Process Optimization And Quality Evaluation Of Oat Millet Laozao Fermented With Different Grain Koji

As characteristic grain crops in Inner Mongolia,oats and yellow rice have high nutritional value and unique flavor,which are ideal bases for the preparation of characteristic fermented foods.Therefore,this test uses oats and yellow rice as raw materials to develop a whole grain laozao.Discussion on the soaking and cooking time of oats and yellow rice kernels.Based on the previous research,the compound cereal koji was selected by antioxidant index,and the saccharification conditions were optimized by single-factor orthogonal test.The optimal yeast was selected by physical and chemical indexes and sensory scores,and the unilateral and bilateral fermentation processes were optimized by univariate response surface test.The main results are as follows:(1)Study the effects of soaking water absorption rate and cooking time of oats and yellow rice at room temperature on the grains of oats and yellow rice.The results showed that the optimal soaking time of oats and yellow rice was 12 h and 6 h,respectively,when the water absorption rate of oats and yellow rice reached a steady state,and the cooking time of oats and yellow rice was the highest gelatinization degree and sensory score at 50 min and 30 min,respectively.(2)Through the compound of different types of grain koji,the compound grain koji with the best antioxidant performance was screened.It was found that the antioxidant activity of oat corn laozao was the best,with flavonoids and polyphenols of 1.55 mg/g and2.54 mg/g,reducing power of 0.305,and DPPH clearance of 88.6%,respectively,and the antioxidant activity of compound aspergilla was better than that of single grain.(3)When the ratio of oat koji/corn koji is 3:7,the reducing sugar content of oat yellow rice laozao is the highest.At this ratio,the optimal saccharification conditions were:saccharification time 12 h,temperature 55 °C,and grain koji addition 20%.(4)Select different Saccharomyces cerevisiae fermentation laozao residues,and screen the yeast for fermentation by reducing sugar and alcohol content.The study found that the reducing sugar content of laozao residue fermented by Fruit Wine Yeast was2.06%,and the alcohol content was 2.97% Vol,compared with the laozao residue fermented by White Wine Yeast and Rice Yeast,the wine was clear and transparent,with a fruity aroma and moderate sour and sweet ratio,so Fruit Yeast was selected as the yeast for subsequent fermentation.(5)The unilateral and bilateral fermentation processes of oats and yellow rice laozao were optimized by single factor and response surface tests.The results showed that the optimal fermentation process of oats and yellow rice laozao was as follows: fermentation time was 3.9 d,fermentation temperature was 29.7 °C,yeast addition was 0.08 g/100 g,sensory score was 88.65 points,alcohol content was 2.93 % Vol,and total acid was 14.32g/L.The optimal process of unilateral fermentation was as follows: fermentation time was22 h,fermentation temperature was 30 °C,yeast addition was 0.11 g/100 g,sensory score was 87.26 points,alcohol content was 3.17 % Vol,total acid was 14.54 g/L,and the sensory score of bilateral fermentation laozao was higher,but the alcohol content and total acid content were weaker than that of unilateral fermentation Laozao.