Effects of drying methods on phenolic acids, flavonoids, and essential oils in three cultivars of Artemisia Argyi

This study systematically investigated how drying methods-non-defoliated sun drying (NSD), non-defoliated shade drying (NSHD), sun drying (SD), shade drying (SHD), hot-air drying (HD) at different temperatures, HD after fixation (FHD), and freeze drying (FD)-affect drying characteristics, flavonoid and phenolic acid content, essential oil yield, and composition of three <i>Artemisia argyi</i> cultivars: Qihui 1, Qiqing 1, and Qihuang 1. HD at 80 °C achieved the shortest drying time but the lowest essential oil yield. Non-defoliated drying remarkably increased phenolic acids and flavonoids. Essential oil profiles varied by cultivar and drying method. Compounds such as thujone, beta-selinene, and bornyl acetate emerged as key differentiating compounds. HD at 80 °C and FHD reduced oxygenated monoterpenes such as eucalyptol and thujone while increasing sesquiterpenes like caryophyllene and neointermedeol. In contrast, FD exhibited lower sesquiterpene hydrocarbons. Overall, our findings provide a foundation for optimizing the processing and application of <i>A. argyi</i> in healthcare and food sectors.