Abstract
Applicatian of the α, α′-dipyridyl method to the determination of total ascorbic acids in food is described. The extract of food with trichloroacetic acid was shaken with activated carbon to remove pigments. The filtrate was first neutralized and then dehydroascorbic acid was reduced to ascorbic acid by incubation with dithiothreitol. After removal of the excess dithiothreitol with N-ethyl-maleimide, ascorbic acid was determined by the α, α′-dipyridyl method. The values obtained by this on 54 different kinds of food were compared with the values obtained by the dinitrophenylhydrazine method. The present method was specific for ascorbic acid as the dinitrophenylhydrazine method in most of the foods, except fungi and black tea.
