Brewing Technology Of Quinoa Beer And Its Flavor Substance Analysis

In recent years,with the progress of society,the change of consumption concept and the enhancement of consumers'health awareness,consumers pay more attention to the diversification,taste and quality of beer products.Quinoa has a high nutritional value and is rich in protein and contains all essential amino acids that the human body cannot synthesize on its own.Quinoa also has a high content of vitamins and minerals,and is rich in a variety of functional nutrients,such as polyphenols and flavonoids.When quinoa is used in beer brewing,the rich nutrients in quinoa can be given to beer and the nutritional characteristics of beer can be increased.Based on these characteristics of quinoa,it is of great research value to apply it to beer brewing.In this experiment,the brewing process of adding quinoa was optimized.White quinoa was selected as raw material and fermented with top-fermenting yeast.Firstly,by single factor orthogonal test,the optimal mashing process was determined as follows:the addition amount of quinoa was 20%,the malt was 80%,the ratio of material to water was 1:4,and the mashing-in temperature was 44?.The physicochemical parameters,sugar spectrum and amino acid spectrum of wort were detected and analyzed.Using sensory evaluation as the index,the addition amount of hop and fermentation process were optimized by single factor response surface test.The optimum conditions were as follows:the dosage of hops was0.78‰,fermentation temperature was 21.8?,and yeast amount was 1.96×10~7CFU/m L,and then the number of living cells,apparent sugar content,diacetyl concentration,alcohol level and p H of young beer were measured during fermentation.After a week of cold storage after fermentation,the physicochemical parameters of the finished quinoa beer were detected.The physicochemical parameters were all within the ideal range.ABTS and DPPH free radical scavenging activities were used to study the changes of antioxidant capacity of beer,quinoa beer was more antioxidant than all malt beer.The original gravity of the final quinoa beer was11°P,the alcohol level was 4.3%vol,the diacetyl content was 0.089 mg/L,and the flavonoid content in the final quinoa beer was determined to reach 108.3mg/L.Finally,the volatile flavor substances in the finished quinoa beer were analyzed by headspace solid phase microextraction gas chromatography.The contents of DMS and acetaldehyde were 0.05 mg/L and 4.71 mg/L,respectively.The contents of ethyl acetate,isoamyl acetate were 23.21 mg/L,4.64 mg/L,respectively.The contents of isobutanol?n-propanol and isoamyl alcohol were22.53 mg/L?53.51 mg/L and 104.27 mg/L,respectively.Quinoa beer has a light yellow body,a white delicate foam,a harmonious aroma and banana aroma and light quinoa fragrance,It has a refreshing taste.In a word,it is a rare characteristic beer.