Carbohydrates in soybeans

The nonstructural carbohydrates in SB can be divided based on their chemical properties (See section Carbohydrates in Soybeans and Soybean Meal), but also on their value as nutrients. The different categories of SB carbohydrates identified based on chemistry are profoundly different in their rate of digestion and their physiological behavior. 

Acetonitrile precipitation has been the subject of some papers dealing with the analysis of mono- and disaccharides in milk and dairy products, oligosaccharides in soybeans, and general methods for sugars in foods (23). Aqueous ethanol has also been frequently utilized in the extraction of lipids as undesirable components along with the carbohydrates. A further treatment with chloroform will free the hydroalcoholic extract from the lipids. 

FIG. 4 Structure of representative saponins found in soybeans (triterpenoid) and eggplant (steroid). The R group represents one or more carbohydrate linkages that may contain rhamnose, xylose, arabinose, galactose, glucose, or glucuronic acid. 

AI. The amount of acetone-insoluble matter (%A1) is a measure of the polar material found in lecithin. In soybean lecithin, the acetone-insolubles typically contain 70-75% phospholipids, with the remaining portion consisting of glycolipids, carbohydrates, and a small amount of residual triglyceride oil. The amount of acetone-insoluble matter is determined by the AOCS Official Method Ja-4-46 (77). 

Another protein in soybeans that is destroyed by extrusion is the trypsin inhibitor, which is produced in the pancreas. Without the action of trypsin, the animal cannot use protein, as it is trypsin that splits or hydrolyzes the protein molecule. Other less important enzyme inhibitors that are denatured by the extruder relate to fats and the carbohydrate fraction of a diet. As the heat needed to deactivate enzymes is less than that needed to prepare oilseeds for oil extraction, the effect on the amino acids is much less severe, thus making them more available to the animal or higher in digestibility. 

This section on chemical factors related to quality in soybeans is divided into subparts on protein and oil, fatty acids, amino acids, tests for protein, carbohydrates and sugars, and other factors that are often discussed, particularly as soybeans are enhanced for more specific end uses. The other factors include tests for fiber, phosphorus, to-copherols, and isoflavones. The intent is to discuss the importance of these factors, to provide background, and, because of increased use of near-infrared spectroscopy as a measurement method for whole and ground soybeans, to include that technology in the discussion of test measurements. While many primary and other methods for measuring these chemical factors are available, this chapter does not intend to cover those methods. 

Table 9.1. Approximate Composition of Totai Carbohydrates in Dehulled Soybean MeaF- ...

Lodhi, G.N. R. Renner D.R. Clandinin. Available carbohydrate in rapeseed meal and soybean meal as determined by chemical method and chick bioassay. J. Nutr. 1969, 99, 413 18. 

Stachyose is the principal transport carbohydrate in the phloem of some herbaceons and woody plants [19,20], Raffinose and stachyose are fonnd in leguminous seeds such as soybean (Glycine max) and lupine (Lupinus spp.) where they prevent desiccation of seeds after maturity [21] and serve as carbon reserves for use during germination [22],... 

Analysis of sugar composition in nectar can be used for detecting variation between flowers or nectaries from different taxonomic varieties, and consequently generate differences in type and frequency of visitation of pollinators. Alves et al. (2010) studied the total sugar concentration in soybean nectar Glycine max L. Merrill) var. Codetec 207 by spectrophotometry, using the general method for carbohydrates determination by phenol-sulphuric technique (Dubois et al., 1956). 

Ferrarese, M., de Souza, N., Rodrigues, J. Ferrarese-Filho, O. (2001). Carbohydrate and Upid status in soybean roots influenced by ferulic acid uptake. Acta Physiologiae Plantarum, 23,421-427. 

Bainy, E.M., Tosh, S.M., Corredig, M. et al. (2008) Varietal differences of carbohydrates in defatted soybean flour and soy protein isolate by-products. Carbohydr. 

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