AbstractsBiology & Animal Science

Results of all vitamin C bioassays by the odontoblast method completed to date in this laboratory were reviewed and discussed. The odontoblast method of bioassay was compared with two chemical methods of assay, the indophenol method of Hochberg, Melnick and Oser and the phenylhydrazine method of Roe and Gesterling. The ascorbic acid potencies of nine vitamin C carriers, assayed biologically in this laboratory and chemically in the Department of Chemistry, served as a basis for this comparison. These assay materials included six fortified juices, freshly opened, and opened and stored apple juices, tomato juice, and three canned orange juices fortified in varying proportions; and three unfortified juices, high and low potency tomato juices and canned orange juice. Statistical analysis of the chemical and biological potencies of fortified and unfortified juices indicated that chemical methods underestimated the biological potencies of the fortified juices. The two chemical methods agreed closely in the estimation of vitamin C potencies of all juices, and satisfactorily estimated the biological potencies of unfortified juices.