On the determination of available lysine in casein and rapeseed protein concentrates using 2,4,6-trinitrobenzenesulphonic acid (TNBS) as a reagent for free epsilon amino group of lysine

1976 ◽  
Vol 70 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Anders Eklund
Keyword(s):  
Amino Group ◽  
Protein Concentrates ◽  
Rapeseed Protein ◽  
Available Lysine

Liquid Chromatographic Determ [nation of Available Lysine in Soybean and Fish Meal

1988 ◽  
Vol 71 (2) ◽  
pp. 350-353
Author(s):  
Joan Rabasseda ◽  
Gemma Rauret ◽  
Teresa M Galceran
Keyword(s):  
Liquid Chromatography ◽  
Simplex Method ◽  
Fish Meal ◽  
Amino Group ◽  
Optimum Conditions ◽  
Available Lysine ◽  
Liquid Chromatographic

Abstract A method for the determination of available lysine on the basis of the reactivity of the e-amino group with fluorodinitrobenzene (FDNB) has been optimized. Hydrolysis is performed in closed vessels in an autoclave. Conditions for different meals were established by using a modified sequential simplex method. Hydrolysis for 4 h was sufficient for the meals studied—soybean and fish. The use of liquid chromatography to determine available lysine was studied, and optimum conditions were established for separation and quantitation of e-DNB-lysine. The proposed method is faster, more accurate, and more precise than commonly used methods

scholarly journals Determination of protein and reactive lysine in leaf-protein concentrates by dye-binding

1979 ◽  
Vol 42 (3) ◽  
pp. 445-454 ◽  
Author(s):  
Ann F. Walker
Keyword(s):  
Convenient Method ◽  
Nutritional Value ◽  
Tungstic Acid ◽  
Leaf Protein ◽  
Processing Conditions ◽  
Acid Orange ◽  
Protein Concentrates ◽  
Dye Binding ◽  
Available Lysine

1. Twenty leaf-protein concentrates (LPC), were produced from different crops and by different processes, the latter being designed to retain maximum nutritional value of the samples.2. The establishment of conditions for the use of CI Acid Orange 12 in a commercial dye-buffer reagent for the determination of protein and reactive (available) lysine in LPC was investigated.3. Values for protein by dye-binding correlated well with those for tungstic-acid-precipitated nitrogen (×6.25).4. Some LPC samples showed a loss of reactive lysine, the greatest loss being associated with the most severe processing conditions.5. For the LPC samples studied, dye-binding provided a convenient method for the concurrent determination of protein and reactive lysine.

New Method for the Determination of Free Amino Groups in Intact Pure Proteins: Relationship to Available Lysine

1976 ◽  
Vol 59 (6) ◽  
pp. 1251-1254
Author(s):  
James M Purcell ◽  
Daniel J Quimby ◽  
James R Cavanaugh
Keyword(s):  
Bovine Serum Albumin ◽  
Bovine Serum ◽  
Free Amino ◽  
Amino Group ◽  
Amino Groups ◽  
Primary Amino ◽  
Available Lysine ◽  
Β Lactoglobulin ◽  
Group Concentration

Abstract A new rapid method for the quantitative and routine determination of free amino groups in intact pure proteins has been developed. Primary amino groups are labeled with fluorescamine and the labeled groups are detected by absorption spectroscopy in the range 375–390 nm. The amino group concentration can be determined in a few minutes without hydrolyzing the labeled protein and extracting a lysine derivative. The method was tested with the following proteins: lysozyme, α-lactalbumin, β-lactoglobulin, bovine serum albumin, ribonuclease, ribonuclease-S-peptide, and αsl-rasciii B. Application of this method to the estimation of available lysine is discussed.

Quantitative Determination of Coumestrol in Dried Alfalfa and Alfalfa Leaf Protein Concentrates Containing Chlorophyll

1975 ◽  
Vol 58 (5) ◽  
pp. 983-986
Author(s):  
Benny E Knuckles ◽  
Raymond E Miller ◽  
E M Bickoff
Keyword(s):  
Quantitative Determination ◽  
Analytical Method ◽  
Leaf Protein ◽  
Improved Method ◽  
Alcohol Extract ◽  
Protein Concentrates ◽  
Coefficients Of Variation ◽  
Lower Standard ◽  
Alfalfa Leaf

Abstract An improved analytical method for the determination of coumestrol in dried alfalfa and leaf protein concentrates is described. In this method, chlorophyll is removed from an alcohol extract prior to the paper chromatographic-fluorometric measurement of coumestrol. Ninety-eight per cent of the coumestrol added to alfalfa leaf protein concentrates is recovered by this method. This improved method gives replicate values with lower standard deviations and coefficients of variation than the literature method.

The Ion Associates of Methyl-, Ethyl- and Isopropyl Derivatives of Dialkylaminoethyl Dialkylamidofluorophosphate with Bromophenol Blue

1992 ◽  
Vol 57 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Emil Halámek ◽  
Zbyněk Kobliha
Keyword(s):  
Extraction Efficiency ◽  
Ion Pairs ◽  
Amino Nitrogen ◽  
Ion Pair ◽  
Amide Group ◽  
Bromophenol Blue ◽  
Amino Group ◽  
Methyl Ethyl ◽  
Derivatives Of

Nine new Tammelin esters were studied on the basis of the chloroform extracts of their ion associates with bromophenol blue. A study was made of the effect of the alkyl on the amino and amido groups of dialkylaminoethyl dialkylamidofluorophosphate and on the extraction efficiency of the ion pair. An increase in the number of carbon atoms on the amide group leads to the increase in the extraction efficiency of the ion pairs as a consequence of the increasing hydrophobicity. A further contribution to the increase in the extraction efficiency with increasing number of carbon atoms in the alkyls of the amino nitrogen is clearly retarded by the increasing basicity of the amino group. An extraction spectrophotometric determination of the test derivatives of dialkylaminoethyl dialkylamidofluorophosphate was developed and the interferences from precursors in the synthesis were examined.

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