The Carotene Content, Vitamin a Potency, and Antioxidants of Butter Fat

Dtermination of Alpha- and Beta-Carotenes

“…The solvent chosen must be one in which carotene obeys Beer's law. Shrewsbury and Kraybill (11) and Barnett (2) have shown that carotene dissolved in fat does not obey Beer's law.…”

“…In previous work (4,11) carotene determinations were made with the spectrophotometer by the method of Schertz (10) at wave length 435.8 µ, using light from a 1000watt incandescent bulb. It is difficult to read transmittancies under these conditions because of the low light sensitivity of the eye and the low intensity of an incandescent lamp in that region.…”

The role of carotene in human health

“…To what extent does man depend upon butter for his carotene requirements, and in what degree does the use of carotene-free commercial butter colors during a part of the year deprive him of his expected carotene intake? Shrewsbury and Kraybill have shown that the carotene of butter may account for an appreciable amount, possibly all, of its vitamin A content (40).…”