Unraveling geographical heterogeneity and spatial distribution of Long pepper fruits: An integrative analytical perspective

Long pepper (LP), a traditional spice, has dried fruits rich in bioactive phytochemicals with nutritional and health benefits. However, the geographic heterogeneity and spatial distribution of key bioactive compounds remain poorly understood, limiting quality standardization and practical applications. This study integrated multidimensional identification, metabolomics, antioxidant evaluation, and spatial metabolomics to systematically examine the geographical variations and distribution patterns of potential quality markers. Initially, 177 compounds were tentatively identified by conventional GC–MS library matching, which was further refined using a multidimensional strategy, leading to the accurate characterization of 113 volatile constituents, with 53 newly reported compounds in LP fruits. Chemometric and correlation analyses revealed 12 significantly differentiated metabolites associated with environmental factors. Six alkaloids were screened as potential quality markers using antioxidant assays and molecular docking. Spatial metabolomics further illustrated their macro- and micro-distributions. This study provides a scientific basis for the quality evaluation and functional food development of LP fruits.