Analysis of flavor characteristic of mulberry brandy with different aging methods by GC-IMS

The volatile flavor components of mulberry brandy with the addition of vanilla and different contents of oak chips during the aging were detected and analyzed by gas chromatography ion mobility spectrometry (GC-IMS). The results were analyzed by fingerprinting, principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA), to compare the differences between the volatile flavor components of mulberry brandy aged by different methods. The results showed that a total of 61 volatile flavor components were detected and characterized in three types of mulberry brandies, including 27 esters, 10 aldehydes, 7 ketones, 13 alcohols (excluding ethanol), 1 acids and 3 others. Fingerprinting and PCA results showed that the 2 wine samples with the addition of vanillin and oak chips were similar in flavor substances types and contents. Based on variable importance in projection (VIP) values, 24 key differential volatile compounds (VIP>1) were screened by the PLS-DA model. The sensory evaluation results indicated that the appropriate addition of vanilla and heavily roasted oak during the aging process was beneficial in upgrading the quality of the first-grade mulberry brandy to the premium grade.