Effect of tempering treatment on drying properties, physicochemical characteristics, VOCs of Amomum villosum Lour

The Zingiberaceae family encompasses a diverse range of species, including Alpinia oxyphylla Miq, Amomum tsao-ko Crevost et Lemaire, and Amomum villosum Lour. Among them, Amomum villosum Lour (AVL) is particularly significant due to its high economic and medicinal value in China. The drying method employed during the initial processing of fresh AVL plays a pivotal role in determining product quality. However, the shell expansion and subsequent breakage during the drying process adversely affect the final quality. To address these issues, this study introduced a three-stage drying (TD) method, examining the effects of the tempering intervals on drying characteristics, physicochemical properties, and volatile organic components of AVL. The results revealed that interval tempering not only reduced the total heat treatment time but also significantly improved drying efficiency. Compared to hot air drying (HD), AVL subjected to three-stage drying exhibited a denser fruit structure, leading to enhanced storage stability and a higher concentration of volatile components, notably alkenes (54%) and camphor (15.43%). These findings underscore the potential of interval tempering as a cost-effective and efficient strategy for drying fresh Chinese traditional medicinal plants, offering a promising alternative to conventional methods.