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

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.

1988 ◽  
Vol 71 (3) ◽  
pp. 603-606
Author(s):  
Maryann C Allred ◽  
John L Macdonald

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


1987 ◽  
Vol 70 (1) ◽  
pp. 171-174 ◽  
Author(s):  
Charles W Gehrke ◽  
Paul R Rexroad ◽  
Robert M Schisla ◽  
Joseph S Absheer ◽  
Robert W Zumwalt

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.


2008 ◽  
Vol 91 (4) ◽  
pp. 907-913 ◽  
Author(s):  
Shane M Rutherfurd ◽  
Paul J Moughan

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.


1972 ◽  
Vol 27 (9) ◽  
pp. 1069-1071 ◽  
Author(s):  
W. C. Kenney ◽  
W. H. Walker ◽  
E. B. Kearney ◽  
R. Seng ◽  
T. P. Singer ◽  
...  

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.


1985 ◽  
Vol 68 (5) ◽  
pp. 1028-1032
Author(s):  
Robert G Elkin ◽  
Joseph E Griffith

Abstract Corn, peanut meal, and soybean meal samples were either untreated or oxidized with performic acid before hydrolysis; the amino acids were determined by cation exchange high performance liquid chromatography (LC) and conventional cation exchange LC using an amino acid analyzer (AAA). Reproducibility of each procedure was assessed by repeated injections of the same calibration standard solution over a period of several days. LC data were more precise with regard to coefficients of variation for amino acid retention times, but were more variable with regard to peak areas. Although some significant differences between methods were noted, feedstuff amino acid values obtained by LC and AAA compared very well. The only consistent differences observed within each feedstuff were that Phe and Tyr values were significantly lower when analyzed by LC compared with AAA. Results of this study suggest that modular LC instrumentation can be used to accurately and reproducibly analyze amino acids in feedstuff hydrolysates. Advantages of using ninhydrin derivatization for feedstuff analysis, as opposed to using o-phthalaldehyde or dansyl chloride, are discussed


1988 ◽  
Vol 34 (12) ◽  
pp. 2510-2513 ◽  
Author(s):  
H M van Eijk ◽  
M A van der Heijden ◽  
C L van Berlo ◽  
P B Soeters

Abstract This inexpensive method for fully automated amino acid analysis combines the advantages of automated precolumn derivatization with o-phthaldialdehyde and favorable analytical conditions to separate and quantify 30 amino acids found in normal plasma. The system can run unattended for almost four days, during which the data are processed automatically by a personal computer and a maximum of 76 samples and 19 standards can be processed (cycle time per analysis: 55 min). Only 1 microL of deproteinized plasma is required per analysis. Coefficients of variation for retention times and areas measured for all relevant amino acids are less than 1% and 3%, respectively. The system described is well suited for quick, sensitive operation in daily practice.


1989 ◽  
Vol 72 (6) ◽  
pp. 912-916 ◽  
Author(s):  
Steven R Hagen ◽  
Beverly Frost ◽  
Jorg Augustin

Abstract A precolumn phenylisothiocyanate derivatization method is described for the determination of amino acids in protein hydrolysates from a wide variety of complex food matrixes, with and without performic acid oxidation pretreatment. Analysis of samples that were not pretreated with performic acid was necessary since this pretreatment destroyed an average of 25% of the histidine and 87% of the tyrosine present in the food samples. This method is rapid and reproducible; coefficients of variation between duplicate analyses of the same food item were less than 5% for a majority of the amino acids. Occasionally, variation between duplicate analyses for histidine and tyrosine was greater than 10%. Recoveries of amino acids added to samples were in the 100% range.


Author(s):  
Aaron J. Cowieson ◽  
Franz F. Roos

SummaryA meta-analysis of the effect of a mono-component bacterial protease (RONOZYME® ProAct) on the apparent ileal digestibility of amino acids in poultry and swine diets was conducted to examine functional patterns, mean effects and variability of response. A total of 25 independently-conducted experiments were included comprising a total of 804 datapoints. The mean response to protease was +3.74% (SE 1.1%, P < 0.001) and this ranged from +5.6% for Thr (SE 1.2%, P < 0.001) to +2.7% for Glu (SE 1.2%, P < 0.05). For the most economically critical amino acids (Lys, Cys, Met and Thr) the mean response was 4.5%. The effect of protease was independent of geography, animal species and diet composition (P > 0.05). However, the inherent digestibility of amino acids in the control diet as a single explanatory term explained around 47% of the variance (P < 0.001) in effect. When the inherent digestibility of amino acids in the control diet was less than 70% protease addition improved amino acid digestibility in 90% of cases with a mean improvement of around 10%. When the inherent digestibility of amino acids in the control diet was more than 90% there was a protease-mediated improvement in digestibility in only 60% of cases with a mean improvement of around 2%. It can be concluded that the inherent digestibility of amino acids in the diet without protease supplementation is the primary explanatory term for the efficacy of this exogenous protease, demonstrating that it is highly effective in improving the digestibility of amino acids across a wide range of feed ingredients. Benchmarking diets or feed ingredients as to their relative nutritional value would enhance the ability of nutritionists to determine the likely return on investment on use of bacterial proteases in their operation.


1995 ◽  
Vol 78 (3) ◽  
pp. 736-743 ◽  
Author(s):  
Hong Ji Liu ◽  
Bi Ying Chang ◽  
Hui Wen Yan ◽  
Feng Hua Yu ◽  
Xing Xiang Liu

Abstract A study of a new amino acid analysis method using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as a precolumn derivatization reagent for the analysis of food and feed is described. All amino acids, including methionine sulfone and cysteic acid, were well separated on a liquid chromatographic system using the optimized chromatographic conditions. Salts in food and feed interfered very slightly with the derivatization yields of all amino acids. Several typical agricultural products and animal feeds, including 2 AOAC test samples, were analyzed with the method. The results agreed well with the data generated by using the classical postcolumn method with ion-exchange chromatography. The average relative standard deviations for corn and broiler starter feed were 0.74 and 0.70%, respectively. Good recoveries of all amino acids were demonstrated (average, 101%), even for a sample with a very complex matrix.


2011 ◽  
Vol 91 (1) ◽  
pp. 103-111 ◽  
Author(s):  
A. Bandegan ◽  
A. Golian ◽  
E. Kiarie ◽  
R. L. Payne ◽  
G. H. Crow ◽  
...  

Bandegan A., Golian, A., Kiarie E., Payne R. L., Crow G. H., Guenter W. and Nyachoti C. M. 2011. Standardized ileal amino acid digestibility in wheat, barley, pea and flaxseed for broiler chickens. Can. J. Anim. Sci. 91: 103–111. Experiments were conducted to estimate ileal amino acids (AA) digestibility in six wheat (exp. 1; 288 birds), seven barley (exp. 2; 252 birds), five pea (exp. 3; 240 birds) and five flaxseed (exp. 4; 216 birds) samples in male Ross broiler chicks. Wheat, barley and pea were the sole source of dietary AA in exps. 1, 2 and 3, whereas, for exp. 4, flaxseed and wheat (50:50 wt/wt) or wheat provided dietary AA. Chromic oxide was the indigestible marker. Birds were fed chick starter for the first 14 d; on day 15 each test diet was randomly assigned to six cages, each with six (exps. 2 and 4) or eight (exps. 1 and 3) birds. On day 21, birds were killed and digesta were sampled to determine the apparent ileal AA digestibility (AID). The standardized ileal digestibility (SID) values were calculated using ileal endogenous AA losses previously determined in our laboratory from birds fed N-free diet. The mean SID values for indispensable AA ranged from 83.7% (Lys) to 93.8% (Phe), 80.4% (Arg) to 90.9% (Phe), 86.0% (Met+Cys) to 94.2% (Arg) and 47.4% (Thr) to 66.7% (Met) for wheat, barley, peas and flaxseed samples, respectively. Overall, SID AA estimates for flaxseed had higher (> 13%) coefficients of variation (CV) compared with other ingredients (CV<6%). These SID AA data will help nutritionists to formulate broiler diets that more closely match the birds' requirements and minimize nutrient excretion.


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