Valid evaluation of volatile flavor composition of fresh and dehydrated Tuber indicum with different drying methods

Abstract

The effects of three drying methods on volatile flavor components of Tuber indicum were studied. After hot air drying (AD), vacuumdrying (VD), and vacuum-freeze drying (FD), flavor components were analyzed by headspace solid phase microextraction GC-MS and electronic nose (E-nose). The results from GC-MS showed that aldehydes (54.8%) and alcohols (31.4%) are the two dominant chemical species in fresh T. indicum and eight carbon (C8) compounds including 1-octen-3-ol, 3-octanol, n-octanol, 3-octanone. After dehydrating, C8 compounds, aldehyde, and ester components reduced, while alkanes, heterocyclic, and sulfur components were produced. Multivariate statistical analysis of the GC-MS revealed the components responsible for the chemical differences between fresh and three drying samples. In addition, E-nose could discriminate fresh and three drying samples. The result obtained by E-nose showed good identity compared with GC–MS. Therefore, FD was the optimal dehydrating method to preserve Tuberaceae with the most retained fresh flavor.