The fine art of flavour
Interest in healthier products and functional food has led to greater demand for flavour-masking ingredients.
In a study on Canadian food trends, Agriculture and Agri-Food Canada (AAFC) predicts that “food for health” will remain among the top 10 market drivers until 2020. As the baby boomers age, and rates of obesity and related illness climb, more consumers will turn to food to manage existing health problems and prevent others. At the same time, says AAFC, new generations of label readers will become more conscious of ingredients and nutritional values and will seek out products that are trans fat-free, low-sodium and low-sugar. They will also be on the lookout for items fortified with vitamins and minerals, and will continue to scrutinize labels for allergen identification and health claims.
Such trends present the food and beverage industry with challenges and opportunities as it works to develop healthy products that taste the way consumers expect. The reality is that in reducing sodium or sugar, boosting fibre, or adding vitamin or herbal extracts, flavour off-notes often result. As a result, any taste that consumers experience as negative has to be masked or blocked, which in turn alters the overall balance of flavours.
For example, the best replacement for sodium, potassium chloride, can produce a metallic aftertaste. “The aftertaste is present when you try to replace more than 20 per cent of a product’s sodium content with potassium chloride,” says Simon Poppelsdorf, vice-president of R&D at Bell Flavors and Fragrances in Illinois.
Soy products, and those with omega-3 fish oils or vitamins and minerals added to them, may also have flavours consumers perceive as unpleasant, notes Karen McPhee, manager of Product Development Services at the Guelph Food Technology Centre in Guelph, Ont. “Some B vitamins have off-notes at certain levels and in certain products,” says McPhee. “Soy has characteristic beany notes that people who aren’t used to eating it may not like.”
Filling the flavour space
Masking or blocking a flavour usually means filling that space with something else. This is the case in manufacturing soy milk, says McPhee. “The producer has to choose the right masking agent to deliver the cleanest flavour profile. This allows for the addition of flavours that work synergistically with soy, such as strawberry or chocolate.”
To deal with the range of challenges posed by different customer applications, flavour houses have developed a full arsenal of strategies, ranging from bitterness maskers and astringency blockers to sodium replacements, sweetness enhancers and inhibitors and savoury (umami) enhancers. Another strategy is to modify aroma. While our taste buds allow us to perceive basic bitter, salty, sweet, and sour notes, we owe much of what we perceive as taste to our sense of smell. Consequently, altering aroma can offer an effective way to shape a product’s flavour.
However modulation takes place, the keys to success include achieving an overall flavour balance and developing a custom approach for each product. “We have some off-the-shelf products that we know work, but every solution has to be customized,” says Jack Fastag, flavour chemist with Philadelphia-based David Michael & Co. “For example, a bitterness masker can be combined with sweetness enhancers and acidity or astringency blockers for more functionality. Depending on the application, flavour-modulating agents can serve a variety of purposes. Using an acidity masker can make something taste sweeter. A sweetness enhancer can block bitterness receptors in the mouth, while a sweetness inhibitor can decrease the perception of sweetness without decreasing the actual sugar levels.”
Poppelsdorf also stresses the importance of customization. “We have a whole toolbox to help us tailor solutions. For example,” he says, ”in the case of sodium replacement, this might involve masking the aftertaste of potassium chloride by using spices, herbs or aroma chemicals. We have a natural flavour system called ReduxSo, which combines potassium chloride and flavour maskers to allow for up to a 50-per-cent salt reduction in processed foods, but we always work with clients to tailor the way it’s incorporated into their products, based on the quantity of sodium replaced and the specific application.”
Another trend in flavour modulation these days is the demand for a “fresh” taste to counter what’s known as the warm-over effect. “This is in demand among chain restaurants and take-out businesses,” says Poppelsdorf. “A piece of meat that’s just been roasted or grilled tastes fresh, but if it’s kept and microwaved the next day, it will lose that flavour and taste warmed over. Again, we would create a unique solution for the client’s needs.”
Growing consumer interest in world flavours is proving useful in modulating the taste of some products, says Mary Maile, Flavours team manager at Innova, a company that specializes in developing authentic meat flavours for vegetarian applications. “Anything ethnic – chili flavours are especially popular these days – helps emphasize the good and cover the negative. Coffee and wine notes also complement meat flavours well.”
A balancing act
A further aspect of modulating flavour is to match the delivery of the ingredient that’s being replaced. Let’s say a client wants to use stevia as a natural, low-calorie stand-in for sugar. Aside from the risk of a bitter aftertaste at higher concentrations, stevia has a slower sweetness onset than sugar. “Nothing sweetens exactly the way sugar does,” explains Donna Rosa, category director at Symrise, an international flavour house with clients in the healthcare, nutrition and beverage sectors. “Besides replacing the sweetness of sugar, we also try to match the sweetness curve it produces.
“Masking is extremely specific to the base,” emphasizes Rosa. “We always work with the base, using the many tools we’ve acquired as a result of our accumulated knowledge and expertise. If you suppress a particular flavour, you need to enhance others as part of an overall flavour system. It’s a balancing act.”