Functional ingredients, such as starch, flour, carrageenan and phosphate, can impact flavor delivery. The ingredients “can impact flavor delivery in an organoleptic sense, particularly taste,” notes Ferrara. “When working to maximize flavor, it’s important to understand the synergy of ingredients in a product.”
Because many ingredients interfere with flavor delivery, flavors are usually application-specific. “High-fat-containing products often require more-concentrated flavors to overcome the effect that fat causes in minimizing flavor strength,” says Richard Dandrea, senior flavorist, Virginia Dare, Brooklyn, NY. “High-protein-containing products also act in reducing flavor delivery. In addition, high acid and even high sweetness levels contribute to final flavor delivery.”
Edwards cautions that certain metals can react with the flavor. This can accelerate oxidation and can interfere with the olfactory characteristics. “Naturally occurring phenols, like those present in chocolate or green tea, may slow browning Maillard reactions in baked flavors,” she says. “Some naturally occurring tannins, like in wine, may unfavorably react with ingredients.”
High heat tends to evaporate or change the light volatiles in many flavors. Plus, according to Cosmos: “citrus flavors are especially vulnerable to oxidation. Water-soluble flavors will evaporate quickly. Oil-soluble flavors tend to have more tenacity, but if any form of oil is used as a diluent it can become rancid quickly by harsh processing.”
In systems where easy dispersion is important, like in dough, “an oil-soluble flavor would work best to control the release of the flavor, since it will incorporate better with the butter and other fats,” says Edwards. While any liquid could easily be incorporated in the dough, a water-soluble flavor can quickly evaporate during baking. “When a food product is heated, the water in the product evaporates, which can then cause steam distillation of the flavors. In other words, the more water-soluble and the lower the molecular weight the flavor components are, the more flavor loss you will encounter. However, the more volatile or water-soluble the flavor, the more aroma (flash off) you will have.”
If the processing steps are known while the flavor is being developed, the flavorist can choose the best solvent system. The solvent is especially important when heat is applied to the product, because they should not flash off too quickly. “This may also be a situation of a twofold system with liquid and dry flavors to provide the optimum profile due to the stress effect on the flavor,” Cosmos says.
The flavorist may also recommend a higher dosage to overcompensate for flavor loss, or the flavor might be applied at a different point in the product-development process than originally planned. When initially added to the product, it may appear to be overflavored, but that will “compensate for the loss due to the effect of high heat/short time, or lower heat over a specific time in baking,” says Cosmos.
Dandrea says that well-balanced flavor will typically contain both volatile and non-volatile components that create the flavor perception from initial impact to aftertaste. “Oftentimes, the solvent or diluents used to carry the flavor can help to minimize any vaporization of the volatile flavor components during processing,” he says. “The introduction of heat during processing can accelerate reactions be-tween active flavor molecules and/or between product actives. The flavor developer must be aware of interactions to help minimize these off effects. Oftentimes, aldehydes, which are key in vanilla, citrus and many fruit flavors, are very reactive and can form detrimental flavor breakdown products. Subtle fruit flavors, including pear, are most likely to be affected from the harsher conditions of certain processing.”
Flavors can be impacted by hot filling or aseptic packaging, as well as chemical preservative systems. “The longer the cooking time involved in thermal destruction of spoilage organisms, the more damage to the flavor occurs,” says Scott Rayburn, beverage applications manager, Cargill Flavor Systems, Cincinnati. “This is particularly intense in cases involving citrus oils. Chemical preservatives cause their own issues with off flavors; also, they need a low-pH environment to work correctly.”
Every flavor has a certain pH range in which it works. “For instance, root beer only works in a higher pH range with significant car-bonation,” says Rayburn. “Usually it is 16% sweeter than typical cola types. Another example is butterscotch flavor; it does not taste good in an acid solution. However, salt works as an excellent flavor enhancer within butterscotch products.”
Flavors are typically encapsulated to help prevent activity between other ingredients that can produce off flavors or loss of flavor. “The encapsulation process involves, in simplistic form, the creation of a barrier, typically a starch or gum, between the core flavor components and the final system or finished application—and, ultimately, aids in extending the shelf life of the flavor. Most encapsu-lated flavors are application-specific and are typically water-soluble, which prevents their use in high-moisture foods or beverages,” says Dandrea.