Yogurt Trends

For a food that’s pushing 4,500 years old, yogurt sure keeps up with the times. “The great thing about yogurt is that it provides significant opportunities for innovation, particularly around fruit combinations, as well as enhancement to support low-fat or low-sugar and functional applications,” says Minerva Calatayud, global product manager, sweet goods, cheese, and dairy, Givaudan Flavors, Cincinnati.

A constellation of trends brings new life to yogurt. Developmental milestones from the past include fruit-on-the-bottom, nonfat and sugar-free, as well as drinkable and kid-friendly squeeze packs. But today’s pace of innovation is in overdrive. “What we see as we add benefits,” says Alan Reed, senior vice president, U.S. manufacturing and ingredient marketing, Dairy Management Inc.™ (DMI), Rosemont, IL, “is that the more compelling the benefit, the more likely it is to increase overall yogurt category growth.”

If any trend promises to shape yogurt’s future, it’s the headlong dive into enhanced wellness benefits.

A functional future

“For many reasons, we’ve recently seen an increase in personal accountability by consumers in the area of health and wellness,” explains Pete Budde, business development manager, probiotics, Cargill Texturizing Solutions, Wayzata, MN. “I believe that we will continue to see the consumption of yogurt increase with market support for products supplemented with value-added ingredients like probiotics.”

Probiotics have found a natural home in yogurt. “Yogurts were not chosen as probiotic delivery vehicles; yogurt and fermented milks are the natural habitat of lactic acid bacteria,” says Mirjana Curic-Bawden, Ph.D., senior scientist, Chr. Hansen, Inc., Milwaukee. “For centuries, fermented milks have been traditionally made and consumed in Europe, the Middle East and Asia. But it was not until the 20th century that we learned about different species and strains, and that some of the strains, such as Lactobacillus acidophilus, Lactobacillus casei/paracasei, Bifidobacteria and Lactobacillus rhamnosus, are able to confer additional beneficial effects.”

Probiotics’ documented benefits stand out in the area of gastrointestinal health. “Clinical documentation exists for regulation of intestinal transit; improvement of infant diarrhea and rotavirus status; reduced incidence of antibiotic-associated diarrhea; positive effect on constipation in the elderly and traveler’s diarrhea; improved status of natural defense and immune-system response; and positive effects on atopic eczema in infants,” Curic-Bawden says. “Some strains have possible effects on irritable bowel syndrome or cholesterol level, but these still need further clinical substantiation.”

Benefits are highly strain-specific. “Not every Bifidobacterium lactis or Lactobacillus casei is the same,” says Curic-Bawden. “In spite of the wide range of products on the market—in both supplements and food—only limited numbers of strains have substantial documentation that qualify them as probiotic.” These strains carry a specific alphanumeric designation, such as BB-12, LGG or CRL-431, which identifies them as probiotic. For a consumer to realize any benefits, however, probiotic organisms must survive passage through the gastrointestinal tract, where low-pH conditions, bile salts and digestive enzymes all threaten survival. Furthermore, Curic-Bawden notes, “a strain has to be able to adhere to mucosal tissue and temporarily colonize the GI tract, thus re-establishing a healthy and balanced microflora.”

They also must also remain viable for the duration of yogurt processing and storage. “Processing steps that can improve probiotic cell counts include inoculation of the proper dose; following yogurt-making procedures with regard to incubation temperature, time and pH; avoiding harmful ingredients—the addition of preservatives like potassium sorbate in a milk base before incubation will slow yogurt cultures and potentially harm probiotics—and the use of proper storage conditions along the cold chain,” Curic-Bawden says.

Even these parameters are strain-sensitive. Some show sensitivity to high sugar concentrations, especially fructose. “Sensitivity is strain-dependant,” says Curic-Bawden. “Some yogurt cultures and probiotics can be slowed down with 10% sucrose or 6% to 7% fructose, but 14% high fructose corn syrup can also do the ‘trick.’ This is relevant only if sugar is part of the milk base; yogurt cultures are not affected if sugar is added after the fermentation through the fruit prep.” Others have a very narrow temperature and pH range for optimum growth. “And even though most of the probiotic strains are anaerobic organisms,” she says, “some of them are more tolerant to oxygen, which makes them more suitable for dairy applications.”

No matter the strain, a yogurt will contain live and active cultures only if it undergoes heat treatment before acidification. The criteria of the National Yogurt Association, McLean, VA, for live and active cultures state that a finished yogurt must contain at least 1 billion live lactic acid bacteria per gram at the time of manufacture, and those cultures must remain active for the stated shelf life. Some research suggests that prebiotics—nondigestible fibers that serve as sources of carbohydrates for probiotics in the GI tract—enhance survival of probiotics in fermented milk and yogurt, and also during passage through the GI tract. “Besides ingredients like inulin, fructooligosaccharides and polydextrose,” Curic-Bawden says, “we’ve witnessed the rapid extension of the range of natural ingredients that have potential prebiotics effects.” Again, those effects are unique to each pro- and prebiotic—or synbiotic—pair. To achieve a synbiotic effect, she says, “a specific prebiotic should selectively favor the probiotic strain. The effect has to be tested in vitro and in vivo.”

Friendly fats

In addition to probiotic cultures, other, less-intuitive functionals are finding their way into yogurt. Among the more popular is the omega-3 fatty acid docosahexaenoic acid (DHA), associated with everything from healthy infant neural development to reduced heart disease risk.

As a long-chain polyunsaturate, DHA is prone to oxidation from prolonged exposure to oxygen, high temperatures and transition metals like copper and iron. Yogurt’s refrigerated storage and short shelf life makes it an ideal medium for omega-3 stability.

Experts offer several tips for working with omega-3s: If a yogurt undergoes high-shear mixing, limit its exposure to the atmosphere by shortening mixing times, keeping temperatures low and covering the mixing vessel. Add the DHA as close to the end of production as possible, such as prior to homogenization. Blend the oil with other ingredients to thermally stabilize it and to reduce its surface area. Better yet, work with encapsulated oils, and take advantage of chelating agents like citric acid and EDTA to sequester pro-oxidant metals. Nonfat applications are harder to fortify than their fat-containing cousins, but even so, some manufacturers have packed as much as 32 mg of DHA into a single 6-oz. serving, qualifying the product for an “excellent source” of DHA claim.

Another healthful fat is conjugated linoleic acid (CLA), a natural constituent of ruminant meat and dairy products with demonstrated weight-management benefits that have prompted some manufacturers to add it to yogurt. “Clinical evidence supports the role of CLA in many aspects of reducing body fat, increasing lean muscle and enhancing healthy, active living,” says Patrick Luchsinger, marketing manager, North America, Lipid Nutrition, Channahon, IL. “This means that products can be positioned not only to help dieters, but also those who want to maintain weight and certainly those who wish to enhance their exercise program for optimal body composition. This increases consumer interest in yogurt at a time when health and wellness is paramount.”

His company markets a form of CLA that “is appropriate for use in all types of yogurt,” Luchsinger says. CLA particularly shines in drinkable applications because the proteins in the beverages double as emulsifiers for it. To establish that emulsion, he suggests adding the CLA to yogurt under continuous mixing and at a temperature around 140°F. After homogenization, applying a heat treatment can extend the product shelf life. The ingredient can withstand UHT and standard pasteurization, and can be added before or after fermentation. “In the case of a fermentation step,” he says, “the CLA can be emulsified in the milk, after which a standard process and fermentation can follow.”

CLA is also a polyunsaturated fatty acid liable to oxidation. Avoiding the usual triggers—oxygen, heat, light, transition metals—is standard, but as with DHA, “other factors may help avoid oxidation, like antioxidants and the chelators citric acid and EDTA,” Luchsinger says. As for the levels that yield a health benefit, clinical trials of his company’s product have pointed to 3 grams as effective. “This can be split into different doses or consumed at one time,” he says, “so manufacturers may choose to add 1.5 grams per serving and note that it contains one half the effective daily dose.”

Protein power

Like CLA, whey protein is a natural component of dairy products that manufacturers are adding to yogurt. According to Reed, the reason for doing so is elementary: “Protein, overall, is a huge trend.” But while health-minded consumers want more protein, they don’t want more chalky, protein-powder shakes. “They’re looking for a comfortable medium that’s familiar to them and that delivers nutrition benefit,” he says. Enter yogurt. “It’s portable, it’s convenient, it’s a reasonably sized serving, and it’s really targeting those active, exercise-involved individuals.”

Why whey? Research suggests that it might help build and maintain lean muscle mass, as well as help people lose more unhealthy abdominal fat than other proteins or carbohydrates. “Whey protein may be uniquely positioned to deliver better results because of its amino acids,” says Brian Sambor, vice president, operations and technology, Tula Foods, Inc., Evanston, IL. “Whey protein is the richest source of branched-chain amino acids like leucine. Compared to traditional diets, reduced-calorie diets rich in leucine have led to greater fat loss and muscle retention, particularly when combined with exercise. When consumed after exercise, whey protein helps tone muscle, stimulates muscle recovery, and allows people to get more from their workouts.”

In yogurt, the proteins are compatible with the typical yogurt-processing heat treatments, as well as with the typical yogurt pH and flavor profile. Whey’s practical benefits go beyond stability to actual textural improvement. “It can be added to achieve specific mouthfeel characteristics,” says Michelle Ludtke, senior food technologist, Grande Custom Ingredients Group, Lomira, WI. And whey “has some water-binding properties for stability purposes. It has a clean flavor, and it’s a natural ingredient that is dairy-based and low in fat. Also, whey proteins contain some natural emulsifying properties.”

Sambor notes that “with our levels of whey protein use and processing, our nonfat yogurt is richer and creamier than many other nonfat yogurts on the market.” Further, a 6-oz. serving delivers 15 grams of protein, 10 grams of which are whey; by contrast, only about 0 to 2 grams of the protein in a standard yogurt comes from whey.

Packing this much protein in a yogurt isn’t easy. Such a heavily whey-fortified formulation “poses significant manufacturing challenges,” Sambor says. “At these levels, the heat denaturation that occurs under typical yogurt production conditions would form unwanted aggregates and an unacceptable product that is often characterized by a grainy texture and flavor defects, such as powdery and burnt notes.”

When flavoring yogurts fortified for wellness, manufacturers may encounter off notes, “sometimes bitter, but otherwise variable,” says Kim Gray, senior application scientist, global application technologies, Givaudan Flavors. “Developers of applications, as well as flavorists, must understand the interactions that can occur with functional ingredients.” Take the substitution of soy proteins for dairy. “These proteins will interact differently with flavor compounds,” she says, “and this needs to be understood or optimized to develop high-impact and high-quality flavors.” Similarly, the instability of long-chain fatty acids like omega-3s, as well as CLA, can lead to off notes. “Antioxidants can help,” she says, “but will not solve the issue.”

Not all functional ingredients pose sensory hurdles. “Actually, some of those products can bring positive attributes to a yogurt,” says Declan Roche, commercial director at Kerry Food Ingredients, Beloit, WI. “Sterols, for example, are very much like waxy, high-melting-point fats. So they can actually bring enhanced richness and mouthfeel to a reduced-fat yogurt if they’re incorporated correctly.”

That’s just what consumers want. “We believe that the good-for-you yogurts will continue to drive yogurt-category growth,” says Daphne Mazarakis, founder and president, Tula Foods. But what “good for you” means will continue to evolve. “In the past,” she continues, “it was about taking out fat and replacing it with simple sugars or artificial sweeteners. We believe that, increasingly, good-for-you yogurts will be more about positive nutrient density. You can find nutrient-dense yogurts in simple, back-to-basics products, as well as in yogurts that have added functional nutrients, such as whey proteins, probiotics or omega-3s. Consumers already associate yogurt with health, so the idea that we can bring them a yogurt with another promising health benefit is credible.”