Open AccessTHE EFFECTS OF STORAGE AND HEATING ON LYSINE AVAILABILITY OF FOOD‐GRADE PROTEINS FROM PASTURE HERBAGE AS MEASURED BY CHEMICAL, BIOLOGICAL AND MICROBIOLOGICAL ASSAYS
Author(s) -
OSTROWSKIMEISSNER HENRY T.
Publication year - 1980
Publication title -
journal of food quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.568
H-Index - 43
eISSN - 1745-4557
pISSN - 0146-9428
DOI - 10.1111/j.1745-4557.1980.tb00705.x
Subject(s) - tetrahymena pyriformis , lysine , pasture , food science , bioassay , biology , protein quality , chemistry , biochemistry , microbiology and biotechnology , tetrahymena , agronomy , amino acid , ecology
Food‐grade protein concentrates isolated from pasture herbage stored and/or heated either alone or with glucose to cause various types of damage to lysine were analyzed for available lysine using chemical procedures and bioassays with chickens, mice, rats and protozoon Tetrahy‐mena pyriformis. There were substantial differences in the results obtained with the various chemical methods which showed their different sensitivities to a particular type of lysine damage which had occurred during storage and heat processing. Overall, chemical procedures gave lower values for available lysine than the biological ones, and thus may underestimate availability. The responses of mice and Tetrahymena pyriformis to various types of lysine damage were similar to those observed with chicks, while rats appeared to be less sensitive test animals in detecting the changes in lysine availability in stored or heat processed foods. The necessity to adapt a rapid system for lysine availability determination in foodstuffs and cereal‐based diets is discussed with reference to the proper quality control of food‐grade proteins, isolated from pasture herbage and subjected to storage or heat processing, before being used in feeding schemes with school children in developing countries. The use of Tetrahymena pyriformis or a simple chemical procedure may provide a built‐in safety margin to insure proper quality control of food‐grade proteins.