Besides contributing directly to flavor and functionality, the composition of traditionally brewed soy sauce also makes it useful as a flavor enhancer. To understand how, let's begin with an overview of the mechanism of taste perception.
The overall flavor experience is a combination of several concurrent reactions in the mouth. First, the molecules of various food components trigger receptors for the basic tastes. While this is happening, aromas enter the nose both through the nostrils and through the roof of the mouth.
Here, olfactory receptors transmit odor perception to the brain, where the information is combined with that of the taste receptors. This combination is finally influenced by physical perceptions transmitted by the mouth's sense of touch. Flavor enhancers help to combine these reactions into a unified, blended flavor experience and to intensify the overall effect.
Soy sauce is a flavor enhancer primarily because of its amino acid content. Many amino acids have been identified both as flavor potentiators and umami contributors -- most notably, glutamic acid. But soy sauce's glutamic acid content isn't the only thing contributing to its flavor-enhancing capabilities. Umami ingredients, such as glutamic acid, may work synergistically with salt to produce an enhancing effect, according to one researcher. Soy sauce, as previously discussed, has plenty of both.
It may seem odd to think of soy sauce in a traditional comfort food like beef stew. However, this application demonstrates the flavor enhancing power of traditionally brewed soy sauce. Soy sauce boosts the flavor of the meat and adds depth and color -- without requiring a lot of preparation time. That makes it ideal for prepared entrees, soups and sauces.