SURVEY OF THE CONJUGATED LINOLEIC-ACID CONTENTS OF DAIRY-PRODUCTS

The objective of this research was to determine the content of conjuga ted linoleic acid, an anticarcinogen, in dairy products. Fifteen chees es, three fermented dairy products (other than cheeses), and four flui d milk products (two brands for each product) were included in the sur vey. Total lipids, fatty acids, protein, moisture, and titratable acid ity were also measured to determine the relationship between the conte nt of these constituents and conjugated Linoleic acid content. The con jugated linoleic acid content of cheeses ranged from 3.59 to 7.96 mg/g of lipid. Blue, Brie, Edam, and Swiss cheeses had significantly highe r conjugated linoleic acid content than the other cheeses. Sharp Chedd ar cheeses tended to have higher conjugated linoleic acid content than the medium Cheddar cheeses, but the increase was not significant. The conjugated linoleic acid content of the other fermented dairy product s ranged from 3.82 to 4.66 mg/g of lipid, and cultured buttermilk had the highest content. The conjugated linoleic acid contents of four flu id milks ranged from 3.38 to 6.39 mg/g of lipid and were not significa ntly different from one another. Multiple linear regressions of conjug ated linoleic acid content and the total fatty acid content indicated a relationship between conjugated linoleic acid content and the conten t of precursors and intermediates of conjugated linoleic acid formatio n, including Linoleic and oleic acids.