Composition of Soybeans

Table 17. Compositions of Soybean Protein Products and Their Uses, wt %...

Recent applications of HPAEC-PAD are many and varied. A representative list includes quantitation of polyglucose metabolites in plasma of dialysis patients,148 analysis of heat-treated milk,149 carbohydrate content in lipopolysaccharides,150 phosphorylated sugars in tissue samples,151 composition of soybean meal,152 carbohydrate composition of recombinant modified tissue plasminogen activator,153 analysis of cyclization products from an enzyme reaction,154 carbohydrate content of glycoconjugate vaccines,155 and monitoring of patients with rheumatoid arthritis.156... 

Amino Acid and Digestible Amino Acid Composition of Soybean Meal, NRC Feeds, and HDG... 

Several groups have investigated the chemical composition of soybean agglutinin. The early amino acid analysis of Wada and coworkers534 differs considerably from the later analyses by Lis and co-workers.538,544 They found almost twice the content of serine, leucine, and lysine, and substantially increased proline than those reported by Wada and coworkers,534 whereas the contents of methionine,... 

Soybeans are comprised of (w/w), 40% protein, 30% carbohydrates, and 20% oil (5, 4). Currently, about 95% of soy protein is used in feed and 4% in food (for human consumption) applications. On the other hand, about 94% of soybean oil is used in food and only about 4% in industrial applications. Soybean oil is a triglyceride, which is a triester of glycerol and three fatty acids. The main fatty acid composition of soybean oil is (w/w) linoleic (54), oleic (23), and linolenic (8), (5). These fatty acids contain 1, 2, and 3 double bonds, respectively, in their hydrocarbon chains. These double bonds or unsaturations are reactive sites and allow for the development of soybean oil for various applications. 

Attempts are being made to modify the fatty acid composition of soybean oil to enhance its usefulness. Oils with less or more saturated acid, with less linolenic acid, and with high levels of oleic acid are in various stages of development (55). 

Table 1 shows the average composition of soybean seed (oU, protein, and some amino acids) grown in the United States during recent years (3). Aside from varietal differences, the composition is affected by various geographic/environmental factors. According to Hurburgh (5), oil is much more variable than protein from year-to-year. States most distant from the center of the Com Belt (probably those with the greatest weather extremes) experience the most variabihty in composition. Table 2 lists some of the environmental and cultivation practices that have an... 

The fatty acid composition of soybean oil changes considerably with maturity and with seed oil deposition (15, 35, 43, 44). In typical soybean triacylglycerols, the palmitate and linolenate tend to decrease with maturity, whereas hnoleate increases. Oleate tends to increase to a maximum and then dechne slightly. Soybeans selected for atypical fatty acid compositions show quite different patterns of change with maturity from typical soybeans. 

The estimated trans-acyl group intake by typical U.S. consumers is 11.1-27.6 g/ person/day (341). A comprehensive review concluded that trans-acyl groups consumed at 4.0% or more of total calories may raise plasma lipid levels (342). As a result of health concerns over the presence of trans-acyl groups in our diet, modifying fatty acid composition of soybean oil to improve its oxidative and flavor stability in ways similar to that obtained by hydrogenation, but without transformation, has become an objective of plant breeders. 

Soybean oil contains 1.5-3.0% phospholipids (71). Crude soybean lecithin has an oil content of about 30%. PC is present at a level of about 16%., PE about 14%, and inositol phospholipids about 12% (7). As can be seen in Table 18 (8), the fatty acid compositions of soybean phospholipids are rich in polyunsaturated fatty acids. Miscellaneous low-level constituents include water, phosphatidic acid, pigments, galactosyl glycerides, various glycolipids, phosphatidylserine, carbohydrates, sterols, and tocopherols. Phosphorus content of crude soybean oil extracted from flours can vary depending on extraction temperature and flour moisture (72). 

A total of 310.3 g of methyl ester were pyrolysed to yield 204.4 g of liquid product which corresponds to a 65.9% actual liquid yield. The theoretical yield based on a typical Cie, C composition of soybean oil, and the y-hydrogen transfer mechanism is approximately 76%. Therefore, the yield based on this limitation is approximately 87%. "niis shows that random cracking of the ester chain does not play a significant role in the reaction. The infrared spectrum shows no carbonyl peaks at 1720 cm. Peaks appearing at 907 cm" and 965 cm arc probably absorptions due to terminal alkenes and trans alkenes, otherwise the spectrum looks like that of a typical alkane. Consistent with these results, elemental analysis gave 83.7% carbon, 14.56%... 

Table 8.2 Main properties and composition of soybean, palm and rapeseed. ...

Ozawa, Y., Sato, H., Nakatani, A., Mori, O., Hara, Y., Nakada, Y., Akiyama, Y. and Morinaga, Y. (2001) Chemical composition of soybean oil extracted from hypocotyl-enriched soybean raw material and its cholesterol lowering effects in rats. J. Oleo Sci., 50, 217-223. 

Perkins, E. G. (1995a) Composition of soybeans and soybean products, in Practical Handbook of Soybean Processing and Utilization (ed D.R. Erickson), AOCS Press, Champaign, IL, pp. 9-28. 

Todd, J.W. M.D. Jellum D.B. Leuck. Effects of southern green stink bug damage on fatty acid composition of soybean oil. Environ. Entomol. 1973, 2, 685—689. 

Kovalenko, I.V. G.R. Rippke C.R. Hurburgh. Determination of amino acid composition of soybeans Glycine max) by near-infrared spectroscopy. J. Agric. Food Chem. 2006a, 54, 3485-3491. 

Schnebly, S.R. W.R. Fehr. Effect of years and planting dates on fatty acid composition of soybean... 

Table 9.5. Composition of Soybean Meals Collected at Ten U.S. Soybean Processing Plants ... 

Karr-Lilienthal, L.K. C.M. Grieshop J.K. Spears G.C. Fahey, Jr. Amino acid, carbohydrate, and fat composition of soybean meals prepared at 55 commercial U.S. soybean processing plants. /. Agric. Pood Chem. 2005, 53, 2146—2150. 

Most lecithins obtained during degumming of edible oils are not suitable for human consumption. Therefore, they are added back to the extracted oilseed meal and used as feed. Only soybean lecithin is snitable for human and industrial uses. Properties required for soybean lecithin are shown in Table 5.4 (adapted after Precise, 1985). The phospholipid fraction of soybean lecithin contains about 30 to 32% phosphatidylcholine, 22 to 28% phosphatidylethanolamine, 18 to 20% phosphatidyUnositol, 3 to 4% phosphatidylserine, and 20 to 29% other snbstances. The fatty acid composition of soybean lecithin is shown in Table 5.5. The technical soybean lecithin obtained by extraction with a hydrocarbon solvent is very different from the phospholipid fraction obtained by extraction with chloroform-methanol (after Folch). 

There may be some nutritional benefits in consuming Immature and germinated soybeans compared to products prepared from mature soybeans. For example, ascorbic acid and 6-carotene are present in rather high amounts in immature and germinated soybeans, whereas mature soybeans are practically devoid of these vitamins. Content of some of the other vitamins and minerals may differ appreciably, but the general composition of soybeans at the three stages of maturity is essentially the same. 

The magnitude of the variation in the composition of rapeseed oil and meal now commercially available has created a need for new terms to describe the products derived from rapeseed. The fatty acid composition of most edible vegetable oils such as soybean, sunflower, or cottonseed oils, varies within narrow limits. Thus, the species or commodity name (e.g., soybean oil) provides a reasonable description of the fatty add composition of soybean oil. In contrast, the erucic acid content of commercially available rapeseed oil may vary from near zero to 55%, and the oleic acid from 10 to more than 60%. A number of terms have been proposed or utilized to describe the new rapeseed oil whose fatty acid composition has been altered by the elimination of erucic acid these include low erucic acid rape-seed oil (LEAR), canbra, and canola. Similar terms such as high erucic acid rapeseed oil (HEAR) and common or traditional rapeseed oil have been used to describe rapeseed oil whose fatty acid composition includes substantial amounts of erucic acid. 

Kasai, T., S. Sakamura, S. Ohashi, and H. Kumagai Amino acid composition of soybean. V. Changes in free amino acids, ethanolamine and two y-glutamylpeptides content during the ripening period of soybean. Agric. Biol. Chem. 34, 1848 (1970). 

The fatty acid composition of soybean oil is influenced by growing conditions, especially temperature during oil deposition in the later stages of seed development. The linoleate and linolenate content of soybeans is increased by low temperature (Howell and Collins, 1957). The linolenate content of A5 particularly can be increased by low temperatures, and it is important to plant this variety early so that it matures under warm conditions (Hammond and Fehr, 1984 Rennie and Tanner, 1989). Although soybean mutants with elevated oleate levels are common, efforts to produce a line with consistently elevated oleate percentages have been frustrated by temperature effects. The line shown in Table 4.3 with an oleate concentration of 70% was produced under warm weather conditions. In a year where the growing season was cool it might drop to <50% oleate. 

Fehr, W.R., Welke, G.A., Hammond, E.G., Duvick, D.N. and Cianzio, S.R. (1993) Expression of combinations of mutant alleles for fatty acid composition of soybean. Crop Sci. submitted. 

Table 14.13. Changes in the composition of soybean oil through cultivation or modification using genetic engineering techniques...

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