Natural Flavors Chemistry & Applications

Originally Published: November 1, 2016
Last Updated: February 9, 2021
The flavor experience is integrated with aroma, taste, color and texture as in these six scoops of ice cream in virbrant colors of the fruit or confection they represent..

November 1, 2016 – “As a flavor scientist for decades, clean labeling is not typically my main focus,” opened Keith Cadwallader, Ph.D., Professor in the Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign. However, he advised, “Natural flavoring or substances may not always be considered clean, and when cleaning up labels, there may be some challenges with flavoring.”

Flavor is complicated, as it involves not only taste and smell but also cultural aspects. “Likings develop over time, and there is an emotional aspect. As we can all relate, aromas go directly to the brain where memories pop up. Flavor is the main determinant of why we eat certain things and whether we will purchase again,” explained Cadwallader.

The experience of flavor is integrated with overall product expectation, and it includes color and texture. Several studies show clear flavor linkages to a color, like red with cherry or strawberry, or green with lime.

Experts understand that naturals often give lower flavor intensity than artificial flavors, so additional natural substances may be needed to boost flavor intensity. Additionally, with natural source material, variation can be expected. Supplies can also be uncertain (i.e., if produced in a geopolitically unstable part of the world).

Natural flavors often contain non-flavor constituents that are not stable and can lead to off-flavors, like limonene in citrus, which tends to oxidize very easily.


Flavor substances allowed in the U.S. are essentially the same as in the EU, but the EU is a little more controlled, and labeling a little more restrictive. Only certain processing techniques are allowed in the EU to generate flavors. In the U.S., the flavor regulations 21CFR 101.22 have been unchanged for decades.

Click for downloadabe pdf of Chart.

There are times when a liquid might work better than a dry flavor. A good example is in functional products with many nutritional ingredients that need to be masked.

In nutrition bars, flavors are pretty stable due to low water activity. Encapsulates work well, as flavor can be released during consumption. The shelflife of encapsulates is also good, so use in bars is generally reasonable. Use of certain encapsulated functional ingredients also helps, especially minerals or others that tend to promote oxidation.

Beverages are different due to their high moisture level, which can create a spoilage concern. Viscosity, consistency and mouthfeel need to be consistent with flavors. A thick beverage, for example, needs an indulgent flavor like chocolate or cream; citrus, however, does not work well in most thick, creamy beverages. Legislative restrictions and differing regulations between countries can also be a challenge.

“Natural and clean label do not necessarily mean the same thing, but here are some considerations,” Cadwallader added. Plant-based flavorings are probably safe to consider for clean label. “Oleoresins, tinctures and alcohol extracts of plant materials (like vanilla extract) have been around for centuries, so they are pretty easy to call ‘clean’” he stated.

Similarly, natural bouillons, concentrated dried stock or aqueous extracts are also likely to be understood by consumers. Process flavors, created by enzymatic modification or thermal processing, are more borderline and may be less likely to fit under the “clean label” umbrella. Considered not so clean by some, although completely natural, are HVPs or yeast extracts.

A natural HVP (i.e., soy sauce) has a good flavor. However, certain consumers may understand it contains MSG and be less accepting of it, even though it is natural. Liquid smoke is also considered natural and has been popular since the 1970s. But, looking at how it is made, one may not consider it so natural or appropriate for clean labels.

Often, GMO technology is used to increase yield and production of essential oils in source materials. With all these considerations, it can be best to involve a flavor house, as they will consider all aspects of the products and have R&D to understand processing and environment. The flavor needs to be considered from processing all the way through storage. Again, natural flavors are not necessarily clean, Cadwallader advised.

“Clean Labeling: The Chemistry and Application of Natural Flavorings,” Keith Cadwallader, Ph.D., Professor in the Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign

November 1, 2016–Global Food Forums, Inc.The summary above is an excerpt from the “2016 Clean Label Conference Magazine,”

This presentation was given at the 2016 Clean Label Conference. To download presentations from this event, go to

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