Postharvest biocontrol agents in fruits and vegetables: mechanisms, applications, challenges, and future perspectives

Postharvest losses of horticultural produce, primarily due to microbial decay, remain a major challenge to global food security, accounting for 35-50% of production annually. To control this, overuse of synthetic fungicides has led to pathogen resistance, environmental contamination, and health concerns, prompting a shift toward sustainable biocontrol agents (BCAs). This review comprehensively examines the potential of microbial antagonists (yeasts, bacteria, and fungi), plant-based agents (essential oils and extracts), and natural compounds (e.g., chitosan, alginate, organic acids, etc.) for managing postharvest diseases in fruits and vegetables. Key mechanisms of action including competition for nutrients and space, production of antifungal metabolites and enzymes, biofilm formation, induction of host resistance, and volatile organic compounds are discussed in detail. Application strategies (pre- and postharvest), synergistic integrations with physical/chemical treatments, advantages over conventional pesticides, and major challenges (e.g., formulation stability, regulatory hurdles, and commercialization) are critically analyzed. Emerging approaches such as omics technologies, microbial consortia, genetic engineering, and nanotechnology offer promising avenues to enhance BCA efficacy and consistency. This review highlights successful examples and future perspectives of BCAs in postharvest diseases control setup and more importantly their co-applications together with other natural disease control methods and technologies. Finally, it underscores BCAs as viable, eco-friendly alternatives that can extend shelf life, preserve quality, and support sustainable postharvest management.