Emerging frontiers in juice processing: The role of ultrasonication and other non-thermal technologies in enhancing antioxidant capacity and quality of fruit and vegetable juices

Fruit and vegetable juices (FVJs) are widely consumed due to their rich profile of vitamins, minerals, and bioactive compounds, particularly antioxidants, which play a critical role in mitigating non-communicable diseases. However, conventional thermal processing methods, while effective in microbial inactivation, significantly compromise the antioxidant capacity (AC), sensory attributes, and nutritional quality of FVJs. In response to growing consumer demand for minimally processed and functionally enriched juices, non-thermal technologies (NTTs) have emerged as promising alternatives. This review comprehensively evaluates recent advancements (2015-2024) in non-thermal processing methods-including ultrasonication, cold plasma, irradiation, and pulsed electric fields-and their influence on the AC and overall quality of FVJs. NTTs enhance juice quality by inducing abiotic stress, activating antioxidant biosynthesis pathways, inactivating spoilage enzymes, and facilitating the release of bound phytochemicals. The review highlights the mechanistic insights, optimal processing parameters, and synergistic effects of combined NTT approaches on juice matrix, antioxidant retention, and enzymatic stability. Furthermore, it discusses the scalability, energy efficiency, and environmental sustainability of these technologies in comparison to traditional thermal methods. Despite promising outcomes at the laboratory scale, commercial adaptation of NTTs faces challenges such as equipment cost, process optimization for diverse juice matrices, regulatory acceptance, and consumer perception. Future directions emphasize the need for multidisciplinary collaborations to decode antioxidant metabolism, validate safety parameters (e.g., ROS/RNS residues), and develop industry-ready, cost-effective, and safe processing units. This review stands out by providing mechanistic insights, comparative efficacy, and optimization strategies of various NTTs specifically aimed at enhancing antioxidant capacity in fruit and vegetable juices. It also integrates a critical discussion on industrial scalability, regulatory challenges, and future biosynthetic pathway investigations, distinguishing it from prior reviews.