Highly prized for its unique taste and appearance, pitaya is a tasty, low-calorie fruit. It has a high-water content, a high metabolism, and a high susceptibility to pathogens, resulting in an irreversible process of tissue degeneration or quality degradation and eventual loss of commercial value, leading to economic loss. High quality fruits are a key guarantee for the healthy development of economic advantages. However, the understanding of postharvest conservation technology and the regulation of maturation, and senescence of pitaya are lacking. To better understand the means of postharvest storage of pitaya, extend the shelf life of pitaya fruit and prospect the postharvest storage technology, this paper analyzes and compares the postharvest quality changes of pitaya fruit, preservation technology, and senescence regulation mechanisms. This study provides research directions for the development of postharvest storage and preservation technology.

The objective of this study is to investigate the effects of carvacrol on the postharvest storage quality and cell wall metabolism of the ’Guichang’ kiwifruit. For this purpose, the ’Guichang’ kiwifruit is selected as the test material and treated with 0.03 mg/mL of a carvacrol solution for dipping. The storage quality and cell wall metabolism of the fruit are then evaluated under ambient conditions (20 ± 1 °C). The results indicate that treatment with carvacrol effectively reduces the postharvest respiration rate and weight loss in the kiwifruit, while preserving the levels of vitamin C (VC), soluble protein, total phenols, flavonoids, soluble solids, solid–acid ratio, and soluble pectin. Additionally, it delays the decline in the starch content and mitigates the increase in soluble sugars. Furthermore, carvacrol significantly decreases amylase activity and inhibits the elevation of polygalacturonase (PG), pectin methylesterase (PME), β-galactosidase (β-Gal), and cellulase (Cx) activity. Consequently, this treatment effectively maintains fruit firmness as well as protopectin (PP) and cellulose content at elevated levels. A correlation analysis shows that firmness is highly and negatively correlated with the cell wall degrading enzymes PG, PME, β-Gal, Cx, and α-L-Af, with R values of −0.88, −0.83, −0.98, −0.94, and −0.93, respectively. The negative correlation values for the control group are all lower than 0. In conclusion, treatment with carvacrol effectively preserves a high level of postharvest ripening quality in the kiwifruit, attenuates the metabolic processes of the cell wall, and delays fruit softening and senescence.

‘Fengtang’ plum, a specialty fruit variety from Guizhou Province, is characterized by its high total soluble solids (TSS) and well-balanced sugar–acid ratio. In this study, widely targeted metabolomics (UPLC-MS/MS) combined with multivariate statistical analysis was employed to systematically monitor dynamic changes in sugar–acid metabolism across three critical developmental stages of the fruit: pre-veraison stage (PR), veraison stage (VR), and full veraison stage (FR). The aim was to elucidate the intrinsic mechanisms underlying high sugar accumulation. The results indicated that TSS content increased significantly during fruit maturation, reaching up to 17%, while titratable acid (TA) content continuously decreased. Consequently, the sugar–acid ratio rose substantially from 21.5 at the early stage to 43.8. A comprehensive metabolomic analysis led to the identification of 2003 metabolites, with notable emphasis on phenolic acids, amino acid derivatives, sugars, and other major classes. Key metabolic pathways from the KEGG database were also examined. Enrichment analysis of these pathways revealed that central metabolic routes—including fructose and mannose metabolism, galactose metabolism, and the tricarboxylic acid (TCA) cycle—played crucial roles in the dynamic accumulation of sugar–acid components. Notably, oligosaccharides such as cottonseed sugar and pine trisaccharide were observed to accumulate significantly during fruit ripening. These findings clarify the metabolic foundation and mechanisms contributing to the high sugar quality of ‘Fengtang’ plum, thereby providing a theoretical basis for precise fruit quality regulation and the optimization of post-harvest preservation strategies.

Vegetable soybean is a major crop in China with significant economic value. However, it is prone to yellowing and browning during postharvest storage, which reduces quality, marketability, and competitiveness. ‘Tongdou No. 6’ was used to evaluate postharvest quality preservation through combined cold shock treatment and nanocomposite polymer packaging. The results demonstrate that the combined treatment effectively slows the green-to-yellow color change by significantly reducing chroma a* value, weight loss, and chlorophyll degradation. Additionally, it markedly reduces the accumulation of malondialdehyde (MDA) and reactive oxygen species (H₂O₂ and O₂·⁻), while decreasing the activities of polyphenol oxidase (PPO) and peroxidase (POD). The treatment also significantly enhanced the levels of antioxidant compounds, including ascorbic acid (AsA), total phenolics, and total flavonoids, and boosted the activities of key antioxidant enzymes—ascorbate peroxidase (APX), superoxide dismutase (SOD), phenylalanine ammonia-lyase (PAL), and catalase (CAT). Moreover, the combined application of cold shock and nanocomposite polymer packaging significantly enhanced the scavenging capacity against DPPH and hydroxyl (OH⁻) radicals. Overall, combining these two techniques effectively delayed senescence-related discoloration by activating the antioxidant system, regulating ROS metabolism, and reducing oxidative damage. This approach is highly effective in maintaining postharvest quality and offers a promising solution to the storage-induced deterioration of vegetable soybeans.