Push the boundaries – the encapsulation process

Throughout the food and beverage industry, flavour needs are becoming more complex. Whereas in the past, manufacturers could get away with providing a relatively basic flavour selection, market pressures are forcing them to up the ante.

To take a particularly pronounced case, just think of chewing gum manufacturers. A decade ago, producing a few varieties of mint and juicy fruit would probably have been enough. But in 2007, Wrigley’s launched 5 Gum, with the ‘5’ alluding to the five human senses and the marketing describing “cooling, warming and tingling sensations”. A few years later, it filed a patent to use a new, tasteless cooling agent that lacked the “objectionable flavour characteristics” of peppermint or menthol.

“Nowadays, you have lots of different types of heat sensations and tingling sensations – everyone wants to do something a bit different,” says Rob McCarthy, head of sales and marketing at TasteTech. “You need new materials and new technologies to deliver these sensations.”

Then there’s the sports-nutrition sector, which has exploded in recent years as mainstream consumers (not just bodybuilders) begin to purchase protein powder. Whey protein blends and the like are no longer niche products, meaning more companies are jostling for supermarket shelf space.

“Maybe ten years ago, you might have had chocolate, strawberry and vanilla flavour, but now they’re much more complex – cheesecake and Belgian chocolates, and maybe more than one type of flavour in one system,” McCarthy explains.

All this said, perhaps the biggest changes are occurring behind the scenes, in the realm of ingredients technology. As the flavour-encapsulation process becomes more sophisticated, manufacturers are experimenting with new possibilities and asserting a higher degree of control.

Who to turn to

TasteTech, a UK-based flavour house, has been offering encapsulation solutions since it was founded in 1992. It is only over the past ten years, however, that market demand has really taken off, with the company’s turnover doubling between 2007 and 2012. Each of its four core markets – chewing gum, bakery, confectionery and sports nutrition – has a challenging and distinctive set of flavour-encapsulation needs.

Flavour longevity, for instance, is particularly critical in the chewing-gum sector (far more so than in, say, the chocolate sector, where the products should ‘melt in the mouth’).

“With chewing gum, you would normally get this burst of initial flavour, which comes from liquid or water-soluble flavours, but it may be gone in 30 seconds,” says McCarthy. “Chewing-gum manufacturers want the flavour in their gum to last longer, and this is achieved by adjusting flavour addition along with other ingredients like sweeteners and acids.”

The sports-nutrition sector, by contrast, is mostly interested in concealing unappealing smells and tastes. Because manufacturers want their strawberry protein shake to taste like strawberry, rather than overpoweringly of whey protein, they may rely on flavour encapsulation to make the finished product more palatable.

Other client demands cut across markets. In particular, they might want to create barrier properties, preventing chemical reactions that would negatively impinge on flavour and function.

“Within a food product, there may be ingredients that don’t react well to other things in the recipe,” says McCarthy. “So by encapsulating a particular particle, you can keep problematic materials away from each other. We’re also trying to protect ingredients from water damage. Creating a barrier there allows protection when needed and allows flavour release to be controlled.”

Alternatively, they might be seeking benefits for storage and handling.

“We can turn something that might normally be a liquid into an encapsulated fine, free-flowing powder,” continues McCarthy. “When it comes to flavours like garlic or onion, encapsulation technology may reduce contamination of machinery, so manufacturers can spend less time cleaning the plant and more time making other things.”

All in the trappings

At its most basic level, flavour encapsulation involves trapping the active substance within a carrier material. This carrier material, while biodegradable, must be sufficiently robust to provide stability during processing and consumption. TasteTech typically uses vegetable fats.

Beyond this, encapsulation as a blanket term refers to a number of different techniques. Core-shell encapsulation, for instance, traps the active ingredient within a thin shell, to create a granular particle 500–1,800μm in size.

Matrix encapsulation (which TasteTech first developed in 1992) is slightly more complicated, dispersing small bubbles of the active ingredient within an insoluble barrier. In this case, more than one ingredient can be included within one granule. The particles, which measure 100–250μm, are designed to resist the most strenuous mixing but will release their active ingredient when heated; for example, through baking.

This is particularly suitable for chewing-gum manufacturers, who want to encapsulate high-intensity sweeteners in addition to flavour.

“Since sweetness enhances flavour, it’s a given that if you lose sweetener in a product you’re going to lose flavour, no matter how much flavour you put in there,” says McCarthy. “So we encapsulate the sweeteners, natural and artificial, that are used in chewing gum and that helps deliver a longer-lasting flavour – every time you chew, you release a little more.”

Then there is spray-drying, which can be used to turn liquid flavours into a fine powder, and is one of the oldest and most commonly used encapsulation techniques in the food industry. Highly economical, it is ideal for high-impact, quick-release flavours and is particularly suitable for blending into powered premixes in the sports-nutrition sector.

Despite the well-attested benefits, manufacturers typically lack the capacity or the expertise to perform these kinds of processes in house. Most choose to partner with a solutions provider at some point during research and development.

“Some very large-scale manufacturers do some encapsulation themselves but they’re few and far between,” says McCarthy. “Encapsulation is seen as very niche, and most companies don’t have the expertise to make that investment. A third party can work hand in hand with those developers to discuss what they’re trying to develop, and come up with the necessary technologies and products.”

In TasteTech’s case, these kinds of conversations have resulted in a number of new solutions, enabling manufacturers to push the boundaries of what can be achieved.

“One of the key solutions we’ve delivered is a product called SorbicPlus – a preservative for the manufacturing of bread or yeast-based products,” says McCarthy. “Sorbic acid, which is a preservative, destroys yeast. We encapsulate the sorbic acid in vegetable fat and the yeast is protected from the encapsulated sorbic acid as the dough proves. When the bread is baked, the fat will melt and the sorbic acid will be released. It can keep bread mould-free for up to 30 days.”

Areas of interest

Another emerging area is the encapsulation of acids, which are often used on the exterior of sour, tangy sweets.

“The problem with these kinds of sweets is they have a lot of water in them, which would normally make the acid go sticky,” says McCarthy. “So we coat the acid particles to protect them from moisture and prevent that from happening. We do something similar with a doughnut, by protecting the surface of the sugar from absorbing moisture. That can be big business in the bakery industry – people aren’t going to choose a doughnut that looks sticky and gooey, but, if you can make it look fresh, it will last another day.”

Most recently, the company launched flavour8, an encapsulation-based flavour system geared towards the fast-growing chocolate market. A powder-base technology, it enables manufacturers to use strong oils without needing to worry about the aromas being prematurely released. 

“This is quite a unique proposition – it’s very low odour, very high impact and very soluble,” says McCarthy. “What that means is you can potentially put different flavours into a bar of chocolate. Most bars of chocolate contain only one type of flavour, because it will leach – you don’t have the ability to segregate flavour – but we’ve created the ability to put several flavours within one bar.”

This could also have implications for the biscuit tin, in which particularly pungent biscuits are normally kept in foil.

“If they weren’t in foil, the whole tin would smell of mint or orange. Our system is so low-odour you can put the flavour into the biscuit crème or the chocolate of the biscuit and it won’t cross contaminate,” McCarthy explains.

Encapsulation technologies are changing, then, in response to specific sector requirements. But they are also following broader industry trends. The clean-label movement is a prime example. Today’s manufacturers – even those producing doughnuts or chocolate bars – are becoming increasingly concerned with natural ingredients.

This means that, while chewing-gum manufacturers are still highly dependent on artificial sweeteners like aspartame, there has been a shift towards natural (albeit more challenging) options such as stevia. And as the market turns away from palm oil and hydrogenated rapeseed oil, companies like TasteTech are using alternative vegetable fats.

All natural

Manufacturers are also becoming more discerning and see natural flavouring as critical to the positioning of their products. Cost is always a major consideration, but has to be balanced to meet customer and market demand for cleaner, sustainable ingredients.

McCarthy expects this trend will continue over the next few years, affecting all corners of the market, but he also feels that manufacturers’ requirements are likely to become even more divergent and complex.

“We’re developing more combination products that combine flavour and functionality – as customers are looking to make more claims surrounding their products’ benefits,” he explains. “So this might be for health reasons, or it may
just be that they’re trying to mask an unpleasant taste.”

Not every manufacturer needs flavour encapsulation, of course, but for others, it’s a way to address technical challenges that would otherwise go unresolved. It can enable them to work with sensitive, volatile compounds, improve shelf life and appearance, cut waste and reduce cross-flavour contamination. Essentially, it gives them more scope for creativity.

As McCarthy puts it, “We see encapsulation not as an added cost but as added value. It enables customers to be able to use things that they wouldn’t normally be able to use or to create a product they’ve never considered before."