Hangjun Chen’s research while affiliated with Zhejiang Academy of Agricultural Sciences and other places

Transitioning to safe, nonthermal, and edible strategies for maintaining fruit and vegetable (F&V) quality, reducing postharvest losses (up to 55% annually), and ensuring food security requires extensive research and innovation in postharvest technologies. This review aims to provide an updated understanding of edible coatings or films (ECF), focusing on their role in reducing F&V postharvest losses, based on data from the last 40 years retrieved from the Web of Science database. The global ECF research network is represented by publication trends, majorly researched F&V, key research areas, influential and emerging authors, and global research ranking. The role of ECF in preserving F&V quality has been assessed by examining critical quality parameters, including weight loss, total soluble solids, titratable acidity, ripening, softening, sensory and organoleptic characteristics, browning, chilling injury, and microbial safety. Furthermore, recent advancements in ECF formulations, including nanoscale ingredients and application methodologies, have been critically discussed. Sources, categorization, application strategies, mode of action, functional properties, sustainable development goals (SDGs), challenges, safety, legislations, and future perspectives in ECF research have also been discussed. The key findings indicate that China (20.34%) and the USA (9.94%) are the leading countries in ECF research. Studies have demonstrated ECF's potential in reducing F&V postharvest losses by maintaining quality parameters through advanced nanoscale compositions and methodologies. Notably, ECF research supports multiple SDG targets, including SDGs 2, 3, 8, 9, 12, 13, and 15. Future ECF research should explore 3D‐printed coatings, nonflavor‐altering components, and potential crosslinking agents to enhance F&V quality and reduce postharvest losses.

Kiwifruit is easy to ripen and soften after harvest. Tea tree oil (TTO) has important application value in postharvest fruit preservation. However, the effect of TTO on kiwifruit fruit ripening, quality maintenance and energy metabolism, has not been studied. In this research, we found that TTO could delay ‘Xuxiang’ kiwifruit ripening, and keep good quality even after 18 days of storage. In three different concentrations of TTO treatments, 2.0 mL L⁻¹ TTO has the best preservation effect on kiwifruit. TTO slowed down the softening and degreening, reduced the respiration intensity and delayed the peak of respiration. Moreover, TTO also delayed the decrease of total sugar, titratable acid (TA) and vitamin C (Vc). The fruit treated with TTO kept higher levels of ATP, ADP and energy charge (EC), and higher activities of succinate dehydrogenase (SDH), cytochrome C oxidase (CCO) and ATPase. Correlation analysis results showed that kiwifruit ripening was closely related to nutritional quality and energy metabolism. To summarize, TTO could delay kiwifruit ripening and keep fruit quality by maintaining higher energy level and activities of energy metabolism‐related enzymes during the late storage. This study will provide theoretical and technical support for kiwifruit preservation.

The bioplastic film polyvinyl alcohol (PVA) /chitosan (CS), i.e., PC, formed by blending PVA with CS, exhibits excellent antioxidant properties and biodegradability. However, it lacks ultraviolet (UV) blocking ability, limiting its capacity to protect adipose-rich foods from photo-oxidation. Lignin possesses remarkable UV shielding ability that inhibits food photo-oxidation and extends shelf-life. However, the dark brown color of lignin negatively impacts the film color and transparency. To address these restrictions, this study incorporated acetylated lignin (ALG) loaded with halloysite nanotubes (HNTs) into conventional PC films (PC-HALG), resulting in a significant reduction in the color intensity of the film by almost 255.3 %, i.e., almost being colorless. The UV-A and UV-B shielding capacities of the PC films were increased by 1347 % and 617 %, respectively. Thus, ALG provided the PC films with excellent UV shielding capacity while reducing their color intensity and maintaining high transparency. Additionally, the loading of HNTS reduced lignin agglomeration, contributing to the improvement in transparency and enhancement of UV shielding effects in PC films. Furthermore, the PC-HALG film retained and even enhanced the biodegradability of the PC film, which exhibited degradability within one week. Freshness preservation experiments confirmed that the oxidation of pecan oil covered with the PC-HALG film under UV irradiation was reduced by 81.3 %–92.2 %. These findings suggest that this bioplastic film can be used in visually displaying food products while preventing their photo-oxidation. Mechanical properties, thermal stability, barrier properties, and antioxidant properties of the developed PC- HALG film were also characterized

Fresh fruits and vegetables (F&V), with their attractive sensory, flavors, and nutrients, occupy a highly valuable part of people's daily diet. Plenty of postharvest studies have focused on the effects of preservation techniques on the edible quality and nutrients of F&V. Therefore, it is crucial to summarize the research methods of those quality and nutritional indicators for F&V. This work reviews the measurement and analysis methods on these parameters of postharvest F&V which have been validated by numerous publications, including firmness, sugars/acids, pigments, phenols, etc. Importantly, some instruments are involved in these experimental methods, such as firmness tester, spectrophotometer, gas chromatograph, and so on. Furthermore, some promising analysis methods in the past decades combined with advanced technologies are also raised in our discussion. This work is expected to provide guidance and normative significance for future research on quality assessment, preservation, and processing characteristics of F&V.

During postharvest storage, the metabolism of cell wall components greatly affects the quality of fruits and vegetables. Utilizing 1‐methylcyclopropene (1‐MCP) as an ethylene receptor inhibitor and modified atmosphere (MA) separately or in combination (1‐MCP+MA) were investigated for their impact on Zizania latifolia quality during postharvest storage. The treatments effectively controlled firmness increase, color degradation, and reductions in soluble protein, reducing sugar, total phenol, and ascorbic acid content, with the combined 1‐MCP+MA showing the most significant effect. These treatments also moderately changed soluble pectin, protopectin, cellulose, and hemicellulose content, preserving the activities of essential enzymes and the expression of enzyme genes. The combined treatment particularly demonstrated superior preservation capabilities, holding promise for reducing postharvest losses and maintain the storage quality of edible produce, offering insights for efficient postharvest storage and freshness maintenance of fruits and vegetables.

The lotus seed embryo, known as “Plumula nelumbinis,” holds significance in Chinese culture as a traditional medicinal and edible herb rich in beneficial bioactive compounds like flavonoids, alkaloids, and polyphenols. Using ultrahigh‐performance liquid chromatography‐quadrupole‐exactive Orbitrap mass spectrometry, we meticulously analyzed the total flavonoids in Plumula nelumbinis (PNF) sourced from Hangzhou's West Lake. Our investigation preliminarily identified 29 flavonoid compounds, including 21 flavonoid O‐glycosides, five flavonoid C‐glycosides, and three aglycones, through comparisons with standards and literature references. Subsequent cellular anti‐inflammatory experiments using lipopolysaccharide (LPS)‐induced RAW264.7 cells demonstrated that treatment with 300 μg/mL of lotus seed flavonoids significantly reduced inflammatory factors' production, such as nitric oxide, prostaglandin E2, tumor necrosis factor, interleukin‐6, and interleukin‐1β. Additionally, PNF effectively lowered intracellular reactive oxygen species levels, mitigated LPS‐induced cell apoptosis, and nuclear translocation of nuclear factor‐κB (NF‐κB) p65 protein, collectively suppressing the NF‐κB p65 inflammatory pathway and demonstrating potent anti‐inflammatory properties. Crucially, the observed gene expression patterns of inflammatory factors aligned with their respective protein secretion levels. This study provides a comprehensive exploration of lotus seed flavonoids' anti‐inflammatory potential, highlighting their significance in potential therapeutic applications and laying the groundwork for future advancements in related functional foods.