Flavor Mask-erade

In todays fast-paced world, families struggle to keep up with two careers and a busy family life. Whether its breakfast on-the-go or a snack between activities, consumers of all ages are clamoring for foods that will improve health, increase energy or just get them through the day. As if that werent enough, they want their good-for-them foods to taste good, too.

But, its good for you

A multitude of ingredients provide desirable physiological benefits, but they arent always on the best flavor list. Soy proteins have long been a staple in the nutritional-ingredient arena. Advances in technology have reduced soys characteristic beany taste; however, developers can be faced with a flavor effect when including the 6.25 grams of soy per serving required for heart-health claims.

Botanicals are functional ingredients derived from plant sources or mixtures of other naturally occurring materials. Today, ginseng, ginkgo biloba, echinacea and St. Johns wort are mainstream ingredients in the nutraceutical arena. But flavor effects, ranging from tea-like to grassy, bitter, medicinal, even astringent, require tremendous attention to ensure a palatable final product.

Paul Riker, manager, beverage applications, Mastertaste, Chicago, suggests recent indications of health benefits have led to significant growth in the herbal market.

This growth has, however, created new challenges for developers. So-called weight-loss ingredients, such as hoodia and EGCG (epigallocatechin gallate), and hydroxycitric acid with alleged satiety benefits, can cause bitter or astringent notes in the mouth, he says.

Another example of a trendy herb is valerian extract, in which the active ingredient is valeric acid, which relieves stress and brings a sense of calm, Riker continues.

The odor associated with the ingredient, however, can be described as putrid.

A growing number of consumers are turning to functional foods for minerals such magnesium, calcium and zinc for total bone health, prostate and immune health, and anti-stress effects. Minerals like iron, copper and potassium typically impart lingering metallic notes. Calcium can lend off-flavors that vary by source. Calcium carbonate can impart soapy or citrus notes, while calcium citrate can contribute to acidic flavor. Calcium chloride can lend bitterness to a finished product.

Vitamins, especially some of the B vitamins, are known to yield undesirable tastes that can become even more pronounced over time. Some vitamins, such as B1, can impart a bitter taste and sulfurous egg aroma, notes Ram Chaudhari, Ph.D., senior executive vice president, chief scientific officer and co-founder, Fortitech, Inc., Schenectady, NY.

Fat goes fishy

Long-chain polyunsaturated fatty acids (PUFAs) are nutritional components of human metabolism that the human body must synthesize for itself. PUFAs are divided into two groups: omega-3 fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); and omega-6 fatty acids, including linoleic acid (LA), gamma-linolenic acid (GLA) and arachidonic acid (ARA).

Fortifying food products with PUFAs presents one of the greatest challenges to developers, as these nutrients often impart a fishy odor and/or flavor. And, while aquatic sources might explain such a flavor effect, Chaudhari suggests fishy notes are not simply a matter of origin. Minimizing oxidation of long-chain PUFAs is a challenge, specifically chains of 18, 20 or 22 carbon atoms with 2-6 double bonds in their composition, he says. Due to these double bonds, these PUFAs become rancid at room temperature. Thus, due to oxidation, it will generate unpalatable peroxide, which results in objectionable odor and taste.

The great masquerade

The art of flavor masking is far more complex than simply covering one taste with another. Taste is, after all, a complex science affected by chemical and physical factors. What we perceive as the flavor of a food is actually a combination of effects. Gustation, or taste, is our response to chemicals in foods as they interact with our taste buds.

We perceive sweet, sour, bitter, salty and the glutamate-induced umami response. Olfaction refers to our response to the aromatic elements of a food. Somato-sensation is how we feel the food. It is affected by the textural attributes of a product, as well as the heating or cooling sensations provided by ingredients such as capsicum or menthol. The balance of these effects creates a perception of flavor that is pleasant. Addition of nutritional ingredients to a given product can upset this balance, creating unexpected, and often undesirable, flavor effects.

Traditionally, flavorists were forced to counter these off-notes with high-sweetness flavors such as chocolate, vanilla and strawberry, notes Markus Eckert, Ph.D., vice president, technical flavors, Mastertaste. Vanilla is, and will continue to be, one of the best masking agents available. The increased demand, however, for an array of choiceshigh-carbohydrate, low-fat, diet, low-carbohydrate/ low-fat, meal-replacement and nutritional-supplement drinkshas created the need for an equally vast array of masking agents, modulating flavors and characterizing flavors to address the needs of the particular beverage segment.

Aspartame and acesulfame-K, both roughly 200 times sweeter than sucrose, may be blended for masking applications. Consider your process, however, as aspartame will lose sweetness during prolonged exposure to heat. Acesulfame-K is water-soluble and very stable during heating and subsequent storage.

More than meets the tongue

Anton Angelich, group vice president, marketing, Virginia Dare, Brooklyn, NY, suggests designing products that have flavors that are compatible and complementary to the end-product expectation. An example of this might be in choosing a characterizing nut flavor for a soy-protein-enhanced snack, where the soy delivers part of the nut flavor and complements the overall taste delivery.

Earthiness associated with botanicals can be addressed by adding fruit flavors such as grape or pineapple. More pronounced off flavors can be overcome by modification of masking agents. A pineapple-flavored system, for example, may be enhanced by the addition of furaneol (also known as pineapple furanone or strawberry furanone) or hexenal, which can create fresh, creamy, sweet notes that will temper grassy, earthy notes associated with vitamins and proteins. Adjustment of the acid profile in a given fruit flavor system may also help. Lactic and malic acids help fruit flavors tartness linger, providing more time for undesirable tastes to dissipate unnoticed.

Mariano Gascon, flavor lab director, Wixon, Inc., St. Francis, WI, suggests using products designed to adjust the way a given ingredient is perceived by the consumer. Taste modifiers are flavor ingredients that have little or no taste or smell of their own, but complement, enhance or otherwise modify the flavor of a food in a variety of ways, he says. They are also known as masking agents, flavor enhancers and, in certain instances, taste inhibitors.

Some of the products are designed to reduce acidic flavor notes without pH change, to reduce the perception of saltiness, the perception of sweetness and even the astringency perception, Gascon continues. Others are used to mask bitterness, green or grassy notes, off-flavors (like potassium salts), metallic or chalky aftertastes, off-flavors from vitamins, and those beany-like flavor notes related to soy.

Functionality of taste modifiers varies with the level of taste perception on which they work. Gascon, in a chapter from the recently published Modifying Flavor in Food (CRC/Woodhead Publishing), describes four mechanisms of action: adaptation, cross-adaptation, taste blocking and taste modifying.

Adaptation is actually a form of fatigue. Continuous exposure to a given taste diminishes the ability to perceive that taste. Adaptation to a single taste can lower, or in some cases increase, the threshold for perception of another taste. This phenomenon is called cross-adaptation.

Taste-blocking utilizes particular compounds to suppress the ability to perceive some or all flavors. Cloves, for example, can be used as an oral anesthetic.

Taste modification occurs when a substance causes an altogether different perception of a given material. Miraculin is a glycoprotein derived from West African Richadella dulcific berries. With no taste of its own, miraculin on the tongue will cause sour materials, such as citric or ascorbic acids, to taste sweet.

Cap-turing runaway flavors

In some cases, the best way to curb an ingredients flavor effects is to create a container for the ingredient. Often thought of as a process for protecting an ingredient from degradation or unwanted interaction with other ingredients, encapsulation and microencapsulation isolate an ingredient by coating particles (vitamins, for example) with another material, such as a lipid.

Encapsulation can provide protection for a product and for the ingredient being coated. Coating PUFAs protects the unstable oils from oxidation, while protecting the product from the flavors and aromas typically imparted.

And, by reducing the amount of off-flavors in a product, one also reduces the amount of flavor masking required to make the product palatable. Encapsulation technology has allowed developers to formulate PUFAs into an array of products, such as nutritional bars, bread, juice and dairy products.

R. J. Foster is a communications specialist with over 15 years of experience in the food industry in Technical Service, Research & Development, Quality Control, Regulatory, and Technical Sales. He can be reached by e-mail at [email protected].