Dietary Sichuan pepper seeds are associated with changes in beef flavor-related precursors, putatively odor-active volatile candidates, and non-volatile metabolism

Dietary manipulation of flavor precursor metabolism may influence meat flavor-related chemistry. This study evaluated Sichuan pepper (Zanthoxylum bungeanum) seeds, an underutilized agro-industrial by-product rich in unsaturated fatty acids and bioactive compounds, as a potential feed ingredient associated with changes in beef flavor-related chemical profiles. Simmental cattle were fed diets supplemented with 0% (CK), 6% (T1), or 12% (T2) Sichuan pepper seeds, and the Longissimus thoracis et lumborum (LTL) muscle was analyzed using electronic tongue, fatty acid profiling, free amino acid analysis, HS-SPME-GC-MS, and non-volatile metabolomics.Compared with CK and T1, T2 was associated with higher levels of polyunsaturated fatty acids and flavor-related free amino acids, together with higher measured levels of several OAV-based putatively odor-active volatile candidates, including aldehydes, ketones, alcohols, and selected sulfur-containing compounds. Odor activity value analysis indicated that octanal, nonanal, 2,4-decadienal, 1-octen-3-one, and 1-octen-3-ol were representative aroma-relevant candidates under the present analytical conditions. Exploratory multivariate analysis suggested that Met and Phe showed relatively strong associations with volatile variation, while C18:2n6c, C18:3n3, and total PUFA were mainly associated with aldehydic and ketonic volatile candidates. Non-volatile metabolomic analysis further indicated that T2 was associated with changes in glycerolipid metabolism and redox-related pathways.These results provide preliminary evidence that dietary Sichuan pepper seed supplementation, especially at 12%, was associated with coordinated changes in beef flavor-related precursors, OAV-based putatively odor-active volatile candidates, and non-volatile metabolic features. Further studies with larger animal cohorts, adequately powered experimental designs, standardized cooking procedures, and sensory evaluation are needed to validate these findings.