Inter- and Intra-Laboratory Variation in Amino Acid Analysis of Food Proteins

Authors

  • G. SARWAR,

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • D. A. CHRISTENSEN,

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • A.J. FINLAYSON,

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • MENDEL FRIEDMAN,

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • L. R. HACKLER,

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • S. L. MACKENZIE,

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • P. L. PELLETT,

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • R. TKACHUK

    1. Author Sarwar is with the Bureau of Nutritional Sciences, Health Protection Branch, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2. Author Christensen is with the Dept. of Animal & Poultry Science, Univ. of Saskatechewan, Saskatoon, Saskatchewan, Canada S7N 0W0. Author MacKenzie is with the Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatechewan, S7N 0W9. Author Finalyson, formerly with NRC of Canada, is now with the Dept. of Food Science, Univ. of British Columbia, Vancouver, British Columbia, Canada. Author Friedman is with the USDA-ARS Western Regional Research Center, Berkeley, CA 94710. Author Hackler is with the Dept. of Foods & Nutrition, Univ. of Illinois, Urbana, IL 61801. Author Pellett is with the Dept. of Food Sciences & Nutrition, Univ. of Massachusetts, Amherst, MA 01003. Author Tkachuk is with the Grain Research Laboratory, Canadian Grain Commission, Agriculture Canada, Winnipeg, Manitoba R3C 3G8.
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  • The data from this study were presented in part at the Sixth Annual Spring Workshop of AOAC, Ottawa, Canada, May 12–14, 1981. The authors acknowledge the statistical advice of G. Jarvis and the technical assistance of H.G. Botting, C Christ, M.J. Farmer, B. Krasin, V.J. Mellish, A.T. Noma and G.F. Parson.

ABSTRACT

Amino acid compositions of casein, egg white, beef, soy isolate, rapeseed concentrate, pea flour and wheat flour were studied by seven collaborating laboratories. Samples were hydrolyzed with 6N HCl, performic acid + 6N HCl, and (with one exception) 4.2N NaOH. Amino acids were then determined by ion-exchange chromatography using automatic analyzers. One laboratory, however, determined tryptophan by treatment with p-dimethylaminobenz-aldehyde. The colorimetric determination of tryptophan was comparable to the tryptophan values determined by ion-exchange chromatography. Interlaboratory variation of tryptophan (coefficients of variation, CV, up to 24%), cystine and methionine (CV up to 17%), was greater than that of most other amino acids (CV up to 10%). Intralaboratory variation for all amino acids was less than 5%.

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