‘Fifth taste’ Umami could be beneficial for health, study
The umami taste could have an important and beneficial role in health, according to Japanese research.
A series of studies published in the journal Flavour in January 2015 found that umami and ‘kokumi’ substances, which modify flavour, could improve the taste of low-fat foods. The series brings together researchers from a range of different disciplines to provide a broad picture of the current understanding of taste.
“In general, our understanding of taste is inferior to our knowledge of the other human senses,” said Ole Mouritsen, Guest editor for the Flavour journal’s special series on umami and Professor of biophysics at the University of Denmark. “An understanding and description of our sensory perception of food requires input from many different scientific disciplines,” he said.
Umami important for health in elderly people
Despite the widely held belief that monosodium glutamate (MSG) is an unhealthy addition to food, researchers from Tohoku University Graduate School of Dentistry, Japan, have shown that the taste it triggers, umami, is important for health, especially in elderly people.
In a small study of 44 elderly patients, the researchers showed that some elderly patients suffered a loss of the umami taste sensation, and that all of the patients studied complained of appetite and weight loss, resulting in poor overall health.
Umami taste receptors also exist in the gut, according to the researchers. They said this suggested that the umami taste sensation functioned in nutrient sensation and modulating digestion in the gut, which could be important for maintaining a healthy daily life.
The researchers suggest that diseases suffered by elderly patients and side effects from their medications could cause taste disorders and reduced salivation. They also found that treatment to improve salivary flow had a beneficial effect on the patients’ taste sensations and could help patients with reduced umami sensitivity.
The discovery of the umami taste
In a separate review, Kumiko Ninomiya of the Umami Information Center in Japan explored umami’s discovery and the hundred-year delay in its global recognition as a basic taste.
Looking at the differences in culinary culture between Europe and Japan, the analysis by Ms Ninomiya highlighted recent collaborative studies with chefs and researchers on the different taste profiles for Japanese and Western soup stocks, and suggests reasons why umami has been more easily accepted by the Japanese.
However, Ms Ninomiya said a recent exchange on cooking methods and diverse types of umami-rich foods in different countries had “facilitated a new approach to culinary science” that could bring “healthier and tastier” solutions.
The importance of umami until now
In 2004 the well-known food commentator Malcolm Gladwell wrote an essay that examined the growing recognition and importance of umami. Mr Gladwell described the move towards using ripe tomatoes, which are a source of umami, by food manufacturer Heinz in its tomato ketchup.
‘Kokumi’ substances ‘significantly’ enhance flavour
Meanwhile, another Japanese study found that ‘kokumi’ substances, such as those found in garlic, onions and scallops, ‘significantly enhanced’ thick flavour, aftertaste and oilness in reduced-fat peanut butter.
‘Kokumi’ substances are known to enhance basic tastes when combined with other flavours, despite having no taste themselves.
The study, undertaken by researchers at the Institute of Food Research and Technologies and the Institute for Innovation in Japan, examined the effect of adding a ‘kokumi’ substance to peanut butter with a reduced-fat content (30 per cent), and had 29 participants compare the taste of this peanut butter with full-fat (50 per cent fat content) peanut butter.
The participants evaluated samples of the reduced-fat peanut butter and full-fat peanut butter model. A panel leader led the group in discussion on the differences and similarities between the samples. They developed a list of sensory attributes that described the sensory characteristics of the products. The participants developed attributes: peanut flavour, saltiness, sweetness, bitterness, thick flavour, aftertaste, continuity of taste, smoothness, and oiliness. The two peanut butters were evaluated based on these characteristics.
The researchers then analysed the data collected from these evaluations and found that the results demonstrated that the addition of the ‘kokumi’ substance increase some sensations that were lacking in the reduced-fat peanut butter. They said these results suggested that the addition of the substance “could improve the flavour of reduced-fat peanut butter” and other low-fat foods.