Characterization of babassu mesocarp flour after fermentation in semisolid state with Saccharomyces cerevisiae and Saccharomyces boulardii

The use of agroindustrial byproducts has proven to be a sustainable and promising strategy for adding value to regional raw materials and developing ingredients with functional potential. Babassu mesocarp, an abundant byproduct rich in carbohydrates and fiber, remains underexplored for use in food formulations. Semi-solid-state fermentation (SSF) emerges as a biotechnological alternative capable of enhancing the release and synthesis of bioactive compounds, in addition to modifying the nutritional profile of the substrate. This study aims to characterize babassu mesocarp flour (BMF) subjected to SSF with Saccharomyces cerevisiae and Saccharomyces boulardii, evaluating its proximate composition, total phenolic compounds, and antioxidant activity (DPPH). The flour was fermented for 24 hours at the optimal growth temperature of 30°C for both yeasts, in a 1:2 ratio (mass:mass) of BMF and liquid, composed of water and BMF hydrolyzate. The amounts of yeast and hydrolyzate, as well as the agitation, varied according to the 2³ experimental design. After FES, the samples were dried, ground, and analyzed for centesimal composition (TACO/IAL), total phenolics (Folin-Ciocalteu), and antioxidant activity (DPPH), with statistical analysis by ANOVA. The fresh BMF had 14.1% moisture, 1.6% protein, 0.3% lipid, 84% carbohydrate, and 1.0% ash (344.9 kcal), confirming its potential as an energy source and carbohydrate. Fermentation with S. cerevisiae showed that total phenolics and DPPH free radical scavenging increased under conditions of lower water and yeast addition, with moderate agitation. While total phenolics showed a similar increase in fermentation with S. boulardii, DPPH free radical scavenging showed a low correlation (R² = 51.91%). These findings demonstrate that FES from BMF, especially with S. cerevisiae, enhances the presence of bioactive compounds and antioxidant activity, highlighting the use of bioprocesses as an effective tool for valorizing agroindustrial byproducts and opening prospects for the application of this fermented flour in food formulations with functional and antioxidant appeal.