beverages exhibited greater immunomodulatory potential, as evidenced by their higher capacity to reduce nitric oxide production under different conditions.