Effects Of Different Soybean Varieties On The Quality Of Fermented Natto

Natto is made from leguminous crops fermented by Bacillus Natto Sawmura.It contains soybean isoflavone,linoleic acid,soybean lecithin and many other functional substances,and contains its unique nattokinase.In this paper,Yuehuang 5,Yuehuang 17,Yuehuang 1,guixia 2,Guangxi bean,Ma Shan Ren Feng black beans,Brazil 10,No.Brazil 13,8 strains of soybean as materials.To explore the difference of natto quality.The results are as follows:The changes of content of components in soybean before and after fermentation.Content of water,crude protein,total sugar,polysaccharide and reducing sugar before and after fermentation were compared.Compared with cooking soybean natto.Water content decreased,The contents of crude protein,total sugar,polysaccharide and reducing sugar increased.Among them,the highest protein content of Ma Shan Ren Feng black bean was 20.83%,and the content of sugar in the c beans was the highest,10.61%.Differences in functional active components of natto fermented by different soybean varieties.An agar-fibrin plate assay to determine Nattokinase activity.The natto kinase activity of natto fermented in the c beans was the highest,reaching 28321 + 811.4 IU/g,which was as high as 21 times as compared with that of the Ma Shan Ren Feng black bean with the least enzyme activity.The activity of nattokinase had a positive correlation with the hundred-grain weight of soybean,The natto kinase activity of natto fermented by small grain soybean was higher than that of big grain soybean;The Total Isoflavones Content and components in soybean varieties before and after fermentation were determined by hplc,Guixia 2 before fermentation of soybean isoflavone content was the highest,0.1616%,No.13 Brazil soybean isoflavone content was the lowest,a difference of about 3.5 times,According to the total amount of soybean isoflavone from big to small order of Guixia 2> Ma Shan Ren Feng black beans>Yuehuang 1>Yuehuang 17>Yuehuang 5>Brazil 10>Brazil 13>Guangxi beans;After fermentation,the soybean isoflavone content of natto was the highest in The c bean fermentation,and was 0.3847%.The soybean isoflavone was still the lowest after the fermentation of Brazil No.13 soybean,and the difference was about 4.6 times,According to the total amount of soybean isoflavone from big to small order of Yuehuang 1>Guixia 2>Yuehuang 17>Yuehuang 5>Ma Shan Ren Feng black beans>Brazil 10>Guangxi beans>Brazil 13.During fermentation,only the Daidzein content did not change significantly.Differences in sensory quality of natto fermented by different varieties of so ybean.By sensory evaluation,the highest scores is Yuehuang 1.Rheological properties of natto mucilage were analyzed by rheometer,According to the viscosity from big to small order are Yuehuang 1>Guixia 2>Brazil10>Brazil13>The a bean>The b bean>Guangxi b eans>Ma Shan Ren Feng Black beans.The composition and characteristics of natto mucus were analyzed.The moisture content in mucus was about 70%,and the sugar content was very large.The main substance was polysaccharide.There was a positive correlation between the wire drawing property and the viscosity of natto mucus.The correlation coefficient was 0.9286,and the P<0.01 reached a very significant difference.The polysaccharide in mucilage is an important factor influencing the viscosity of drawing and the drawing property of mucilage.The polysaccharide has positive correlation with the content of polysaccharide contained in the mucus of natto,the correlation coefficient is 0.9594,and the P<0.01 reaches the very significant difference.The activities of protease,cellulase and xylanase in natto vary greatly.According to the activity of cellulase from large to small order of Guangxi beans?Yuehuang 5?Ma Shan Ren Feng Black beans?Yuehuang 17?Yuehuang 1?Brazil 13?Guixia 2?Brazil 10,The maximum activity of Guangxi beans was 30.8 + 0.5 U/g,and the activity of Brazil 10 was the smallest,14.8 + 0.4 U/g;According to the activity of xylanase from large to small order of Guixia 2?Brazil 10?Guangxi beans?Ma Shan Ren Feng Black beans?Yuehuang 17?Brazil 13?Brazil 10?Yuehuang 5.Guixia2 most active,215.5 + 0.3 U/g,Yuehuang 5 xylanase activity is the lowest,121.1 + 0.7 U/g;according to the protease activity in descending order for Yuehuang 17?Yuehuang 1?Yuehuang 5?Guangxi beans?Guixia 2?Brazil 10?Brazil 13?Ma Shan Ren Feng Black beans.The activity of Yuehuang 17 was the highest,77.6 + 0.6 U/g,and Ma Shan Ren Feng Black beans activity was 16.1 + 0.7 U/g.The free amino acids in natto were analyzed,The total amount of free amino acids in fermented natto from big to small order of Ma Shan Ren Feng Black beans>Guixia 2>Yuehuang 17>Yuehuang 1>Brazil 13>Guangxi beans>Yuehuang 5>Brazil 10.The highest content of Ma Shan Ren Feng Black beans was highest,the total amount was 3162.8 μg/mg,and the content of Brazil 10 was the lowest,and the total amount was 636.54 μg/mg.In flavor amino acids,According to the content from high to low are bitter amino acid>flavor amino acid>sweet amino acid> tasteless amino acid.The content of bitter amino acid was the highest,which was about 70%.The volatile flavor compounds of fermented natto were analyzed by HS-SPME-GC-MS,and 67 volatile compounds were identified.Among them,ketone content is the most,and its relative content is the highest.Brazil 13 has the highest content of 62.07%.According to the evaluation of the odor in the sensory evaluation of natto,it was indicated that the substance of furazolidone played a decisive role in the special flavor of natto.