You may have heard the statement, “milk is nature’s perfect food.” Nutritionally speaking, that is true. But is the quality of dairy products we consume always perfect?

Have you noticed that when you lift a freshly baked pizza slice, the melted cheese has a wide range of stretching? Or the consistency of yogurt occasionally disappoints you with a not-so-creamy texture, unlike you expect?

Dairy product quality is generally good overall, but not always perfect. So how do we make it perfect?

Dairy products have been satisfying our taste buds and nutritional needs for many thousands of years. In 2018, the combined sales revenue of top 20 global dairy companies was about $200 billion, and continued growth is expected (1). Fermented dairy products such as yogurt are the largest category globally other than fresh milk, accounting for over 70 billion pounds per year (1).

Yogurt

For the last several decades, yogurt consumption has increased significantly, partly because of its benefits, particularly with regard to gut health (as advertised subtlety or sometimes more directly in the media). For the credibility of the brand, selecting the right probiotic microorganisms with clinically proven benefits is essential.

Equally important to the mind of consumer are the flavor and texture of the yogurt, which are affected by ingredients and processing variables in making the product.

Yogurt is produced by fermenting milk for about three to six hours at about 100-110 degrees Fahrenheit (2). During incubation, two friendly culture bacteria work together to covert lactose to lactic acid to produce a desirable taste and soft creamy texture.

It sounds so simple, but there are so many ways yogurt quality can be affected during production. For example, incubation temperature alone can cause major changes, even when using the same starter culture and production equipment. A lower incubation temperature will favor the growth and activity of one of the two friendly culture bacteria: That will make the texture more stable and the flavor less tart, which is preferable for many consumers.

Cheese

In terms of global dairy production, cheese is the next largest dairy category, accounting for 46 billion pounds per year (1). The United States is the largest producer of cheese in the world, making 13 billion pounds in 2018, though Europeans consume much more cheese per capita.

In the United States, mozzarella has overtaken the classic cheddar in terms of annual production quantity. With the increasing popularity of pizza around the world, the functional properties of mozzarella cheese play a key role in meeting the quality expectation of customers and consumers.

On baked pizza, that interesting stretching appearance of cheese is important, as is oil release during baking, in satisfying consumer expectation. Overall browning, as well as the size and number of darker spots (blisters) upon baking, is also strictly evaluated by customers. Those quality attributes are affected by ingredients (such as cultures and enzymes) and the production process (from milk treatment to curd handling) in making mozzarella.

Compared to other cheeses, mozzarella cheese undergoes a unique processing step toward the end of cheesemaking: The finished cheese curd is heated in hot water to be stretched and molded. This step profoundly affects the quality attributes on the baked pizza. Changes as simple as hot water temperature can affect the final product quality and cheese yield. A higher water temperature during the heating/stretching/molding step will inactivate more enzymes in the cheese, making it less likely to soften with aging and maintain good stretching characteristics on pizza upon baking (3).

Balance is critical

However, like everything else in life, balance is important in dairy processing. Yes, you can change the incubation temperature of yogurt or the heating/stretching/molding temperature of mozzarella cheese to achieve desirable quality attributes. But by changing one production parameter, unintended consequences on another aspect of production steps or product quality will occur.

For example, a lower incubation temperature could slow down yogurt production, which can reduce production efficiency. Mozzarella cheese made with a high stretching temperature may be good for retail sales with a longer shelf presence. However, it may cause frustration for a foodservice application designed for immediate use. Therefore, production parameters need to adapt to the needs of plant operation and customer specifications.

It is not always easy to make everyone happy at home or in business, but through collaboration, a team approach can identify optimum solutions for common goals. Sound reasoning based on scientific evidence is helpful in making decisions, and for that you need experts in quality, safety and regulatory requirements. Whether your expertise is in-house or you enlist outside experts such as consultants, choosing the right mix of capabilities can help you realize your goal faster and more effectively.

References:

1. International Dairy Federation. 2019. The World Dairy Situation. P22, 190, 196.
2. Tamine and Robinson. 2007. Yoghurt Science and Technology. P.85.
3. Fox et al. ed. 2004. Cheese. Vol 2. Pasta-Filata cheeses (by Kindstedt et al.). P 254.