Effects of Drying Method on the Physicochemical Properties and Volatile Organic Compound Profiles of Panax...

Panax quinquefolius L. (PQ) is used extensively in healthcare and daily diets, requiring post-harvest drying for preservation and distribution. The effects of hot air drying (AD), vacuum drying (VD), microwave drying (MD), freeze drying (FD), sun drying (SUD), and shade drying (SHD) on the physicochemical properties of PQ were examined, and the volatile organic compounds (VOCs) were analyzed using electronic nose (E-nose), gas chromatography-ion mobility spectroscopy (GC-IMS), and headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). MD had the lowest unit energy consumption, and FD preserved the color and structure of fresh PQ. VOCs analysis showed terpenes, aldehydes, alcohols, acids, and esters as major volatiles. The GC-IMS results showed that MD had the highest VOC content, while the GC-MS results suggested that SUD and SHD had the highest VOC content. Both sets of results indicated that FD had the lowest VOC content. Furthermore, 27 differential VOCs were screened, and five key flavor VOCs and two flavor-contributing VOCs were selected by calculating the relative odor activity value (ROAV). Aldehyde compounds (3-methylbutanal, hexanal, and (E)-2-octenal) exhibit higher concentrations and ROAV among all flavor compounds, potentially indicating their greater contribution to flavor formation. This study provides a basis for selecting drying methods for PQ based on product quality and flavor. PRACTICAL APPLICATIONS: This study discusses the effect of different drying treatments on the physicochemical properties, volatile components, and flavor. The finding provides an important basis for selecting a suitable drying method for PQ and confirms that combining GC-IMS with GC-MS is a suitable approach for comprehensive flavor analysis.