The effect of churning on the vitamin A and carotene content of milk fat

The vitamin A and carotene content of 14 samples of butter fat churned from milk in the usual way has been compared in spectrophotometric and Lovibond tintometer tests with figures similarly obtained for the ether-extracted fat from the same milks. On the assumption that there is no loss of either carotene or vitamin A in the course of the ether extraction, it has been found that some carotene is lost in churning but that vitamin A is not appreciably affected.