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Effects of different distillation patterns on main compounds of Chinese Luzhou -flavour raw liquors

2017; Wiley; Volume: 123; Issue: 3 Linguagem: Inglês

10.1002/jib.422

2050-0416

Xiaofei Ding, Jun Huang, Chongde Wu, Rongqing Zhou,

Phytochemicals and Antioxidant Activities

Journal of the Institute of BrewingVolume 123, Issue 3 p. 442-451 Research articleFree Access Effects of different distillation patterns on main compounds of Chinese Luzhou-flavour raw liquors Xiaofei Ding, Xiaofei Ding College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 ChinaSearch for more papers by this authorJun Huang, Jun Huang College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 ChinaSearch for more papers by this authorChongde Wu, Chongde Wu College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 ChinaSearch for more papers by this authorRongqing Zhou, Corresponding Author Rongqing Zhou zhourqing@scu.edu.cn College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 China National Engineering Research Center of Solid-State Manufacturing, Luzhou, 646000 ChinaCorrespondence to: Rongqing Zhou, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, China. E-mail: zhourqing@scu.edu.cnSearch for more papers by this author Xiaofei Ding, Xiaofei Ding College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 ChinaSearch for more papers by this authorJun Huang, Jun Huang College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 ChinaSearch for more papers by this authorChongde Wu, Chongde Wu College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 ChinaSearch for more papers by this authorRongqing Zhou, Corresponding Author Rongqing Zhou zhourqing@scu.edu.cn College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065 China Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, 610065 China National Engineering Research Center of Solid-State Manufacturing, Luzhou, 646000 ChinaCorrespondence to: Rongqing Zhou, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, China. E-mail: zhourqing@scu.edu.cnSearch for more papers by this author First published: 21 April 2017 https://doi.org/10.1002/jib.422Citations: 10AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract This study aimed to investigate the effects of different distillation patterns on main compounds of Chinese Luzhou-flavour liquor. Results showed that more volatiles of raw liquor might originate from fresh grains for a newly constructed pit. A modest (p = 0.05) increase in the total amount of volatiles was found in the heart liquor from fermented grains added to fresh grains and rice hulls to distillate (AG pattern), reaching a maximum value of 1012.22 mg/L. The percentage of esters in the AG pattern ranged from 81.22 to >95.03% compared with samples from fermented grains only added to rice hulls to distillate (NG pattern). Acids in the heart liquor obtained by the AG pattern were higher than those for NG, but the corresponding proportion was opposite. Alcohols were detected at ~1.62% in NG pattern but were 1.42% in AG. Cyanide and ethyl carbamate content in the head liquor were far higher than those in the heart and tail liquor. In particular, cyanide content dramatically increased after adding fresh grains during the distillation process. Copyright © 2017 The Institute of Brewing & Distilling Introduction Distillation is an important link in the production of liquor and closely correlated with quality and yield. Compared with brandy, whisky, cachaça, etc., the distillation pattern of Chinese liquor is entirely different. It is carried out in a steaming bucket apparatus (called as Zeng-tong), which is similar to a packed column and filled with solid particle mixture, including fermented grains, grain hull and fresh grains 1. As one of the most famous Chinese liquors, the distillation mode of Luzhou-flavour liquor differs from MaoTai-flavour and light-flavour liquor. The distillation and cooking of newly added crushed sorghum, rice, glutinous rice, wheat and corn can be completed simultaneously. This involves not only concentration and fractionation, but also gelatinization and liquidation of starch in cereals as well as non-enzymatic catalysis reaction. For example, both 3-furancarboxaldehyde and benzofuran may be pyrolysis products 2. Undoubtedly, fresh grains, as a fraction of raw materials, are endowed with special flavours in the distillate. According to previous documents, ethyl carbamate (EC), a suspected carcinogen, may be present in fermented foods and distilled beverages, and is mainly produced in the fermentation and distillation stage 3. Cyanide-type compounds have been recognized as possible precursors of EC, which is a degraded product of cyanogenic glycosides contained in higher plants, such as cassava, stone fruit, sugar cane and sorghum 4, 5. Moreover, other compounds containing carbamyl groups, such as urea and citrulline, are also the precursors of EC, and are usually metabolites of Saccharomyces cerevisiae or lactic acid bacteria during fermentation 6. These precursors would easily react with alcohol to form EC during distillation, resulting in levels that exceed maximum legal levels in final products. Hence, various technologies have been developed to decrease its content, which involve reducing precursor formation 7 and improving distillation technology 8. However, until now, it is unclear what the influence of raw material during distillation on EC content is for Chinese liquor, especially Luzhou-flavour liquor. Consequently, the aim of this study was to investigate the effects of different distillation patterns on cyanide and EC content, meanwhile monitoring changes in volatile compounds of Chinese Luzhou-flavour liquor. To the best of our knowledge, this is the first report that compares the quality of Chinese Luzhou-flavour raw liquors obtained by application of different distillation patterns. Materials and methods Sampling Fermented grains were taken from three different aged pits (2, 10 and 40-year aging). For the 2- and 10-year pits, fermented grains were taken from the bottom layer of the pit, and the 40-year pit was sampled from the middle and bottom layers of the pit. Experiment process As depicted in Fig. 1, two different distillation patterns were adapted to explore the influence on flavour profile, EC content and its derivative during actual process. One (referred to as NG pattern below) was that fermented grains only were added to rice hulls to distillate, and another (referred to as AG pattern below) was that fermented grains were added to a mixture of fresh grains (sorghum, rice, glutinous rice, wheat and corn) and rice hulls before distillation. The experiment was carried out at Xufu Co. Ltd (Yibin City, Sichuan province, China), which is a well-known liquor-producing enterprise. As shown in Table 1, 24 raw liquors were collected from the head, heart and tail stages. For each sample, five key points were selected to sample at equal time intervals; ~100 mL was collected, pooled together and immediately poured into glass bottles, then sealed for storage at 4°C until analysis. Figure 1Open in figure viewerPowerPoint Schematic diagram of two different Chinese Luzhou-flavour liquor distillation patterns. [Colour figure can be viewed at wileyonlinelibrary.com] Table 1. Sampling numbers and their related positions in the fermentation pit Pit age and spatial positions Distillation process NG pattern AG pattern Head liquor (H) Heart liquor (A) Tail liquor (T) Head liquor (H) Heart liquor (A) Tail liquor (T) Bottom layer of 2-year pit 2-BH-NG 2-BA-NG 2-BT-NG 2-BH-AG 2-BA-AG 2-BT-AG Bottom layer of 10-year pit 10-BH-NG 10-BA-NG 10-BT-NG 10-BH-AG 10-BA-AG 10-BT-AG Middle layer of 40-year pit 40-MH-NG 40-MA-NG 40-MT-NG 40-MH-AG 40-MA-AG 40-MT-AG Bottom layer of 40-year pit 40-BH-NG 40-BA-NG 40-BT-NG 40-BH-AG 40-BA-AG 40-BT-AG Determination of cyanide Cyanide was determined according to colourimetric method by modified König reaction, using barbituric acid–pyridine as the oxidant owing to its sensitivity and stability 9. Determination of EC EC was evaluated by an improved solid-phase extraction method 9 with an SLE (diatomite column, 3 mL) solid-phase extraction column, which was purchased from Swell Scientific Instruments Co. Ltd (Chengdu, China). Extraction of volatile compounds DVB/CAR/PDMS fibre has proved to be appropriate for trapping a range of volatiles with different polarities and efficient in covering a wide range of physical–chemical properties of flavour volatiles because of its intermediate polarity 10. Thus, a 50/30 μm DVB/CAR/PDMS fibre (Supelco, Inc., Bellefonte, PA, USA) was used for aroma extraction. To begin with, the sample was diluted with deionized water to a final concentration of 15% (v/v) ethanol, and then saturated with sodium chloride. Head space–solid-phase microextraction (HS-SPME) conditions were based on a reported method with slight modifications 11. Subsequently, sample and internal standards were combined in a 15 mL vial and hermetically sealed with a silicon septum. Then the vial was equilibrated at 60°C in a magnetic stirring plate for 15 min and extracted for 40 min. Finally, the fibre was immediately introduced into the injection port of gas chromatography–mass spectrometry (GC–MS) to thermally desorb the analytes at 250°C for 3 min. GC/MS analysis The extraction of volatile compounds was carried out on a Trace GC Ultra gas chromatograph–DSQ II mass spectrometer (Thermo Electron Corporation, Waltham, MA, USA) equipped with an HP-INNOWAX capillary column (30.0 m × 0.25 mm × 0.25 μm; Agilent Technology, CA, USA) and a flame ionization detector. The mass spectrum was generated in the electron impact mode at 70 eV ionization energy using full-scan mode (45–400 amu). The GC operation condition was achieved according to protocols reported previously 2. The constituents were tentatively identified by matching the mass spectrum with the NIST05 spectrum database and verified by comparison of their Kováts retention indices with the retention indices reported in the literature, which was calculated using C8–C20 n-alkanes. The odour description of compounds in this paper was reported at www.flavornet.org. The relative concentration of volatile compound was estimated as: where C2 is the concentration of volatile compounds of sample (mg/L), C1 is the concentration of internal standard [mg/L; internal standards 10 μL 2-octanol (0.93 mg/L) and 10 μL methyl octanoate (0.88 mg/L) for alcohols and the rest, respectively], S2 is the peak area of the analyte and S1 is the peak area of the internal standard. Data analysis All assays were conducted in triplicate and results were expressed as mean ± standard deviation. The analysis of variance (ANOVA) was used to test the significance of assay (p < 0.05) with software SPSS 17.0. Likewise, principal component analysis (PCA) was performed with software SPSS 17.0. Odour activity values were calculated by dividing concentrations with their respective odour thresholds. Results and discussion Differences of cyanide and EC with different distillation patterns A total of 24 raw liquors were analysed and results were summarized in Fig. 2. Cyanide occurred in all samples except for 10-BA-NG, and cyanide content in the 10-BT-NG, 10-BA-AG and 10-BT-AG samples was very low. On account of high volatility, cyanide content in the head liquor was far higher than in the heart and tail liquor, except for 2-BH-NG and 2-BH-AG, and EC also performed analogous rule. This might be caused by the volatility of ethanol being much higher than that of EC, and its solubility in ethanol exceeded that in water, so both of them were steamed out together. In Fig. 2(B), for the NG pattern, the cyanide content showed slight differences between samples obtained from the middle and bottom layers of the 40-year pit, as did EC content. This suggested that the spatial position had little effect on cyanide and EC. More importantly, cyanide content dramatically increased with the addition of fresh grains during the distillation process, especially for the 10- and 40-year pits. This might be due to the cyanogenic glycoside dhurrin being degraded by specific β-glucosidases or pyrolysis, contained in sorghum 12. In addition, cyanide was the most important precursor forming EC and easily reacted with ethanol to form EC in the presence of cupric ion (Cu2+) 3. It was proved that part of cyanide in cereals was converted to form EC, and the rest was distillated into raw liquor. Furthermore, it could be inferred that the contents of cyanide and EC were affected by various factors such as process parameter, species and origin of raw material and pit age. Aging is a vital process for high-quality liquor. Hence, it is essential to exploit the effect of cyanide content in fresh liquor on EC content in the finished liquor to avoid a potential risk of exceeding authorized maximum allowed content. Figure 2Open in figure viewerPowerPoint Distributions of cyanide and ethyl carbamate (EC) content in the raw liquors from different distillation patterns: (A) different pit ages; (B) different spatial positions. Effect of distillation patterns on volatile compound of raw liquors Tables 2 and 3 summarize the volatile compounds identified from different distillation patterns. Fifty-nine volatiles were identified and classified in the following families: alcohols (6), acids (12), esters (28), phenols (4), aldehydes (3), furans (1), ketones (4) and miscellaneous (1). Of them, 10 kinds of constituents were detected in each sample, and accounted for an average of 81.93% of total volatile amounts. These constituents were 1-butanol, hexanoic acid, ethyl hexanoate, butyl hexanoate, isoamyl hexanoate, ethyl heptanoate, ethyl octanoate, ethyl decanoate, ethyl hexadecanoate and ethyl elaidate. As described in Fig. 3, a modest (p = 0.05) increase in the total amount of volatiles was observed in the heart liquor of AG pattern compared with NG, reaching a maximum value of 1012.22 mg/L in the 40-BA-AG. Obviously, volatiles amount in each liquor of the NG pattern depended on pit age as well as sampling position. For the majority of samples of the AG pattern, the order of volatiles profile was as follows: heart liquor > head liquor and tail liquor. The amount of volatiles in the 2-BH-AG (1124.51 mg/L) was far greater in 2-BH-NG (542.95 mg/L) compared with the other corresponding samples. This suggested that more volatiles of raw liquor might originate from fresh grains for a newly constructed pit. Table 2. Mean values (mg/L) with standard deviations (SD, n = 3) of volatile compounds in the raw liquors from NG pattern Compounds NG pattern 2-BH-NG 2-BA-NG 2-BT-NG 10-BH-NG 10-BA-NG 10-BT-NG 40-MH-NG 40-MA-NG 40-MT-NG 40-BH-NG 40-BA-NG 40-BT-NG 3-Furanmethanol 3.7642 ± 0.3127 0.2034 ± 0.0123 2.3563 ± 0.4389 0.4500 ± 0.0447 0.5099 ± 0.1022 1.8448 ± 0.0011 1.7643 ± 0.3699 1.6032 ± 0.0440 1.6321 ± 0.2307 0.4895 ± 0.1411 0.3725 ± 0.0843 1.1888 ± 0.2285 n-Butyl alcohol 3.7456 ± 0.2631 0.0701 ± 0.0133 1.0456 ± 0.2331 0.3309 ± 0.0290 0.2217 ± 0.0564 0.1654 ± 0.0037 0.4684 ± 0.0849 0.4774 ± 0.1558 0.6776 ± 0.1033 0.1614 ± 0.0501 0.5088 ± 0.1020 1.3621 ± 0.4779 3-Methyl-1-butanol 3.5848 ± 0.3043 0.2002 ± 0.0423 2.1037 ± 0.5436 1.3923 ± 0.3209 0.8948 ± 0.1092 2.6299 ± 0.0426 2.5618 ± 0.5044 1.7134 ± 0.0092 0.1005 ± 0.0304 1.0947 ± 0.2564 2.4761 ± 0.5032 4.6201 ± 1.2458 2-Pentanol 0.1369 ± 0.0349 0.2960 ± 0.1993 0.1720 ± 0.0390 2.2879 ± 1.5425 1.0062 ± 0.2099 0.4419 ± 0.0145 0.0117 ± 0.0005 0.1827 ± 0.0215 0.3946 ± 0.0465 0.6234 ± 0.1007 2.1984 ± 0.0343 1.7538 ± 0.6834 1-Hexanol 5.7048 ± 2.0219 5.0509 ± 0.0264 4.9180 ± 0.5695 6.0825 ± 0.3099 6.4893 ± 0.6788 7.9362 ± 0.8094 6.7470 ± 0.6720 6.4076 ± 0.5867 5.2908 ± 1.2033 7.0089 ± 1.0013 7.0037 ± 1.3044 6.3443 ± 1.9020 Phenylethyl alcohol 0.8475 ± 0.5690 0.7644 ± 0.0793 2.3430 ± 0.3982 0.3433 ± 0.0503 0.4395 ± 0.0556 2.7856 ± 0.1782 1.3462 ± 0.3231 1.5234 ± 0.2361 2.1387 ± 0.2682 0.3129 ± 0.0769 0.2395 ± 0.0034 2.1078 ± 0.3024 Acetic acid 0.0086 ± 0.0012 0.4017 ± 0.0637 2.4800 ± 0.4561 0.7628 ± 0.0281 0.0003 ± 0.0001 0.1890 ± 0.0073 0.0017 ± 0.0004 0.0015 ± 0.0011 0.0212 ± 0.0045 0.7429 ± 0.3026 0.5150 ± 0.1092 0.3323 ± 0.1321 Isobutyric acid 2.1010 ± 1.3660 0.0284 ± 0.0055 0.0916 ± 0.0129 1.0565 ± 0.2020 0.7297 ± 0.1034 0.6869 ± 0.0837 0.9732 ± 0.2100 0.4471 ± 0.0380 0.5845 ± 0.0898 1.6364 ± 0.9085 0.4449 ± 0.0636 1.3939 ± 0.4820 Butyric acid 3.2928 ± 0.0296 0.1093 ± 0.0122 2.2425 ± 0.6354 2.6866 ± 0.0421 1.2308 ± 0.3088 1.0112 ± 0.2052 1.2596 ± 0.1292 0.9792 ± 0.2229 0.5228 ± 0.0678 1.9800 ± 0.1831 1.1656 ± 0.0228 2.2906 ± 0.4129 3-Methyl butyric acid 0.5129 ± 0.2212 0.1615 ± 0.0323 0.6922 ± 0.1006 1.9117 ± 0.0522 0.6055 ± 0.3394 0.5025 ± 0.1455 1.0942 ± 0.2108 0.8718 ± 0.4531 0.0016 ± 0.0003 1.2183 ± 0.6566 0.7921 ± 0.0977 1.2747 ± 0.5777 Pentanoic acid 2.1980 ± 0.4089 0.8238 ± 0.1302 1.8523 ± 0.4129 1.5465 ± 0.0738 0.7094 ± 0.3713 2.5175 ± 0.0435 2.3658 ± 0.2927 2.1715 ± 0.0624 0.8118 ± 0.1204 1.6680 ± 0.0420 1.4603 ± 0.0861 3.5639 ± 1.8111 Hexanoic acid 24.4815 ± 6.9495 85.7160 ± 8.9109 79.9668 ± 18.3094 74.9672 ± 5.5265 43.4208 ± 2.0527 125.6430 ± 1.2397 78.7874 ± 19.9444 69.9192 ± 2.8154 85.4276 ± 12.6224 87.4774 ± 26.1999 97.9814 ± 5.0438 140.1973 ± 1.8139 Heptanoic acid 0.4269 ± 0.2312 1.5091 ± 0.1178 3.9136 ± 0.2658 1.8893 ± 0.0329 1.9243 ± 0.0458 4.8621 ± 1.6799 2.0502 ± 0.4369 2.9352 ± 0.7938 7.7551 ± 0.8304 2.7592 ± 0.6521 3.3297 ± 0.1245 10.5321 ± 0.7191 Decanoic acid 2.4483 ± 0.5633 0.4949 ± 0.1002 2.8323 ± 0.6781 0.6282 ± 0.2488 0.3079 ± 0.0465 1.8025 ± 0.2339 1.9927 ± 0.7432 1.7437 ± 0.0376 1.8607 ± 0.8660 0.5842 ± 0.0151 0.2094 ± 0.1038 3.9179 ± 0.0735 Benzeneacetic acid 0.3412 ± 0.1309 0.0234 ± 0.0056 0.0815 ± 0.0235 0.0357 ± 0.0029 0.0194 ± 0.0088 0.0289 ± 0.0128 0.0285 ± 0.0110 0.0399 ± 0.0011 0.0302 ± 0.0079 0.0278 ± 0.0094 0.0158 ± 0.0059 0.0496 ± 0.0054 Hydrocinnamic acid 0.0102 ± 0.0022 0.1008 ± 0.0232 0.4202 ± 0.0363 0.0556 ± 0.0369 0.0066 ± 0.0011 0.2465 ± 0.1814 0.4461 ± 0.3166 0.2893 ± 0.1319 0.9360 ± 0.6288 0.0326 ± 0.0083 0.0121 ± 0.0045 0.2198 ± 0.0245 Myristic acid 1.6796 ± 0.3277 0.1485 ± 0.0163 1.0853 ± 0.0276 0.2184 ± 0.0979 0.0244 ± 0.0196 0.3134 ± 0.1866 0.6175 ± 0.4365 0.4687 ± 0.0503 1.3313 ± 1.0053 0.2058 ± 0.0811 0.0535 ± 0.0086 0.5525 ± 0.0046 Hexadecanoic acid 0.0405 ± 0.0148 0.2904 ± 0.0488 0.4545 ± 0.0598 0.1438 ± 0.0676 0.0557 ± 0.0132 0.1603 ± 0.0805 0.4680 ± 0.3238 0.5341 ± 0.0551 0.7470 ± 0.3132 0.1527 ± 0.0879 0.0390 ± 0.0101 0.2655 ± 0.0684 Hexyl acetate 4.9369 ± 0.4229 0.5160 ± 0.0890 0.3242 ± 0.2512 0.8361 ± 0.5299 1.2428 ± 0.2385 0.8781 ± 0.1233 2.3089 ± 0.5281 0.3044 ± 0.0216 0.2035 ± 0.0423 3.1756 ± 1.9497 0.3837 ± 0.1766 0.8957 ± 0.1334 Ethyl phenylacetate 1.3006 ± 0.4089 3.3987 ± 0.5321 27.6707 ± 3.4556 2.5455 ± 0.0105 5.3132 ± 0.7373 25.0002 ± 1.4316 8.4391 ± 1.1285 15.0273 ± 0.8772 25.0476 ± 2.1708 1.7858 ± 0.8795 3.7354 ± 0.3162 21.3650 ± 1.4008 Ethyl lactate 2.0519 ± 0.4963 5.4903 ± 1.0349 12.3089 ± 2.3366 2.1033 ± 0.4089 1.0077 ± 0.0023 2.8463 ± 0.7303 7.8878 ± 2.4697 11.1276 ± 3.2651 0.6267 ± 0.1122 2.4099 ± 0.3056 4.2473 ± 0.1035 5.5935 ± 1.7317 Phenethyl butyrate 1.3098 ± 0.2033 1.2078 ± 0.1038 21.5407 ± 4.2112 1.4554 ± 0.5884 1.6854 ± 0.1762 35.0642 ± 6.3841 13.2345 ± 3.6052 15.4238 ± 0.1694 19.9889 ± 0.4842 1.1778 ± 0.0678 1.6895 ± 0.6907 42.6553 ± 1.8980 Ethyl hydrogen succinate 0.0615 ± 0.0122 0.0013 ± 0.0003 0.0721 ± 0.0033 0.0678 ± 0.0231 0.0259 ± 0.0055 0.2374 ± 0.0417 0.3631 ± 0.2939 0.1829 ± 0.0542 0.2356 ± 0.0433 0.1000 ± 0.0172 0.0401 ± 0.0089 0.7327 ± 0.0262 Ethyl pentanoate 12.4542 ± 5.3278 3.4675 ± 1.8626 0.4605 ± 0.3726 6.7109 ± 1.6982 2.0668 ± 1.4938 2.2710 ± 0.3404 6.3299 ± 1.3859 1.8495 ± 0.6291 1.4903 ± 1.1183 6.2095 ± 0.2390 2.0633 ± 0.5994 2.2952 ± 0.0790 Ethyl hexanoate 102.5538 ± 25.4916 385.6255 ± 94.3799 180.3213 ± 45.0968 455.0837 ± 85.3543 175.3163 ± 76.2714 217.7668 ± 25.8397 235.1259 ± 51.0280 220.4459 ± 10.7502 162.0624 ± 90.3387 355.9457 ± 81.2710 230.9286 ± 11.8623 591.7082 ± 45.7601 Butyl hexanoate 37.2273 ± 2.4657 22.3507 ± 0.4038 11.0961 ± 2.6682 8.4323 ± 1.2334 6.2127 ± 0.9356 5.5979 ± 0.0812 14.5928 ± 0.8913 5.1751 ± 0.0427 0.7244 ± 0.1059 20.1033 ± 2.5609 10.0026 ± 3.0023 3.1000 ± 0.9280 Propyl hexanoate 8.6626 ± 1.5954 9.9686 ± 4.1151 0.7732 ± 0.4983 0.7546 ± 0.1099 0.0463 ± 0.0073 4.7877 ± 0.1560 0.3222 ± 0.1502 0.7543 ± 0.0503 0.6216 ± 0.1029 1.6099 ± 0.6072 0.4412 ± 0.0609 5.5184 ± 0.2715 Isoamyl hexanoate 43.1087 ± 2.2620 47.8025 ± 1.9825 31.9509 ± 3.1298 67.3089 ± 4.6756 78.2793 ± 6.7946 60.2033 ± 9.3027 52.5442 ± 8.6264 24.7561 ± 1.2326 30.2498 ± 0.1295 40.9033 ± 7.2076 27.0829 ± 4.3048 30.4075 ± 3.0687 Furfuryl hexanoate 0.7765 ± 0.1391 2.8645 ± 0.2870 6.1036 ± 1.1243 0.2150 ± 0.0162 0.3515 ± 0.0774 5.5725 ± 0.7900 1.5528 ± 0.2740 2.2434 ± 0.4519 2.7120 ± 0.0343 0.3249 ± 0.0682 0.7426 ± 0.0893 4.6518 ± 0.1572 Ethyl heptanoate 56.6166 ± 7.0801 20.0021 ± 6.0017 10.2249 ± 2.1850 35.1700 ± 5.3089 15.1130 ± 3.0297 20.0934 ± 3.4545 6.7381 ± 1.2457 15.7914 ± 0.0805 11.9979 ± 1.2863 25.6769 ± 4.0928 27.7903 ± 8.0223 30.2928 ± 7.3049 Furfuryl heptanoate 0.0399 ± 0.0067 0.0252 ± 0.0036 0.0817 ± 0.0054 0.0619 ± 0.0136 0.0214 ± 0.0148 0.1961 ± 0.0124 0.1217 ± 0.0366 0.0533 ± 0.0031 0.2987 ± 0.0545 0.0251 ± 0.0111 0.0367 ± 0.0119 0.2240 ± 0.0090 Ethyl octanoate 120.0770 ± 7.8979 70.1125 ± 0.0014 68.1400 ± 17.3102 130.9864 ± 18.3902 123.7308 ± 40.0403 60.2324 ± 4.5748 117.4875 ± 10.2354 57.8145 ± 5.2565 55.3294 ± 6.3849 151.4939 ± 9.3032 100.3902 ± 14.0920 84.3009 ± 13.2040 Octyl octanoate 0.0492 ± 0.0023 0.6984 ± 0.1306 0.0015 ± 0.0003 0.0137 ± 0.0011 0.5037 ± 0.0014 0.0120 ± 0.0012 0.0054 ± 0.0013 0.6817 ± 0.1752 0.6051 ± 0.0335 0.1321 ± 0.0077 3.1540 ± 0.0563 6.0324 ± 0.7054 Ethyl nonanoate 6.4484 ± 0.3876 5.8013 ± 3.3832 4.7824 ± 0.4667 1.8960 ± 0.3214 3.1427 ± 1.1205 6.3907 ± 0.4347 8.8613 ± 1.4646 4.6328 ± 0.1603 7.2260 ± 0.6286 2.9075 ± 0.1318 0.3224 ± 0.0724 10.3116 ± 0.0728 Ethyl decanoate 12.0391 ± 0.4655 22.5378 ± 5.5104 22.3774 ± 4.8890 3.3658 ± 0.1188 2.1122 ± 1.0787 36.2878 ± 4.4136 1.7694 ± 1.2484 20.3462 ± 2.0421 23.8735 ± 0.3794 3.7426 ± 0.1974 21.5493 ± 1.1953 46.5944 ± 2.6165 Ethyl undecanoate 1.1965 ± 0.1197 2.3015 ± 0.8774 0.2251 ± 0.1680 0.5925 ± 0.2192 0.6431 ± 0.1856 0.5605 ± 0.0656 0.6357 ± 0.1279 0.4488 ± 0.0852 1.1922 ± 0.5936 0.7567 ± 0.3109 0.1071 ± 0.0071 0.5388 ± 0.0047 Ethyl hydrocinnamate 1.7950 ± 0.4545 9.1229 ± 0.7604 28.8836 ± 6.2686 1.8333 ± 0.0853 4.0658 ± 0.9496 35.7083 ± 2.4919 11.2132 ± 2.4777 20.0779 ± 1.0696 31.8155 ± 0.1133 3.5227 ± 0.9461 27.2035 ± 0.0848 48.0051 ± 1.0457 Ethyl tridecanoate 0.4041 ± 0.1527 2.4112 ± 0.6401 1.4544 ± 0.3442 0.2387 ± 0.0834 0.0738 ± 0.0009 1.5232 ± 0.0583 1.7769 ± 0.4687 1.4033 ± 0.2741 2.1327 ± 0.0019 0.4239 ± 0.1216 0.1633 ± 0.0205 2.1089 ± 0.2851 ethyl myristate 10.8486 ± 4.1245 59.1669 ± 10.3732 51.8033 ± 1.1650 0.0591 ± 0.0267 7.4429 ± 0.3371 85.0600 ± 19.2438 1.4533 ± 19.0103 63.5196 ± 6.6481 61.2307 ± 5.8416 0.0978 ± 0.0066 60.2221 ± 0.0476 53.2597 ± 0.3385 ethyl pentadecanoate 1.2314 ± 0.4632 8.1438 ± 0.8419 8.2133 ± 5.9677 0.7544 ± 0.0097 0.9428 ± 0.0663 6.8431 ± 2.8065 9.2613 ± 1.6918 7.1293 ± 0.4539 11.8528 ± 1.7166 0.5721 ± 0.0149 0.3382 ± 0.0723 13.3214 ± 0.8045 Ethyl hexadecanoate 20.9043 ± 7.6394 0.4730 ± 0.0402 100.9721 ± 91.4890 35.4742 ± 12.4021 32.4655 ± 2.9690 122.2802 ± 60.2357 117.6277 ± 20.4948 80.7592 ± 9.2254 124.3573 ± 17.8821 25.4464 ± 1.4281 112.3702 ± 10.2831 182.2298 ± 1.8028 Ethyl heptadecanoate 0.0254 ± 0.0030 0.2612 ± 0.0361 0.4135 ± 0.0522 0.0456 ± 0.0045 0.0462 ± 0.0027 0.2008 ± 0.1558 0.3004 ± 0.1962 0.2487 ± 0.1080 0.4346 ± 0.0555 0.0271 ± 0.0001 0.0110 ± 0.0026 0.3146 ± 0.0134 Ethyl oleate 1.3685 ± 0.6023 1.0956 ± 3.6244 0.2565 ± 0.0309 0.6362 ± 0.0302 3.4135 ± 0.0412 0.0027 ± 0.0011 0.8756 ± 0.1423 0.0423 ± 0.0069 0.0045 ± 0.0010 0.7029 ± 0.2039 0.0787 ± 0.0205 0.0253 ± 0.0033 Ethyl linoleate 1.1983 ± 0.3967 17.2146 ± 2.6704 7.7111 ± 1.2304 1.7978 ± 0.6321 1.2634 ± 0.0534 7.7331 ± 1.0075 27.3330 ± 20.5617 25.6831 ± 3.5176 18.7045 ± 8.1928 0.7241 ± 0.1902 0.2715 ± 0.0530 11.6061 ± 0.0835 Ethyl elaidate 27.9122 ± 2.3433 4.9561 ± 0.4695 28.7736 ± 5.6077 10.3435 ± 0.9890 0.3184 ± 0.2608 16.6275 ± 13.1168 24.9887 ± 18.0476 14.8631 ± 6.9973 13.1948 ± 4.9606 2.0011 ± 0.6407 0.6293 ± 0.0554 19.8518 ± 0.9985 Ethyl linolenate 0.3435 ± 0.0067 0.4528 ± 0.1207 0.6841 ± 0.2130 0.0051 ± 0.0012 0.0854 ± 0.0139 0.0333 ± 0.0337 0.3568 ± 0.3310 0.3345 ± 0.0348 0.3562 ± 0.0478 0.0046 ± 0.0009 0.0016 ± 0.0002 0.0386 ± 0.0045 4-ethyl-2-methoxyphenol 0.0767 ± 0.0066 0.0817 ± 0.0029 0.0970 ± 0.0093 0.1296 ± 0.0728 0.4563 ± 0.0122 0.0929 ± 0.0020 0.0343 ± 0.0022 1.0906 ± 0.1133 1.0902 ± 0.0045 0.2140 ± 0.0995 0.1690 ± 0.0655 0.4635 ± 0.0429 4-Methylphenol 0.8685 ± 0.2945 0.2579 ± 0.1455 0.9780 ± 0.4535 0.3158 ± 0.1447 0.0551 ± 0.0446 0.2167 ± 0.0875 0.3349 ± 0.0832 0.5486 ± 0.2489 0.8529 ± 0.3801 0.2662 ± 0.0946 0.0684 ± 0.0432 0.2155 ± 0.0001 4-Ethylphenol 0.0522 ± 0.0112 0.0053 ± 0.0014 0.0451 ± 0.0093 0.0405 ± 0.0157 0.0018 ± 0.0003 0.0439 ± 0.0170 0.0397 ± 0.0022 0.0636 ± 0.0336 0.1871 ± 0.1530 0.0054 ± 0.0016 0.0012 ± 0.0001 0.0070 ± 0.0001 2,4-di-tert-Butylphenol 0.0400 ± 0.0162 0.3113 ± 0.0526 2.4324 ± 0.7306 0.0397 ± 0.0272 0.0306 ± 0.0020 0.2020 ± 0.0995 0.4095 ± 0.1492 0.3843 ± 0.0958 0.4544 ± 0.0506 0.0220 ± 0.0027 0.0144 ± 0.0030 0.1493 ± 0.0078 3-Furancarboxaldehyde 4.5621 ± 0.6784 1.7023 ± 0.9237 6.1693 ± 1.0834 2.4702 ± 1.5062 2.0192 ± 0.6723 1.9431 ± 1.7701 0.8868 ± 0.5507 2.3506 ± 0.4314 9.4634 ± 1.6808 0.0525 ± 0.0050 0.9891 ± 0.2306 0.0144 ± 0.0163 Benzaldehyde 0.9393 ± 0.1241 2.2561 ± 0.3894 3.5879 ± 0.5643 1.3463 ± 0.0729 2.2110 ± 0.4563 2.5071 ± 0.0648 1.9942 ± 0.6819 2.8439 ± 0.6339 1.4546 ± 0.8401 2.9119 ± 0.6903 2.3955 ± 0.5430 4.4423 ± 0.0669 2-Nonenal 0.0155 ± 0.0062 0.1222 ± 0.0223 0.0188 ± 0.0066 1.5434 ± 0.3888 0.0359 ± 0.0347 0.0016 ± 0.0008 0.0447 ± 0.0055 0.0239 ± 0.0030 0.0373 ± 0.0043 0.0089 ± 0.0031 0.0318 ± 0.0055 0.0028 ± 0.0001 2-Acetyl furan 0.1897 ± 0.0232 0.0037 ± 0.0009 0.0148 ± 0.0034 0.9445 ± 0.2519 0.1565 ± 0.0346 0.5672 ± 0.0377 0.8038 ± 0.4814 0.8823 ± 0.0813 0.8250 ± 0.1204 1.5957 ± 0.2334 0.4121 ± 0.0324 1.8408 ± 0.2450 3-Hydroxy-2-butanone 1.1479 ± 0.0587 0.0431 ± 0.0110 0.0098 ± 0.0013 1.3259 ± 0.1279 0.2105 ± 0.0306 0.0232 ± 0.0067 2.5617 ± 0.4039 0.6768 ± 0.0783 0.0789 ± 0.0112 0.0432 ± 0.0111 2.2321 ± 0.1425 0.0226 ± 0.0033 Acetophenone 2.0125 ± 0.7458 1.1703 ± 0.2531 0.0118 ± 0.0022 0.3613 ± 0.0527 0.0340 ± 0.0067 0.2146 ± 0.0188 0.2248 ± 0.0404 0.1304 ± 0.0071 0.8136 ± 0.0232 0.4060 ± 0.1662 0.1180 ± 0.0201 0.1047 ± 0.0178 2-Pentadecanone 0.1766 ± 0.0545 0.8875 ± 0.1232 1.3607 ± 0.5415 0.0118 ± 0.0068 0.2533 ± 0.0327 0.4253 ± 0.0555 0.6593 ± 0.1888 0.5223 ± 0.0615 0.9358 ± 0.0163 0.0316 ± 0.0120 0.0285 ± 0.0156 0.9984 ± 0.1263 Perhydrofarnesyl acetone 0.1295 ± 0.0515 1.1499 ± 0.1415 0.0036 ± 0.0011 0.0804 ± 0.0340 0.0663 ± 0.0021 0.8039 ± 0.3675 1.4103 ± 0.2443 1.0110 ± 0.3017 1.8266 ± 0.2730 0.0878 ± 0.0269 0.0353 ± 0.0066 1.5819 ± 0.0795 γ-Nonanolactone 0.4688 ± 0.0678 0.0919 ± 0.0113 0.4302 ± 0.1585 0.0529 ± 0.0150 0.0231 ± 0.0044 0.1315 ± 0.0518 0.3328 ± 0.2346 0.2077 ± 0.0339 0.7746 ± 0.6672 0.0361 ± 0.0028 0.0337 ± 0.0059 0.2654 ± 0.0104 Table 3. Mean values (mg/L) with standard deviations (SD, n = 3) of volatile compounds in the raw liquors from AG pattern Compounds AG pattern 2-BH-AG 2-BA-AG 2-BT-AG 10-BH-AG 10-BA-AG 10-BT-AG 40-MH-AG 40-MA-AG 40-MT-AG 40-BH-AG 40-BA-AG 40-BT-AG 3-Furanmethanol 0.5563 ± 0.0304 1.5817 ± 0.3874 2.0868 ± 0.5381 0.2390 ± 0.0106 1.4575 ± 0.0189 1.8999 ± 0.1990 1.2389 ± 0.2405 2.1495 ± 0.1936 2.5183 ± 0.0144 0.3437 ± 0.0438 1.2322 ± 1.0470 1.2253 ± 0.5758 n-Butyl alcohol 0.9011 ± 0.1022 1.0819 ± 0.2372 1.2775 ± 0.6012 0.0813 ± 0.0013 0.0914 ± 0.0043 0.1379 ± 0.0030 0.4892 ± 0.0010 0.6335 ± 0.0241 0.6211 ± 0.0233 0.0415 ± 0.0023 1.1771 ± 0.2508 0.8024 ± 0.2221 3-Methyl-1-butanol 2.8400 ± 0.0101 3.1935 ± 0.4190 3.7741 ± 1.7908 1.0289 ± 0.1124 2.1750 ± 0.1313 1.8094 ± 0.2279 2.4127 ± 0.1121 2.4102 ± 0.1152 2.3548 ± 0.6877 2.1233 ± 0.5322 4.5503 ± 1.4854 3.7513 ± 0.6231 2-Pentanol 0.6962 ± 0.0917 0.7250 ± 0.2380 0.7989 ± 0.1034 0.2030 ± 0.0769 0.2006 ± 0.0022 0.1034 ± 0.