Abstract
The production of kaoliang wines in Taiwan is on top three among a wine industry. Varieties of kaoliang wines are available in market with a varying price. Hence, it became difficult to choose among them. This motivated us to develop a method to obtain kaoliang wine’s fingerprint profile. Moreover, in 2011, the Taiwan food scandal demonstrated that detecting specific compounds alone from samples can’t give complete information. We may miss the chance to discover illegal additives. In this study, we develop gas chromatograph-mass spectrometer method to identify components in 31 kaoliang wines and differentiate 6 brands by their fingerprint profiles. The methanol content of wine was analyzed by gas chromatograph-flame ionization detector. In GC-MS part, the compounds were separated into nonvolatile and volatile. The nonvolatile analytes were divided into three components viz basic/neutral, acid and water soluble by dispersive liquid-liquid microextraction and rotavapor techniques. Qualitative analysis of 74 analytes was successfully carried out. 1,1,3,triethoxypropane, hexanoic acid, 1,1-diethoxy-2-methyl propane, ethyl octanoate, 1,1-diethoxy-3-methylbutane were able to differentiate wine brands and the classification correctness was found to be 100%. We were able to identify 50 volatile components by using purge and trap technique. The classification correctness was found to be 94.12% using 1,1-diethoxyethane, acetaldehyde, 2-methyl-1-propanol, ethyl butanoate, 3-methylbutanal as variables. The results showed nonvolatile components have better ability to differentiate brands. Finally, GC-FID was used to quantify methanol concentration. The method detection limit was 0.34 ppm and recovery was within 80%~120%. This study has successfully analyzed the components in kaoliang wines and confirms the feasibility to distinguish brands of wine by specific analytes.