Enrichment of Pecorino cheese with conjugated linoleic acid by feeding dairy ewes with extruded linseed: effect on fatty acid and triglycerides composition and on oxidative stability

The aim of the study was to characterize the composition and the oxidative stability of lipids from Pecorino cheese enriched with conjugated linoleic acid (CLA), obtained by supplementing the diet of dairy ewes with extruded linseed. In the enriched cheese, the contents of cis-9, trans-11 CLA, trans-11 C18:1 and alpha-linolenic acid were increased by 290%, 197% and 250%, respectively. The triglyceride profile of enriched cheese was characterized by a two fold increase of triglycerides ranging from 52 to 54 carbon atoms. Changes in lipid composition did not increase the amount of cholesterol oxidation products and slightly increased the thiobarbituric acid-reactive substances, strongly suggesting that CLA-enriched cheese does not represent any potential risk related to increased intake of lipid oxidation products. In addition, the enrichment of alpha-linolenic is sufficient to be claimed as "omega-3" dietary source according to the European Union rules.