New research could bring CLA-fortified milk one step closer to the dairy case.

Consumer interest in the anti-cancer benefits of CLA — conjugated linoleic acid — has spurred researchers to pump up the amount of CLA in milk. To date, that has been accomplished by modifying diets fed to dairy cows.

Problem is, you would have to drink 30 glasses of milk per day from cows fed increased levels of CLA to acquire any benefit. However, that may change as researchers begin to explore the possibility of adding CLA directly to milk.

And that’s just what food scientists at North Carolina State University have done.

In the first study of its kind, the researchers added CLA directly to 2% milk to study the impact of CLA fortification on milk quality and consumer acceptance. They found CLA-fortified milk decreased overall acceptance, flavor and freshness perception of the milk. In particular, the findings reveal several intriguing results:

  • Sensory panelists detected a “grassy” or vegetable oil flavor in milk fortified with 1 percent or 2 percent CLA. However, this off-flavor subsided after one week of refrigerated storage.
  • Consumers didn’t like the taste of CLA-fortified milk as well as non-CLA-fortified milk. However, they liked milk with a 1-percent CLA, 1-percent milkfat combination better than milk containing 2 percent CLA.
  • Chocolate flavor increased consumer acceptability of milk fortified with 1 percent CLA, but had little impact on the acceptability of milk fortified with 2 percent CLA.
  • Milk fortified with CLA is less white in appearance than milk without added CLA.
  • HTST — high-temperature, short-time pasteurization — destroyed a significant amount of the cis-9/trans-11 CLA isomer in the milk. The cis-9/trans-11 isomer is the predominant CLA isomer found naturally in milk and meat.

Despite these mixed results, a market exists for CLA-fortified milk. According to a survey of 100 consumers conducted during the study, 89 percent say they might be willing to, or would definitely pay more for nutraceutical or functional foods — like milk fortified with CLA. Other surveys reveal similar findings.

However, researchers will have to work out some of the kinks before CLA-fortified milk hits the shelves. One way to increase consumer acceptance, say the researchers, is to reduce the concentration of CLA added to milk — that is, add 0.5-percent CLA instead of 1 percent or 2 percent. “The addition of chocolate or strawberry flavors is another realistic solution to increase consumer acceptability,” the researchers add.

The study’s results were reported in the January 2003 Journal of Dairy Science.