Effects of drying methods on the functional components and volatile organic compounds of Atractylodes chinensis

Different drying methods affect the functional components and the odor composition of medicinal plants. This study investigated the effects of sun drying (S), shade drying (Y), hot air drying (H), microwave drying (W), and freeze drying (D) on the functional components, odor response intensity, and volatile organic compound composition (VOCs) of Atractylodes chinensis using an electronic nose and GC-MS. Results showed that the content of functional components was higher in groups D and Y, and lower in group H. The electronic nose had the highest response values in the W1W (terpenes), W2W (organic sulfides), and W5S (nitrogen oxides) channels. The odor response intensity of groups D and Y was higher, while group H was lower, showing a strong positive correlation with VOCs. The VOCs of A. chinensis were mainly terpenoids, esters, phenols and ketones, and the contents of differential VOCs in group D were mainly atractylodin, atractylone, bornyl acetate, and other substances with woody, camphor, and bitter and hot odors. The biosynthesis of secondary metabolites and the biosynthesis of terpenoids and steroids were the main metabolic pathways. In conclusion, drying methods affect the functional ingredients and odor of A. chinensis. Hot air drying lost more of these functional components and odors, while more were retained through freeze drying.