Umami and Sodium Reduction

By Teresa Esquivel, Managing Editor

Some describe it as savory; others call it meaty or brothy or delicious. Umami is all that. Although it is now widely accepted as the fifth primary taste, umami is decidedly more complex than its sweet, sour, bitter and salty counterparts. In addition to having its own taste quality, umami enhances other flavors and increases mouthfeel. As such, umami is a food product developers friend when it comes to developing low-sodium formulations. Such foods often suffer from a lack of consumer acceptance, as subsequent flavor loss leaves the product tasting bland.

Umami is the middle flavor, its the center of the flavor experience and can make a dish more fulfilling and satisfying," says Eric Justice, vice president culinary development, P.F. Changs and Pei Wei Asian Diner, Scottsdale, AZ.

Umami occurs naturally in fish, soybeans, tomatoes, mushrooms, parmesan, meat and poultry, but there are other ways for food manufacturers to capture umami goodness in their products.

As a single stimulus that elicits umami, most taste scientists point to the amino acid glutamate, more commonly known as MSG in its neutralized sodium salt form," says Paul A.S. Breslin, Ph.D., member, Monell Chemical Senses Center, Philadelphia. The compounds that contribute to umami typically are amino acids, or sometimes small peptides made up of amino acids," he continues. The best example is glutamate, and the second best is aspartate. There are also compounds that interact with glutamate to stimulate highly enhanced umami taste. The best known of these synergies are the 5' ribonuclotides of DNA fame, particularly IMP (inosine monophopshate) and GMP (guanosine monophosphate). Some scientists claim there are many more umami enhancers out there to be extracted and isolated from foods."

Until then, developing umami in a food product is largely achieved via the addition of MSG or other glutamates, GMP, IMP, yeast extracts, flavor enhancers rich in amino acids, fermented flavors or fermented products, like soy sauce.

The umami power of naturally fermented soy sauce comes from low-molecular-weight (less than 500 Da) amino acids that arise from the soy protein during the fermentation process (Journal of Food Science, 2010; 75(3):R71-R76). Specifically, these amino acids have been identified as fructosyl pyroglutamic acid, fructosyl valine, fructosyl methionine, pyroglutamylglutamine and pyroglutamylglycine (Bioscience, Biotechnology, and Biochemistry, 2011; 75(7):1,275-1,282).

 Studies have also demonstrated that soy sauce can effectively be used to replace some sodium without sacrificing appeal. In one study, for example, the researchers were able to reduce sodium in salad dressing, soup and stir-fried pork by 50%, 17% and 29%, respectively, without losing flavor intensity or diminishing product appeal (Journal of Food Science, 2009; 74(6):S255-S262).

Sponsored by Kikkoman Sales USA, Inc.