Research On The Effect Of Nutrient Changes During Soybean Germination On The Output Ratio Of Soybean Sprouts

Soybean sprouts are a popular vegetable in China,which are cool and refreshing,crisp and tender,low in calories,and also contain fiber and vitamin C.They are also useful in preventing digestive tract cancers and cardiovascular diseases.In this study,166 varieties were tested for germination in northeastern China,and the dynamic changes in germination patterns of soybean varieties were investigated according to the phenotypic traits of each variety and the output ratio of soybean sprouts.Through the determination of nutrient content at different germination periods,the relationship between the level of output ratio and the nutrient content among varieties was investigated to provide a theoretical basis for screening and breeding of special varieties of sprouting beans with high quality and high bean sprouting output ratio,which has certain reference value for improving the yield of bean sprouts in bean sprout production.In this experiment,166 soybean varieties were grown continuously in 2021 and 2022 in Northeast China,and germination tests were conducted after autumn harvest,and phenotypic indicators were sampled and observed after 98 h of continuous incubation.The data from the two years of observation were analyzed together,from which four soybean varieties each with high and low yield ratios were selected for further analysis of the trend of growth dynamics at 144 h of germination of soybean.The nutrient content and enzymatic activity of these five periods were measured,and the influence of the nutrient content of soybean cotyledons on the output ratio of soybean sprouts was analyzed in depth by identifying the dry bean period,the swelling point period,the germination point period,the fastest growth period and the terminal period of each variety according to the trend of soybean germination dynamics.The main results are as follows:1.The joint ANOVA for each bean sprout trait for two years yielded significant and highly significant variety effects for output ratio,hypocotyl length and 100-grain weight,with no significant year effects.2.From the analysis of germination dynamics of soybean varieties with high and low output ratios,it was found that the growth rate of output ratio and hypocotyl length of soybean showed a "slow-fast-slow" process during germination,and the whole period conformed to the "S" type growth curve.The four varieties with higher output ratios emerged earlier in the germination process and had faster hypocotyl elongation,while the four varieties with lower output ratios emerged later in the germination process and had slower hypocotyl elongation in the growth process.3.The analysis of nutrient contents at different germination periods showed that the trend of nutrient changes during germination of soybean was the same for all varieties,but the nutrient contents reached significant differences among varieties at different periods.The changes in starch and soluble sugar content showed a rapid decline at the dry bean-swelling point,followed by a steady decline;the water-soluble protein content showed an almost "S"-shaped trend with the prolongation of germination time;the changes in fat content showed an increase after swelling,followed by a rapid decrease with the prolongation of germination time;the changes in fat The trend of fat oxidase activity was similar to that of fat content;β-amylase activity increased before the germination period,and reached the maximum value during the germination period,and then decreased.4.The correlation analysis showed that the bean sprout output ratio was highly significantly and positively correlated with bean sprout hypocotyl length,highly and negatively correlated with100-grain weight,significantly and negatively correlated with soybean soluble protein content,and significantly and positively correlated with fat and starch content.The 100-grain weight of soybean was negatively and significantly correlated with dry bean starch and fat content,and positively and significantly correlated with protein and soluble sugar content.5.The correlation analysis of nutrient changes in cotyledons during each period concluded that starch was the first nutrient to be initiated during soybean germination,and fat played a major role in the later stages of soybean germination.The amount of change in starch was significantly and positively correlated with germination potential and germination rate;β-amylase activity was significantly and positively correlated with the amount of change in starch;the amount of change in starch at the point of swelling was significantly and negatively correlated with the final output ratio and hypocotyl length of soybean sprouts.The amount of fat change after the point of germination was significantly and negatively correlated with bean sprout output ratio and hypocotyl increase;it was significantly and positively correlated with the activity of fat oxidase.In summary,soybean germination process starch and fat play an important role,so in the selection of soybeans for germination when the choice of 100 grain weight is small,full,less watersoluble protein content and higher fat and starch content varieties,can effectively improve the output of soybean sprouts than to increase economic efficiency.