Establishment Of Acid-esters Balance Model And Research Of Quality Evaluation Of Luzhou-flavor Liquor

Chinese liquor is favored by consumers because of its excellent quality,unique color,taste and style.There is a vast market at home and abroad.However,the evaluation of liquor is mainly based on the sensory evaluation of experts and lack of objective models.Consumers can not accurately know the quality of Chinese liquor.They can only judge the quality of Chinese liquor by the initial taste and feelings after drinking.At present,there are only a few common indicators of Chinese liquor such as total acids,total esters,higher alcohols.Therefore,in this paper we established a corresponding objective evaluation model and determined the concentration ranges of main substances,which are of great significance for the evaluation of Chinese liquor,and can also provide corresponding guidance for the choice of consumers.Firstly,the equilibrium ratio of acetic acid to ethyl acetate and the equilibrium ratio of hexanoic acid to ethyl hexanoate in Chinese liquor was calculated by theoretical calculation.(?)Secondly,the effects of temperature and alcohol content on the equilibrium ratio of acetic acid to ethyl acetate and the equilibrium ratio of hexanoic acid to ethyl hexanoate were studied.The equilibrium ratio of acetic acid to ethyl acetate and the equilibrium ratio of hexanoic acid to ethyl hexanoate was significantly negatively correlated with the liquor’s alcohol content,and was positive correlated with temperature,and the alcohol content factor predominated.Therefore,the alcohol content of high-quality liquor should reach 45%vol or more and this liquor can be stored in sealed environment for long time.Liquor with lower than 45%vol alcohol content should be drunk between 1 and 2 years.Afterwards,the quality of this liquor will be decreased quickly.Then the acid,ester substances in the aroma substance were studied,and the influence on the flavor of liquor was analyzed to determine the concentration ranges of the main acids and esters in the high-quality Luzhou-flavor liquor.For liquor with lower than 45%vol alcohol content,the acetic acid concentration should be controlled in the range of 500-650mg/L,and the ethyl acetate concentration should exceed 400mg/L.For liquor with higher than 45%vol alcohol content,the total acid concentration should be about 2000mg/L,and the total acetate concentration should exceed 3000mg/L.Acetaldehyde and higher alcohols were studied as the main substances produced irritation in Luzhou-flavor liquor as well.For liquor with higher than 45%vol alcohol content,the concentration of acetaldehyde should be controlled under 200mg/L.Furthermore,for high quality liquor,the concentration of acetaldehyde should be controlled less than 100mg/L.The concentration of n-propanol is about 150 mg/L,and the concentration of isobutanol is about 100 mg/L,and the concentration of isoamyl alcohol is about 250 mg/L.Because of the stability of higher alcohols,production process of liquor should be monitored for producing less higher alcohols.At the same time,in order to reduce irritant substances,the concentration of acetaldehyde should be controlled in high alcohol content Chinese liquor.Finally,the components of various Luzhou-flavor liquors were studied to verify the accuracy of Luzhou-flavor liquor quality evaluation model.As a way to judge the quality of Luzhou-flavor liquor quickly,this model can filter out low quality liquor with a large difference in acid/ester.At the same time,it can select high quality liquor by the concentration of main aroma substances.Therefore,this model has certain accuracy and applicability.