Study On The Correlation Between Isoflavone Content And Main Quality Index Of Soybean Varieties In Gansu Procince

In this study,the main quality indexes of crude protein and crude fat were detected and analyzed in 172 soybean samples which were 86 cultivated and 86 local cultivars respectively that been planted in 2014-2015 in Gansu Province.The extraction process of soybean isoflavones was optimized by response surface method.The contents of soybean isoflavones and their 5 components were determined by high performance liquid chromatography(HPLC).The correlation between soybean isoflavone components,crude protein and crude fat was also studied,providing data support for soybean product development and breeding in Gansu Province.The main results are as follows:1.The extraction process of soybean isoflavones was optimized by response surface method.The results showed that the extraction rate of soybean isoflavones was significantly affected by the methanol concentrations(P< 0.05).The effect on respective factors showed a dose-response relationship of methanol extract concentration>extraction time>solid-liquid ratio.we modified the extraction conditions of a solid-liquid ratio of 1: 50,45 min for the extraction time,and 85% methanol extraction solvent.Under the conditions,which basically agrees with predictive value,confirmed the accuracy and practicability of the regression equation of our method obtained by response surface,and can be used to detect large quantities of samples.2.The results that used the optimal method showed that the average content of 172 varieties of soybean isoflavones was.Among them,Jingyuan,the black and yellow,black beans,black beans,fried black eight total isoflavone content is higher than 8000mg/kg,which belongs to the high quality varieties.3.The analysis of the correlations between the main quality indexes of soybean and five soybean isoflavonecontents.The crude protein content and crude fat content of a total of 172 soybean cultivars in Gansu province and landraces was determined according to the national standard method GB5009.6-2010 and GB5009.6-2010.The results showed the average crude protein content of soybean was 409.3 g/kg ranging from 340.5 to 511.1g/kg and coefficient of variation was 6.80%.Crude fat content ranged from 153.1 to 233.4 g / kg with an average content of 191.4 g/kg and a coefficient of variation of 10.4%.Among which the crude fat content of 28 soybean cultivars was more than 210 g/kg,accounting for 16.3% of the all samples,however,6 of local cultivars was above 210g/kg,accounting for 3.49% of the total samples.Obviously,it was concluded that the content of high fat in cultivars was much more than in local variety resources.4.The total content of soybean isoflavones showed a negatively correlation with crude protein content,and a significantly negative correlation with fat content,similarly,the content of crude fat and daidzin,daidzein,genistein and daidzein yellow bean four components the content was negatively correlated.After determination,a conclusion was drew that the average total content of isoflavones and its main compositions of daidzin and genistincontents in local varieties are much higher than in cultivated soybean.