• AEW, HVEF and AEW + HVEF treatments can inhibit softening. • AEW, HVEF and AEW + HVEF treatments can inhibit the activities of cell wall degrading enzymes. • AEW, HVEF and AEW + HVEF treatments can maintain cell membrane integrity. • AEW, HVEF and AEW + HVEF treatments can enhance antioxidant capacity. • AEW + HVEF treatment exhibits the best effect.

One main fraction of Selenium-enriched Pleurotus ostreatus (P. ostreatus) polysaccharide (Se-POP-1) was extracted and purified by DEAE-52 and sephadex G-100. Se-POP-1 was an approximate homogenous polysaccharide with an average molecular weight of 1.62 × 10⁴ Da, and mainly composed of glucose, mannose and galactose, with molar ratio of 5.30:1.55:2.14. The absorption peaks at 941 cm⁻¹ and 1048 cm⁻¹ in FT-IR analysis were ascribed as C-O-Se and Se=O bonds. Pr-treatment of Se-POP-1 (400 μg/mL) increased the cell survival of H₂O₂-stimulated PC12 cells and inhibited intrinsic apoptosis and oxidative stress in H₂O₂-stimulated PC12 cells via limiting DNA degradation and decreasing the reactive oxygen species (ROS) generation. In addition, up-regulation of anti-apoptotic protein Bcl-2, down- regulation of pro-apoptotic protein Bax, cleaved caspase 3, and cytochrome c were also observed. Se-POP-1 presented an obvious effect to alleviate oxidative damage and apoptosis in PC12 cells induced by H₂O₂. Therefore, Se-POP-1 possessed potent antioxidant and biological activities with the ability to prevent oxidation via scavenging ROS and free radicals in cells. It could be developed as organic selenium dietary supplement and functional food.

The yellowing of green broccoli is a phenomenon that indicates a serious deterioration of freshness. The green broccoli has been more popular than the yellow one, with its higher nutritional value. Chitosan coating has been employed in vegetables for green-keeping, owing to its functions of regulating chlorophyll metabolism and antioxidant defense. Furthermore, selenium was commonly utilized in the pre-harvest of fruit and vegetables as an antioxidant and chlorophyll regulator. However, there have not yet been concerns about the effects of selenium-chitosan on vegetable yellowing. This study first investigated the impact of selenium-chitosan on the quality of fresh-cut broccoli yellowing during storage by analyzing the chromatic aberration and phytochromes. Additionally, then, the gene expression related to chlorophyll metabolism (POR, CAO, HO, CHLI, NYC1), carotenoid metabolism (VDE, CCS, LCYE, ZEP, HYD), and transcription factors (NAC92, ZIPPER, bHLH66, APL, PIF4) were analyzed using the RT-qPCR technique. Test results showed that treatment with selenium-chitosan can slow down the reduction in h° (Hue angle values) and reduce ethylene release rate and respiration intensity. Via the molecular approach, it was further identified that this treatment could inhibit chlorophyll degradation and carotenoid biosynthesis, accompanied by lower expression levels of heme oxygenase (HO), chlorophyllide A oxygenase (CAO), violaxanthin de-epoxidase (VDE), β-carotene 3-hydroxylase (HYD), NAC92, basic leucine zipper (ZIPPER), bHLH66, PIF4 and APL, and higher expression levels of magnesium chelatase subunit I (CHLI) and lycopene ε-cyclase (LCYE) genes. This work can be used to explore the molecular mechanism of selenium-chitosan in inhibiting the yellowing of fresh-cut broccoli. This study will be of great economic importance in marketing and export by increasing the shelf life of fruits and vegetables.

Root mustard is plentiful in vitamins and minerals but shrivels and molds easily. In this study, freshly harvested root mustard was fumigated with various concentrations of 1-Methycyclopropene(1-MCP) (1 µL L⁻¹, 1.5 µL L⁻¹, and 2.0 µL L⁻¹) for 24 h and stored at ambient temperature (17 ± 1 °C) for 35 d. Our data showed that 1-MCP fumigation had a striking preservation effect on maintaining weight loss, fruit firmness, lignin, Vc content, and moisture content, inhibiting respiratory intensity and ethylene release rate, as well as decreasing cell permeability and malondialdehyde (MDA) accumulation and maintaining cell membrane integrity of root mustard. In addition, lipoxygenase (LOX), pyruvate dehydrogenase (PDH), and polyphenol oxidase (PPO) activities were significantly reduced throughout the storage period. In contrast, the activities of succinate dehydrogenase (SDH), superoxide dismutase (SOD), ascorbate peroxidase (APX), phenylalanine deaminase (PAL), and peroxidase (POD) remained at high levels. Results showed that 1-MCP treatments were effective in maintaining the quality of root mustard, and the preservation effect of 1.0 μL·L⁻¹ 1-MCP was better than other concentrations of 1-MCP. This study could serve as a theoretical reference for root mustard preservation.

Postharvest Hupingzao jujubes are prone to softening and reddening during storage. To investigate the influence of glycine betaine on the fruit quality of cold-stored jujubes, the jujubes were immersed in a 15 mmol L⁻¹ glycine betaine solution for 10 min, then stored at 0 ± 1 °C for 100 days. The relevant physical and chemical quality indicators were determined every 20 days. The results indicated that glycine betaine treatment effectively maintained fruit firmness, reduced weight loss, slowed down the respiration rate, and lessened the redness of the fruit peel. Compared with the control group, the malondialdehyde and H₂O₂ contents in glycine betaine-treated fruit decreased by 26.65% and 9.04%, respectively. In addition, glycine betaine treatment elevated the contents of non-enzymatic antioxidants, including ascorbic acid, total flavonoids, total phenols, and proanthocyanidins. Meanwhile, the activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase in the jujube fruit were enhanced after glycine betaine treatment. In conclusion, glycine betaine treatment preserved the quality of the jujube fruits by enhancing the antioxidant metabolism. The results establish a scientific basis for the potential application of glycine betaine in postharvest fruit preservation, providing a strategy to mitigate storage-related quality deterioration.