Abstract
This study investigated the efficacy of a combined non-thermal treatment consisting of lactic acid (0.1 or 0.15%), mild heat (50 °C), and ultrasound for the inactivation of major foodborne pathogens in apple juice. The influence of the combined treatment on juice quality was evaluated by measuring color parameters, non-enzymatic browning indices, total phenolic content, and DPPH radical scavenging activity. Apple juice samples inoculated with Salmonella Typhimurium and Listeria monocytogenes were subjected to simultaneous LA + H + US treatments. The combined treatment achieved significant microbial reductions, ranging from approximately 2.0 to greater than 5.77 log CFU/mL for both pathogens. Importantly, the combination treatment did not cause significant changes in the color characteristics, non-enzymatic browning, total phenolic content, or antioxidant capacity of the apple juice. These results demonstrate that the combined LA + H + US process is a promising intervention strategy for enhancing microbial safety of apple juice while preserving its quality.