Nonstructural carbohydrates

Beauchemin, K. 1995. Optimizing structural and nonstructural carbohydrate concentrations in dairy cow diets/project. In Agriculture and food industry. Agriculture Canada, Edmonton. 

Jerusalem artichoke had a similar methane production potential for repeated cuttings in the Finnish trials, whereas other leafy energy crops assessed, such as giant knotweed (Reynoutria sachalinensis F. Schmidt ex Maxim.) and sugar beet tops (Beta vulgaris L.), had methane potentials that increased at later harvests. Lignin levels were also unusually constant for the tops of Jerusalem artichoke, regardless of maturity, while nonstructural carbohydrates (fructans) increased in the stems... 

Most analysis methods for the determination of carbohydrates in biomass incorporate a two-stage acid hydrolysis to separate individual polymers and hydrolyze them to simple compounds that can be readily analyzed by chromatographic or spectroscopic techniques. The first stage subjects the biomass sample to a concentrated acid that disrupts the noncova-lent interactions between biomass polymers. A second, more dilute stage follows, which is optimized for complete polymer hydrolysis and minimized degradation of monomeric sugars. Failure to remove nonstructural materials may result in incomplete hydrolysis of... 

Research pertaining to the composition and structure of SB carbohydrates is ongoing, but is not yet as mature as research on proteins and lipids. Nevertheless, in this chapter, the available literature on SB and SBM carbohydrates is reviewed and categorized. Soybean and SBM carbohydrates are discussed based on their functionality in the plant (nonstructural or structural), and their value as feed or food ingredients. 

The carbohydrate concentration in whole SB is lower than in SBM, due to the concentrating effect of lipid extraction on the latter. Whole SB contain approximately 27% nitrogen free extract (NFE) and 6% crude fiber (CF) on a dry matter basis (DMB), whereas SBM with or without hulls contains 36% NFE and 8% CF or 34% NFE and 4% CF, respectively (Potter Potchanakorn, 1984). Although NFE (plus CF) is not commonly used today because of the limited information it provides on carbohydrates from a nutritional standpoint, it provides a reasonable indication of the gross carbohydrate content of a feed- or foodstuff. The NFE contains the nonstructural carbohydrates and part of the structural carbohydrates, and CF contains part of the structural carbohydrates. 

The remainder of carbohydrates in SB and SBM not accounted for in the nonstructural carbohydrates belongs to the structural carbohydrates. The structural carbohydrates are, by definition, polysaccharides because of their function in the plant and include those fractions that can be quantified by common fiber analysis assays. Con-... 

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. 

J. D. Trent and S. Christiansen, Determination of Total Nonstructural Carbohydrates in Forage Tissue by p-Hydroxybenzoic Acid Hydrazide Flow Injection Analysis. J. Agric. Food Chem., 34 (1986) 1033. 

REICHENBACKER, R.R., SCHULTZ, R.C., HART, E.R., Artificial defoliation effect on Populus growth, biomass production, and total nonstructural carbohydrate concentration, Environ. Entomol, 1996, 25, 632-642. 

Solomon, R., Chase, L.E., Ben-Ghedalia, D., and Bauman, D.E. (2000) The Effect of Nonstructural Carbohydrate and Addition of Full Fat Extruded Soybeans on the Concentration of Conjugated Linoleic Acid in the Milk Fat of Dairy Cows, J. Dairy Sci. 83,1322-1329. 

Murray SC, Sharma A, Rooney WL, et al. 2008b. Genetic Improvement of Sorghum as a Biofuel Feedstock I. Qtl for Stem Sugar and Grain Nonstructural Carbohydrates. Crop Sci. 48 2165-2179. 

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