Fortified and functional products come in all shapes, sizes and applications. Whether your offering is high protein, high vitamin or low carb; a bar, beverage, cereal or snack; or includes vitamins, minerals, herbals or botanicals, one thing remains the same—it must taste good. And the flavour of the product is arguably the most important element in achieving this goal.
The first challenge in flavouring is getting people to think about the flavour perception of the overall product as opposed to the "flavour" itself. The inherent flavours of a formula and the actual "flavour" that you add to your product should never be separated in development as they have to work together in the finished product. When you address flavour perception, remember that the first thing that impacts a consumer is the product's appearance.
Most people readily accept that you can trick your brain because the response to visual stimuli can be manipulated. When told beforehand what to expect, most people will see the expected image first.
The combination of colour and flavour works the same way. For example, cola can easily be confused with a lemon-lime soft drink when the colour is removed. Likewise, the intensity of colour suggests strength—the flavour in a more intensely coloured product will usually be perceived as stronger compared to a version with a weaker colour. Too much colour can impart an "off" flavour perception such as burnt.
When it comes to eating and drinking, the brain processes the multiple stimuli and combines them into a response that is perceived as the overall taste of the product. The aroma of a product accounts for up to 80 per cent of this stimulus. The additional 20 per cent is supplied by the five basic taste perceptions of sweet, sour, salty, bitter, and umami, or mouthfeel.
Keep the consumer in mind
In the not-too-distant past, consumers didn't expect much from healthy or functional foods. But today's consumer has higher expectations that focus on functionality, performance, superior taste, and, of course, convenience. The product development challenge is to balance the level of active ingredients with the rest of these consumer expectations to provide a given functionality with the best taste possible.
Deciding your target audience and establishing its threshold levels for taste and nutrient fortification early in the process are imperative. While this can be done in detail with full-scale market research and consumer panels, smaller organisations have also done it successfully through the use of trained descriptive panels and smaller expert groups. When developing a product, it's important to consider whether consumers will eat it once or several times a day to decide the needed level of fortification per serving.
Whenever possible, it's best to use the minimum amount of active ingredients required to meet the fortification needs of a product. This is because active ingredients typically pose the most serious flavour challenges. Likewise, it's a good idea to use the highest quality active ingredients because of the taste impact.
For example, using a standardised botanical extract with a higher level of active ingredient provides the same level of functionality with a smaller impact on flavour compared to a less-pure source that would require more of the botanical to be used. Be sure to communicate all the active ingredients in your formula to your flavour supplier so they can avoid predictable interactions with flavour components.
If your product label does not allow the use of antioxidants, wherever possible choose ingredients not susceptible to oxidation. An alternative option when using an ingredient severely prone to oxidation, such as omega-3 fatty acids from fish oil, is to use it in an encapsulated form. Encapsulation helps protect against oxidation and minimises the potential reactions between ingredients.
Encapsulated ingredients have another benefit in that they can often prevent an ingredient from contributing bitter or off notes to the product. For example, in a tablet that melts quickly on the tongue, there is not enough dissolve time or compaction force (chewing) to break down the encapsulated active ingredient in the mouth. In exchange for these benefits, encapsulated ingredients often cost more and potentially have a slower or less-stable release or functionality in the body.
Masking and enhancing
When developing a fortified or functional food, there are two distinct yet interrelated flavour challenges that must be addressed. The first is to neutralise the base flavour profile as much as possible. This is done with masking techniques that may involve manipulating ingredient components such as salt and active levels, adding background flavours to smooth out an unbalanced base, or employing a more complicated flavour masking system. The second is to apply and balance a characterising flavour that works well in the product to deliver consumer satisfaction. An example of these two tactics in application would be an oatmeal pecan energy bar, which includes sweetness enhancers and brown flavours to round out the bar base, and an oatmeal pecan flavour to supply the characterising flavour.
Unfortunately, there is no silver bullet for masking undesirable notes in all fortified products. However, many flavour suppliers offer masking agents specifically designed to reduce undesirable attributes in a given environment that can be very effective.
Another alternative—flavour enhancers—is specifically designed to enhance desirable attributes within a given environment. These options are frequently used as part of a complete flavour system. Masking agents and flavour enhancers are often product-specific and may have markedly different results with different actives and applications. It's best to rely on your flavour vendor's experience to help you get the best result quickly.
While there are multiple strategies for overcoming the bitter principles associated with most functional actives, sweetness enhancement is the most popular because of its proven ability to mask bitterness. Sweeteners and sweetener blends can be used to manipulate the bitter-to-sweet ratio of a product, thereby manipulating the taste buds into a less harsh reaction to the bitter actives present.
Suggestions for complementary flavour profiles
- Sweet: Mixed fruits, berries, vanilla, maple, honey, citrus blend or tea
- Bitter: Citrus blends, grapefruit, dark chocolate, herbal blends (lemon ginger)
- Sour: Citrus, root beer, anise, raspberry, cherry, apple, strawberry
- Salty: Melon, raspberry, citrus blend, nut, butterscotch, maple
- Alkaline: Mint, chocolate, cream, vanilla
- Metallic: Grape, lemon-lime
- Cooked Protein Off-Notes: Cooked brown flavours, caramel, chocolate, butterscotch
- Fish Off-Notes: Citrus and fruit blends
Thanks, in part, to the low-carb craze, product developers have a plethora of polyols, bulk sugar replacers and high-intensity sweeteners to choose from. Different sweeteners impart their own inherent flavour and impact on the finished profile of a product. When surveying the options of sweeteners available for use, it's important to consider the desired final flavour profile as much as the product label you are targeting. One caution with sweeteners—just as sweetness can mask bitterness and enhance flavour, too much sweetness will overwhelm taste buds and render them incapable of registering the rest of the flavours.
In addition to sweetness, saltiness has also been found to mask bitterness in some cases. Although the exact mechanism for this phenomena is debated, researchers agree that when two or more intense components, such as bitter and salt, are present, the individual components retain their specific sensory qualities, but are perceived as being less intense than when tasted alone.
A flavour with character
One of the best ways to overcome flavour challenges is to select a characterising flavour profile that blends and allows the off note to contribute positively to the overall profile. Carol Militescu, senior flavour chemist at Flavors of North America expands on this point: Choosing the appropriate flavour, flavouring material or the combination thereof is the most effective way to overcome the unique challenges posed by various functional ingredients.
"For example, we've found that citrus blends and mixed fruits, such as fruit punch, work well to mellow vitamins. Caramel or toffee works well with products that have cooked or oxidized milk notes. Products featuring calcium can be improved through the addition of a flavour enhancer to help smooth out the overall mouthfeel of the product. Individual herbs have different profiles, so selecting flavours that will complement the herbal profile rather than attempting to mask it often yields the best finished product."
Development of a custom flavour system for a product may be necessary to leave out a part of the flavour profile. For example, you may need a grapefruit flavour without the bitterness because it is being supplied by a functional ingredient in the formula. Rebalancing a flavour in an application may also be necessary to raise or lower the impact of notes that may be either lost or overwhelming in the finished product due to processing or chemical reactions such as flavour/protein binding. Talk to your flavour supplier about the appropriate length of time to wait before evaluating a product to allow for equilibration of the overall product flavour.
One of the final flavour challenges is the difficulty inherent in evaluating these products and gauging improvement. Repeated tasting of these products frequently leads to desensitisation or adaptation. Off-notes, an aftertaste or a masking agent in one product will impact your ability to evaluate the bitterness of the next sample unless enough time and preventive measures are taken. Future "e-tongue" applications, which promise computerised analytical assistance without the burnout, are on the way, but they have a long way to go before they are anywhere near as sensitive as the tasting apparatus nature gave us.
Suzanne C Johnson, PhD, R&D manager, and Tracy Cesario, marketing manager, work for flavours supplier FONA International. www.fona.com.