Application of Stable Isotope Technique on Distinguish Between Chinese Spirit by Traditional Fermentation and Chinese Spirit Made from Traditional and Liquid Fermentation

It is a technical problem in Chinese spirit industry to distinguish between Chinese spirit by traditional fermentation and Chinese spirit made from traditional and liquid fermentation. Methods for the determination of δ¹³C values of major volatile substances (such as acetaldehyde, ethanol, isobutanol, isoamyl alcohol, ethyl lactate, etc) in Chinese spirit by gas chromatography combustion coupled to isotopic ratio mass spectrometry （GC-C-IRMS) were developed. The average δ¹³C value of ethanol in Chinese spirit made by traditional fermentation is （-17.65±1.31）‰，and the value of what is called traditional Chinese spirit in market is （-15.30±1.41）‰, so t-test result is significant difference(P<0.01). The simulation test show that the carbon isotope ratio of ethanol observed in Chinese spirit are positive relative to those of the corresponding maize ethanol; it is significant differences on δ¹³C of isoamyl alcohol and ethyl lactate between reference samples and commercial samples. The results show that the δ¹³C value of ethanol and volatile aroma components in Chinese spirit (made from traditional and liquid fermentation) will be changed when added maize ethanol and exogenous volatile aroma components, so stable isotope technique will be used in distinguish between Chinese spirit made by tracitional fermentation and Chinese spirit made from traditional and liquid fermentation.