144
Study on the Vitamin A Activity of Carotene in Green Fodder
2. Biological tests have shown that the chemical method of assay is a fair index of the true
carotene content in green fodders, and carotene in the form of an extract is quite as effective in the
system as that present in the plant tissues. ß-carotene appears to be predominant in these materials.
3. Carotene in green fodders as estimated chemically is about 85-98 per cent pure as shown by
chromatographic adsorption through dicalcium phosphate, whereas in other roughages a consider-
able part is non-carotene in nature.
4 Faecal excretion of true carotene by rats at 1-2 µg. level of dosage is shown to be 10-13
per cent according to the biological method, although the apparent excretion is as high as 40-52
per cent
5. When standard carotene is compared biologically with cod-liver oil vitamin A, the former
is found to be only about half as active as an equal weight of the latter. On this basis, the vitamin
A value of the various green fodders is only half of their true carotene contents.
REFERENCE
Archibald, J.G. Bennett, E. and Ritchis, W.S. (1943). J. Agric. Res. 66, 341
Austin, C.R. and Shipton, J. (1944). J. Coun. Sci. Industr. Res. Aust. 17, 115
Bolton, W. and Common ,R.H. (1942). J. Soc. Chem. Ind. 61, 50
Booher, L.E. and Callison, E.C. (1939). J. Nutrit. 18, 159
—,
Callison, E.C. and Hewston, E.M. (1939). J. Nutrit. 17, 317
Coward, K.H. (1933). Biochem. J. 27, 445
—,
(1938). Biological Standardization of the Vitamins, 29, 218. London ; Bailliers, Tindall & Cox
Felice, D.De and Fellers, C.R. (1937). Proc. Amer. Soc. Hort. Sci. 34, 728
Gorter, F.J. and Spruyt, J.P. (1939). Arch. neerl. Physiol. 24, 122. Chem. Abstr. (1939), 33, 8726
Greaves, H.C.H. (1942). Chem. & Ind. 61, 8
Guggenheim, K. (1944). Biochem. J. 38, 260
Guilbert, H.R., Howell, C.E. and Hart, G.H. (1940). J. Nutrit. 19, 91
Hodgson, R.E., Murer, H.K. and Knott, J.C. (1939). Ann. Rep. West. Wash. Agric. Exp. Sta., 16
Moore, L.A. (1940). Industr. Engng Chem (Anal. ed.) 12, 726
Morton R.A. (1942). The Application of Absorption Spectra to the Study of Vitamins Hormones and Coenzymes
2nd ed. 95, 102. London ; Adam Hilger.
Peterson, W.H. Hughes, J.S. and Freeman, H.F. (1937). Industr. Engng. Chem. (Anal. ed.) 9, 71
Ramasarma, C.B. and Hakim, D.N. (1942). Nature, Lond., 149, 611. Ann. Biochem. Exp. Med. 2, 181
Russell, W.C., Taylor, M.W., Walker, H.A. and Polskin, L.J. (1942). J. Nutrit. 24, 199
Seshan P.A. and Sen K.C. (1942a). J. Agric. Sci. 32, 194
—,
(1942b). J. Agric. Sci. 32, 202
—,
(1942c). J. Agric. Sci. 32, 275
—,
(1942d). J. Agric. Sci. 32, 286
Smith, A.M. and Robb, M. (1943). J. Agric. Sci. 33, 119
Smith, M.C. and Otis, L. (1941). Food Res. 6, 143
Stimson, C.R. and Tressler, D.K. and Maynard, L.A. (1939). Food. Res. 4, 475
Taylor, M.W., Russell, W.C. and Bender, C.B. (1939). J. Dairy Sci. 22, 591
Treichler, R., Kemmerer, A.R. and Fraps, G.S. (1942). J. Nutrit. 24, 57
Woods, E., Shaw, A.O., Atkeson, F.W. and Johnson, R.F. (1942). J. Dairy Sci. 15, 475
Woods. E., Atkeson. F.W., Wellhousen, H and Johnson R.F. (1935a). J. Dairy Sci. 18, 547
—,
Shaw, A.O., Slater, I.W. and Johnson R.F. (1935b). J. Dairy Sci. 18, 573
—,
Slater, I.W., Arndt, C.D. and Johnson R.F. (1935c). J. Dairy Sci. 18, 639
Zimmerman W.I., Tressler, D.K. and Maynard, L.A. (1940). Food Res. 5, 93
—(1941).
Food Res. 6, 57