Procedure for Chromatographic Separation and Microbiological Assay of Pyridoxine, Pyridoxal, and Pyridoxamine in Food Extracts

Vitamin Value Assay, Comparison of Vitamin B6 Values of Selected Food Samples by Bioassay and Microbiological Assay

“…The data were calculated according to the equations of Bliss (2,8) to obtain the values of the means with their 95% confidence limits. The microbiological assays were made according to the procedures of Toepfer and Lehmann (6) using A carlsbergensis as the test organism and the media and techniques there described.…”

“…The chromatographic separation of food extracts into pyridoxine, pyridoxal, and pyridoxamine fractions, using an ion exchange column with Dowex 50 resin, has made it possible to assay for these three factors individually and to calculate the total vitamin B6 content of the food (3,6,7).…”

“…The purpose of this paper is to compare vitamin B6 values obtained by the rat bioassay of Richardson et al ( 5) and free and total vitamin B6 values of a few selected food samples assayed by the yeast microbiological procedure (6) on nonfractionated extracts and on the individual fractions of pyridoxine, pyridoxal, and pyridoxamine obtained by chromatographing the extracts.…”

Conversion of pyridoxine into 6-hydroxypyridoxine by food components, especially ascorbic acid.

“…Reduction in the vitamin B6 content during food processing and storage has also been reported in plant foods (3)(4)(5)14). Since vitamin B6 in plant foods is known to occur mainly as pyridoxine (PN) and its bound forms (15)(16)(17)(18), a lowering of the vitamin B6 content should be due to a reaction(s) different from those described in animal foods. For the present, there are no available papers concerning the mechanisms of PN loss in plant foods.…”

Assay of Vitamins and Amino Acids With Cultured Tissue Cells and Antimetabolites

“…A particularly interesting problem was exploring the possibility of assaying trace amounts of vitamin B6 in a mammalian cell system. The disparity of growth response of Saccharomyces carlsbergensis to the three isotels of this vitamin (Toepfer and Lehmann, 1961) reflects the view of Hutner, Cury, and Baker (1958) that there is no satisfactory assay for B6 in natural materials.…”