Effects of Different Toasting Degrees of Lychee Wood on the Flavor of Lychee Brandy Analyzed by Electronic Nose and Gas Chromatography-Mass Spectrometry

In order to study the effects of lychee wood chips with different toasting degrees used in the aging process on the flavor of lychee brandy, the quality and volatile flavor components of lychee brandy aged with lightly toasted (LT), moderately toasted (MT) or heavily toasted (HT) lychee wood chips were evaluated and analyzed using sensory evaluation, electronic nose and gas chromatography-mass spectrometry. Raw and aged lychee brandy with heavily toasted oak chips were used as controls. The results of electronic nose analysis were in good agreement with those of sensory evaluation, and the brandy aged with heavily roasted lychee wood chip wood had the highest overall sensory score. A total of 44 volatile aroma compounds were identified in the five brandy samples, and the types and contents of volatile components varied greatly among these samples, each with their unique olefinic flavor substances. The major volatile components of aged lychee brandy were alcohols, esters, olefins, along with lesser amounts of aldehydes and ketones, alkanes, and aromatic hydrocarbons. Ethyl decanoate, ethyl acetate, ethyl caprylate, 2-methylbutanol, isoamyl alcohol, isobutanol, alpha stigmasterol and beta stigmasterol together constituted the major flavor profile of the aged lychee brandy. Therefore, aging with a moderate amount of heavily roasted lychee wood chips resulted in better improvement in the quality of lychee brandy compared to heavily toasted oak chips.