Absorption of Minimal Doses of Carotene by Vitamin A-Deficient Rats

A study on the vitamin A activity of carotene in green fodder

“…(3) Absorption of fodder carotene in avitaminotic rats Although the chemical, chromatographic and biological methods of assaying carotene in green fodders have given similar results, it was of interest to determine if the activity manifested in the biological assay was really due to the absorption of the total amount of carotene ingested and to what extent the amount absorbed was converted into vitamin A in the system. It has been reported recently by Ramasarma & Hakim (1942) that 10-15% of carotene fed to rats at 1-2 fig. level of dosage is excreted via the faeces.…”

Determination of Carotene in Plant Materials

“…THE determination of carotene in plant tissues, the two general methods of removal of noncarotenoids are phasic and chromatographic separations (4,30,34)• In view of the recognized variations in the extent of digestion and absorption of carotene and its interdependence on the presence of varying amounts of antioxidants (1,7,14,15,16,39,40), complete chromatographic analysis, involving the separation of various carotene isomers, is neither practical nor necessary for routine analytical purposes, particularly in the nutritional evaluation of foods, feeds, and fodders (89). The phase separation method, on the other hand, is not always quantitative (11,83,24,25); certain biologically inert degradation products are also taken up in the epiphasic layer (36,50). In addition, a small percentage of the xanthophylls remains in the petroleum phase and appreciable amounts of carotene are taken up in the hypophasic methanol layer (21,46).…”