Milk is unique in that it is readily converted to a variety of foods through the use of minimal processing and the addition of a few simple ingredients. In the case of cheese and fermented dairy foods, such as kefir, sour cream and yogurt, those ingredients include cultures and enzymes.

“Cultures and enzymes are biological catalysts for dairy product production,” said Steve Funk, senior cheese technologist, Nelson-Jameson, Marshfield, Wis. “These hard-working elements work quietly behind the scenes.

“Dairy processors aim to strike a balance between tradition and innovation. Consumers count on the availability of their favorite dairy products, but they also want new flavors and formats,” said Funk. “Cultures and enzymes keep consumers happy by providing consistently produced dairy staples as well as inventive products that introduce new tastes and textures. They can also impact how well a cheese melts, browns or blends, providing additional variety to culinary usages.”  

Understanding cultures

There are four primary categories of cultures used in the production of cheese and fermented dairy foods. These are lactic acid bacteria (LAB), which are often referred to as starter cultures, along with adjunct cultures and probiotic cultures.

Unlike LAB and adjuncts, probiotics typically have little or no impact on taste or texture. They are live microorganisms, which when administered in adequate amounts, confer a health benefit on the host. Suppliers typically market individual probiotic strains that have been shown to exert specific health benefits in clinical trials.

Lactobacillus rhamnosus (LGG) is the world’s most documented probiotic strain, for example. Marketed worldwide since 1990, Chr. Hansen Inc., Milwaukee, Wis., supplies it as an ingredient for food and dietary supplements. It has been extensively studied across various health areas, and has been described in more than 250 publications of human studies.

Numerous meta-analyses have shown that probiotic cultures, as a class, are beneficial to humans. As a result, some suppliers offer probiotic blends that provide a spectrum of functions, some of which involve capabilities unique to only one or a few strains but others that are more general to larger groups of microbes.

“Probiotic cultures encompass the broadest range of clinically documented stable and biodiverse strains,” said Rossana Rodriguez, global marketing director, cultures and food enzymes, IFF, Leiden Biosciencepk, The Netherlands. “Probiotics are carefully selected to enhance various beverages, plant-based dairy alternatives and traditional dairy products, adding a valuable dimension of health and nutrition.”

Chr. Hansen, for example, offers natural bioprotective cultures that delay spoilage from contaminants, such as yeast and molds. They help to naturally extend shelf life and lower food waste without any use of artificial preservatives or chemicals.

IFF recently extended its range of consumer-friendly protective culture solutions. They are designed to protect against unwanted contaminants, while delivering better control on post-acidification.

“They help keep dairy products fresher for longer with minimal effects on sensory experience and taste,” said Rodriguez. “The cultures support the industry shift from ‘use by’ to ‘best before’ dates on labels, helping manufacturers and consumer households alike to reduce food waste.”

LAB also assist with food safety. They ferment milk’s inherent lactose to lactic acid, providing desirable sour notes. By lowering the product’s pH, shelf life is also extended, as the acidic environment controls the growth of spoilage microorganisms.

Milk inherently contains LAB, and over time, sours naturally. However, in commercial manufacturing, end-product specific bacterial strains are added as starter cultures. Because cultures are living microorganisms, suppliers are always trying to fine-tune the strains to improve efficiency. This enables a predictable fermentation time and yield, as well as a consistent finished product that meets flavor, texture and shelf life specifications. It is also necessary for suppliers to control for bacteriophage, which are viruses that infect bacteria and contribute to fermentation failure.

IFF launched a new range of starter cultures at the beginning of the year. They are specific for aged cheddar cheese.

“These cultures promote a smooth, clean-cut texture with no bitterness or crumbliness throughout the cheese ripening process and from batch to batch,” said Rodriguez.

For fresh fermented dairy products, IFF has crafted a culture series that incorporates its patented pH-stop technology. This enables producers to offer products with a premium taste experience and unique mildness that is maintained until the end of shelf life, according to Rodriguez.

Katlynn Albiniak, marketing coordinator at Chr. Hansen, said, “We are always developing new cultures and enzymes to address industry needs, enhance sustainability and offer improved productivity.”

Chr. Hansen is home to more than 50,000 microbial strains, she said. This enables the company’s microbiologists to develop a “cocktail” of microorganisms to solve industry needs as they surface.

“We test the cultures in relevant model systems to verify performance,” said Albiniak. “By using bioscience and non-GMO techniques, we are able to create and improve upon our strains to offer our customers the best solution for their needs.”

When customers came to Chr. Hansen asking for assistance with developing plant-based cheeses, the company’s microbiologists stepped up to the challenge. The company developed a range of cultures specific to dairy alternatives.

“It can be daunting for producers to select and ferment the wide array of plant bases, such as coconut, almond, oat, pea, soy and even blends that combine these bases,” said Ross Crittenden, senior director of commercial development at Chr. Hansen. “The result is a portfolio of resilient and flexible options that take the worry out of fermentation performance.”

The company’s vegan culture kit is the culmination of years of testing and screening for strains that deliver robust performance across the gamut of plant bases. It includes starter cultures, as well as adjuncts. They can help boost productivity by accelerating fermentation speed without losing texture, according to the company. The adjuncts fuel creativity by offering different volatile profiles during fermentation to provide flexibility to optimize taste.

Flavor and visual

Adjunct cultures, also referred to as non-starter lactic acid bacteria, are used in the manufacture of many cheeses to influence the flavor as well as visual appearance. Adjunct cultures are also responsible for eye development in certain cheeses.

The cultures are added deliberately by the cheesemaker for a specific sensory effect. For example, adjuncts give blue cheese its pungent flavor, crumbly texture and characteristic blue veins.

Many plant-based cheeses rely on adjunct cultures to assist with developing dairy-like flavors. Nourish LLC, St. Albans, Vt., for example, developed vegan brie and bleu cheeses that use a vegan sourced Penicillium candidum to develop the hard, outer white bloom associated with a traditional dairy brie and responsible for imparting authentic flavor.

The cheeses took five years to develop. They are made with a cashew nut base that is cultured, fermented and aged. They are manufactured into 6-oz rounds and packaged in breathable cheese wrap.

“The cheeses continue to grow their bloom and ripen as they age,” said Ric Lavallee, corporate team lead. “We release the cheese for sale at two to three weeks, with the cheeses reaching full maturity at four to six weeks, depending on the environment it is kept in.”

Another type of adjunct culture influences the texture and mouthfeel of fermented dairy foods. Exopolysaccharide-producing non-starter lactic acid bacteria, for example, create a ropy, often slimy, solution that can assist with increasing the viscosity of kefir or drinkable yogurt. They can also assist with improving the texture of low-fat cheese.

Speeding up reactions

Unlike cultures, which are living organisms, enzymes are inert materials made of proteins and remain unchanged until deactivated by either heat or a drop in pH. They function as biological catalysts that speed up chemical reactions in a natural way, thus improving fermentation efficiencies. In cheesemaking, enzymes are responsible for coagulation, the conversion of milk to curd.

“Lactases are key in enabling the production of lactose-reduced dairy products without undesirable off-flavors, promoting both sugar reduction, and some lactase types promote gut health,” said Rodriguez. “[There are also] viscosity-modulating enzymes for fermented dairy and plant-based alternatives, as well as coagulant and ripening enzymes specifically tailored for cheese production.

“Some texturing enzymes are effective in both dairy and dairy alternative matrices,” said Rodriguez. “However, since dairy alternatives lack lactose, many lactose-acting enzymes used in dairy are not applicable to dairy alternative applications. Proteases, enzymes that act on proteins, play a more prominent role in dairy alternatives. They can be used to alter taste and texture in these applications.”

Albiniak concluded, “It is important to note the global challenge of increasing costs. There is a need to get more out of less. We believe these challenges present opportunities for producers to optimize processes for enhanced efficiency and sustainability. Improving productivity can be as simple as honing recipes in ways that improve yield, reduce waste or decrease production time. By taking natural resources — cultures and enzymes — and applying them in targeted ways, producers can enjoy the benefits of improved productivity without sacrificing the superior taste, texture, safety and quality that their customers love and have come to expect.”

Lactase helps eliminate added sugars

Many processors continue to focus on reducing, and when possible, eliminating added sugars in dairy foods in efforts to appeal to the growing number of consumers who are avoiding these empty calories associated with weight gain and diabetes.

The dairy industry is uniquely poised to use the lactase enzyme to assist converting milk’s inherent sugar-lactose, a disaccharide — into its sweeter-tasting monosaccharide units: glucose and galactose. It’s a win-win for marketers who want to make an added sugar content claim and consumers who avoid lactose because of digestive issues.

Approximately 65% of the human population has a reduced ability to digest lactose, according to the National Institutes of Health.

Early this year, Clover Sonoma, Sonoma, Calif., rolled out Clover the Rainbow Milk with a Splash of Flavor. The milk comes in three varieties and is made with organic 2% lactose-free milk. Lactase enzyme is added to eliminate lactose and assist with natural sweetness.

Chocolate has 2 grams of added organic cane sugar, along with organic cocoa and organic natural flavors. Strawberry has no added sugars. It is made with strawberry juice concentrate and natural flavors. Vanilla also has no added sugars.

Recently, Thor’s Skyr, Portland, Maine, began adding lactase to its Icelandic skyr, enabling the company to make a no-added-sugar claim. When no sugar is added, protein content increases.

“We know consumers are looking for more protein and less sugar, so we are excited to be able to launch our new formula that will help introduce skyr to a wider demographic,” said Unnar Beck Daníelsson, chief executive officer. “Not only does the skyr taste delicious and refreshing, but it allows people with lactose intolerances and stomach sensitivities to enjoy the product as much as anyone else.”