Workflow for the quantification of soluble and insoluble carbohydrates in soybean seeds

Authors: MORETTI, ADEMAR - University Of North Texas; ARIAS, CINTIA - University Of North Texas; MOZZONI, LEANDRO - University Of Arkansas; CHEN, PENGYIN - University Of Missouri; McNeece, Brandon; Mian, Rouf; MCHALE, LEAH - The Ohio State University; ALONSO, ANAPAULA - University Of North Texas

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/19/2020
Publication Date: 8/21/2020
Citation: Moretti, A., Arias, C.L., Mozzoni, L.A., Chen, P., Mcneece, B.T., Mian, R.M., Mchale, L.K., Alonso, A.P. 2020. Workflow for the quantification of soluble and insoluble carbohydrates in soybean seeds. Molecules. https://doi.org/10.3390/molecules25173806.
DOI: https://doi.org/10.3390/molecules25173806

Interpretive Summary: The total carbohydrate and carbohydrate profiles of soybean seed are very important for its end uses. Increases in oil and protein content have been historically pursued by breeders and genetic engineers, consequently, rapid methods for their quantification are well established. The interest in complete carbohydrate profile in mature seed, on the other hand, has increased in recent years due to numerous attempts to redirect carbohydrates into oil and protein, or to offer specialty seed with a specific sugar profile to meet animal nutritional requirements. In this work, a sequential protocol for quantifying reserve and structural carbohydrates in soybean seeds was developed and validated. Through this procedure, the content of soluble sugars (glucose, fructose, sucrose, raffinose, and stachyose), starch, hemicellulose and crystalline cellulose can be determined in successive steps from the same starting material using colorimetric assays, LC-MS/MS, and GC-MS. The entire workflow was evaluated using internal standards to estimate the recovery efficiency. Finally, this workflow was successfully applied to eight soybean cultivars harvested from two locations and the resulting correlations of carbohydrate and oil or protein are presented. This methodology has the potential not only to guide soybean cultivar optimization processes but also to be expanded to other crops with only slight modifications. This new methodology has the promise of making seed carbohydrate profiling more efficient.

Technical Abstract: Seed composition of soybean has a profound impact on its market value and commercial use as an important commodity. Increases in oil and protein content have been historically pursued by breeders and genetic engineers, consequently, rapid methods for their quantification are well established. The interest in complete carbohydrate profile in mature seed, on the other hand, has increased in recent years due to numerous attempts to redirect carbohydrates into oil and protein, or to offer specialty seed with a specific sugar profile to meet animal nutritional requirements. In this work, a sequential protocol for quantifying reserve and structural carbohydrates in soybean seeds was developed and validated. Through this procedure, the content of soluble sugars (glucose, fructose, sucrose, raffinose, and stachyose), starch, hemicellulose and crystalline cellulose can be determined in successive steps from the same starting material using colorimetric assays, LC-MS/MS, and GC-MS. The entire workflow was evaluated using internal standards to estimate the recovery efficiency. Finally, this workflow was successfully applied to eight soybean cultivars harvested from two locations and the resulting correlations of carbohydrate and oil or protein are presented. This methodology has the potential not only to guide soybean cultivar optimization processes but also to be expanded to other crops with only slight modifications.