Optimization of Ohmic Heating Pasteurization for Passion Fruit Juice and Comparison with Conventional Thermal Treatment

This research optimized the parameters of Ohmic Heating Pasteurization (OHP) for passion fruit juice utilizing a Box–Behnken design. Researchers assessed how temperature (75–95°C), holding time (15–45 s), and voltage gradient (10–30 V/cm) influence the system performance coefficient (SPC), total color difference (ΔE), and vitamin C retention. The op-timal conditions were 82.5°C, 25 s, and 18.5 V/cm, achieving a microbial reduction exceeding 5 log CFU/mL, 45% retention of vitamin C, minimal color alteration (ΔE = 7.56), and an SPC of 0.85. Traditional pasteurization (85°C, 25 s) preserved merely 10% of vitamin C, induced a more significant color alteration (ΔE = 14.87), and resulted in a reduced SPC (0.54). The OHP-treated juice demonstrated superior antioxidant activity and prolonged shelf life (70 days at 8°C) in comparison to conventionally processed juice (28 days). The research as-sessed enzymatic activity (POD, PPO), demonstrating that OHP achieved superior inactiva-tion, thereby enhancing color stability and long-term product quality. These results indicate that OHP is a promising and sustainable thermal technology for high-acid fruit juice pas-teurization, combining energy efficiency with superior quality retention and enzyme inac-tivation.