Advances in culture and enzyme use create new opportunities for consistency, development and efficiency.

A new culture of opportunities for cheese and other dairy processors is being created on the R&D front of cultures and enzymes. Reliable flavor notes and an accelerated aging process go hand in hand with emerging cultures in development by dairy scientists.

Health and wellness trends are tapped with the emergence of cultures to infuse cheeses with probiotics or create low-fat and non-fat cheeses with palatable taste and texture. New cultures and improved delivery systems are expected to improve not only opportunities for new products, but also overall cheese quality and bottom-line production costs.

Compared to previous versions, the latest generation of cultures features higher concentration, higher functional activity, scientifically proven health benefits and creation efficiency gains that have resulted in decreased costs to processors, says Peggy Steele, product manager for fresh dairy at Danisco Cultures Division, Madison, Wis.

Søren Herskind, the Hørsholm, Denmark-based marketing director of cheese cultures for the Chr. Hansen A/S Cultures & Enzymes division, agrees. “As demands for flavor modification differ greatly, future ranges of ripening cultures may include new strains used for fermentation of other food ingredients, new combinations of known strains or traditional strains with new and improved properties,” Herskind says.

“With cheese production, sometimes you add cultures and whatever flavor you get, you get,” says Dean Sommer, cheese and food technologist for the Wisconsin Center for Dairy Research (CDR) in Madison. “But now, people are adding cultures for reasons that have nothing to do with acid and everything to do with making cheddar cheese more desirable.”

Cultures that reliably produce and even acceleration the formation of specific desirable flavor compounds in the cheese are another focus area for CDR and industry suppliers. “The current level of interest in cheese flavor development is unprecedented,” says Terri Rexroat, global product manager of lactic cultures for Cargill Texturizing Solutions, Waukesha, Wis. Cargill has found cultures (both bacteria and yeast) and enzymes with optimal protease, aminopeptidase and esterase activities provide an ideal overall flavor package to cheddar, parmesan and Swiss-type cheeses.

CDR researchers have identified cultures containing an enzyme system that reliably produces desirable flavors, and at more intense levels than currently achievable with current methods A classic example of flavor needs is the nutty and fruity, burnt pineapple flavor tones found in premium parmesan cheeses, Sommer says. Though parmesan is aged a minimum of 10 months prior to sale, fruity and nutty tones aren’t typically detectable until eight or nine months, he explains, and current methods to achieve full parmesan flavor require a lengthy — and expensive — 20 to 24 months of maturation.

“Fruity and nutty are really desirable flavor tones,” he says. “In commercial production, some companies are good at coming up with those flavors reliably, and others really struggle with it.”

Flavor as well as texture can be provided to low-fat and no-fat cheeses through culture use. “One of the biggest defects of low-fat cheese is that you don’t get the natural flavor of say, a cheddar,” Sommer says. CDR has worked with a culture from Iowa’s Medipharm that provides, even in reduced-fat and low-fat cheeses, what Sommer describes as “a nice, balanced, cheesy flavor.”

The heat partially inactivated lactobacillus helveticus is an adjunct culture added to the milk prior to cheesemaking at the same time as lactic acid cultures. Already utilized broadly in low-fat European cheeses and proprietary applications by some U.S. processors, the Medipharm culture has been found by CDR to be effective.

Meanwhile, what Sommer describes as “rubbery-chewy texture” of non- and low-fat cheeses is being addressed by a major research initiative led by the Dairy Management Inc. (DMI) National Dairy Foods Research Center Program. The goal of DMI’s low-fat cheese expert panel is to find cultures that create more intense cheesy flavors while at the same time break down the body of the cheese to get an acceptable texture.

Cultures and enzymes can also improve cheese yield and functionality. Chr. Hansen, for instance, offers the YieldMAX™ pL enzyme, which creates a 2 percent yield increase to pasta filate (mozzarella) production.

As consumer enthusiasm for beneficial bacteria grows, U.S. product development trends follow those of Europe, with increasing availability of specific probiotic culture strains in yogurt and even cheese.

“Some of the real cutting-edge and exciting cultures and cheese research is in the area of probiotic cultures,” Sommer says of the bacteria considered beneficial to digestive health and immune system enhancement. “We’ve done a lot of work here, and it turns out that cheese is a very good vehicle for probiotic delivery. Now, we are trying to see which probiotic cultures work best in which cheese varieties. You have to know which strains are the right strains that have probiotic characteristics. That’s the current cutting-edge part of the industry right now. It’s not one-size fits all.”

To accommodate the aging process, industry researchers are testing to see which common probiotic strains in yogurt — Bifidobacterium bifidus, Lactobacillus acidophilus and Lactobacillus casei — survive over time in various cheese applications, Sommer says. The goal of probiotic culture addition is to keep active levels of live probiotics in cheese at 10 million per gram or greater.

Lactobacillus casei is already found in naturally in cheddar and many other cheeses as they age, and Sommer reports research success with survivability in relatively high numbers with the addition of adjunct cultures. Lactobacillus acidophilus likewise survives “very nicely” in cheese, Sommer says. While bifido bacteria, the probiotic strain associated with babies and mother’s milk, is effectively incorporated in yogurt, it does not currently seem to be as durable for cheese applications, Sommer says: “It works, but not as well as L. casei or L. acidophilus.”

The probiotic culture influence on cheese flavor and texture — either positive or negative — is also being studied. “Typically you’re adding cultures to produce lactic acid — that’s the main purpose of a culture,” Sommer says. “But in this case, we’re adding cultures for probiotic health effect, so what we don’t want is unintended flavors or textural defect.”

For instance, a certain strain in a cheddar cheese might result in production of gas, in turn creating cheddar with undesirable Swiss-cheese-like eye development.

Danisco is proposing its range of Howaru™ premium probiotics for incorporation in both hard and semi-hard cheeses. “Professionals are starting to consider cheese as one of the best vehicle for probiotic daily-doses in terms of stability during shelf life for manufacturers and convenience for consumers,” Steele says. “The further enrichment of cheese with calcium against osteoporosis, pre- and probiotics for gut health benefits and plant sterols/stanols as blood cholesterol-lowering agents represents a new and very promising field of development in the cheese segment.”

This spring, Kraft Foods became the first to launch a probiotic cheese in Canada with Kraft LiveActive, in cheddar and marbled varieties; a U.S. launch is expected in September.

With an eye on the ongoing boom of probiotics-infused yogurt and smoothie products for the children’s market, CDR is also looking into the feasibility of probiotics in string cheese. “Kids love string cheese, they like to play with it,” Sommer says. “So what better medium than string cheese for probiotics for kids?”

Development of low pH beverages with probiotics is also expected to boom. In anticipation, Danisco is developing an adapted process for Howaru cultures for stability in this application.

In general, use of cultures and enzymes can overcome some of the challenges and considerations inherent in large-scale cheese production. For instance, CDR research is defining use the cultures to address formulation and functionality challenge of debittering aged cheeses. “One of the biggest defects in cheeses today is unwanted bitterness, particularly in cheeses like cheddar cheese and other aged cheeses,” Sommer says.

Sommer credits dairy microbiologist Jim Steele as a key to extensive research on debittering cultures. Research pinpoints causes of bitterness in cheese, as well as preventative measures through the addition of aminopeptidase enzymes.

Long-c:hain peptides are in place immediately in fresh cheese. Aging then forms longer and shorter peptides that often break right down to the amino acids, creating desirable flavor profiles. But during protein breakdown, an imbalance of the aminopeptidase enzyme system caused by certain cultures creates medium length peptides that cause bitter cheese. The solution is the use of aminopeptidase to break down mid-chain length peptides into smaller chain peptides and amino acids during the aging process, Sommer says.

Two methods have proven effective at battling bitterness: utilization of adjunct cultures with very strong aminopeptidase systems to break down bitter peptides and addition of produced aminopeptidase enzymes during cheesemaking.

Cultures can also increasingly function to protect cheese systems from crashing. Mozzarella, cheddar and cottage cheese applications demand good phage resistance and fast acid development, says Chr. Hansen’s Herskind. The company developed its pHage Control™ and ST-M cultures with highly robust mesophilic and thermophilic cultures to be particularly resistant to attack from bacteriophages.

Dairy scientists continue to seek cultures that show resistance to attack by bacterial viruses. The goal is to ensure “cheese manufactures don’t get caught by culture systems that crash because they were attacked and destroyed by bacteria crash phage viruses,” Sommer says. “It’s a constant battle.”

To inhibit growth of yeasts and molds in yogurt, fresh cheese or other fermented dairy products, Danisco offers a line of Holdbac™ protective cultures and Microgard™ fermentates, as well as the antimicrobials Natamax™ and Nisaplin™. Its protective culture Holdbac YM has been shown to inhibit the growth of molds and fulfill the requirement of 28-day shelf life for yogurt, with the new culture Holdbac™ YM-C proven to successfully prolong yogurt shelf life to more than 42 days.

Direct-to-vat culture additions create improved function and viability and have gained cost efficiency to become competitive with bulk culture systems, according to culture houses with various proprietary direct-vat culture and delivery systems. The direct-vat addition of adjunct cultures in cheese, for instance, is designed to improve effectiveness at providing desired flavor notes as well as increases in probiotic survival rate. Overall, direct-vat timing and dispersal improves cheese consistency.

The cheese industry has been slow to utilize due to a higher cost-in-use of compared to bulk batch cultures, Steele says. “But recent evolutions are catalyzing a change in attitude,” he says, noting that Danisco currently has direct-to-vat cultures available for mozzarella and cheddar applications.

Chr. Hansen has likewise driven direct inoculation for consistency, quality and control via its Direct Vat Set (DVS) system. Meanwhile, Cargill has introduced Tempo and Max-Gro cultures for direct vat methods.

The growing U.S. and international market for alternate-make cheeses such as non-standardized Hispanic-type cheeses is creating new challenges for the ingredients industry as well as cheese processors. Rexroat notes that Cargill is committed to product and application development of cultures, enzymes, flavors and texturizing agents for alternate-make cheese technology.

Duplication of Italian parmesan reggiano cheese utilizing pasteurized milk instead of raw milk is another possible culture application being sought by CDR. The European raw-milk cheese typically has intense, fruity flavor due to the natural flora of lactic acid bacteria in raw milk. However, it is costly to produce as it is aged two years or longer to achieve an extremely dry body, which carries a corresponding loss of yield. “We’re trying to come up with and understand the science to develop that with pasteurized milk, and in shorter periods of time,” Sommer says.

Areas to watch for development in enzymes include those suitable for kosher products. Cheeses such as asiago, romano and provolone rely on the lipase enzyme to target triglycerides and cleave off free-fatty acids. The result is the traditional hard Italian cheese flavor, which features a balanced, desirable rancidity, Sommer says. Traditionally lipase enzymes are isolated from animal tissues; Kosher lipases from non-animal sources are typically microbial. But Sommer explains kosher microbial lipases cleave off different chain-length fatty acids than animal-based ones. The result is a flavor profile that tends to be soapy and bitter.

“The nirvana is for us or for culture houses to find another source of lipase that is kosher from non-animal sources,” Steele says, “but that will produce flavor similar to the more traditional cheeses: balanced, sweet, pleasant and acceptable to consumers.”

A flurry of DMI-funded research by prominent university dairy researchers is working to determine genetic code of lactic acid starter cultures for cheese, which Sommer describes as “beyond cutting edge.”

Once a determination of how genes are triggered to create flavor compounds during aging is made, Sommer expects dairy scientists to be able to custom manufacture and control the cultures to produce the specific flavors, textures and desirable profiles. “I can’t tell you how long before that gets commercialized, but I can tell you undoubtedly it will come to fruition in the future.”