| 英文摘要 |
Chinese baijiu has a long history and is very popular among consumers at home and abroad. China has a vast territory and various baijiu making techniques have its own characteristics, making baijiu of various types and styles. According to the production process, saccharification starter, storage container, and fermentation container, the liquor is divided into 10 kinds: strong aroma, sauce aroma, light aroma, rice aroma, and other flavors. Among them, the strong flavor baijiu market has the largest share, and the annual consumption reaches about 70%. Zhijiang baijiu is produced in the middle and lower reaches of the Changjiang River and is one of the typical representatives of strong aroma baijiu. Therefore, the analysis and research on the trace components of Zhijiang baijiu is a great significance for mastering the flavor of stong aroma baijiu and improving the quality. This paper takes Zhijiang strong aroma baijiu as the research object, and systematically studies the trace components and analytical techniques. A comprehensive qualitative and quantitative analysis was carried out on the trace components in Zhijiang baijiu. Four important methods were used to summarize the flavor characteristics of strong flavor liquor. The changes of 31 important trace components during storage were studied. The characteristic flavor of Zhijiang baijiu was refined, and the fingerprint characteristic of Zhijiang was established to improve and stabilize the product quality. The main research contents and results are as follows: 1.Qualitative study on the trace components of strong-aroma Zhijiang baijiu Aiming at the content and characteristics of trace components in Zhijiang baijiu, a systematic sample preparation technique and analysis method were established, including acid-alkaline separation and concentration, separation and concentration according to polarity, direct injection analysis, disposable liquid and liquid. The extraction and concentration methods were used to accurately separate and concentrate the trace components, and the chromatographic peaks were qualitatively analyzed by GC-MS. 908 trace components were detected from the selected strong-aroma Zhijiang baijiu samples. There are 23 aldehyde compounds, 29 acetal compounds, 29 ketone compounds, 78 alcohol compounds, 182 ester compounds, 45 fatty acids, 11 terpenoids, 22 sulfides, and aromatics. 59 kinds of compounds, 8 kinds of pyridine and azole compounds, 12 kinds of pyrazines, 23 kinds of furan compounds, 108 kinds of other compounds, and 279 kinds were unknown components (with chromatographic peaks but not currently determined). 2.Quantitative study on the trace components of strong-aroma Zhijiang baijiu Based on the qualitative research of Zhijiang baijiu, different analytical methods were applied to quantitatively analyze different kinds of compounds in the range of content of trace components. The chromatographic framework components were directly analyzed by gas chromatography (GC) capillary direct injection; the complex trace flavor components were quantitatively analyzed by headspace solid phase microextraction and GC/MS; and the sulfur compounds were quantitatively analyzed by GC-MS; The nitrogen-containing compounds were analyzed by headspace solid phase microextraction and gas chromatography-mass spectrometry; the organic acids and polyols were quantitatively analyzed by ion chromatography. Using the above quantitative analysis method, 156 kinds of trace components were quantified, among which 132 kinds of Zhijiang baijiu could be quantitatively detected, most of which were trace flavor components with content less than 1 ㎎/L, and about 24 undetected. Zhijiang baijiu has the highest ester content, accounting for 69.26%, fatty acids, accounting for 14.42%, alcohols accounting for 9.43%, and carbonyl compounds accounting for 5.75%. The ethyl hexanoate content in the baijiu is high, accounting for 41.96% of the total ester, followed by ethyl lactate, accounting for 28.27% of the total ester. Four ethyl esters (ethyl acetate, ethyl hexanoate, ethyl lactate, butyl) Ethyl acetate accounted for 93.82% of the total ester. Correspondingly, the sum of acetic acid, caproic acid, lactic acid and butyric acid accounts for about 91.60% of the total acid amount. 3.Study on the aroma compounds of strong-aroma Zhijiang baijiu The sample pretreatment technology was studied, including acid-base separation and dilution. 94 kinds of flavored active ingredients were smelled by GC-O. The OAV value of the flavor component was calculated, and 23 kinds of important aroma components were obtained. Based on the results of four methods, such as direct injection analysis, Osme analysis, AEDA analysis and OAV analysis, the important flavors of Zhijiang baijiu were determined to be ethyl hexanoate, ethyl octanoate and ethyl ester. Caproic acid, acetal, acetic acid, ethyl butyrate, butyric acid, ethyl lactate, 2-ethyl-6-methylpyrazine, isoamyl alcohol, ethyl acetate, ethyl valerate, isovalerate There are 19 kinds of esters, isovaleraldehyde, phenylacetaldehyde, ethyl 2-methylbutyrate, n-propanol, methyl hexanoate and ethyl isobutyrate. 4.Analysis of trace components changes during storage of different flavors of Zhijiang baijiu According to the time sequence of liquor distillation in production, 72.7% vol, 65.3% vol, and 55.8% vol were taken. The 31 important trace components were followed up for 27 months. The results showed that the higher the degree of alcohol extraction, the higher the content of main aldehydes, alcohols and linear lower fatty acid ethyl esters, but the lower the content of main acid substances. "Baijiu head" has a high content of aldehydes, alcohols, and linear low-grade fatty acid ethyl esters, and the content of acid substances in "baijiu tail" is high. The acid, aldehyde, alcohol and ester of different alcoholic beverages have the same change trend during storage, and will not change with the degree of picking. As a whole, the content of lower fatty acid ethyl esters gradually increased during storage, and the content of alcohols mostly increased. Most of the acid content increased after 24 months, especially the detection of lactic acid content. The content increased by 4 times during the period. 5.Establishment and application of "flavor fingerprint" on Zhijiang baijiu Taking 5 kinds of Zhijiang baijiu as research objects, according to the tasting and scoring of the samples by the sommelier, the musk, ester, multi-grain, sweet and mellow, aftertaste, wine taste, softness and refreshing were determined. Based on the 10 main flavor characteristics such as sense, fullness and coordination, the flavor fingerprints were established, and the unique "flavor feature score judgment score table" and "product consistency judgment score table" were developed. Combining the flavor fingerprint and the two scoring tables designed the application of baijiu authenticity identification and determination of product quality stability was applied. Key words: strong-aroma baijiu; trace components; storage change; fragrant compounds; fingerprint
|
