Q
How can dairy processors deliver more health benefits through probiotics in dairy products?
A
Probiotics have been proclaimed a "bacterial bonanza" on national television and hailed for their health benefits in general magazines. As more and more consumers get comfortable with the association between "healthy bugs" and the yogurt they enjoy, savvy dairy processors are seizing the opportunity to boost sales by incorporating more probiotics into their dairy products and touting their health benefits.Sometimes called "friendly bacteria," the term "probiotic" literally means "for life." There's debate within the industry over which bacteria qualify. The yogurt starter culturesLactobacillus bulgaricusandStreptococcus thermophilushave been shown to improve lactose digestion in individuals with reduced lactase levels, but they are not resistant to conditions in the stomach and small intestine and generally don't survive intestinal transit in significant numbers. This prompts some experts to say they are not true probiotics. Newer research shows, however, that specific strains ofL. acidophilus, various bifidobacterium species as well as some of the other lactobacilli may play a role in improving health at various sites on the body, including the mouth and stomach, suggesting that survival through the intestine may not be critical to all probiotic effects. While the debate continues, surviving intestinal transit is definitely a plus, according to Mary Ellen Sanders, Ph.D., Dairy and Food Culture Technologies, Centennial, Colo.
The science related to the heath benefits of probiotics is still emerging. The effect of certain probiotics on risk for, and duration of, diarrhea has been well documented, but the body of science is still being built on other potential benefits such as enhancing immunity, promoting intestinal health, improving lactose tolerance, improving vaginal health, combating Helicobacter pylori in the stomach and reducing the incidence of allergies. Any benefits would be specific to certain probiotic strains and doses, and companies must have the necessary science to be able to substantiate any claims they make.
For example, the Dannon Company Inc., White Plains, N.Y., asserts that its Activia yogurt product contains a specific culture Bifidobacterium animalis DN-173 010 that helps to regulate the digestive system and speed up slow intestinal transit. Two randomized studies were conducted and demonstrated the efficacy of Activia in reducing transit time in elderly subjects, particularly those with long transit times. A dose-dependent effect was observed (from 1 to 3 cups).
This product is one contributing to the positive trends for yogurts with added probiotics and for kefir, a probiotic beverage. Both categories have shown double-digit growth in recent years. Here's two examples of companies that identify the specific cultures used in their products. Stonyfield Farm Lowfat Yogurt Smoothie touts six live active cultures in their ingredient legend includingL. acidophilus,Bifidus,L. casei, andL. reuteri. Lifeway Lowfat Kefir Cultured Milk Smoothie displays a list of 10 Live and Active Kefir Cultures on the product label. This list includesL. lactis,B bacterium longum,Leuconostoc cremoris, andS diacetylactis.
Usprobiotics.orgis a non-profit research and education website made possible by the California Dairy Research Foundation and Dairy & Food Culture Technologies. It is a comprehensive, up-to-date resource on activities, research and new developments in the area of probiotics and dairy products in the United States as well as a reference to what's going on in the rest of the world. Its website includes highlights of recent clinical studies on probiotics.
"Dairy products are a preferred delivery vehicle because of their short shelf life and refrigerated storage," notes Greg Leyer, probiotic technical director, Danisco USA Inc., Madison, Wis. The company has studied sugar levels, pH and how the culture is added in the milk and allowed to ferment, among other variables. According to Leyer, a pH below 4.0 is generally less favorable to viability than a pH between 4.0 and 4.2. High sugar levels can also affect culture levels. "Still, there are no clear predictive criteria to ensure viability in yogurt, and the best recommendation is to evaluate probiotic levels in the product of interest, as the results are product- and formula-specific."
Research continues into dairy's synergies with probiotics. Todd Klaenhammer, director, Southeast Dairy Foods Research Center, Raleigh, N.C., explains his investigation into the nature of the dairy-probiotic relationship, "Recent genome information on lactic acid bacteria used as probiotics in dairy products has now identified many different genes implicated in carrying out probiotic functions. Genes that direct attachment to the intestinal epithelium communicate with host tissues and the immune system and provide resistance to acid and bile. Research can now ask, ‘Do milk components and the conditions encountered in dairy products positively impact the expression of these important probiotic gene sets?'
If so, delivery of probiotics via dairy may be the preferred route to promote the viability and beneficial activities of these probiotic cultures."
Beyond the added probiotics, the fermentation process itself may offer possibilities for healthier products. "During the fermentation of dairy foods, new products such as functional peptides are formed, which research shows may have beneficial effects," according to Miguel Freitas, Dannon medical marketing mgr.
While yogurt and other fermented dairy products are already a good source of calcium, protein and other essential vitamins and minerals, having probiotics moves them into the fast-growing category of functional foods-definitely a worthwhile area for processors to explore.
To learn more about probiotics and dairy, visit www.innovatewithdairy.com. Technical Support Consultant Sharon Gerdes can be reached at 800/248-8829.
