Amino acid in soybeans

O Adeola, JG Buchanan-Smith, RJ Early. Gas and high-performance liquid chromatographic analyses of amino acids in soybean meal, corn and triticale. J Food Biochem 12 171-181, 1988. 

Takahashi, M., Uematsu, Y., Kashiwaba, K., Yagasaki, K., Hajika, M., Matsunaga, R., Komatsu, K., Ishimoto, M. 2003. Accumulation of high levels of free amino acids in soybean seeds through integration of mutations conferring seed protein deficiency. Planta 217 577-586. 

Nimaiyar, S. Measurement of Isoflavones, Fatty Acids, and Amino Acids in Soybeans Using FT-NIR Spectroscopy. M.S. Thesis. University of Illinois, Urbana- Champaign, IL, 2004. 

Dilger, R.N. J.S. Sands D. Ragland O. Adeola. Digestibility of nitrogen and amino acids in soybean meal with added soyhulls./. Anim. Sci. 2004, 82, 715-724. 

Table 18.1. Metabolizable Energy and Protein Concentration and True Digestibilities of Amino Acids in Soybean Meal and Other Oilseeds Fed to Poultry ...

Table 18.2. Concentration of Energy, P, and Amino Acids in Soybean Products Fed to Swine ...

PROFILE OF ESSENTIAL AMINO ACIDS IN SOYBEANS COMPARED TO MILK-A HIGH-ODALITY PROTEIN... 

Albin, D. M., Wubben, J. E., and Gabert, V. M., Effect of hydrolysis time on the determination of amino acids in samples of soybean products with ion-exchange chromatography or precolumn derivatization with phenyl isothiocyanate,. Agr. Food Chem., 48, 1684, 2000. 

Characteristically, legume seeds are rich in protein and contain intermediate to high levels of lysine and threonine which are important in balancing the deficiencies of these essential amino acids in cereal diets. Certain legume proteins, such as soybean, also exhibit strong functional properties, especially water solubility, water and fat binding and emulsification. Thus soybean flours, protein concentrates and isolates have been used widely as nutritional supplements and functional ingredients in foods. 

Temperature-Dependence of Amino Acid Uptake in Soybean. The uptake of amino acids by plants into the soluble pool can be an energy-requiring process (52-54), as is the support of protein synthesis. We wished to show the temperature-dependence of influx of amino acids into soybean trifoliate leaf discs taken from control and ozonated seedlings in order to confirm this for the present system. Table II shows that amino acid influx during 30 min was reduced by the lowered temperature by about 70%, and protein synthesis by about 85%, when labelling of control discs proceeded at ice bath temperatures. Qualitatively similar reductions occurred in discs taken from ozonated (50 5 pphm,... 

Sulfur amirro acids, methionirre arrd cysteine, are limiting in partially defatted flours prepared from heated and unheated morama beans, containing 0.4 g methionine/100 g flours and 0.1 g cysteine/100 g flours. The major amino acids in morama flours are glutamic acid, aspartic acid, as well as tyrosine. This is in agreement with amino acid composition of morama beans reported by various researchers (Bousquet, 1982 Bower et al., 1988 Dubois et al., 1995 Maruatona et al., 2010). Morama bean flours seem to be comparable in terms of essential amino acids composition to commercial soybean flours (Maruatona et al., 2010). 

It may also be surprising how easily this racemization may occur. Friedman and Liardon (126) studied the racemization kinetics for various amino acid residues in alkali-treated soybean proteins. They report that the racemization of serine, when exposed to 0.1M NaOH at 75°C, is nearly complete after just 60 minutes. However, caution must be used when examining apparent racemization rates for protein-bound amino acids. Liardon et al. (127) have also reported that the classic acid hydrolysis, employed to liberate constituent amino acids, causes amino acids to racemize to various degrees. This will necessarily result in D-isomer determinations that are biased high. Widely applicable correction factors are not possible since the racemization behavior of free amino acids is different from that of amino acid residues in proteins (which can be further affected by sequence). Of course, this is not a problem for free amino acid isomer determinations since the acid hydrolysis is unnecessary. Liardon et al. also describe an isotopic labeling/mass spectrometric method for determining true racemization rates unbiased by the acid hydrolysis. For an extensive and excellent review of the nutritional implications of the racemization of amino acids in foods, the reader is directed to a review article written by Man and Bada (128). 

Table 4.4. True digestibility coefficients for poultry of some key essential amino acids in canola meal and soybean meal. (From Heartland Lysine, 1998.)...

ALS herbicides. Two classes of ALS-inhibiting herbicides are the sulfonylurea herbicides, discussed in Sections 2.1.2.1 and 2.2.3.1, and the imidazolinone herbicides. A third class of ALS-inhibiting herbicides is the 1,2,4-triazolo [1,5-a]pyrimidine-2-sulfonanilides. The triazolopyrimidine sulfonanilides act by disrupting the biosynthesis of branched chain amino acids in plants. Representatives of this class of herbicides include florasulam (Boxer , Nikos ) [151], initially introduced in Belgium in 1999 and used for the postemergence control of broadleaf weeds in cereals and corn, and flumetsulam (Broadstrike ) [152], used alone or in combination with other herbicides for the control of broadleaf weeds in soybean and corn. 

Improvement of Solubility of Soybean Protein. Denatured soybean protein is relatively insoluble in aqueous media, which is a disadvantage in processing this protein. This problem might be solved by incorporating a large amount of certain hydrophilic amino acid into soybean protein through its enzymatic degradation and resynthesis. Yamashita et al. (73,... 

Some of the early work on amino acid NIR calibrations was performed by Pazdernik et al. (1997) (Table 6.10). They developed NIR equations to measure 17 amino acids in ground and whole soybean samples on a NIRSystems 6500. They had 90 samples in their calibration set and 26 in the validation set derived from 408 soybean lines. Samples were grown in Minnesota in 1994 and 1995. Samples were analyzed first as whole beans and then ground in a Fred Stein mill for 1 min. Results are reported in grams per kilograms of crude protein. 

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