Classification of barley shochu samples produced using submerged culture and solid-state culture of koji mold by solid-phase microextraction and gas chromatography-mass spectrometry.

An easy and fast method of analyzing volatile components contained in shochu, by headspace solid-phase microextraction and gas chromatography-mass spectrometry, was established to determine the difference in the content of the various components of barley shochu produced using a submerged culture of koji mold (submerged-culture shochu) and a solid-state culture of koji mold (solid-culture shochu). The contents of the volatile components between the two types of shochu were compared. The results of the comparison revealed that the content of ethyl lactate, ethyl benzoate, 3-methyl-1-pentanol, diethyl succinate, citronellol, and 2-phenethyl acetate differed between the submerged-culture and the solid-culture shochu samples. In addition, the classification of barley shochu samples, including those on the market, into submerged-culture shochu and solid-culture shochu, was carried out by multivariate analysis using the quantitative values of the above-mentioned six compounds, and distinct discrimination was found possible.