Integrated application of e-nose, e-tongue, GC–MS, and LC–MS/MS reveals volatile profile and metabolic pathway variations of Fuji apples from Aksu and Yili producing regions

Fuji apples from the Aksu production region are highly favored by consumers. In contrast, those from the Yili region exhibit marked differences in flavor profiles, the mechanisms of which remain unclear. This study investigated the flavor variations in Fuji apples from these two producing regions by integrating analyses of both volatile and non-volatile metabolites. The results from the electronic nose and electronic tongue indicated that the sensors for W1W, W2W, W5S, and sourness exhibited the most pronounced responses in Fuji apples from the Aksu region. 16 key aroma-active compounds and 143 non-volatile differential compounds were identified. The aroma of Fuji apples was predominantly characterized by esters and terpenoids, with representative compounds including hexyl 2-methylbutanoate, 3-Methylbutyl acetate, 2-Methylbutyl acetate, and citronellol. These compounds collectively impart fruity, sweet, and floral notes. Furthermore, the peel of the ‘Yanfu 6’ cultivar from Aksu exhibited distinctive rosy and woody notes, while its pulp possessed a pineapple-like aroma. KEGG pathway enrichment analysis demonstrated that amino acid metabolism, fatty acid metabolism, and phenylalanine metabolism are interconnected. This study provides valuable insights for systematically understanding the formation of characteristic aromas in Fuji apples from the Xinjiang region