Varietal-dependent flavor dynamics in Piper nigrum L. under thermal processing: Unraveling key aroma compounds and processing adaptability mechanisms.

This study comprehensively evaluated the changes in flavor and quality of four pepper varieties (White Dapo, Black Dapo, White Kampot, Black Kampot) under roasting and boiling conditions. The analyses encompassed color difference, piperine content, glutamic acid levels, volatile compounds, sensory traits, and multivariate statistical analyses for identifying key flavor compounds. The results demonstrated that both pepper variety and processing method jointly determined the final quality, with black peppers being more suitable for high-temperature roasting (140-160 °C) and better retaining piperine, while white peppers exhibited superior quality when roasted at lower temperatures (100-140 °C). Boiling for 30 min was optimal for releasing piperine, glutamic acid, and volatiles such as terpenoids, ketones, and β-caryophyllene. Sensory evaluation revealed that black peppers had stronger pungency and umami flavors, while Kampot varieties demonstrated superior flavor stability. VIP/OAV analysis identified specific key flavor compounds-including terpenoids (β-caryophyllene), acids (acetic acid), and aldehydes (nonanal)-that were primarily responsible for the sensory differences between pepper varieties and processing treatments. These findings provide valuable insights for targeted processing strategies aimed at optimizing the flavor profiles of different pepper varieties.