Occurrence of γ-Tocopherol and Variation of α- and γ-Tocopherol in Bovine Milk Fat

It was confirmed that 7-tocopherol in addition to a-toeopherol naturally occurred in milk fat as a normal component. 7-Tocopherol fractionated from milk fat was identified by thin-layer and gas-liquid ehromatography, ultraviolet and infrared absorption spectra, and coupling reaction. This component was found in all samples of mixed milk and individual milk analyzed. The mean values of a-and y-tocopherol content in mixed milk estimated by the thinlayer chromatographic method for a year were 28.3 (range, 17.0-39.3) and 1.5 (range, 0.5-2.9) /~g per gram of fat, respectively. Throughout seasons, a-tocopherol varied from 29.2 to 39.3 (mean, 33.8) in summer (May-October), and from 17.0 to 28.0 (mean, 21.6) /~g per gram of fat in winter (November--April). 7-Tocopherol varied from 1.0 to 2.5 (mean, 1.8) in summer and from 0.3 to 2.9 (mean, 1.1) /~g per gram of fat in winter. Toeopherols other than a-and ~,-tocopherol were not detected in any samples analyzed.