Terpenoids in Baijiu: sensory evidence, formation pathways and analytical confidence

Terpenoids are structurally diverse, isoprene-derived compounds, several of which are volatile and contribute to aroma complexity in fermented foods. In Baijiu, although less abundant than esters and alcohols, low-threshold terpenoids such as β-damascenone, linalool and α-terpineol can shape floral, fruity, herbal and woody notes. Current evidence links their occurrence to raw materials, microbial transformation during solid-state fermentation, and reactions during distillation, storage and aging, but cross-study comparison remains limited by inconsistent flavor types, sampling designs, analytical platforms and identification criteria. This review distinguishes reported occurrence from sensory validation and evaluates formation pathways, application relevance and analytical confidence of Baijiu terpenoids. Key gaps include incomplete annotation, poor quantitative comparability, weak pathway validation and limited sensory confirmation. Addressing these gaps will require targeted and untargeted volatilomics, multi-omics, isotope tracing, controlled fermentation, and odor activity, omission and recombination tests to strengthen the mechanistic basis for flavor regulation and Baijiu quality assessment.