Characteristic Flavor Substance Analysis Of Black Glutinous Rice Wine And Construction Of Flavor Library

Guizhou Huishui black glutinous rice wine was a traditional fermented rice wine,which was fermented with black glutinous rice using the unique brewing process of the Yi people.This wine has a clear and transparent color,a full-bodied and full-bodied flavor,and it has the characteristics of a local clan.In 2012,it was approved as a geographical indication protection product by AQSIQ.The unique production process and raw materials of black glutinous rice wine create a unique and complex aroma characteristic of the wine body.However,the composition of flavor substances in the wine has an important impact on product quality.At present,there was a relative lack of systematic research on the flavoring substances of black glutinous rice wine,which limits the understanding of its quality.This paper mainly detects and analyzes the organic acids and flavor substances in black glutinous rice wine from different regions,selects the characteristic flavor substances in black glutinous rice wine,combines the sensory evaluation to construct the black glutinous rice wine flavor library,and integrates multiple techniques to analyze the flavor of black glutinous rice wine during aging Material changes.The main research contents and results are as follows:(1)Physical and chemical indexes of black glutinous rice wine and optimization of organic acid detection methodThe physical and chemical indexes and organic acids of black glutinous rice wine were analyzed by national standard method and high performance liquid chromatography(HPLC).The results showed that the p H value of all samples ranged from 3.40 to 4.20,the total acid content ranged from 4.20 to 7.10 g/L,and the total sugar content ranged from 95.00 to 210.00 g/L.The amino acid nitrogen was 0.33?0.84 g/L,and the total solids were 122.27?248.37 g/L.The optimal chromatographic conditions were as follows: mobile phase 0.03 mol/L sodium dihydrogen phosphate solution;PH2.90;The injection volume is 10 m(L);Column temperature: 35 ?;Flow rate: 0.00-4.00 min,flow rate was 1.0 m L/min;4.00?10.00 = 0.30 m L/min;The flow rate was 1.0 m L/min after 10.00 min.Detection wavelength: 210 nm.The standard curve R2 was 0.999?1.000,the repeatability RSD was 0.15?0.87%,the precision RSD was 0.024?0.543%,the detection limit was 0.0149?0.219 mg/L,the standard recovery was 94.39?104.73%,and the 10 organic acids could be separated at baseline within 10 min.Based on the optimized chromatographic conditions,10 organic acids were detected in black glutinous rice wine,including oxalic acid,tartaric acid,pyruvate,malic acid,l-ketoglutaric acid,lactic acid,citric acid,acetic acid,pyroglutamic acid and succinic acid.(2)Analysis of characteristic flavor substances of black glutinous rice wineThe flavoring substances of black glutinous rice wine from different regions were analyzed by electronic nose and headspace solid-phase microextraction combined with gas chromatography-mass spectrometry(hs-spme-gc-ms).The results showed that the contribution rate of PCA in the electronic nose was 98.15%,higher than 85.00%.A total of 52 volatile flavor substances were identified,including 26 esters,13 alcohols,4 acids,5 aldehydes and ketones,3 alkanes and 1 naphthalene.Phenyl alcohol,ethyl acetate,ethyl palmitate,ethyl succinate,isoamyl alcohol,ethyl decanoate,ethyl octanoate,ethyl hexanoate,ethyl tetracylate,1,3-dimethoxypropane are the main flavor substances.Based on the analysis of OAV value,it was found that n-decanoic acid,ethyl valerate,ethyl heptanoate,ethyl succinate,ethyl dl-leucine,ethyl laurate and phenylacetaldehyde were the characteristic flavor substances of black glutinous rice wine,and PCA analysis of characteristic flavor substances showed that there was a certain correlation between black glutinous rice wine from different regions and characteristic flavor substances.(3)Quantitative description method for sensory evaluation of black glutinous rice wineThe sensory evaluation of black glutinous rice wine from different regions was carried out by quantitative description analysis,and a total of 23 high-frequency words were obtained as the main sensory indexes of black glutinous rice wine,such as floral,fruity and caramel aroma.Duncans multiple comparison method and multivariate statistics were used to analyze the data of sensory scoring intensity,and it was concluded that the determined aroma,taste and taste indexes could be used to evaluate the sensory characteristics of black glutinous rice wine,and there were some differences between the two indexes in different regions.The correlation analysis of organic acids,volatile flavor substances and sensory indexes showed that the acidity was strongly correlated with tartaric acid and acetic acid.There was a strong correlation between aroma and ethyl hexanoate and ethyl nicotinate.(4)Analysis of changes in flavor substances during the aging process of black glutinous rice wineThe physical and chemical indexes,organic acids and flavor substances in the aging process of black glutinous rice wine were analyzed.The results showed that the alcohol content increased first and then decreased,the total sugar content decreased,the contents of amino acid nitrogen,total acid and non-sugar solids increased all the time in the aging stage,and the change trend of amino acid nitrogen was not significant.The analysis of volatile flavor substances showed that 64 kinds of volatile flavor substances were detected in the aging stage of black glutinous rice wine.Esters are the most abundant substances in black glutinous rice wine.The relative contents of black glutinous rice wine aged for one year,two years and three years are 64.68%,42.11%,48.76% and 50.97% respectively.The relative contents of isoamyl alcohol,phenyl alcohol,ethyl octanoate and ethyl decanoate were the highest in the aging process.Aldehydes and ketones showed an increasing trend in general,while the acid content was relatively low,and the overall change trend was not large.The analysis of non-volatile substances showed that a total of 50 kinds of non-volatile flavor substances were detected,including 10 organic acids,2 fatty acids,10 amino acids,19 sugars and their derivatives and 9 other compounds.In the aging process,the organic acids are generally on the rise,which are mainly characterized by lactic acid.The contents of amino acids generally showed a decreasing trend,which was mainly characterized by valine and 4-aminobutyric acid.The contents of xylose,sucrose and fructose showed a decreasing trend,and the changes were obvious.