A portion of cheddar contains more salt than a bag of crisps, according to a report published by Consensus Action on Salt and Health (CASH) at the end of November. CASH also highlighted that many cheese products, such as Roquefort, cheese slices, feta and halloumi, have higher salt concentrations than seawater.
This is bad news for a sector that relies on promoting a healthy, natural image. According to Mintel, nine in 10 consumers agree that cheese is a good source of calcium, for example, while a quarter would choose one cheese over another because it is lower in fat.
On the other hand, Mintel points out that the market for cheese is benefiting from growing interest in stronger flavours, with nearly 75% of consumers saying they prefer stronger-tasting cheese. "Strength is deemed to be the most important factor when choosing cheese, having more of an impact on consumer behaviour than low price or promotional activity," reports the analyst. So the chances of getting consumers to compromise on flavour and opt for low-salt alternatives that don't deliver the same punch as regular cheeses are slim.
"From a marketing perspective, taste is the biggest issue," says Timothy Wallace, marketing manager for dairy enzymes at ingredient specialist Chr Hansen. "There have been a number of reduced-salt cheeses on the market but none has been particularly successful because the flavour profile and texture has not been as good as regular cheese."
But taste isn't the only barrier to salt reduction in cheese. "Unlike other foods to which salt has been added, salt is intrinsically linked to cheese's manufacturing process, rate and degree of maturation, and contributes to the preservation effect," says Dr Phil Kelly, who is co-ordinating the Irish government's 1.3M national cheese research programme, known as CheeseBoard 2015. "By being intrinsically linked, it contributes to the unique character of individual cheese varieties. Hence, at a variety level, there will be limits to which salt can be reduced by how much it is far too early to say just yet."
Salt and shelf-life
Salt levels have an important influence on the texture and shelf-life of cheese, as well as its taste. The importance of the three factors varies significantly between products. "Shelf-life is especially important in cheeses that are aged for a long time, such as mature cheddar," says Wallace. "In mature cheeses there are flavour contributions from many other sources but in young cheese the main flavour driver is salt."
"Taste, texture and shelf-life are very interactive parameters so you couldn't separate safety from flavour aspects or flavour from texture," says Kirsten Kastberg Møeller, development scientist with Chr Hansen.
So, to reduce salt successfully you need to consider the entire system, and that's what Chr Hansen is doing this year with its SaltLite approach. This aims to reduce salt levels without adding non-traditional cheese ingredients.
SaltLite is the result of Kastberg Møeller's PhD research, which was in collaboration with Chr Hansen and the University of Copenhagen. "Most solutions add additional ingredients, but many firms are not interested in that. We're developing a solution using traditional ingredients," she says.
"The overall idea is that we think of cheese as a whole complex system. Traditionally, salt is added together with lactic acid bacteria and coagulant. The diverted functionality of the salt has to be taken care of by those other original ingredients. If you want to adapt to a low-salt recipe you need to adjust the process parameters and adapt the functionalities of the lactic acid bacteria and use a specific coagulant that's especially beneficial."
"When you reduce salt you lose flavour and the bitterness becomes more pronounced," says Wallace. "You need to replace the flavour lost and reduce or find a way to hide the bitterness. You can remove it with the right coagulant but that won't add flavour."
There are a range of other considerations, such as moisture and stability. Wallace stresses that this "holistic" approach will often require changes in the production process as well as in the ingredients, so it will take close collaboration between the ingredient supplier and customer to achieve the desired results.
Kastberg Møeller's initial research focused primarily on cheddar, so the SaltLite solution is more advanced in this segment, but the eventual aim is to apply the same approach across a wide range of cheeses.
Work is continuing, with Chr Hansen recently signing up to a joint salt reduction research programme with Denmark's two largest universities, two major Danish dairy firms and Norwich Research Park. The work is expected to last between three and five years. "Most of all, it's a competence development project looking at all aspects of removing salt in cheese and various approaches to quality," says Kastberg Møeller. CheeseBoard 2015 aims to take a similarly broad approach, according to Kelly: "An advantage of the CheeseBoard 2015 project is that it enables some multidisciplinary approaches to be brought together. There are certainly some interesting ideas, which are being supported by advanced analytical and molecular tools."
He's reluctant to discuss details at such an early stage. "In the interest of protecting potential IP [intellectual property], it is necessary to give the researchers from the participating institutions the scope to explore their ideas in the medium term before divulging detail," he says. He also stresses that there are no guarantees that any of the experimental approaches will succeed.
Of course, there are already ingredients on the market that aim to reduce salt in specific cheeses, including yeast extracts and mineral salts. Arla Foods Ingredients, for example, has developed a range of functional milk proteins that it says enables manufacturers to reduce the salt content of spreadable, block and sliceable processed cheeses and cheese sauces by between 50 and 65% without having an adverse effect on texture, thanks to their emulsification properties.
Claus Andersen, cheese application group manager at Arla Foods Ingredients, says: "Global consumption of processed cheese continues to rise, and 12% of all natural cheese production worldwide is now used to formulate processed cheese products. Our Nutrilac CH-6540 and CH-6608 functional milk proteins can help firms take advantage of this trend, while ensuring their products score well with consumers by offering a great-tasting healthier option."
Fat is the other big bugbear, and there are a number of successful niche products on the shelves delivering reduced fat options. But there is no "one size fits all" solution for fat reduction, according to Kelly: "Most firms have adopted their own proprietary approaches to what is a delicate balancing act in terms of immobilising more water, controlling body and flavour in circumstances where maturation is also affected."
And there has even been some research that suggests consuming saturated fats in cheese isn't bad for you. Eating saturated fat in cheese has no adverse impact on 'bad' cholesterol levels, say the researchers, in contrast to consuming the same amount of fat from butter. The work was carried out by Julie Hjerpsted and her colleagues at the University of Copenhagen and published in the American Journal of Clinical Nutrition in 2011.
Hidden obesity weapon
Meanwhile, other research suggests that milk and possibly cheese could even be a hidden weapon in the fight against obesity. It's something Kelly and his colleagues are keen to explore: "Recent science has projected a favourable picture on how calcium in milk in conjunction with vitamin D influences adiposity at cellular level. This is a very positive message for milk at a time when western society is exposed to an obesity pandemic. CheeseBoard 2015 intends to pursue to what extent this happens when cheese is used instead of milk. This task is scheduled to commence in early 2014."
Ultimately, Kelly argues that cheese is already a healthy food, being high in protein, low in carbs and rich in other important nutrients. Reduced salt and fat options are really about giving consumers choice, he says: "Consumers who are well informed about their food choices are entitled to have access to cheeses that conform to 'Reduced in ' compositional claims. Scientists and technologists will attempt to adapt the well-known cheese varieties as far as possible to meet these demands. If this is too technically challenging, it should still be possible to provide 'cheeses' that depart from the character of identifiable varieties but conform to nutritional needs."