Dairy is a nutrient-rich food group, with milk alone boasting 13 essential nutrients including protein, calcium, vitamin B12, phosphorus, iodine, and more.
Fermented dairy such as yogurt, kefir and labneh offer gut health benefits, and a growing body of evidence suggests that full-fat dairy does not negatively impact cardiovascular health.
Enhancing dairy foods with bioactives poses opportunities for both food manufacturers and public health authorities – but factors such as consumer acceptance remain important in forging a positive image for fortified dairy.
Which bioactives work in dairy – and which do not?
Fortification of dairy milk (for example, with vitamin D) is mandatory in certain countries, such as Finland, China and Canada.
But not all types of bioactives work in dairy by direct addition – meaning that other methods of fortification need to be leveraged.
Research has shown that milk proteins interact with bioactives and form complexes, hindering antioxidant functions.
For example, iron binds with casein to form a complex that prevents the very absorption of iron in the body. That interaction also impacts taste, creating off-flavors due to oxidation.
Milk proteins can also form a complex with vitamin E, which leads to a similar reduction in bioactives availability.
There are also production and environmental challenges, such as light exposure and temperature fluctuations, that can impact the bioactives’ stability and function.
On the upside, boosting the levels of dairy minerals – e.g. increasing zinc, calcium levels – has led to improved taste; while adding dietary fibers such as inulin has also been successfully piloted in various functional dairy, from yogurts to beverages.
Fortification methods
Enhancing dairy with bioactives can be done in several ways – from direct addition, such as adding vitamin D to liquid milk, to microencapsulation, to fermentation.
All methods have benefits and downsides – here’s the gist . . .
Direct addition
Adding bioactives directly to formulations is almost as straightforward as it sounds – but there are potential health and safety and sensory challenges in tow.
For example, certain ingredients’ stability can be impacted if they are added directly – think probiotics not surviving in the gut before reaching the gastrointestinal tract – while others can adversely impact taste (e.g. omega-3 fatty acids in milk).
Bioactives such as vitamins, beta-glucans, dietary fibers and minerals can all be added to dairy via direct addition.
Encapsulation
Bioactives can be encapsulated to remain stable and protected in the body until they need to be ‘released’ – for example, probiotics that need to survive in the gut in order to be activated in the gastrointestinal system.
There are two types of encapsulation – nano- and microencapsulation.
Nanoencapsulation is effective in adding omega-3 fatty acids in to milk and yogurt. Research has also shown that vitamins and minerals that are nanoencapsulated resist oxidation better and have improved sensory characteristics – crucial for manufacturers wishing to address off-flavors and scents in fortified dairy products.
Meanwhile, microencapsulation has been applied in yogurt and cheese fortification and can notably enable probiotics to survive during harsh processing conditions, e.g. pasteurization or UHT treatment.
Bioactives that have been added to dairy via encapsulation include omega-3 fatty acids, polyphenols, and carotenoids.
Fermentation
Finally, there’s fermentation – or using probiotic strains to enhance bioactivity. Here, selecting the right probiotic strains is key, as well as optimizing fermentation conditions.
Peptides and probiotics can both be used to fortify dairy via fermentation.
What are the health benefits of consuming fortified dairy?
Consuming fortified dairy has been linked with several health benefits depending on the bioactives the products have been enhanced with.
For example, consuming dairy fortified with calcium and vitamin D has been shown to bolster bone health; dairy fortified with vitamin A has been linked to vision support and reduced risk of night blindness; and vitamin B12 and folic acid fortification has been associated with improved nerve function.
Do consumers want fortified dairy?
There are clear health benefits to fortified dairy – so what would make consumers buy such products?
Taste is the number one consideration here, with research suggesting that fortified dairy must be on a par or better in terms of flavor, texture and functionality. In fact, taste comes first even to the product’s purported nutritional benefits, according to Shegelman et al. 2019.
Similarly, affordability is key – with the potentially high cost of fortified products likely to create a barrier to acceptance.
Communicating the health benefits effectively on-pack is also crucial to stimulate purchasing – with manufacturers urged to incorporate messaging that can transparently communicate any science-backed claims while also highlighting how repeat purchases could benefit the consumer’s health in the long run; potentially justifying price premiums.
However, it’s vital to not overstate any therapeutic potential and to be guided by regulation depending on the market the product is marketed in.
