Research Progress on the Pungency of Capsaicinoids

Capsaicinoids are a class of alkaloids with vanillyl and medium/long-chain fatty acid amide structures, and capsaicin and dihydrocapsaicin are the most pungent capsaicinoids. Some capsaicinoids activate related receptors and induce the transmission of nociceptive and thermic neural signals, leading to pungency perception. The Scoville scale is the most common method for pungency evaluation. However, it cannot reflect the actual pungency of samples because the result is only correlated with the contents of pungent substances. Time-intensity approach provides several quantitative indexes to measure pungency and is more useful. In addition to increasing the content of capsaicinoids, using aqueous-based carrier, increasing the temperature, sensitization, and some sensory stimuli can enhance the pungency perception of capsaicinoids, which deserves special attention in sensory evaluation. In summary, this paper reviewed the structure and distribution of capsaicinoids, mechanism and evaluation methods for pungency perception, as well as factors that may influence the perception of spiciness. This article provides some reference for the pungency prediction and development of spicy foods.