Research progress of postharvest in-situ packaging of fruits and vegetables: realization form, functional mechanism and future trend

Postharvest losses of fruits and vegetables (F&W) remain a critical challenge, with packaging serving as an essential means for preservation. Among various packaging approaches, in-situ packaging, which constructs functional layers directly on produce surfaces, has emerged as a research hotspot in postharvest preservation due to its excellent conformability, precise release control, and environmental sustainability as a highly efficient packaging form. This review systematically summarizes recent advances in in-situ packaging for F&W. It first elucidates the core concept and distinctive advantages of in-situ packaging over conventional approaches, followed by a comprehensive review of 3 major implementation forms (coatings, fibrous membranes, and hydrogels) and their fabrication techniques. Then, it systematically analyzes the multifunctional preservation mechanisms of in-situ packaging, including antimicrobial activity, antioxidant protection, microenvironment regulation, physical cushioning, and intelligent monitoring. Finally, current bottlenecks in material adaptability, scalable fabrication, cost control, safety evaluation, and long-term stability are discussed, and future directions are outlined from 5 perspectives: efficient film-forming technologies, green process integration, intelligent responsiveness, self-healing capability, and digital interconnection. This review provides a systematic reference for both technological innovation and industrial application of in-situ packaging in postharvest preservation.