Umami differs from sweet, sour, salty, and bitter tastes by providing a meaty, savoury sensation.
Although umami taste receptors have recently been confirmed, from a culinary perspective the umami taste is not new. Fermented fish sauces and intense meat and vegetable extracts have been valued in world cuisines for more than 2000 years, writes Marcus.
In 1866, Ritthausen identified the amino acid glutamic acid which elicited the umami taste in humans. Later, in 1908, Ikeda proposed umami as a separate, distinct taste.
But the umami taste took off in the 20th century with the advent of monosodium glutamate (MSG), formulated in Japan in 1909 and launched into the US markets by 1917.
MSG and nucleotides are often used by product development technologists to enhance natural umami flavours.
"MSG, glutamate and nucleotides may together help provide food technologists with the "missing links" in recipes," says Marcus.
This may be because combined they work in synergy to round out food flavours when a food is missing something that has not been clearly identified.
Foods cooked in steam kettles may not achieve the full, meaty, and savoury flavours that are available to the home cook, so addition of umami-rich ingredients can help fill out flavour profiles, she writes in the May issue of Food Technology.
Marcus claims that umami can also cut costs for food firms, since its natural flavour may allow for a reduction of more expensive umami-rich ingredients.
For example, by using flavour enhancers with umami, developers could reduce the amount of expensive dried mushrooms in a recipe formulation.
"They can also help make a finished product taste "more than the sum of the ingredients", adds the assistant professor and chair at Kendall College, Chicago.
An imbalanced product tends to create taste fatigue. It may taste good initially but lose its appeal after a few bites. This can give the eater the impression that the food does not taste good, unless there are delicious, lingering after-effects which umami activators may provide, adds Marcus.
She highlights the example of low fat and low sodium foods that could create imbalances so great that reformulation is required.
Umami can be used to impart fuller flavour with less total sodium and calories.
In Western foods the umami taste comes from bouillon (originally formulated by the Swiss flour manufacturer Julius Maggi) which gives a similar meaty flavour to Asian dashi. In addition to MSG and glutamate, other umami taste activators are hydrolysed proteins, inosine monophosphate and guanosine monophosphate.