Fatty acid and CLA composition of Brazilian dairy products, and contribution to daily intake of CLA

In the present study, the conjugated linoleic acid (CLA) contents of dairy products most consumed by the population living in the southeast region of Brazil (whole milk, “Prato” cheese and butter) were determined. In addition, the contribution of these dairy foods to the daily intake of CLA isomers was estimated. Fatty acid composition was determined by gas chromatography. Quantitative analysis of CLA isomers was done by silver-ion high-performance liquid chromatography (HPLC) and their identification was achieved by gas chromatography–mass spectrometry (GC–MS) of dimethyloxazoline (DMOX) derivatives. Eleven CLA isomers were identified and the predominant were cis-9,trans-11 and trans-7,cis-9. The total CLA contents in whole milk, “Prato” cheese and butter ranged from 4.0 to 8.4 mg/g fat and were similar to those reported for dairy products from other countries. Whole milk samples had significantly higher contents of total CLA, when compared to “Prato” cheese and butter, and the total CLA contents were significantly different between the commercial brands of each dairy product. The estimated average daily intake of total CLA in southeastern Brazil was 36 mg/day, which was lower than those of European and North American countries, and milk was the main food source of CLA in the diet.