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. Here’s what they have learned so far:

The flavor could be better
During the study, the researchers served three different milk products with  2 percent milkfat — one fortified with 2 percent CLA, one fortified with 1 percent CLA and one containing no added CLA — to trained sensory panelists, as well as a consumer panel.

The researchers found that CLA decreased the overall acceptance, flavor and freshness perception of the milk. In particular, the sensory panelists detected a “grassy” or vegetable-oil flavor in milk fortified with either 1 percent or 2 percent CLA. Although this off-flavor subsided after one week of refrigerated storage, it did not totally disappear, notes MaryAnne Drake, a food scientist involved in the study.

Meanwhile, consumers who sampled the CLA-fortified milk didn’t give the flavor a “thumbs up” either. However, they liked milk with a combination of 1 percent CLA and 1 percent milkfat better than milk with 2 percent CLA.

When the food scientists added chocolate flavor, consumer acceptability increased. However, that was only true for milk fortified with 1 percent CLA. Chocolate flavor had little impact on the acceptability of milk with 2 percent CLA.

In addition to these findings, the food scientists examined the color of milk fortified with CLA. They found it to be less white in appearance than milk without added CLA.

Furthermore, they noted that HTST — high-temperature, short-time — pasteurization destroyed a significant amount of the cis-9/trans-11 CLA isomer in the CLA-fortified milks. The cis-9/trans-11 isomer is the predominant CLA isomer found naturally in milk and meat. It is known for its anti-cancer benefits.

Consumers would buy it
Despite its less-than-appealing taste, a market exists for CLA-fortified milk. And although the addition of CLA could increase the cost of milk about 20 to 25 cents per 8-ounce serving, consumers say they would be willing to pay it. 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. Previous surveys have revealed similar findings.

However, before consumers can buy CLA-fortified milk, researchers will have to work out some of the kinks to improve its flavor. 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,” they add.

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