The Experimental Study On Beer Brewing Using Extruded Black Rice As Adjunct

In order to simplify the beer production process,increase the utilization rate of raw materials,improve the specifices and quality of beer,the black rice was chosen as adjunct to produce beer.Parameter of saccharification process was optimized and the components of wort and beer was analyzed,meanwhile,the quality of beer was evaluated in this paper.Specific content as follows:The mashing procedures parameters of beer brewing using extruded black rice as adjunct was optimized.Response surface methodology was selected as optimization technique with five response variables: content of extruded black rice,water/grain ratio,holding time at 50℃,saccharifying time at 63℃ and saccharifying time at 70℃.The SAS 9.1.3 software and ridge regression method were employed to study the impact that the saccharification procedures parameters on the ratio of the wort and so on.The results were shown as follows: content of extruded black rice was 31%,water/grain ratio was 4.00,holding time at 50℃ was 61 min,saccharifying time at 63℃ was 55 min and saccharifying time at 70℃ was 29 min.The fermentable sugar components in wort was analyzed.High performance liquid chromatography method was applied to determine the fermentable sugar components in wort,qualitative analysis and quantitative analysis.The results showed that the content of five fermentable sugar components(fructose,sucrose,glucose,maltose and maltotriose)were 0.12g/100mL、0.21 g/100mL、1.13 g/100mL、6.30 g/100mL、1.17 g/100 mL,respectively.The flavor components and functional composition in beer brewing using extruded black rice as adjunct was analyzed.The solid phase microextraction and gas chromatograph-mass spectrometer(GC-MS)was employed to analyze the volatile flavor components in beer,including qualitative analysis and quantitative analysis.The results showed that the beer contained 35 kinds of volatile flavor components which took up 89.04% of the total peak area and included nine kinds of alcohols(15.87%),twenty-three kinds of esters(71.48%),one kind of acid(1.56%),one kind of alkane(0.05%),one kind of phenols(0.03%).Qualitative analysis and quantitative analysis were used with the method of headspace injection combined with gas chromatography to analyze the volatile flavor components in beer.The contents of anthocyanin in wort and beer were determined with polyamides-66.The method of Folin-reagent and AlCl3 were selected to analyze the contents of total polyphenol and flavone in beer.The results showed that the content of eight volatile flavoring were acetaldehyde(14.16 mg/L),n-propanol(28.32 mg/L),ethyl acetate(12.60 mg/L),isobutanol(16.05 mg/L),isoamyl alcohol(70.33 mg/L),isoamyl acetate(3.85 mg/L),ethyl caproate(0.40 mg/L)and ethyl caprylate(0.37 mg/L).They were all within the normal range to beer.The contents ofanthocyanin in beer was 23.80mg/L.The contents of total polyphenol and flavone in beer were79.98 mg/L and 61.30 mg/L,respectively.The contents of protein and amino acid in wort and beer were determined.Protein and polypeptides’ distributions in wort and beer were analyzed by acetone precipitation combined with the sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE).The content of protein was determined by Lundin fraction method.The free amino acid in wort and beer were analyzed by amino-acid analyzor.The analytical results showed contents of total soluble nitrogen and nitrogenous substances of high,middle and low molecular in wort were 475.07mg/100 mL,108.51 mg/100 mL,100.24 mg/100 mL and 266.32 mg/100 mL,respectively.The range of molecular weight of protein components in wort were 19~22 ku,25~28.5 ku,30~32ku,35.5~38 ku and 42~45 ku.The contents of total soluble nitrogen and nitrogenous substances of high,middle and low molecular in beer were 322.05 mg/100 mL,63.21mg/100 mL,77.04 mg/100 mL,181.79 mg/100 mL.The range of molecular weight of protein components in wort were 20~22 ku,25~28.5 ku,30~32 ku,37~39 ku and 43~46 ku.There were all 16 kinds of free amino acid in wort and beer produced using extruded black rice as adjunct.The content of amino acid in experimental group were higher than that in control group.The total contents of amino acid in wort and beer which comes from experimental group were 159.10 mg/100 mL and 108.09 mg/100 mL.The total contents of amino acid in wort and beer from control group were 123.00 mg/100 mL and 71.79 mg/100 mL.