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Availability of lysine in protein concentrates and diets using carpenter's method and a modified silcock method
Author(s) -
Ostrowski H.,
Jones A. S.,
Cadenhead A.
Publication year - 1970
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740210212
Subject(s) - lysine , chromatography , chemistry , food science , biochemistry , amino acid
A comparison was made of methods for the evaluation of the available lysine in protein concentrates and diets. Some modifications of the Silcock method, developed by Roach et al. for lysine determination are suggested, and the optimum range of lysine concentration in samples has been evaluated. With animal protein concentrates, the Silcock method for measuring the total and residual lysine, after treatment with 1‐fluoro‐2,4‐dinitrobenzene, gave results in close agreement with those for available lysine obtained using Carpenter's method. The short‐column system appeared to be free from carbohydrate interference which with Carpenter's method was probably responsible for higher values for available lysine especially for vegetable protein concentrates and cereal diets. The differences between the methods in values obtained for the available lysine in vegetable protein concentrates were significant. The modified short‐column technique improved the separation of ornithine and lysine. The optimum range of lysine concentration that is recommended for application to a column is between 25 and 75 μg in 1 ml. By the use of the technique suggested it is possible to carry out a large number of analyses without the use of the automatic analyser system as used by Roach et al.