Composition, structure and flavor mechanism of numbing substances in Chinese prickly ash in the genus Zanthoxylum: A review

Chinese prickly ash is known for producing a typical pungent sensation in Sichuan Cuisine. Accumulating evidence suggest a series of health benefits and pharmacological effects associated with prickly ash. Therefore, a systematic analysis of the composition, structural properties, detection, and flavor mechanism of numbing substances is highly necessitated to address their future application. Sanshool-based unsaturated amides are the primary cause of tingling. The numbing substances have poor stability and are prone to oxidation and decomposition reactions due to their highly unsaturated conjugated diene structures. Pungent sensations evoked by different sanshools are distinct, which is attributed to different mechanisms of interaction with membrane ion channels (TRPV1, TRPA1, and KCNK). In this paper, the composition, structural properties (such as isomerization, oxidation), detection, and flavor mechanism of numbing substances of prickly ash were summarized. The prospective application and future research direction of numbing substances in the prickly ash industry were also proposed.