title: Cheese manufacture with milk with elevated conjugated linoleic acid levels caused by dietary manipulation.
abstract: The objective of this study was to assess the effect of dietary supplementation of cows on pasture with sunflower oil for conjugated linoleic acid (cis-9, trans-11 CLA) enrichment of milk, for the production of CLA-enriched cheese. A group of 40 autumn-calving dairy cows were assigned to either a control group (indoor feeding on grass silage ad libitum and 6 kg/d of a typical indoor concentrate) or an experimental group (on pasture, being fed 6 kg of a supplement containing 100 g/kg of sunflower oil per d). These diets were fed for 16 d, during which time milk was collected for pilot-scale hard cheese manufacture. The pasture-based diet with sunflower oil resulted in a significant effect on the milk fatty acid CLA content. The concentration of cis-9, trans-11 CLA in the milk produced from cows on this diet increased to 2.22 g/100 g of fatty acid methyl esters (FAME) after 14 d, compared with 0.46 g/100 g of FAME in milk produced on the control indoor diet. The content of cis-9, trans-11 CLA in the cheese manufactured from the indoor control milk was 0.78 g/100 g of FAME and that from the pasture-based sunflower oil milk was 1.93 g/100 g of FAME. The cheese was assessed during the ripening period and CLA concentrations were stable throughout the 6 mo of ripening. Other cheese variables (microbiology, composition, flavor, free AA) were monitored during the ripening period, and the cheese with the elevated CLA concentrations compared favorably with the control cheese. Thus, a pasture-based diet supplemented with an oil source rich in linoleic acid resulted in an enhanced CLA content of bovine milk fat, compared with an indoor grass silage-based diet.
authors.affiliation: Teagasc, Moorepark Food Research Centre, Fermoy, Co. Cork, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Coakley
authors.forename: E
authors.initials: E
authors.lastname: Barrett
authors.forename: J J
authors.initials: JJ
authors.lastname: Murphy
authors.forename: R P
authors.initials: RP
authors.lastname: Ross
authors.forename: R
authors.initials: R
authors.lastname: Devery
authors.forename: C
authors.initials: C
authors.lastname: Stanton
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D002611:Cheese / Q000032:analysis*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000378:metabolism; D019587:Dietary Supplements; D005260:Female; D005285:Fermentation; D058870:Food, Organic; D044243:Linoleic Acids, Conjugated / Q000008:administration & dosage* / Q000032:analysis* / Q000378:metabolism; D008892:Milk / Q000737:chemistry*; D010938:Plant Oils / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D011897:Random Allocation; D000074242:Sunflower Oil
chemical_list: D004042:Dietary Fats, Unsaturated; D044243:Linoleic Acids, Conjugated; D010938:Plant Oils; D000074242:Sunflower Oil