Cross-food-cultural study of metabolite differences in Asian spicy fermented pastes using combined CIL-LC-MS and GC–MS analysis

Food culture, shaped by regional environments, ingredients, and fermentation systems, significantly influences the metabolites of fermented foods. Gochujang (GCJ) from Korea and Pixian-Douban (PXDB) from China are widely consumed spicy fermented pastes made from chili peppers and legumes, distinguishing them from hot sauces. However, how fermentation traditions lead to distinct metabolite profiles has not been systematically investigated. In this study, we performed the first comparative metabolomics analysis of 40 GCJ and PXDB samples using GC-MS and chemical isotope labeling LC-MS, a high-coverage method applicable to high-salt foods. We detected 461 non-volatile and 88 volatile metabolites, with 141 and 33 showing significant differences, respectively. GCJ had higher levels of sugars and short-chain fatty acid esters, whereas PXDB exhibited more amino acids and medium- to long-chain fatty acid esters. This comparative metabolomics elucidates the contribution of different food cultures in shaping metabolite profiles, and offers insights for developing innovative cross-cultural fermented foods.