Vitamin B6 In Foods Research Articles

Effect of Pepsin on the Absorption of Food Vitamin B12 and Iron

Effect of Pepsin on the Absorption of Food Vitamin B12 and Iron

INTESTINAL DISTRIBUTION OF INTRINSIC FACTOR AND VITAMIN B12 ABSORPTION.

Evidence is presented that intrinsic-factor (IF) activity is present in the small intestine as far down as the ileal end. Physiologic doses of radioactive vitamin B12 without IF were applied directly into various levels of the intestine by surgical and other means in man and rats, and significant absorption was obtained from the small intestine. Absorption inhibition by ethylenediaminetetraacetate and its counteraction by Ca ion demonstrated that such absorption was dependent on IF action. The large intestine was shown to be incapable of physiologic absorption of vitamin B12, and IF was totally ineffective. It is proposed that physiologically, gastric IF descends with some activity in the small intestine, where more of the food vitamin B12 is liberated by digestion and subjected to IF.

Recent Developments in the Analysis for Vitamin B6 in Foods

Publisher Summary In foods and like materials, vitamin B 6 occurs naturally as pyridoxine, pyridoxal, and pyridoxamine, either free or combined with other substances such as phosphate. No one assay procedure has been satisfactory for all three forms; therefore, procedures for separating and determining them individually are important and essential developments for the vitamin B 6 assay. This chapter discusses four different procedures for separating and determining vitamin B 6 : microbiological procedures, chromatographic separation, comparative data, and fluorometric procedures. Microbiological procedures have been used successfully in the assay of foods and biological materials for vitamin B 6 content, but physical and chemical methods were satisfactory only with relatively concentrated and pure preparations. Chemical procedures were proposed for the determination of pyridoxine, pyridoxal, and pyridoxamine based on the fluorescence of the lactone of 4-pyridoxic acid. Several ion exchange resins were used, depending on circumstances, to separate pyridoxine or pyridoxal from the extracts or solutions.

THE DETERMINATION OF VITAMIN B6 (PYRIDOXINE) IN FOODS

THE DETERMINATION OF VITAMIN B6 (PYRIDOXINE) IN FOODS

Chemical Estimation of Vitamin B6 in Foods by Means of the Diazo Reaction and the Phenol Reagent

THE recent investigations of Kuhn and his co-workers1 and Harris and Folkers2 have shown that vitamin B6 is 2-methyl-3 hydroxy-4:5 di(hydroxymethyl)-pyridine. It contains a hydroxy group in the position of the pyridine ring, which gives the characteristic red coloration of true aromatic phenols with ferric chloride. The vitamin also gives colour reactions with diazotized aromatic amines and the phenol reagent of Folin and Ciocalteu3.