Determination of Sulfur Amino Acids and Tryptophan in Foods and Food and Feed Ingredients: Collaborative Study

1988 ◽  
Vol 71 (3) ◽  
pp. 603-606
Author(s):  
Maryann C Allred ◽  
John L Macdonald
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Collaborative Study ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Protein Hydrolysis ◽  
Sulfur Amino Acids ◽  
Feed Ingredients ◽  
Food And Feed

Abstract Samples of 4 foods, 1 animal feed, isolated soy protein, and 0-lao toglobulin were analyzed by 9 laboratories to determine concentrations of cysteine as cysteic acid, methionine as methionine sulfone, and tryptophan. Sulfur amino acids were determined by AOAC method 43.A08-43.A13 for food and feed ingredients, in which samples are oxidized with performic acid before protein hydrolysis with 6N HC1. Tryptophan was determined after protein hydrolysis with 4.2N NaOH. In both methods, free amino acids were separated by ionexchange or reverse-phase chromatography. Each laboratory was provided with detailed methods and with sealed vials containing solutions of standards. Samples were analyzed in duplicate, and variation between laboratories was determined. Coefficients of variation between laboratories for the 6 samples ranged from 5.50 to 11.8% for methionine as methionine sulfoxide, 8.59 to 17.3% for cysteine as cysteic acid, and 3.87 to 16.1% for tryptophan. Amino acid recoveries were determined by analysis of β-lactoglobulin and were based on expected levels of each amino acid obtained from amino acid sequence data. The mean recovery of cysteine was 97% with a range of 88-119%. For methionine, mean recovery was 98% (range 89-115%) and for tryptophan, 85% (range 59-102%). Method 43.A08- 43.A13 for food and feed ingredients has been adopted official first action for determination of cysteine and methionine in processed foods. The alkaline hydrolysis method has been adopted official first action for determination of tryptophan in foods and food and feed ingredients

Oxidation and Hydrolysis Determination of Sulfur Amino Acids in Food and Feed Ingredients: Collaborative Study

1985 ◽  
Vol 68 (5) ◽  
pp. 826-829 ◽  
Author(s):  
John L Macdonald ◽  
Mark W Krueger ◽  
John H Keller
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Feed Ingredients ◽  
Methionine Sulfone ◽  
Coefficients Of Variation ◽  
Food And Feed ◽  
The Mean

Abstract Samples of 6 food and feed ingredients and a purified protein, plactoglobulin, were analyzed by 7 laboratories to determine the concentrations of cysteine as cysteic acid and methionine as methionine sulfone. Samples were oxidized by reaction with performic acid before hydrolysis with 6N HC1. The free amino acids were then separated and measured by ion-exchange chromatography on dedicated amino acid analyzers. Each laboratory was provided with a detailed method as well as sealed vials containing solutions of standards. For the determination of cysteine as cysteic acid, the coefficients of variation between laboratories for duplicate samples ranged from 7.13 to 10.8% for the 6 ingredients. For the determination of methionine as methionine sulfone, the coefficients of variation between laboratories for duplicate samples ranged from 1.18 to 12.8% for the 6 ingredients. Cysteine and methionine recoveries were determined by analysis of β-Iactoglobulin and were based on expected levels of each amino acid from amino acid sequence data. The mean recovery of cysteine was 95% with a range of 91-101%. The mean recovery of methionine was 101% with a range of 98-106%. This method has been adopted official first action.

scholarly journals Determination of Sulfur Amino Acids in Foods as Related to Bioavailability

2008 ◽  
Vol 91 (4) ◽  
pp. 907-913 ◽  
Author(s):  
Shane M Rutherfurd ◽  
Paul J Moughan
Keyword(s):  
Methionine Sulfoxide ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Acid Oxidation ◽  
Separate Determination ◽  
Sulfur Amino Acids ◽  
Methionine Sulfone ◽  
Quantitative Impact ◽  
Selection Of

Abstract During the processing of feedstuffs and foods, methionine can be oxidized to methionine sulfoxide and methionine sulfone, and cysteine can be oxidized to cysteic acid. Methionine sulfone and cysteic acid are nutritionally unavailable, but methionine sulfoxide can be utilized, at least to some degree. The degree of utilization depends on the levels of methionine, cysteine, and methionine sulfoxide in the diet, but there is no consensus in the literature on the quantitative impact of these dietary constituents on methionine sulfoxide utilization. Methionine and cysteine are most often determined after quantitative oxidation to methionine sulfone and cysteic acid, respectively, using performic acid oxidation prior to hydrolysis. However, this method may overestimate the methionine content of processed foods, as it will include any methionine sulfoxide and methionine sulfone present. A selection of analytical methods has been developed to allow the separate determination of the 3 oxidized forms of methionine, the merits of which are discussed in this review. An additional consideration for determining methionine and cysteine bioavailability is that not all dietary methionine and cysteine is digested and absorbed from the small intestine. Selected methods designed to determine the extent of digestion and absorption are discussed. Finally, a concept for a new assay for determining methionine bioavailability, which includes determining the digestibility of methionine and methionine sulfoxide as well as the utilization of methionine sulfoxide, is presented.

Recent Advances in the Chemistry of Covalently Bound Flavin Coenzymes

1972 ◽  
Vol 27 (9) ◽  
pp. 1069-1071 ◽  
Author(s):  
W. C. Kenney ◽  
W. H. Walker ◽  
E. B. Kearney ◽  
R. Seng ◽  
T. P. Singer ◽  
...  
Keyword(s):  
Amino Acid ◽  
Absorption Band ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Hypsochromic Shift ◽  
Ninhydrin Reaction ◽  
Acid Environment ◽  
Definite Proof ◽  
Covalently Bound

Following elucidation of the structures of the flavin components of succinate dehydrogenase (SD) as N (3) -histidyl-8α-FAD and of monoamine oxidase (MAO) as cysteinyl-8α-FAD and determination of the peptide sequences around the flavin sites of these enzymes, attention has been focused on the covalently bound FAD of Chromatium cytochrome c-552. As documented in preliminary communications, the FAD moiety of this enzyme is also substituted at the 8α-position, as judged from ESR hyderfine structure of the free radical cation and the characteristic hypsochromic shift of the second absorption band of the neutral flavoquinone in purified preparations of the flavin. Definite proof has come from the liberation of 8-carbxyriboflavin on performic acid treatment of the enzyme. In regard to ESR and optical spectra and the tendency of the purified flavin (liberated by proteolysis) to undergo autooxidation with a further hypsochromic shift of the second absorption band and increased fluorescence, the flavin resembles the MAO flavin. The fact that fluorescence is >90% quenched at all pH values even at the FMN level and doees not vary with pH between 3.2 and 8 also suggests a thioether linkage as in cysteinyl riboflavin. In many respects, however, the Chromatium flavin differs from cysteinyl riboflavin. Highly purified preparations from tryptic-chymotryptic digests give a positive chloroplatinic test. Electrophoresis clearly shows the presence of carboxyl and amino groups but the peptide gives no characteristic ninhydrin reaction and amino acid analysis of performic acid oxidized samples yields cysteic acid and threonine in amounts less than equimolar to the flavin. The amino acid environment around the flavin may account for these results although a linkage other than a thioether remains a possibility.

scholarly journals Response of broilers to digestible sulfur amino acids and threonine intake: maximum economic return

2020 ◽  
Vol 33 (4) ◽  
pp. 239-251
Author(s):  
Matheus De-Paula Reis ◽  
Mirella Cunha-Melaré ◽  
Gabriel Silva-Viana ◽  
Daniella C Zanardo-Donato ◽  
Nilva Kazue-Sakomura
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Broiler Chicken ◽  
Bodyweight Gain ◽  
Sulfur Amino Acids ◽  
Gross Margin ◽  
Inclusion Level ◽  
Feed Costs ◽  
The Ideal

Background: The determination of amino acid supplements for broiler chicken requirements based on performance does not always reflect maximum profitability. Objective: To estimate the optimal levels of digestible threonine (Thr) and sulfur amino acids (SAA) in diets for broilers based on an economic analysis. Methods: Two dose-response assays were conducted, and each assay was divided into three phases: initial (1-14 days), grower (15-28 days), and finisher (29-42 days). Five hundred and sixty male Cobb 500® broilers were randomly distributed to seven treatments with increasing levels of the amino acid (SAA or Thr), with four replicates and 20 birds each. Bodyweight gain (BWG) and feed intake (FI) were used to fit a segmented model. Gross income (GI), total feed costs (TFC) and gross margin (GM) were calculated based on local values. Results: Increasing levels of amino acid elicited a response in BWG and FI for all evaluated phases. The estimates for maximum profit based on GI and TFC were 223, 504, and 975 mg SAA/bird/d, and 236, 696, and 1,042 mg Thr/bird/d in starter, grower and finisher phases, respectively. Conclusion: Varying the AA prices affected only slightly the economic optimal intake of Thr and sulfur amino acids. Despite market fluctuations, the economic approach presented in this study demonstrates to be a helpful tool to choose the ideal inclusion level of amino acids in the feed.

Determination of Amino Acids in Feeds: Collaborative Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1362-1402 ◽  
Author(s):  
Cynthia R Llames ◽  
Johannes Fontaine
Keyword(s):  
Amino Acids ◽  
Acid Hydrolysis ◽  
Hydrobromic Acid ◽  
Collaborative Study ◽  
Performic Acid ◽  
Acid Oxidation ◽  
Sodium Metabisulfite ◽  
Hydrolysis Method ◽  
Relative Standard

Abstract A total of 28 laboratories (including authors’ laboratories) participated in a collaborative study for determination of amino acids in feeds using 3 complementary procedures. Each collaborator analyzed 5 blind duplicate samples of feed and ingredients used in the poultry industry. The amount of amino acids in these materials ranged from 0.10 to 8.50%. Twenty-three laboratories conducted analyses using performic acid oxidation with acid hydrolysis—sodium metabisulfite method, 16 laboratories performed analyses using performic acid oxidation with acid hydrolysis—hydrobromic acid method, and 15 laboratories used acid hydrolysis method. The repeatability relative standard deviation values for all amino acids for all 3 procedures ranged from 1.1 to 5.6% for broiler finisher feed, 1.1 to 4.73% for starter feed, 1.3 to 9.6% for corn, 0.8 to 3.96% for fishmeal, and 0.8 to 12.7% for poultry meal. The reproducibility relative standard deviation values for all amino acids ranged from 3.71 to 19.80% for broiler finisher feed, 4.1 to 16.93% for starter feed, 4.4 to 28.2% for corn, 3.46 to 18.96% for fishmeal, and 3.73 to 24.1% for poultry meal. The performic acid oxidation with acid hydrolysis—sodium metabisulfite and hydrobromic acid methods, and acid hydrolysis method for determination of amino acids in feeds have been adopted first action by AOAC INTERNATIONAL.

Quantitative Analysis of Cystine, Methionine, Lysine, and Nine Other Amino Acids by a Single Oxidation-4 Hour Hydrolysis Method

1987 ◽  
Vol 70 (1) ◽  
pp. 171-174 ◽  
Author(s):  
Charles W Gehrke ◽  
Paul R Rexroad ◽  
Robert M Schisla ◽  
Joseph S Absheer ◽  
Robert W Zumwalt
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Content ◽  
Performic Acid ◽  
Acid Oxidation ◽  
Hydrolysis Method ◽  
Methionine Sulfone ◽  
Limiting Amino Acid ◽  
Hydrolysis Of

Abstract The sulfur-containing amino acids cystine and methionine play important roles in animal, especially avian, nutrition. Because these ndror-containing amino acids are destroyed to varying extents by 6N HC1 hydrolysis, oxidation and hydrolysis of cystine to cysteic add and methionine to methionine sulfone have been widely used for determination of cystine and methionine. Lysine is considered the next limiting amino acid after the sulfur amino acids in poultry •ntrition; therefore, determination of the amino acid content of rations focuses first on these 3 amino acids. The objective of this investigation was to establish whether lysine and other amino acids could be accurately determined in proteinaceous materials which had mdergone performic acid oxidation. To perform this evaluation, lysine was determined in a variety of protein-containing materials both with and without performic acid oxidation. Performic acid oxidation followed by 6N HC1 hydrolysis at 145°C for 4 h allows accurate measurement of 3 amino acids especially important to poultry nutrition, cystine, methionine, and lysine, in a single preoxidized hydralysate; this method can be extended to another 9 protein amino adds.

The amino acid composition of cat (Felis catus) hair

1998 ◽  
Vol 67 (1) ◽  
pp. 165-170 ◽  
Author(s):  
W. H. Hendriks ◽  
M. F. Tarttelin ◽  
P. J. Moughan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Total Nitrogen ◽  
Compartmental Model ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Hair Colour ◽  
Non Linear

AbstractThe amino acid composition of cat hair was determined by conventional 24-h acid hydrolysis and non-linear least-squares extrapolation to time zero of the amino acid composition data from a series of hydrolysis intervals. Twenty-five individual samples of cat hair, consisting of four colours, were also analysed (24-h hydrolysis) to determine if there was an effect of hair colour on amino acid composition. Amino acids were determined following HCl hydrolysis (6 mol/l) with cysteine and methionine determined by performic acid oxidation of the sample prior to hydrolysis.There was no significant (P > 0·05) effect of hair colour on the amino acid composition of cat hair. The non-linear compartmental model used to determine the amino acid composition of cat hair took into account the simultaneously occurring processes of hydrolysis and degradation of amino acids over time. The amino acids cysteic acid, methionine-sulphone, threonine and serine exhibited high loss rates during 6 molll HCl hydrolysis while the peptide bonds involving valine and leucine were slowly hydrolysed. Amino acid nitrogen accounted for 0·94 of the total nitrogen in cat hair when determined by conventional 24-h hydrolysis and 0·99 of the total nitrogen when the compartmental model was applied. The average nitrogen proportion in cat hair protein was found to be 0·175. The amino acid composition of cat hair protein is comparable with that of dog, horse, sheep and human hair although the proline content of cat hair protein appears to be lower than that in the other species.

scholarly journals Liquid Chromatographic Determination of Lysine, Methionine, and Threonine in Pure Amino Acids (Feed Grade) and Premixes: Collaborative Study

2000 ◽  
Vol 83 (4) ◽  
pp. 771-783 ◽  
Author(s):  
Johannes Fontaine ◽  
Marcelle Eudaimon ◽  
J Bargholz ◽  
M W Empie ◽  
S Eriksson ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Collaborative Study ◽  
Cation Exchange Resin ◽  
Chromatographic Determination ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract A total of 17 laboratories (including one author's laboratory) participated in a collaborative study for determination of lysine, methionine, and threonine in trade products or concentrated amino acid premixes. Thirteen samples, 4 pure amino acids and 6 premixes, including 3 Youden matched pairs, were analyzed. The applied liquid chromatographic (LC) method using cation-exchange resin and post-column derivatization with ninhydrin or o-phthaldialdehyde was shown to be accurate and specific for the analytes. Titration procedures, normally used for the assay of pure amino acids, are unspecific and the accuracy of the results can be affected by impurities. Repeatability relative standard deviations, RSDr, ranged from 0.84 to 1.17% for pure amino acids and from 0.50 to 1.68% for premixes; reproducibility relative standard deviations RSDR, ranged from 1.52 to 2.31% for pure amino acids and from 1.48 to 2.59% for premixes. Recoveries were between 97.5 and 102.8% of the expected amino acid assays. The method has been adopted Official First Action status by AOAC INTERNATIONAL.

scholarly journals Simultaneous Determination of L- and D-Amino Acids in Proteins: A Sensitive Method Using Hydrolysis in Deuterated Acid and Liquid Chromatography–Tandem Mass Spectrometry Analysis

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 309 ◽  
Author(s):  
Marianne Danielsen ◽  
Caroline Nebel ◽  
Trine Kastrup Dalsgaard
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Simultaneous Determination ◽  
Protein Quality ◽  
Protein Isolate ◽  
Mass Spectrometry Analysis ◽  
Spectrometry Analysis ◽  
Relative Standard ◽  
Food And Feed

Determination of the L- and D-amino acid composition in proteins is important for monitoring process-induced racemization, and thereby protein quality loss, in food and feed. Such analysis has so far been challenging due to the need for sample hydrolysis, which generates racemization, thereby leading to an overestimation of D-amino acids. Here, validation of an LC–MS/MS-based method for the simultaneous determination of L- and D-amino acids in complex biological matrixes, like food and feed, was performed in combination with deuterated HCl hydrolysis. This approach eliminated a racemization-induced bias in the L- and D-amino acid ratios. The LC–MS/MS method was applied for the analysis of 18 free amino acids, with a quantification limit of either 12.5 or 62 ng/mL, except for D-phenylalanine, for which quantification was impaired by background interference from the derivatization agent. For hydrolyzed samples, the composition of 10 L- and D-amino acids pairs could be determined in protein. The average relative standard deviation was 5.5% and 6.1%, depending on the type of hydrolysis tubes. The method was applied on a green protein isolate (lucerne), which contained an average of 0.3% D-amino acids. In conclusion, this method allows for an unbiased analysis of L- and D-amino acid ratios in complex protein samples, such as food and feed.

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