Analysis and comparison of seed protein, oil, and sugars in edamame dried using two oven-drying methods and mature soybeans

Authors: JIANG, GUO-LIANG - Virginia State University; Katuuramu, Dennis; XU, YIXIANG - Virginia State University; REN, SHUXIN - Virginia State University; RUTTO, LABAN - Virginia State University

Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2020
Publication Date: 5/13/2020
Citation: Jiang, G., Katuuramu, D.N., Xu, Y., Ren, S., Rutto, L.K. 2020. Analysis and comparison of seed protein, oil, and sugars in edamame dried using two oven-drying methods and mature soybeans. Journal of the Science of Food and Agriculture. 100:3987-3994. https://doi.org/10.1002/jsfa.10443.
DOI: https://doi.org/10.1002/jsfa.10443

Interpretive Summary: Edamame is a vegetable soybean grown mainly in Asia and is known to have high nutritional and economic value. However, this soybean crop is a relatively new crop in the United States and there is insufficient knowledge on seed composition attributes. In this study, a USDA, ARS scientist has collaborated with a team at Virginia State University to identify the nutrient composition in seeds of Edamame soybean. The scientists used advanced near-infra red technologies to characterize the seed content of the different soybean accessions, identifying high levels of protein, oil, and complex sugars that are beneficial for human consumption and health. This study elucidates the nutritional value of Edamame soybean. The results of this study are useful for researchers and plant breeders aiming to develop sweet Edamame soybean varieties with high content of protein, oils, and healthy sugars.

Technical Abstract: Edamame, a vegetable soybean (Glycine max) grown mainly in Asia, has high nutritional and market value and is a relatively new crop to North America. By two years of field trials, we evaluated the seed composition traits in 54 genotypes to analyze the differences and relationship between edamame seeds dried by two oven drying methods and mature soybeans. The genotypic differences were significant for all the traits investigated. Significant differences also existed between the two sets of dried edamame and the mature seed. Protein content in mature soybean averaged 426.8 mg g-1, and 432.8 and 405.6 mg g-1 for the shelled-dried and unshelled-dried edamame. Oil content in the shelled-dried and unshelled-dried edamame averaged 206.3 and 212.6 mg g-1 respectively, while 195.8 mg g-1 for the mature soybean. Sucrose content in mature soybean (60.2 mg g-1) was approximately 1.5 and 3 times of the unshelled-dried and shelled-dried edamame. Mature soybean also exhibited the highest concentrations of stachyose and total sugars, followed by the unshelled-dried and shelled-dried edamame. The broad-sense heritability estimates of traits in mature soybean (49.41-89.16%) were higher than those of edamame (10.26-78.96%). Higher broad-sense heritability was uncovered for protein and oil, but lower estimates for sugars, fiber, and ash. Positive correlations were detected between the two sets of edamame seeds and the mature soybean for protein and oil (r = 0.63-0.88). The result suggests that indirect selection through mature seeds is helpful for the improvement of protein and oil in edamame, while the improvement of seed sugars in edamame is more challenging.Edamame, a vegetable soybean (Glycine max) grown mainly in Asia, has high nutritional and market value and is a relatively new crop to North America. By two years of field trials, we evaluated the seed composition traits in 54 genotypes to analyze the differences and relationship between edamame seeds dried by two oven drying methods and mature soybeans. The genotypic differences were significant for all the traits investigated. Significant differences also existed between the two sets of dried edamame and the mature seed. Protein content in mature soybean averaged 426.8 mg g-1, and 432.8 and 405.6 mg g-1 for the shelled-dried and unshelled-dried edamame. Oil content in the shelled-dried and unshelled-dried edamame averaged 206.3 and 212.6 mg g-1 respectively, while 195.8 mg g-1 for the mature soybean. Sucrose content in mature soybean (60.2 mg g-1) was approximately 1.5 and 3 times of the unshelled-dried and shelled-dried edamame. Mature soybean also exhibited the highest concentrations of stachyose and total sugars, followed by the unshelled-dried and shelled-dried edamame. The broad-sense heritability estimates of traits in mature soybean (49.41-89.16%) were higher than those of edamame (10.26-78.96%). Higher broad-sense heritability was uncovered for protein and oil, but lower estimates for sugars, fiber, and ash. Positive correlations were detected between the two sets of edamame seeds and the mature soybean for protein and oil (r = 0.63-0.88). The result suggests that indirect selection through mature seeds is helpful for the improvement of protein and oil in edamame, while the improvement of seed sugars in edamame is more challenging.