EFFECT OF TOTAL SOLUBLE SOLIDS AND pH ON SOME QUALITY PARAMETERS OF FERMENTED BEVERAGE FROM BLUEBERRY ( Vaccinium corymbosum L.)

Abstract

Aims: to investigate the effects of total soluble solids and pH on the physical and chemical composition, as well as the sensory quality of fermented blueberry beverages (Vaccinium corymbosum L.). Methods: The study investigated the effects of pH levels (3.8, 4.0, and 4.2) and total soluble solids (18, 20, and 22°Brix) on the quality attributes of the beverage. Results: The optimal fermentated conditions were found to be 20°Brix and pH 4.0. Under these conditions, the beverage showed high alcohol content (4%Vol.), low residual sugar (7.43%), total acidity (0.3%), and anthocyanin content (58.36mg%) after 4 days of fermentation. The 20°Brix - pH 4 treatment received high sensory scores across all attributes: appearance (4.54), color (4.46), aroma (4.43), and taste (4.66). This resulted in a product characterized by a balanced sweet-and-sour flavor, a vibrant red color, and a moderate ethanol content. Unlike wine, the ethanol level was not overly high, aligning well with current preferences for fermented beverages. Conclusion: Both pH and total soluble solids significantly influenced key quality indices. The fermentation process of blueberry beverages was identified with the optimal total soluble solids and pH values.