Effects of thermal drying methods on characteristic volatile organic compounds in Rosa roxburghii pomace.

This study investigated the effects of various thermal drying methods on the characteristic volatile organic compounds (VOCs) of Rosa roxburghii pomace (RRP) using E-nose, HS-SPME-GC-MS, HS-GC-IMS, and multivariate analysis methods. The results revealed that HS-SPME-GC-MS and HS-GC-IMS identified 115 and 94 VOCs, respectively. HS-SPME-GC-MS demonstrated superior sensitivity in detecting esters, alcohols, and hydrocarbons, whereas HS-GC-IMS was more effective for aldehydes, and ketones. It was concluded that thermal drying methods significantly influenced the characteristic VOCs in RRP. Eleven characteristic VOCs, including leaf alcohol, were identified in fresh RRP, contributing to its rich aromatic profile. Microwave drying (MD) exhibited the highest loss rate of seven characteristic VOCs, such as ethyl hexanoate. Conversely, heat pump drying (HPD) showed the best retention rate of characteristic VOCs, generating new compounds such as hexanal and amyl acetate, thereby enriching the aroma profile of RRP. This research provides valuable insights for the processing of RRP.