Pulsed Electric Field-Assisted Valorisation of Rosehip Seed Meal and Baobab Pulp to Produce a Fermented Beverage

The growing demand for sustainable functional beverages has stimulated interest in the valorisation of agro-industrial by-products. This study investigated the effect of Pulsed Electric Field (PEF) treatment on the physicochemical properties, phenolic content, and antioxidant activity of a rosehip seed meal (RSM) and baobab pulp (BP) fermented beverage. RSM was subjected to PEF of 1.5 and 3.0 kV/cm. A yeast (Saccharomyces cerevisiae)-fermented beverage was formulated with RSM, BP and other ingredients. Physicochemical parameters—including pH, total soluble solids (°TSS), alcohol by volume (%ABV), and colour (L*, a*, b*)—were evaluated together with total phenolic content (TPC), DPPH radical scavenging activity, and ferric reducing antioxidant power (FRAP). Fermentation significantly (p < 0.05) decreased TSS and increased %ABV content, confirming microbial metabolism, while pH remained relatively stable throughout the process. Colour changes involving an increased lightness and decreased red and yellow intensities were observed after fermentation. TPC increased significantly (p < 0.05) from 499.30 to 602.41 mg GAE/L, with the highest value observed for 3.0 kV/cm after 24 h fermentation. Similarly, FRAP values increased from 362.49 to 467.55 µmol TE/L, whereas DPPH activity remained constant. The results demonstrate that PEF pretreatment can enhance fermentation by increasing the extraction of phenolic compounds, thus affecting the antioxidant potential. This highlights the potential for PEF as a green technology for developing sustainable, value-added functional beverages.