Comparative Evaluation of Spectral, Phenolic Content, and Antioxidant Properties in Plinia sp. Beverages Fermented with Saccharomyces cerevisiae and Saccharomyces pastorianus

Plinia sp. (jaboticaba) fermented beverages is an interesting source of bioactive compounds with antioxidant activity. The aim of this study was to evaluate the physicochemical characteristics and antioxidant capacity of jaboticaba fermented beverages obtained from two different fermentation processes. The first fermentation (SCF1) used Saccharomyces cerevisiae yeast at 26°C, while the second (SPF2) employed S. pastorianus yeast at 18°C. The final products were bottled and subjected to storage for a period of up to six months, during which they were analyzed for their physicochemical characteristics using standard methods. Spectral features including color density (CD), hue, total color (TC), total pigment color (TPGC), and polymeric pigment color (PPC) were determined. Additionally, assessments employing spectrophotometric methodologies were made for total phenolic (TPC), flavonoid (TFC), tannins (TTC), and monomeric anthocyanins (TMA) contents, as well as antioxidant capacity. The main physicochemical characteristics of both fermented beverages included low pH and high acidity, remaining stable during the storage time. SCF1 and SPF2 did not differ in TPC levels, which showed only few variations during the months (2.5 to 4.0 g GAE.L-1). However, SCF1 showed the highest values of TFC (2.8 to 3.1 g QE.L-1), TTC (0.68 to 0.9 g TAE.L-1), and TMA (80 to 101 mg Cy3GE.L-1) during the evaluated period. Despite this, a progressive decrease on the amounts of these chemical classes was observed regardless the type of fermentation. In addition, the spectral features CD, TC, and TPGC showed decreasing values over six months. Similarly, the samples' antioxidant capacity showed a slight decrease as well. Taken together, the results presented here demonstrated that jaboticaba fermentation at 26 °C resulted in a beverage with enhanced amounts of bioactives. However, the fermented beverage's chemical and spectral properties proved to be sensitive to storage conditions.