Did you know that we have 5 basic tastes– not four? It was once thought that our four basic tastes were comprised of sweet, sour, salty, and bitter; every food that we ate was a various combination of these four tastes. However, as early as 1910, a Japanese researcher found that we actually have sensory cells that detect a fifth taste, called savory or umami. Umami is a meaty or savory taste. The word umami is the Japanese name for this taste, a term that has gained in popularity and is now commonly used to refer to this fifth taste.
We use several senses to detect taste. Of course, we perceive the taste with our tongue, but we also incorporate the smell, texture (liquid, bumpy, rough, smooth, hard, soft, gritty, chewy, lumpy, squishy), and temperature of the food into our calculations. Believe it or not, the “taste” actually happens through our nose! A food’s flavor is detected only when the taste is combined with the smell. When we are sick and our nose is stuffed up, our perception of taste is dulled as well.
Our sense of taste, as well as our sense of smell and sight, is closely linked to our emotions because these senses are connected to our involuntary nervous system. Have you ever even just looked a scrumptious piece of moist chocolate cake or smelled your favorite dish and your mouth began to water? Or conversely gagged at an offensive smell or flavor? This is because sights, smells, and flavors can create an automatic nervous system response; ones that are appetizing can instantly promote the production of saliva and gastric juices, making your mouth water; ones that are offensive can elicit the gag reflex.
When we taste a food, we enlist one or several of the five basic qualities of taste. Many dishes are made up of a combination of different tastes. For instance, some dishes taste sweet and sour, while others are salty and savory.
The U.S. Library of Medicine describes the five basic tastes as follows:
Sweet: What we perceive as sweetness is usually caused by sugar and its derivatives such as fructose or lactose. But other types of substances can also activate the sensory cells that respond to sweetness. These include, for example, some protein building blocks like amino acids, and also alcohols in fruit juices or alcoholic drinks.
Sour: It is mostly acidic solutions like lemon juice or organic acids that taste sour. This sensation is caused by hydrogen ions, chemical symbol: H+, split off by an acid dissolved in a watery solution.
Salty: Food containing table salt is mainly what we taste as salty. The chemical basis of this taste is salt crystal, which consists of sodium and chloride. Mineral salts like the salts of potassium or magnesium can also cause a sensation of saltiness.
Bitter: Many fundamentally different substances bring about bitter taste. In total there are about 35 different proteins in the sensory cells that respond to bitter substances. From an evolutionary standpoint, this can be explained by the many different bitter species of plants, some of which were poisonous. Recognizing which ones were indeed poisonous was a matter of survival.
Savory: The “umami” taste, which is somewhat similar to the taste of a meat broth, is usually caused by glutamic acid or aspartic acid. These two amino acids are part of many different proteins found in food, and also in some plants. Ripe tomatoes, meat and cheese all contain a lot of glutamic acid. Asparagus, for example, contains aspartic acid. Chinese cuisine uses glutamate, the glutamic acid salt, as flavor enhancers. This is done to make the savory taste of foods more intense.
Many foods have the umami flavor: fish, shellfish, cured meats, ripe tomatoes, spinach, celery, cheese, broth, soy sauce. Incidentally, our first encounter with the umami flavor is breast milk, which has about the same amount of umami as broths.
And, guess what other food is considered to have a strong umami flavor? Yep, MUSHROOMS! Mushrooms are perceived to have a similar flavor to meat. For example, oysters, shiitake, and pioppino have a similar flavor to meat, lion’s mane to seafood, and crisped shiitake mushrooms to bacon. For this reason, in addition to the fact that mushrooms contain protein (350 calories of oyster mushrooms contains 33 grams of protein or 340 calories worth of shiitake mushrooms contain 22.4 grams of protein) that many people are turning to mushrooms as a meat substitute. Now we can see why mushrooms are becoming one of the fastest growing, healthy, unprocessed meat substitutes in the country.
USDA Nutrient Database, USDA Agricultural Research Service, National Agricultural Library, April 2014
U.S. National Library of Medicine, How Does Our Sense of Taste Work, January 6, 2012. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0033701/
“Umami taste receptor identified”. Nature. Retrieved 26 June 2013.
Agostini C, Carratu B, Riva E, Sanzini E (August 2000). “Free amino acid content in standard infant formulas: comparison with human milk”. Journal of the American College of Nutrition 19 (4): 434–438.doi:10.1080/07315724.2000.10718943. PMID 10963461
OTHER SELECTED READINGS:
Lindemann, B; Ogiwara, Y; Ninomiya, Y. “The Discovery of Umami”. Oxford Journals.
Edmund Rolls (September 2009). “Functional neuroimaging of umami taste: what makes umami pleasant?”. The American Journal of Clinical Nutrition 90 (supplement): 804S–813S. doi:10.3945/ajcn.2009.27462R.PMID 19571217