Yinmei Luo

China boasts abundant cultivated resources of pitahaya, with Guizhou Province being one of its core producing areas. Quality differences in red-fleshed pitahaya among local producing areas have not been fully clarified, and a standardized quantitative evaluation system for these differences remains lacking. This study seeks to identify the key factors influencing regional variations in quality and establish a comprehensive evaluation standard. In this study, 15 samples of red-fleshed pitahaya were collected from four major producing areas in Guizhou and used as research materials. Based on 15 quality characteristic indicators of the fruits, an analysis of quality differences and establishment of an evaluation system were carried out using multivariate statistical analysis. The results showed that 14 of the 15 quality indicators exhibited significant differences among pitahaya samples from different producing areas (p < 0.05), with the a* value being the sole exception. Cluster analysis classified the 15 samples into four groups. Principal component analysis (PCA) extracted four principal components, with a cumulative variance contribution rate of 81.07%, which clearly identified betacyanin, betaxanthin, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical scavenging rate, vitamin C, fruit shape index, and transverse diameter as the core evaluation indicators. This study systematically clarifies the differences in quality characteristics and the internal correlations among quality indicators of red-fleshed pitahaya from different major producing areas in Guizhou. It further provides an important scientific basis for pitahaya variety breeding, cultivation regulation, and market positioning in this region and fills the research gap existing in the field of comprehensive quality evaluation of pitahaya. This is of significant practical importance for promoting the standardized upgrading of local specialty fruit industries, enhancing the market competitiveness of products, and facilitating the high-quality development of the agricultural economy.

This research sought to analyze the nutritional composition of red-fleshed dragon fruit cultivated in various regions of Guizhou, focusing on samples obtained from three distinct production areas: Guanling (GL), Zhenfeng (ZF), and Luodian (LD). The findings revealed notable regional variations in nutritional constituents. Specifically, the GL samples exhibited the highest concentrations of betacyanin, vitamin C, total phenolics, and flavonoids; ZF samples demonstrated the greatest levels of soluble sugars alongside the lowest titratable acidity, whereas LD samples presented the opposite trend. Through non-targeted metabolomic profiling, a total of 4515 metabolites were identified. Multivariate analyses, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), indicated that metabolic differences corresponded with geographical origin. Furthermore, the OPLS-DA S-plot identified L-Histidine, Glu-Leu, Uridine, Leu-Glu, (2S)-2-Isopropylmalate, 2-amino-4-({1-[(carboxymethyl)-C-hydroxycarbonimidoyl]-2-[(3-hydroxy-2-methyl-4-oxobutan-2-yl}sulfanyl]ethyl)-C-hydroxycarbonimidoyl)butanoic acid, Leu-Leu-Ser-Pro-Tyr, 1,1′-bis(iso-13-carbon saturated acyl)-2-(iso-12-carbon saturated acyl)-3-[(9Z,11Z)-octadecadienoyl] cardiolipin. The eight characteristic metabolites under scrutiny can evidently differentiate dragon fruits from disparate regions and thus serve as potential markers for distinguishing their origins. This study offers a theoretical foundation for quality assessment, investigations into health benefits, and the sustainable advancement of the dragon fruit industry.

Peaches are highly susceptible to rapid deterioration and bacterial infection during postharvest transportation and storage, leading to significant losses. In order to maintain peach fruit postharvest quality and extend its shelf life, it is critical to understand the physiological changes in postharvest fruit and implement effective postharvest technologies. This paper reviews the major postharvest physiological changes in peach fruit, including respiration, ethylene, hormones, texture, sugars, amino acids, phenolics, and volatiles, analyzes the major postharvest peach fruit diseases and their control techniques (covering brown rot, soft rot, and gray mold), and summarizes approaches to extend the storage life of peach fruit and maintain quality through physical, chemical, and biological preservation techniques. This review evaluates the advantages and disadvantages of postharvest peach fruit preservation techniques by analyzing postharvest physiological and nutritional quality, and suggests future research directions aimed at ensuring peach fruit safety and quality assurance.