Simple chemical and biological methods used at Purdue University to evaluate cereals for protein quality

THE RECENT DISCOVERY THAT CEREAL PROTEINS CAN BE IMPROVED THROUGH GENETIC MANIPULATION HAS MADE DETERMINATION OF THE PROTEIN QUALITY OF THESE GRAINS ESSENTIAL. THIS REPORT DETAILS THE SIMPLE METHODS BY WHICH EVEN THE MOST ELEMENTARY EQUIPPED LABORATORY CAN PRODUCE RELIABLE DATA FOR A PLANT-BREEDING PROGRAM FOR PROTEIN QUALITY. CHEMICAL REAGENTS AND PROCEDURES ARE DESCRIBED FOR NITROGEN CONTENT ANALYSIS, TRYPTOPHAN DETERMINATION IN MAIZE, LYSINE LEVELS IN NON-PIGMENTED CEREALS, LYSINE SCREENING USING A NINHYDRIN REAGENT, AND DYE BINDING FOR HIGH LYSINE CEREALS. PROCEDURES FOR BIOLOGICAL ASSAY, BASED ON THE DIETS OF YOUNG RATS WHO RECEIVE ALL THEIR PROTEIN FROM CEREALS, IS ALSO PROVIDED. BOTH THE NINHYDRIN AND DYE BINDING TESTS ARE RECOMMENDED FOR MASS SCREENING OF LARGE POPULATIONS.