Representative determination of the butyric acid content in European milk fats.

摘要

This study was performed in order to determine a reliable mean value for butyric acid in pure milk fat based on a representative choice of samples. Thus, 136 milk fats from 9 European countries (10 from the UK, 5 from Spain, 10 from the Netherlands,4 from Italy, 10 from the Irish Republic, 4 from Greece, 5 from France, 10 from Switzerland and 78 from Germany) were selected on the basis of their content of the triglyceride C54 (as an indicator of different feeding and lactation conditions) to represent a normally-distributed collection of samples from most different feeding conditions. In these milk fats, the content of butyric acid was determined by gas chromatography using an internal standard. The individual results expressed as weight fractionof fat were also almost normally distributed. The resulting mean content of 3.42 g butyric acid/100 g of fat led to a factor of 29.24 that allowed calculation of the proportion of milk fat from the butyric acid content analysed in a mixed fat. It is concluded that the mean content of butyric acid in milk fat determined appears to be representative for Europe, and the expression in g/100 g fat enables the determination of the proportion of milk fat in mixed fats.