Qualitative analysis of the main aroma compounds associated with traditional Musalais processing in Xinjiang, China

Musalais has a unique flavour owing to the traditional technique of spontaneously fermenting the boiled substrates from compressed local grape juice and the grape residue. Liquid–liquid extraction followed by gas chromatography–mass spectrometry of 11 samples collected at different time points during the fermentation identified the aromatic compounds associated with traditional Musalais processing. The results showed that boiling completely destroyed the original aroma of the grape (16 compounds) and grape juice (16 compounds) and produced distinct furan‐derived compounds in the initial fermented substrates (10 compounds). During the fermentation, the aromatic compounds, with phenethyl alcohol as the major compound, accumulated within 24–40 days. Within a year of aging, over 40 compounds had increased and around half of these were esters, with ethyl caprylate, ethyl caprate, 2‐phenylethyl acetate and diethyl succinate as the major aromatic compounds. Boiling the grape derivatives, spontaneous fermentation and a short maturation time produced the three classes of aromatic components related to furans, alcohols and esters, respectively. These compounds contributed to the strong mellow flavour of fresh Musalais and the ester fragrance of a mature Musalais along with a distinctive caramel aroma. The results provide useful information on the origin of the flavours of Musalais wine and the associated wine‐making technology. Copyright © 2012 The Institute of Brewing & Distilling