The following experts shared their knowledge:
Mirjana Curic-Bawden, senior scientist, application manager, fermented milk and probiotics, Chr. Hansen
Ardy van Erp, product manager, dairy enzymes, DSM Food Specialties USA
Mike Bush, vice president of business development, Ganeden Biotech
Mary Keely, technical service representative, Dupont Nutrition and Health
Pete Budde, product line manager – cultures & enzymes, Cargill Texturizing Solutions
Dairy Foods: Tell us about your newest culture systems. What are their properties and benefits?
Curic-Bawden: Our latest yogurt cultures are focused on improving the quality of nonfat and low-fat yogurts. They provide extra-high viscosity, a good “thickness” of mouthfeel, a high level of smoothness, high gel firmness and an improved creaminess. We also have cultures specially designed for drinkable yogurts that provide excellent viscosity, a high level of smoothness and improved stability. Each culture range has a version with added probiotics for stirred yogurt and drinkable yogurt applications.
van Erp: Our new culture family for locally sourced fresh fermented milk products facilitates the fast-growing, large-scale production of homemade products as well as capturing their authentic taste and texture. We also have a new fast-acting Streptococcus thermophilus bulk set culture range available for the production of pasta filata (“pulled curd,” a type of fresh mozzarella). These cultures contribute to a firm body and texture due to their low proteolysis, and provide a reduction of blistering and browning.
Bush: Our patented Bacillus coagulans is a spore-forming probiotic bacterium. Inside the bacterial cell is a hardened structure, or spore, which is analogous to a seed. This spore safeguards the cell’s genetic material from the heat and pressure of manufacturing, which challenges shelf life, and the acid and bile it is exposed to during digestion. Once it is safely inside the small intestine, the viable spore is then able to germinate and produce new vegetative cells, or good bacteria.
Keely: Our newest cultures are based on the possibilities we have with the Crisper Technology for Streptococcus thermophilus. The benefits include resistance to known bacteriophages, perpetuation of strains and isofunctional rotation. To the industry, this means an ability to limit the economic impact of bacteriophages.
Budde: Cargill is working on new culture systems for fast-growing applications such as yogurt, cottage cheese and other cheeses. The new culture systems were designed to help customers reliably — and more cost-effectively — create popular dairy products with the taste and texture that consumers expect. The new culture systems resist phage attack and require no significant process adjustments for plants replacing their current culture programs.
For example, Cargill’s culture program for cottage cheese provides fast, consistent set times and a faster vat turnover, as well as a large rotation of cultures to help combat phage and reduce losses from slow and “dead” vats. The combination of cultures, coupled with Cargill’s technical service support, provides enhanced curd retention, and has been shown to increase cottage cheese yields in some plants.
Also, Cargill’s cultures for Cheddar cheese allow customers to use an inoculation rate about 30% lower than traditional DVC cultures. The cultures provide superior flavor development and a high-quality body and texture characteristic of American and Cheddar styles of cheese. Specially formulated strain profiles provide cheesemakers with improved phage resistance and consistent performance throughout the series.
Dairy Foods: Dairy processors create flavors to fit regional preferences. Discuss how your cultures aid in the creation of different flavors.
Curic-Bawden: In most countries and regions, yogurts and fermented milks are made using just milk and cultures; no starch or stabilizers are allowed. In some areas, milk contains lower protein levels, and in others, keeping milk cold throughout the chain is a challenge. Therefore, the quality of yogurt depends exclusively on the quality of milk, the right choice of cultures and adequate process parameters.
By careful selection of all ingredients and process parameters, one can achieve mild or traditional strong yogurt flavors. Strong and medium yogurt flavors are desired for drinkable yogurts containing fruit or Greek-style drinkable yogurts. Mild yogurt flavors are a better fit for products formulated for desserts or indulgent flavors such as vanilla, caramel or chocolate.
van Erp: Our new cultures are inspired by the cultures naturally found in regional, authentic products. We utilize our application insight to form the right blends from our versatile culture strain collections to tap into the local flavor preferences.
Keely: DuPont has a large collection of lactic acid bacteria, probiotics, adjunct ripening and protective cultures which allow the development of special taste and texture profile and fit shelflife or food-safety requirements for the different regional products, including cheese and fresh fermented dairy.
Budde: In the production of cheese and fresh fermented products such as yogurt, sour cream, quark and buttermilk, cultures play a crucial role during all manufacturing phases. During cheese manufacture and ripening, proper culture selection contributes to development of the desired flavor, texture and appearance as well as preventing the development of undesirable flavors. Cultures also play a key role in determination of final moisture level and yield. In the production of yogurt and other fermented milks, cultures are used to produce acid, flavor and, in some cases, carbon dioxide and/or polysaccharides. These ensure the development of the desired taste, texture and appearance.
In addition to providing specific culture functionality, we share comprehensive knowledge and expertise with our partners as we work closely to develop, support or enhance our customer’s final product targets. And, we offer a wide range of acidifying cultures, adjunct cultures and enzymes available as mix-and-match components, allowing manufacturers to select a customized combination of culture and enzyme components to meet the specific needs of their customers and markets.
Dairy Foods:Please share an example of a product using such a culture.
van Erp: A perfect example is the Dahi culture range with local flavor preference developed specially for India. Another example is our sour cream range, which is tailored to different unique regional taste and texture preferences from fresh lactic to buttery-creamy, and from high-fat to low-fat texture. Our Ayran culture range uses a precise culture combination to deliver the desired mouthfeel and the fresh lactic taste for a Turkish yogurt drink, which has a high water content.
Bush: Red Mango frozen yogurt includes our probiotic in all of its frozen yogurt flavors and many of its tea beverages.
Dairy Foods: Yogurt, in all its forms, is very popular. Talk about cultures for spoonable, drinkable and frozen yogurts, as well as for smoothies.
Curic-Bawden: High-protein yogurts (Greek style, separated or fortified with protein) have become very popular in the United States. The choice of cultures for Greek yogurt depends on the desired taste and texture, protein and fat level, and technology used to make yogurt. Generally speaking, separated yogurts are made with milder cultures that have low process post-acidification, while fortified yogurt (protein added in milk base) tolerates — and usually requires — cultures able to reach higher acidity and provide medium yogurt flavor.
Nonfat and low-fat yogurts, without added starch and stabilizers, attract health-conscious consumers. But without these additions, cultures need to do the heavy lifting, that is, provide high viscosity, smoothness, “thickness” of mouthfeel and gel firmness, with no syneresis [separation of water from the gel].
van Erp: We have distinctive culture ranges for set, stirred and drinkable yogurt applications, focusing on flavor variation and, in particular, pleasant mouthfeel and texture improvement for different recipes. The cultures need to deliver the desired organoleptic features while at the same time offer functional benefits with added Lactobacillus bifidobacteriumin the blends to promote digestive health. The optimal culture blends are required to work in different recipes with different protein, fat or sugar compositions, and also to take into consideration of the manufacturing parameters, such as fermentation time, mechanical stress, cooling temperatures etc.
Bush: Our probiotic ingredient is used fermentation. Therefore it can easily be used in many forms, whether spoonable, drinkable, frozen, powder form, etc.
Keely: Our yogurt cultures are blends of lactic acid bacteria specially selected for optimum manufacturing of fermented dairy products. For spoonable yogurts, cultures must improve the mouthfeel of low- or reduced-fat/calorie products; provide robust and consistent fermentation time for optimized production; allow for reduction of sugar contents (mild cultures); allow for reduction of milk solids (extra-thick cultures); permit “all natural” and/or “organic” labeling; and contain probiotics.
Drinkable yogurt and smoothies require thick, smooth and stable yogurt cultures with an ideal yogurt flavor suited for these products. For frozen yogurt, a customer can choose from our core yogurt cultures for fermented yogurt, or from our culture lines specifically designed for adding directly to a frozen-yogurt mix before freezing.
Dairy Foods: How are cultures affected by the inclusion of other functional ingredients — protein, soluble fibers, for example?
Curic-Bawden: The addition of protein (milk powder, milk-protein concentrate, whey protein concentrate or the blends) in milk, or evaporation of water, is a traditional way to improve texture of all natural yogurts. Higher protein level in the milk base increases buffering capacity which causes slightly longer fermentation time (more acid needs to be formed to reach the same pH/acidity).
Choice of protein is very important for the texture of yogurt. Whey protein concentrate has many benefits; it has more water binding capacity and can improve gel firmness and smoothness. If not carefully selected, formulated and processed, however, too much whey protein can cause grainy texture. Soluble fibers usually do not have an impact on fermentation time, but they usually slightly improve texture/viscosity.
van Erp: The functionality of our cultures is not affected by nondairy ingredients because they originate from dairy and therefore grow optimally on dairy components. However, other ingredients might have an effect on the functionality of the dairy product. Protein and fat levels are the key variables that influence the end-product features. Low protein/low fat recipes are more sensitive to mechanical stress. This also can cause an end product with low viscosity and less mouthfeel.
On the other hand, the high protein level can also result in increased fermentation time. In such cases, carefully selecting the right cultures and fine-tuning the type and quantity of cultures is needed to overcome the product challenges, while fulfilling the desired organoleptic profile of the dairy product.
Keely: High protein yogurt takes more time; it slows down the growth of bacteria due to their buffering capacity. However, we have not found that soluble fibers affect our cultures yet.
Dairy Foods:How do cultures affect the stability of natural colors in these different media?
Curic-Bawden: Some lactic acid bacteria, such as mesophilic cultures, and some probiotic species are able to degrade synthetic red colors (e.g. sulfonated azo-dyes). Yogurt cultures do not have an impact on stability of natural colors as long as colors are stable at low pH.
van Erp: Our cultures do not directly affect the stability of natural colors, but the increased acidity of the dairy product as result of the acid produced by our cultures might affect natural colors in a way that causes the product to not have the same appearance as under natural pH.
Keely: DuPont ran a recent study in yogurt which was made with homogenized skimmed milk and cream, using starter culture, multifunctional protective cultures plus colored fruit preparations. This was to determine the effect of our cultures on the stability of natural and synthetic colors.
The natural colorings — beta-carotene, carmine and enocianin — and the fruit’s own color were stable during the trial. The synthetic coloring, for example Quinoline Yellow, was stable. The synthetic coloring tartrazine was stable in combination with [our starter and protective cultures]. The other five synthetic colorings — Sunset Yellow, carmoisine, Allura Red (Red#40), Ponceau 4R and Brilliant Blue —showed extensive bleaching during the trial.
Dairy Foods: What problems are your customers trying to solve, and what role do your products play?
Curic-Bawden: All-natural low-fat yogurts and simple and clean-label yogurts are getting more popular in the United States. Our cultures provide high viscosity and excellent gel firmness, as well as mild and creamy flavor.
At the same time, if one is already making all-natural stirred or drinkable yogurts, these cultures have higher texture and can offer savings in protein without compromising quality. This also offers the opportunity to make nonfat or low-fat products with superior viscosity, mouth-feel and creaminess.
van Erp: The industry today faces a number of challenges, from internal production-related issues to meeting increased customer demands. Those issues require a culture system that performs equally under each condition and delivers the same acidification performance over and over.
Today’s consumers are increasingly health conscious, but they don’t want to stop enjoying their favorite dairy products. It can be a challenge to create better-for-you options that do not sacrifice taste or indulgence. A combination of enzymes together with adjunct cultures, for example, is very successful in providing these solutions for low-fat cheeses.
Issues of sustainability are here to stay. We’ve assured production and usage of DSM cultures keeps the carbon footprint minimal.
Bush: Most of our customers are trying to solve stability issues. They want to deliver as many live cells as possible at the time of consumer consumption. Our culture withstands the heat and pressure of manufacturing processes, challenges of shelflife and the acid and bile of the digestive system. It also requires no refrigeration and can be formulated into products to have up to a two-year shelflife.
Keely: Our customers are looking for cleaner labels and “all-natural” ingredients. Our cultures, by building thickness in products such as buttermilk, sour cream and yogurt, allow stabilizers to be removed. Also, customers are asking for faster process times to increase the throughput of their plants. More speed is required from the cultures system.
In terms of acid production, the profile of the products needs to be less acidic (lowest post-acidification) and have a protective effect against spoilage bacteria, yeast and mold. Cultures are an all-natural way to extend shelf-life of food and we apply this concept to our starter cultures.
Budde: Providing day-in, day-out consistent performance in real world environments is a critical area of expertise for Cargill. This includes working with customers to maximize yield and shelflife, optimize flavor development and minimize bacteriophage problems. Cargill’s technical service team includes experts with many years of industry experience in the development of high-quality dairy products, and works closely with customers to help them cost-effectively create winning products.
Dairy Foods:Discuss what’s new with your company’s enzymes systems, and especially lactase enzymes.
Curic-Bawden: Lactase can have a dual role in yogurt making. It is used to make lactose-free products, but at the same time, degradation of lactose into glucose and galactose increases ‘internal’ sweetness of milk and allows reduction of added sugars. This approach can give a good level of sweetness in products in which the amount of carbohydrates is limited, e.g. school milk or school yogurt. Ha-Lactase can be added to pre-treat milk, or it can be inoculated at the same time with a yogurt culture.
van Erp: Our lactose ingredient [Maxilact] increases digestibility by hydrolyzing lactose. This enables people who suffer from lactose intolerance to enjoy dairy products. The sweetness of the reaction products (glucose and galactose) is greater than the sweetness of the substrate (lactose). Therefore, the dairy product is increased in sweetness by simply hydrolyzing the naturally present lactose.
An example of this is yogurt with enhanced sweetness. This also has a beneficial effect on the mouthfeel of the yogurt. Another example is whey permeate drinks, where through the addition of Maxilact, a 30% sugar reduction can be achieved.
Reduction of crystallization is another issue. It’s impossible to maintain ice cream at the same temperature from production to the consumer’s home freezer. As a result, lactose can re-crystallize. With time, small crystals increase in size until they create a sandy feeling. Hydrolyzing the lactose prevents crystallization, improving both the quality and shelf life. [Maxilact] has been used for many years to reduce the crystallization of dulce de leche. Hydrolyzing lactose also decreases the freezing-point. Improving meltability means better scoopability and the possibility to reduce additives such as maltodextrin.
Keely: We improved sugar reduction in fermented fresh dairy by the use of lactase, while getting a sweeter taste at the same time.