| In recent years,my country's economy has developed rapidly,and people's dietary structure and living habits have gradually changed.The refined diet and reduced exercise volume have led to chronic metabolic-related diseases,such as hyperlipidemia,hypertension,diabetes,obesity and cardiovascular disease.Diseases have gradually become a major problem that endangers human health.Oats is an annual herbaceous plant belonging to the Gramineae Oats genus,and highland barley is a crop of the Gramineae barley genus.Oats and highland barley are rich in active and nutrient components,are green,pollution-free,healthy and have health benefits,so they are attracting more and more attention.The nutritional components of the two are in line with the"three highs and two lows"nutritional model we are pursuing,namely high protein,high fiber,high vitamins,low fat and low sugar.Distilled spirits are fermented from glutinous rice,with clear color,strong aroma,and nutritious fermented alcoholic beverages.However,the law of strains in the fermentation process is still unclear.Among them,the utilization of dominant strains and the changes in fermented ingredients need to be studied.Shaanxi is the birthplace of fermented glutinous rice with abundant strains.In this experiment,the representative local fermented fermented rice in Shaanxi was used.High-throughput sequencing was used to analyze the changes of bacteria and fungi in traditional fermented fermented fermented rice.Through screening,the strain with the most fermentation performance was selected.The mold and a strain of yeast are compounded to obtain fermented koji.Using ordinary oats and superheated steam to treat oats,yellow barley and black barley as raw materials,they are matured and fermented,and the physical and chemical properties(color,total sugar,total acid,p H)of the original grains,matured grains and fermented grains during the treatment process(color,total sugar,total acid,p H),And the determination of nutrients(starch,protein,dietary fiber,?-glucan),and finally the determination of its phenolic substances(free phenols,bound phenols,free flavonoids,bound flavonoids,anthocyanins)and antioxidant activity,It is expected to provide a reference for the development of oats and barley.The main findings are as follows:(1)The changes of bacteria and fungi in different fermentation times of traditional fermented riceHigh-throughput sequencing technology was used to analyze the succession of microbial communities in traditional fermented wines with different fermentation times.The results showed that bacteria obtained a total of 550,407 pairs of effective columns;fungi obtained a total of 614,646 pairs of effective columns;the pass rates were all 85-100%,and the Q20 and Q30 of the sample are above 95%,the sequencing result can reflect the true situation of the sample.The sparsity curve results prove that the sequencing depth is sufficient to reflect the diversity of the microbial community in the current sample,and the Alpha diversity indicates that the h0 group is rich in species composition and high in abundance.Beta diversity shows that there is a significant difference between the h0 group and the h72 group.The biggest difference is h72(bacteria 0.6187,0.6428)(fungi 0.1763,0.1770),which indicates that fermentation directly causes significant differences between bacteria and fungi in the fermentation system of wine fermentation.Taxonomic analysis shows that there are 311bacterial genera.The three bacterial genera with the highest abundance are Lactobacillus,Pediococcus,and Lactococcus.Among them,Acetobacter accounts for the largest proportion in the 24-hour fermentation.The content of Lactobacillus increases significantly in the 24-hour and 48-hour fermentation samples.0.8%increased to 58%.There are 117 fungal genera,and the diversity of bacterial species composition is more abundant than that of fungi.The first four genera with the highest abundance are Rhizopus,Wickham's yeast,Cyberlindnera,and Miller's yeast.Rhizopus is the dominant species.(2)Preparation of fermented koji and observation of strain morphologyThe fermentation koji was identified from the results of preliminary laboratory research,which are Aspergillus niger and Cyberlindnera of Yeast respectively.Aspergillus niger grows fast on the culture medium.It is white at first and then becomes black velvet.Under an optical microscope(40 mesh),the spores are spherical,dark brown,hyphae are developed,and branched.Yeast,opaque,smooth,moist,viscous,easy to be provoked,milky white.Under an optical microscope(100 mesh),it is oval.(3)The effect of fermentation on the physical and chemical properties and nutritional components of oats and highland barleyComparing the oats and the superheated steam treatment oats group with the yellow barley and black barley after maturation and fermentation,fermentation can improve the color of the food,increase its acidity and total sugar,and have a good flavor.For oats,the main flavor substances are esters,alcohols,alkanes,and aldehydes and ketones.Ethyl acetate accounts for the largest proportion of the flavor substances in the oatmeal group treated with superheated steam,and the largest proportion after maturation is 4-hydroxy-2-Butanone(84.93%)and 3-methyl butyl acetate(50.45%)had the highest proportion after fermentation.The unique substances in the fermentation group are acetates and alcohols.After yeast fermentation,the content of esters increases.After maturation and fermentation,the content of esters increases significantly.Among them,the content of 3-methylbutyl acetate(fruit aroma)is the most..For highland barley,the only acidic methyl esters before fermentation are converted into acetates after fermentation,while alkanes,aldehydes and ketones are basically non-existent after fermentation.Grains are matured and fermented to decompose and utilize starch,release small-molecule protein,increase protein content significantly,release soluble dietary fiber and?-glucan,which provide a reference for the development of oats and highland barley.(4)The effect of fermentation on the phenolic substances and antioxidant activity of oats and highland barleyAfter oats,superheated steam treatment oats,yellow barley,and black barley are matured and fermented,the maturation destroys the content of phenols,but the fermentation causes free phenols to be released again.The anthocyanin in the barley is extremely unstable,resulting in a decrease in the content after the maturation treatment and the fermentation treatment.Based on DPPH·scavenging ability,ABTS·~+scavenging activity and reducing power,it shows that fermentation can improve its antioxidant activity. |
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