Characterization of Aroma Compounds of Chinese “Wuliangye” and “Jiannanchun” Liquors by Aroma Extract Dilution Analysis

Abstract

Aroma compounds in Chinese "Wuliangye" liquor were identified by gas chromatography-olfactometry (GC-O) after fractionation. A total of 132 odorants were detected by GC-O in Wuliangye liquor on DB-wax and DB-5 columns. Of these, 126 aromas were identified by GC-mass spectrometry (MS). Aroma extract dilution analysis (AEDA) was further employed to identify the most important aroma compounds in "Wuliangye" and "Jiannanchun" liquors. The results showed that esters could be the most important class, especially ethyl esters. Various alcohols, aldehydes, acetals, alkylpyrazines, furan derivatives, lactones, and sulfur-containing and phenolic compounds were also found to be important. On the basis of flavor dilution (FD) values, the most important aroma compounds in Wuliangye and Jiannanchun liquors could be ethyl butanoate, ethyl pentanoate, ethyl hexanoate, ethyl octanoate, butyl hexanoate, ethyl 3-methylbutanoate, hexanoic acid, and 1,1-diethoxy-3-methylbutane (FD > or = 1024). These compounds contributed to fruity, floral, and apple- and pineapple-like aromas with the exception of hexanoic acid, which imparts a sweaty note. Several pyrazines, including 2,5-dimethyl-3-ethylpyrazine, 2-ethyl-6-methylpyrazine, 2,6-dimethylpyrazine, 2,3,5-trimethylpyrazine, and 3,5-dimethyl-2-pentylpyrazine, were identified in these two liquors. Although further quantitative analysis is required, it seems that most of these pyrazine compounds had higher FD values in Wuliangye than in Jiannanchun liquor, thus imparting stronger nutty, baked, and roasted notes in Wuliangye liquor.

Volatile Compounds of Raw Spirits from Different Distilling Stages of Luzhou-flavor Spirit

“…Esters especially ethyl esters represented the largest group in the number and concentration of volatile compounds identified. This result was coincided with the previous study (Fan and Qian, 2006a) which also reported that ethyl ester was the main group in esters. Ethyl hexanoate was considered to be the dominant compound in…”

“…In the spirit samples, 10 acid derivates were identified (Table 2), and 9 of them were also indentified in previous studies (Fan and Qian, 2006a). The total concentration decreased from 239 mg/L in the heart raw spirit to 167 mg/L in the tail raw spirit.…”

“…In some previous literatures, numerous sample preparation methods, such as LLE, solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE), coupled with GC-MS were used to determine volatile compounds in Chinese spirits and wines (Hernandez-Gomez et al;, Sanchez-Palomo et al, 2009Fan and Qian, 2006a). LLE represented a better applicability for sample preparation in previous experiments because all volatile compounds (low, medium and high volatility) can be analyzed in one or more extraction steps (Hernanz et al, 2008;Caldeira et al, 2007).…”

“…LLE represented a better applicability for sample preparation in previous experiments because all volatile compounds (low, medium and high volatility) can be analyzed in one or more extraction steps (Hernanz et al, 2008;Caldeira et al, 2007). Prior to GC-MS detection, the main volatile compounds determined in previous literature (Fan and Qian, 2006a) were used to validate the accuracy of the detection method in the present research. The peak area ratios (neutral fraction/methyl caprylate and acidic fraction/caprylic acid) were used for the quantification of each compound.…”

Changes in Volatile Compounds of Chinese Rice Wine Wheat Qu During Fermentation and Storage

“…Esters, which impart fruity and floral odors to Chinese rice wine wheat Qu, could be formed either via the esterification of alcohols with fatty acids or through the synthesis in the microorganism's cells by alcohol acetyltransferase using acetyl-CoA and higher alcohols as substrates during fermentation. Generally speaking, the latter plays a more important role in the formation of esters during the fermentation 6 . Therefore, ester formation can be influenced by the concentration of the two substrates (acetyl-CoA and higher alcohols) and the activity of alcohol acetyltransferase.…”