Study On Chinese Liquor Brewing Using Extruded Sorghum As Material

Single-screw extruder was applied to extrude the sorghum powder in Chinese liquor brewing.Influence of extrusion parameters on extrusion of sorghum power and the effect of fermentation parameters on Chinese liquor were investigated to obtain the optimum extrusion and fermentation parameters.The flavors in Chinese liquor made by extruded sorghum(CLES)and Chinese liquor made by cooked sorghum(CLCS)was compared based on the optimum fermentation parameters.The purpose of this paper was provide reference data for brewing Chinese liquor with extruded materials.The main results were as follows:The optimum extrusion parameters of extruded sorghum in brewing Chinese liquor was determined.The four factors five levels quadratic rotation orthogonal experimental design was applied.Reducing sugar content,gelatinization degree,puffing degree,apparent specific gravity,viscosity and water absorption was selected as main indicator.The SAS 9.1.3 software and response surface methodology was used to study effect of extrusion parameters on the indexes of sorghum puffing.The optimum extrusion parameters were obtained by ridge regression: the barrel temperature was 75 ?,the diameter of die orifice was 8mm,the moisture of material was 20%,and the screw speed was 170 r/min.Under the extrusion parameters,the content of reducing sugar was 2.7021 g/100 g.The range of material viscosity fit for microbial growth and the quantity of rice husk were determined.The material viscosity for microbial growth,600 Pa·s ~ 900 Pa·s,was obtained by the single test.There was no obvious effect of extruded-material water absorption on the growth of microorganism,and the rice husk dosage was 20 g /100 g.The optimum fermentation parameters of extruded sorghum in brewing Chinese liquor was determined.The four factors five levels quadratic rotation orthogonal experimental design was applied.Yield of liquor,total ester content,total acid content and starch content of fermented grains out of pit was selected as indexes.The SAS 9.1.3 software and response surface methodology was used to study the effects of every test factor.The optimum fermentation parameters were obtained by ridge regression: moisture content of fermented grains was 57%,addition of Daqu was 24.5 g/100 g,addition of rice husk was 25 g/100 g and the fermentation time was 25 d.Under this fermentation conditions,the yield of liquor of CLES was 58.15%,it was higher than yield of liquor of CLCS 4.84%.Volatile compounds and contents were detected by combination of HS-SPME(Headspace solid phase microextraction)and GC-MS.Extruded sorghum was used as raw material in Chinese liquor brewing with the optimum extrusion parameters and the optimum fermentation parameters(CLES).Under the same fermentation process,Using cooked sorghum as raw material brew Chinese liquor(CLCS).Volatile flavor compounds was analized in this two kinds of Chinese liquor,76 volatile compounds with 66.8% relative content in CLES,and 70 volatlie compounds with 63.61% relative content in CLCS.The species and total contents of esters in CLES were higher than that in CLCS,while the aldehyde content in CLES was less than that in CLCS.In general,the flavor of the experimental group was better than that of the control group.