“While many people are looking for food that contributes to health and wellness, some also are monitoring food labels to avoid consuming certain ingredients,” said Greg Miller, executive vice-president of research, regulatory and scientific affairs for the National Dairy Council, Rosemont, Ill. “Even though cheese only contributes 8% of the sodium to the U.S. diet, the dairy industry isn’t taking this concern lightly.”
Avoiding entirely would not be a smart option as the body needs significant amounts of sodium (one of the two molecules that make table salt, also known as sodium chloride) to properly function, but many in the medical community believe not as much as currently consumed. Federal guidelines say the average American should consume about 2,300 mg of sodium daily, while some population segments should consume closer to 1,500 mg. The Centers for Disease Control and Prevention says the average American consumes 3,400 mg per day.
Function and flavor
Cheese, and foods made with cheese, such as pizza, are a noteworthy source of sodium for many consumers. Because cheese needs salt for functionality, it is not easy for cheese makers to simply reduce added salt.
During the manufacture of natural cheese, salt is added to the curd after the desired pH is reached. This helps control fermentation and proteolysis by regulating starter cultures and enzymes. Salt also lowers the water activity of cheese, which prevents the growth of undesirable microorganisms. Without added salt, natural cheese would be bitter and bland, with an unacceptable soft body and very short shelf life due to undesirable microbial growth and enzymatic activity.
Process cheese differs from natural cheese in that it is not made directly from milk; however, the main ingredient of process cheese is natural cheese. Process cheese is produced by blending natural cheese of different ages and degrees of maturity with emulsifying salts and other dairy and nondairy ingredients followed by heating and continuous mixing to form a homogeneous product with an extended shelf life. The emulsifying salts are responsible for making process cheese flow when heated, rather than stretch, which is what occurs with melted natural cheese.
Using potassium chloride
Finding a suitable substitute for sodium chloride for either cheese type historically has been difficult because of salt’s unique clean taste and flavor-enhancing properties. However, when it comes to function, sodium and potassium work similarly in managing moisture to reduce microbial growth and control the onset of pathogens, which is why cheese makers often replace some sodium chloride with potassium chloride in order to reduce sodium content.
The drawback to traditional potassium chloride is its salty flavor is tasted slower than that of sodium chloride. It also has a bitter aftertaste. In recent years, suppliers have managed to identify various technologies to overcome or mask potassium’s bitterness with the use of other ingredients or processing technologies.
With a growing number of consumers reading product labels, Cargill Salt, Minneapolis, conducted a series of consumer studies to understand how consumers view potassium chloride in their foods, including cheese. The company asked 564 U.S. households to compare two cheese products by reviewing their respective Nutrition Facts labels.
Product A contained traditional salt only, with a 1-oz serving providing 170 mg of sodium. Product B had some of the salt replaced by potassium chloride, which reduced the sodium content to 120 mg per 1-oz serving. The households were asked which cheddar cheese product they would be more likely to purchase. Half (50%) indicated they would purchase Product B, while 18% chose Product A, the fully salted cheddar. A third (32%) said they would purchase either.
Households were further asked if there was a clear sodium-reduction claim callout on the packaging, which cheddar cheese product would they then be more likely to purchase. Interestingly, 50% again said they would buy Product B, but the number that would purchase the fully salted cheese now jumped to 30%, suggesting that consumers are skeptical of sodium-reduced cheese. Possible prior experiences with sodium-reduced foods makes them unwilling to take the chance that the product will meet taste expectations. Thus, when reducing sodium in cheese, it might be best to not call it out on front labels. Rather, simply reveal the stealth reduction in the Nutrition Facts.
Controlling salt variability
In addition to decreasing the amount of sodium added to cheese, managing salt addition through rapid product analysis may assist, too. This approach is currently being investigated by the Cheese and Sodium Task Force of the Innovation Center for U.S. Dairy, Rosemont, Ill. All participants are members of the Innovation Center and represent nearly 80% of the U.S. cheese market by volume.
“The dairy industry is collaborating to identify technology with the potential to quickly and accurately measure sodium content during the cheese making process so variability can be controlled on the spot, even in cases where potassium chloride is being used,” Mr. Miller said. “This work is critical to the dairy industry being able to demonstrate its commitment to proactively finding a solution to the cheese and sodium challenge identified by public health organizations and some consumers.”
The group worked with Oxford Instruments in the United Kingdom to use x-ray fluorescence (X.R.F.), which is a technology previously only used for other applications and industries, for rapid sodium testing of cheese.
“Previously, sodium in cheese had been calculated via an indirect method using a chloride analyzer or using inductively coupled plasma (ICP), which is more expensive and is not rapid,” Mr. Miller said. “A direct and rapid method of sodium detection is needed in the industry due to the increasing use of sodium replacers and to allow for rapid results during the cheese making process to control variability.”
The rapid sodium testing technology has application in both natural and process cheeses.
“Early in the process there was trouble with brined cheeses because the salt is not uniformly distributed throughout the cheese,” Mr. Miller said. “Currently we are evaluating potential solutions in pilot plant trials where we are confirming the technology in an industrial setting. Preliminary testing has provided promising results, and additional trials are still needed.
“An added benefit of X.R.F. is that you should be able to simultaneously and rapidly measure other elements in the cheese sample with good repeatability. This is something you cannot do with any other method.”
Additional testing will be conducted and completed by three cheese companies and results will be shared. The technology will help cheese makers control variability, which will allow them to use a minimum amount of overrun to still hit minimum sodium targets for functionality and safety. They may therefore reduce the average sodium content by lowering upper limits.
“Then they can, in a controlled fashion, reduce the average sodium within a safe and acceptable range,” Mr. Miller said. “It also will allow cheese makers to measure sodium in the presence of salt alternatives as well as the amount of those alternatives, which current technology will not allow on a rapid basis.”
The need to go low for school
The U.S. Department of Agriculture has worked with cheese manufacturers to lower the sodium in the cheese the U.S.D.A. purchases as part of the national school meal programs. This is because according to new regulations, the total sodium content of meals offered through the breakfast and lunch programs will be lower effective July 1, 2014. And by the 2022-23 school year, those levels will be halved.
For example, this coming school year, lunch served to high school students (grades 9 to 12) must contain 1,420 mg or less, as averaged during the course of a week. Come 2022, that figure drops to 740 mg. The current weekly average is 1,588 mg.
Weekly averages help provide flexibility to schools to continue offering cheese in meals. But in order to get to these lower levels, all components of the meal need to contain less sodium. With cheese-based foods a favorite among students, it is imperative that cheese makers reduce sodium content.
“California is currently the No. 1 provider of cheese for U.S.D.A. foods,” said Shannan Young, senior project manager for the Dairy Council of California, Sacramento. “The U.S.D.A. foods are products purchased by U.S.D.A. to support American agricultural producers by providing cash reimbursements for meals served in schools and other child nutrition institutions.
“Food manufacturers that purchase cheese for prepared foods sold to school nutrition programs are very interested in purchasing lower-sodium cheese in order to keep their products in the program.”
Cheese manufacturers have been working to provide solutions that will satisfy consumer needs and also help to address public health priorities. Collectively, the industry has reduced the maximum amounts of sodium in mozzarella cheese currently distributed to schools by approximately 25% through working with the U.S.D.A., as well as reduced sodium to at least 25% less sodium or 200 to 300 mg per ounce for nearly all the process American and blended cheese the U.S.D.A. sends to schools.
In addition to the sodium restrictions on meals, there are also new sodium regulations for foods sold a la carte in schools. This is where a great deal of string cheese and other snacking cheeses are sold.
Effective July 1, 2014, snack items and side dishes sold a la carte must contain 230 mg or less sodium per item as served. Effective July 1, 2016, the upper limit drops to 200 mg. The good news is the regulations are per item, not per a designated reference value; therefore, cheese makers may simply reduce the portion size to reduce the sodium content in order to be compliant.