Liqin Zhu

Background: The Xinyu tangerine is a geographical indication agricultural product from Jiangxi province, China. During postharvest storage, nutrient loss and pathogen‐induced decay reduce fruit quality. The selection of appropriate preservatives is therefore important for maintaining postharvest quality. Previous studies have shown that tea saponin–cinnamaldehyde nanoemulsion (TS‐CNE) exhibits excellent antifungal activity and physicochemical properties suitable for citrus preservation. This study investigated the preservation efficacy and underlying mechanism of TS‐CNE in Xinyu tangerines using metabolomics. Results: The TS‐CNE treatment maintained fruit firmness and color, reduced the decay rate, decreased malondialdehyde (MDA) and H ₂ O ₂ accumulation in the peel, and increased the total phenolic, flavonoid, and anthocyanin content in the pulp. Untargeted metabolomic analysis showed that the levels of nobiletin, 4′‐methoxyflavanone, kaempferol, neoliquiritin, deoxyloganic acid, xanthohumol, melilotoside, d ‐arabinose, and epigallocatechin in the peel were higher in the TS‐CNE‐treated group than in the control group. Treatment with TS‐CNE can regulate pathways related to adenosine triphosphate‐binding cassette (ABC) transporters, flavonoid biosynthesis, and phenylpropanoid biosynthesis. Conclusion: The TS‐CNE treatment effectively preserved postharvest Xinyu tangerines. The preservation mechanism may involve reduced fruit decay during storage through increased accumulation of stress‐responsive metabolites, including flavonoids and phenylalanine, in the peel. These findings provide a theoretical basis for the development and application of TS‐CNE for postharvest disease control in citrus fruit. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

BACKGROUND: Fresh‐cut lettuce suffers diminished market value due to surface color degradation. This experiment investigated how sodium dehydroacetate (SD) delays discoloration in fresh‐cut lettuce by analyzing its effects on chlorophyll content and energy metabolism. RESULTS: The results demonstrated that a 0.1 g L ⁻¹ SD treatment maintained significantly higher L * values as well as lower a * and b * values. It also resulted in higher levels of chlorophyll a, chlorophyll b, and total chlorophyll. Furthermore, this treatment enhanced ATP and AMP production as well as energy charge, which was associated with the regulation of key metabolic genes including HK , PK , CS , IDH , OGDH , DLD , G6PDH , and 6PGDH . CONCLUSION: SD inhibited color change in fresh‐cut lettuce by increasing the gene expression of enzymes related to the Embden–Meyerhof–Parnas pathway, tricarboxylic acid cycle, and pentose phosphate pathway, increasing ATP production, and enhancing cellular energy level. These results indicate that SD application may represent a promising and cost‐effective strategy for preserving fresh‐cut lettuce. © 2026 Society of Chemical Industry.

Background: Hydrogen sulfide (H ₂ S) is an important gaseous signaling molecule in plants. It has been shown in our previous studies to maintain the storage quality of postharvest fruits at low concentrations. Navel orange, a fruit relatively high in vitamin C (ascorbic acid), experiences a rapid decline in this nutrient during postharvest storage, which reduces its nutritional value. However, the effect of H ₂ S on ascorbic acid (AsA) metabolism of postharvest navel orange from molecular level has not been reported. This study investigates the application of exogenous H ₂ S to regulate AsA metabolism in navel orange. Methods: Postharvest navel orange fruits were fumigated with 25 μl L ⁻¹ H ₂ S (air as control) for 30 min, and stored at 20 °C for 18 days. Fruit samples were collected every three days for analysis. The content of total AsA, and AsA was quantified. Concurrently, general quality parameters including weight loss, soluble solids content (SSC), and titratable acidity (TA) were also monitored. The expression levels of key genes involved in AsA metabolic pathway were analyzed using quantitative real-time PCR. Results: Fumigation with 25 μl L ⁻¹ H ₂ S significantly inhibited the increase in weight loss, maintained SSC, and delayed the decline in TA, total AsA, and AsA content in navel oranges during the 18-day storage period. The expression level of genes involved in the ASA metabolic pathway was modulated by H ₂ S treatment. Up-regulated genes of AsA biosynthesis ( CitPGI, CitPMM, CitGME, CitGGP, CitGPP, CitGalDH, CitGalLDH , and CitGalUR ) and regeneration ( CitMDHAR and CitGR ), as well as down-regulated genes of degradation ( CitAO ), all contributed to the increased AsA content during storage. Conclusion: Application of exogenous 25 μl L ⁻¹ H ₂ S effectively preserved the postharvest quality and nutritional value of navel orange. Further studies showed that H ₂ S primarily regulated the expression of genes involved in the AsA metabolism pathway in fruits via the L-galactose pathway, while cooperating with D-galacturonic acid, AsA cycle and degradation pathways to accelerate the synthesis and accumulation of AsA in fruits. These findings demonstrate that H ₂ S treatment helps maintain higher vitamin C content in navel orange by regulating key genes in the AsA metabolic pathway.

BACKGROUND: Soft rot caused by Botryosphaeria dothidea is a common disease in postharvest kiwifruit. Kiwifruit cultivars show varying susceptibility, but the molecular mechanisms underlying these differences are poorly understood. RESULTS: This study revealed that the ‘Jinyan’ (JY) kiwifruit cultivar exhibited greater resistance to B. dothidea and higher contents of total phenolics, flavonoids, and lignin compared to ‘Jinkui’ (JK). Transcriptome analysis revealed that 4011 genes were differentially expressed, with 1892 being upregulated and 2119 downregulated, between the resistant (JY) and susceptible (JK) kiwifruit cultivars on the first day post‐inoculation. GO and KEGG enrichment analyses indicated that differentially expressed genes (DEGs) were primarily associated with defense response functions and metabolic pathways. The DEGs related to phenylalanine metabolism ( DHQS , ADT , TAT , GOT2 , 4CL , CHS , CHI , CCR , F5H , BGLU , BGLU2 , BGLU4 , POD12 , POD55 ), calcium (Ca ²⁺ ) signaling pathway ( CALM2 , CML23 ), transcription factors ( WRKY22 , MYC2 ), plant hormone signaling pathway ( ATP7 , ETR , EBF1_2 , PP2C16 , SAPK2 ), and MAPK signaling pathway ( MKK4_5 ) were identified as key markers of resistance to B. dothidea . The expression patterns of these genes related to the key pathways were further validated by real‐time quantitative polymerase chain reaction; most of these genes show higher expression levels in JY than in JK. In total, these candidate genes and their associated pathways were found to be associated with kiwifruit resistance to B. dothidea ‐induced soft rot. CONCLUSION: This study revealed the functional genes and defense pathways involved in governing soft rot resistance in kiwifruit against B. dothidea . These results contribute to understanding the molecular differences in disease resistance between resistant and susceptible kiwifruit cultivars. © 2026 Society of Chemical Industry.

This study used glucose, fructose, maltose and dextran to explore the effects of different carbohydrates on the Maillard reaction of casein phosphopeptides (CPP). The color parameter results showed that heating time from 1 to 5 h led to brown color, which was consistent with the observed increased in browning intensity. Fourier transform infrared spectroscopy results verified that four carbohydrates reacted with CPP to produce Maillard conjugates. Fluorescence spectroscopy showed that the Maillard reaction changed the tertiary structure of CPP by decreasing the intrinsic fluorescence intensity and surface hydrophobicity compared with the CPP-carbohydrate mixture. At the same time, the Maillard reaction effectively improved the emulsifying properties, reducing power and DPPH radical scavenging activity of CPP. Furthermore, this study also found that glucose and fructose improved CPP more than maltose and dextran. Therefore, monosaccharides have good potential in modifying CPP via the Maillard reaction. Graphical Abstract

In the present study, Auricularia auricular polysaccharides (AAP) and Auricularia auricular proteins (AAPR) obtained from the waste products of Auricularia auricular were incorporated into pullulan (PUL) to obtain active packaging films/coatings. Results showed that incorporating AAP/AAPR into PUL-based films decreased their transparency, but increased the compactness, thermal stability, antioxidant, and antimicrobial properties. Adding 2% PUL films with 10%:10% of AAP/AAPR exhibiting good mechanical properties were applied to fresh-cut potatoes to avoid spoilage during eight days of storage, with significantly decreased in browning index, weight loss, microbial growth prevention and the total soluble solids was maintained. These results substantiated that pullulan containing AAP/AAPR as an active film/coating with antioxidant and antimicrobial properties has significant potential for maintaining safety and quality of fresh-cut potatoes and extending their shelf life.

Cucumber fruit is very sensitive to chilling injury, which rapidly depreciates their commodity value. Herein, the effect of fucoidan treatment on cucumber under cold stress were investigated. Fucoidan treatment of cold-stored cucumber alleviated the occurrence of chilling injury, delayed weight loss, lowered electrolyte leakage and respiration rate, and retarded malondialdehyde accumulation. Different from the control fruit, fucoidan treated fruit showed a high level of fatty acid unsaturated content, fatty acid unsaturation, and unsaturation index and increased ω-FDAS activity, along with upregulated expression levels of CsSAD and CsFAD genes. Fucoidan reduced the phosphatidic acid content and membrane lipid peroxidation, lowered the phospholipase D (PLD) and lipoxygenase (LOX) activity, and downregulated the expression levels of CsPLD and CsLOX genes. Collectively, fucoidan treatment maintained the integrity of cell membrane in cold-stress cucumbers. The results provide a new prospect for the development of fucoidan as a preservative agent in the low-temperature postharvest storage of cucumbers.