Optimization and characterization of a value-added fermented ready-to-serve whey-based beverage with high antioxidant potential

Abstract

This study was conducted to optimize the process parameters for developing a Ready-To-Serve fermented whey beverage using pineapple juice and mint and characterize the drink. The levels of pineapple juice (20-40%), sugar (5-10%), and mint powder (1-3%) on pH, DPPH, TSS, and overall acceptability were investigated using a central composite design. The optimized process conditions achieved were 39.42% (v/v) of pineapple juice, 5.75% (w/v) of sugar, and 1.01% (w/v) of Mentha. The beverage had 89.41% mg GAE/ml total phenolic content and 83.88% DPPH radical scavenging activity. FTIR spectrum confirmed the presence of the O-H stretch of phenolic compounds between 3200 cm^-1– 3518 cm^-1 and conformational changes in the secondary structure of the whey protein at 1625-1647 cm^-1 in the fermented sample. The beverage possessed all essential amino acids, the highest being Leu, Val, and Lys and PUFA (ω6/ω3=1.52) and MUFA levels of 6.7±0.96 and 21.57±0.02 mg/100mL, respectively. In addition, hypercholesterolemic fatty acids (C12:0, C14:0, C16:0) were significantly reduced after fermentation. Therefore, a serving of 100mL would contribute 3.53%, 2.96%, and 2.41% towards the RDA of Fe, K, and Mg, for an adult man, respectively. The whey beverage had acceptable microbiological quality on the 30^th day of storage under refrigerated conditions. Fermentation with Pediococcus pentosaceus NCDC 273 reduced the coliform count by 5.57% and 4.04% and the Y&M count by 2.2% and 2.9% on the 15^th and 30^th day of storage, respectively.