Tocopherol Content of Canadian Butterfat and Its Use in Detecting Adulteration

A rapid procedure for determining the tocopherol content of butterfat has been developed (5).This method has proved useful in detecting the adulteration of butter, because the tocopherol content of butterfat is low, whereas that of most vegetable fats and oils, with the exception of coconut oil, is considerably higher.Usually, therefore, the adulteration of butter with hydrogenated vegetable fats will result in a significant increase in the tocopherol content of the adulterated fat.The literature indicates that although the tocopherol content of butterfat is low, it is, nevertheless, subject to considerable seasonal variation.Harris et al. (4) found the mean tocopherol content to be 42 p.p.m, for summer milk fat and 23 p.p.m, for winter milk fat.Parrish et al. (6) reported a tocopherol content as low as 8 for milk fat.In a more recent survey, Bird et al. (1) found the tocopherol contents for milk fat to range frond 10 to 45 p.p.m.The foregoing data indicate tocopherol contents of 8 to 45 p.p.m, for butterfat with seasonal variation accounting for a large portion of this range.Since these data do not apply to Canadian butterfat, it was considered desirable to initiate a survey to establish the range and seasonal variation of the tocopherol content of Canadian commercial butterfat by employing our tocopherol procedure (5). EXPERIMENTAL PROCEDURE AND RESULTSButter samples were collected at monthly intervals from 29 selected manufacturers located in eight provinces over a period of 1 year.Each figure reported in Table I represents the average of two analyses conducted on the same butterfat sample.The butter from which these samples were taken was churned under the supervision of Provincial dairy instructors.It should be emphasized that the factories supplying these samples derived their milk from large numbers of cows (28,000 to 56,000) which were fed, housed, and milked according to commercial practices.It is believed, therefore, that the results of this survey are representative of Canadian commercial butterfat production for the period June, 1953, to June, 1954.These results are given in Table 1.