Abstract

The fermentation of tropical fruits has gained significant attention in recent years due to its potential to produce novel, healthful beverages, particularly in the expanding functional food and drink market. Among these, dragon fruit stands out for its rich nutrient profile and unique flavor, though its high pectin content presents challenges in juice extraction and clarity. To develop a high-quality fermented dragon fruit beverage, this is the first report to investigate the use of Saccharomyces cerevisiae HG 1.3 as the primary fermentation agent, in combination with commercial S. cerevisiae RV002 yeast strain. We used different pectinase concentrations (0.03%, 0.035%, 0.04%, and 0.045% w/w) to examine juice yield and clarity and then used the central composite design with response surface methodology to optimize the key fermentation parameters (soluble solids contents, pH levels, yeast ratios, and fermentation time). The results showed that pectinase concentration of 0.04%, soluble solids content of 22°Brix, and pH of 4.6 could successfully improve the dragon juice yield and clarity while promoting favorable yeast activity. A yeast concentration of S. cerevisiae HG 1.3% of 1.5% and commercial S. cerevisiae RV002 of 0.04% and a fermentation period of 48 hours were identified as the ideal conditions to achieve the best balance of alcohol content, flavor complexity, and sensory appeal. Sensory evaluations confirmed the beverage’s high quality in terms of color, aroma, and taste. These results offer practical applications for commercial production while also laying the groundwork for future studies on process scalability, stability, and potential probiotic integration.

Key words: dragon fruit, Saccharomyces cerevisiae, mixed fermentation, pectinase enzyme, response surface methodology