Application of Hydrodynamic Cavitation for Quality Enhancement and Shelf-Life Improvement of Mixed Fruit Juice Blend

Hydrodynamic cavitation (HC) is an emerging non-thermal technology that is capable of improving the quality and shelf life of fruit juices while retaining heat-sensitive bioactive compounds. This study optimized a mixed-fruit juice (MFJ) blend—60% mandarin, 25% pineapple, and 15% watermelon using a D-optimal mixture design. The MFJ was subjected to HC at varying pressures (4–6 bar) and times (40–60 min) and compared to thermal treatment (90 °C for 30 s). The optimized predicted HC treatment (5 bar/52 min) effectively maintained pH, titratable acidity, and TSS. Notably, HC at 6 bar for 60 min reduced the sedimentation index by 2% and lowered viscosity to 3.56 cP. Compared to thermal processing, the optimized HC-treated sample demonstrated superior nutrient retention, preserving 82.29% of vitamin C, 93.50% of total phenolics, 87.43% of flavonoids, and 61.67% of antioxidant activity. Microbial safety was also improved, achieving a 1.35 log CFU/mL reduction in total plate count and 47.96% peroxidase inactivation. While sensory evaluation showed slightly lower acceptability for HC-treated juice (6.36) versus the control (7.14), it significantly outperformed thermal treatment (3.83). Furthermore, the cavitated sample demonstrated superior bioactive retention after 14 days of storage at 4 °C, with total phenolic content retained at 31.55 ± 0.9 mg GAE/100 mL. The findings suggest that hydrodynamic cavitation can be considered a promising non-thermal processing technology for improving physicochemical stability, preserving bioactive compounds, and extending the shelf life of functional fruit beverages. This underscores HC’s potential as a viable, high-quality alternative to traditional pasteurization in the beverage industry.