Analysis Of Sugar And Sugar Alcohols In Liquor

Chinese baijiu is one of the six major distilled liquors in the world.The main components are ethanol and water,accounting for 98%?99% of the total content.The remaining 1-2% of the trace components are important flavor components in Baijiu,including easy volatile components and non-volatile components,which determine the aroma and flavor characteristics of the liquor.Although the volatility of the trace components is different,they are very important for the presentation of the liquor style.The hardly volatile components affect the release of the easily volatile components,and the easily volatile components adjust the taste characteristics of the hardly volatile components,and finally achieve the balance and harmonious state of Baijiu flavor and taste.So far,the main research object of baijiu is to explore its volatile aroma components.In terms of taste,there are a few domestic studies on its bitterness,astringency and other undesirable tastes,but the research on substances with sweet taste in the body is very rare.Therefore,the study of the main sugar and sugar alcohols in Baijiu and their contribution to sweet taste are of great significance to better understand the sweetness of Baijiu.This subject uses derivatization combined with gas chromatography-mass spectrometry technology to qualitatively and quantitatively analyze sugars and sugar alcohols in different liquor samples.Secondly,the threshold value of sweet substances in 53° ethanol solution is determined by sensory evaluation.Measure and analyze their sweetness contribution in liquor.Then,sensory evaluation combined with electronic tongue technology was used to explore the mechanism of sweetness.Finally,Raman spectroscopy is applied to the analysis of molecular interactions between sugars and sugar alcohols,and the relationship between molecular interactions and their sweetness is preliminarily explored.The details are as follows:(1)Using the BSTFA derivatization method to pre-process a total of 52 liquor samples with outstanding sweetness in the sensory evaluation of the three flavored liquors,and combine with GC-MS analysis to qualitatively quantify the sugars and sugar alcohols in the samples.A total of 12 substances were detected in the Jiang-flavor liquor samples,including 6 sugars(rhamnose,mannose,xylose,fructose,glucose,galactose)and 6 sugar alcohols(glycerol,erythritol,sorbitol,xylitol,arabinol,mannitol);13 kinds of substances were detected in Nong-flavor liquor samples,including 6 kinds of sugar substances(rhamnose,arabinose,xylose,fructose,Glucose,galactose)and 7 sugar alcohols(glycerol,erythritol,xylitol,arabitol,ribitol,mannitol,sorbitol);and a total of 9 substances were detected in the samples of Laobaigan-flavor liquor,including 3 kinds of sugar substances(xylose,fructose,glucose)and 6 kinds of sugar alcohol substances(glycerol,xylitol,arabitol,ribitol,mannitol,sorbitol).(2)Using headspace solid-phase microextraction combined with GC-MS technology to analyze the volatile trace components of the above samples,compare the obtained spectrum with the NIST 08 library to obtain the volatile components and relative content of each sample.In this experiment,the content of esters in the Jiang-flavored liquor with outstanding sweetness basically accounted for more than60% of the volatile components of each liquor,while the esters of common Jiang-flavor liquor accounted for about 35%-60% of the aroma components,and only 47% of the finished liquor.The content of esters in Nong-flavor liquor samples was more than 85%,while esters in common liquor samples accounted for about 70%of the volatile components.The content of esters in Laobaigan-flavored sweetness liquor samples was more than 65% of the total volatile components,while the content of esters in general liquor was 64.08%.The content of esters in the three types of liquor samples with outstanding sweetness was higher than that in the ordinary samples,which indicated that the sweetness of these wine samples might be related to the esters in the Baijiu.(3)The sweetness threshold of 6 kinds ofsugars and sugar alcohols in Baijiu was determined.The sweetness thresholds of these substances in the 53° ethanol-water solution system from low to high were glycerin(0.2023 mg/L),glucose(0.2227mg/L),rhamnose(0.3969 mg/L),arabinol(0.4046 mg/L),mannitol(0.5197 mg/L)and sorbitol(0.5298 mg/L).Combining the sweetness threshold of sugars and sugar alcohols,calculate the taste vitality values of the 6 sugars and sugar alcohols of 39Jiang-flavor liquor samples with outstanding sweetness,and analyze the contribution of each substance to the sweet taste for the liquor.Because the liquor samples are the round wines and vintage wines taken from different wineries,the composition and content of the substances in the samples from different wineries or different years are different,but generally speaking,glycerin and glucose contribute a lot to the sweet taste of liquor.(4)Through the previous analysis of trace substances in wine samples and the threshold analysis results of sweet substances,compared with the sweetness threshold of the above-mentioned substances in the literature and the literature,the threshold in the 53° ethanol-water solution system.To explore this phenomenon,we plan to conduct a preliminary exploration of the sweetness mechanism of liquor.We prepared a series of samples with different alcohol levels and different sweetening substance concentrations for sensory evaluation experiments,and found that ethanol molecules and ethyl caproate The introduction of the sample enhances the sweetness of the sample,and the organoleptic sweet taste is more comfortable than the pure sweet substance solution and is closer to the sweetness of liquor.In the course of the experiment,when you taste the high-alcohol series solution and then taste the low-alcohol series solution,it is found that the sweetness of the low-alcohol series will be more obvious,so it is speculated that the ethanol molecule stimulates the sweet taste receptor on the tongue Thereby,the human body's recognition threshold of sweet substances is lowered,and the sweetness becomes obvious.This indicates that the interaction between ethanol and sugar alcohols in the wine body is related to the sweet taste of the wine body,or the presence of high concentrations of ethanol molecules amplifies the tongue's perception of sweet substances.Subsequently,we used the electronic tongue to detect the sweetness intensity of the sensory evaluation samples,and found that the sweetness change rule of each sample was basically the same as that in the sensory evaluation,which verified the reliability of the sensory evaluation results.(5)Raman spectroscopy is widely applied in exploring intermolecular interactions.In this paper,we first explore the application of Raman spectroscopy in the analysis of sugar and sugar alcohols in Baijiu,and analyze the spectrogram data of mixed liquor with different concentration and different alcohol precision.We can see that the center position of OH bond peak is displaced between different products.This indicates that the hydrogen bonding effect of substances in solution system is different,which can provide an analytical basis for the explanation of sugar and sugar alcohols in sweet baijiu.