Zanthoxylum armatum DC. (Z. armatum) is a versatile plant species valued for its aroma oil and nutritional components. However, the variability of chemical composition in Z. armatum fruits in the field remains largely unknown, and it is still unclear how harvest parameters affect the aroma and nutritional quality of the fruits. To address this gap, Z. armatum fruits from varying harvest times, tree ages, and fruiting positions were analyzed for physicochemical properties, nutrients, minerals, aroma profiles, and antioxidant activity. A quality assessment method was developed based on key Z. armatum fruit parameters. Results showed significant differences in the size, weight, total phenol, flavonoid and sanshool content of Z. armatum fruit from different harvest parameters. Z. armatum fruits contained abundant minerals, showing diverse harvest-condition variations. In vitro antioxidant assays showed higher ABTS/DPPH scavenging activity and reducing capacity (23–54 mg/g). HS-SPME-GC-MS identified 64 aroma compounds, encompassing terpenes, alcohols, etc. Linalool was the predominant constituent (46.65%). PLS-DA and Volcano plot analyses highlighted significant differences in VOCs among harvest times and tree ages, while fruit positions showed minimal impact. The Mantel test identified aroma-active compounds associated with antioxidant activity. These findings facilitate a science-based harvesting strategy to standardize Z. armatum fruit quality and marketability.

Carbon (C), nitrogen (N) and phosphorus (P), and non-structural carbohydrates (NSCs) are basic nutrients and energy sources for flower development. In this study, the morphological traits, C, N, P, and NSC concentrations, and C:N:P ratios in pistil, stamen, and petal of C. maxima flower at three phenophases (BBCH54, BBCH59, and BBCH61) were comparatively analyzed. Morphology diverged markedly among the three phenophases, whereas relative water contents were stable. C, N, P, and NSC showed larger variations at three phenophases and parts in C. maxima flower. Maximal C:N, C:P, and N:P occurred in pistils, pistils, and petals at BBCH61, respectively. C:N:P stoichiometry was the most responsive to ontogeny, indicating development-specific elemental storage and biomass partitioning of C. maxima flowers. NSC contents (glucose, fructose, sucrose, starch) differed significantly among organs and phenophases, and peak NSC appeared in the pistils at the three phenophases. High correlations between NSCs and C:N:P ratios suggested coordinated resource allocation. Correlation analysis showed that significant differences occurred at three phenophases for the accumulation and allocation of C, N, P, and NSCs. Principal component analysis (PCA) ordinated samples along PC-1 (44.2%) and PC-2 (24.4%), cumulatively explaining 68.6% of variance, corroborating development- and organ-dependent divergence. These data elucidated the intricate regulatory dynamics of nutrient contents among the three parts during the flower development of C. maxima, providing a robust quantitative framework for targeted nutrient management strategies.