Study Of Method On Esterification Technology Of Luzhou Flavor Fermented Grains And Design Of Fermentation Vessel

In this experiment,the fermented grains after esterification,which out of cellar from a winery in Sichuan was used as the test object.The physical and chemical indexes detection and flavor components of the fermented grains under different acidity,different temperature and different alcohol content were analyzed,and the best esterification was obtained through single factor test and orthogonal test.The effects of different esterification methods(overturn operation and no overturning operation)on the physical and chemical indexes and flavor components of the fermented grains were studied under the optimal esterification conditions,and the effects of different esterification methods on the flavor components and sensory evaluation of liquor were studied through pilot experiments.A new type of fermentation vessel was designed on the basis of the esterification test.The results of the study are as follows:(1)Analysis of physical and chemical indexes and flavor components of fermented grainsWith the increase of initial alcohol content,the alcohol content and starch content of fermented grains after esterification decreased significantly(P<0.05);reducing sugar,acidity,acidity reduction value and ethyl caproate content all increased significantly(P<0.05);The content of total esters,ethyl lactate and ethyl acetate generally increased first and then decreased.The content of total esters reached the maximum value when the acidity was 4.0 mmol/10g,which was 2.08 g/kg.With the increase of esterification temperature,the alcohol content and starch content of fermented grains after esterification decreased significantly(P<0.05);reducing sugar and ethyl caproate contents all increased significantly(P<0.05);The contents of acidity,total esters,ethyl lactate and ethyl acetate generally increases first and then decreases.The total esters reach the maximum at a temperature of 30℃,which was2.19 g/kg.With the increase of initial alcohol content,the content of starch,acidity,and reducing sugars after esterification of fermented grains decreased significantly(P<0.05),alcohol content,ethanol consumption value,total esters,ethyl caproate,and ethyl lactate contents all significantly increased(P<0.05),the ethyl acetate content increases first and then decreases,the total ester reaches the maximum value at 9%vol,which was 2.28 g/kg.On the premise of single factor experiment,the orthogonal experiment was designed.The optimal esterification conditions obtained by orthogonal test are:acidity 4.0 mmol/10g,temperature 30℃,alcohol content 9.5%vol.Compared with the non-reversed esterification method,the physical and chemical indexes and flavor components of the fermented grains were significantly higher(P<0.05).(2)Analysis of Baijiu Flavor Components and Sensory Evaluation of Liquor SamplesThe optimum esterification conditions were selected by orthogonal test,under this condition,the pilot test was carried out.Analysis of distilled Baijiu,which was from the fermented grains after esterification.The results are as follows:Most of the flavor components,ester content,and acid content in the test group were significantly higher(P<0.05)than the control group and the blank group,while the ethyl acetate content was significantly lower(P<0.05)than the control group and the blank group.Group:The contents of most higher alcohols in the blank group was significantly higher(P<0.05)than the test group and the control group,while the content of n-propanol was significantly lower(P<0.05)the test group and the control group.Sensory evaluation was conducted according to the Luzhou-flavor liquor scoring and evaluation standard table,and the scores were in order of test group>control group>blank group.(3)Design new fermentation equipmentIn order to meet the requirements of esterification experiments,a new type of fermentation vessel was designed.The design results are as follows:According to the conditions required for the esterification test,a new type of fermentation vessel is designed.The volume of the vessel is 2.6 m~3.The vessel is mainly composed of an outer frame,some steel plates for pit mud,a liquid injection port,a one-way valve,a water outlet,some hooks,for fixing pit mud,and a fixed card.The pit mud is fixed by steel plates,the mixed liquid is injected into the liquid injection port,the gas is discharged from the one-way valve,and the hooks is fixed by the bridge crane to carry out the operation of entering and leaving the pit.The steel plates for pit mud are fixed by bolts,and finally,The container is sealed by a bottom plate,bolts,and rubber.