Experience-induced changes in taste identification of monosodium glutamate

Abstract

Taste sensitivity for a given subject generally has been thought to be genetically determined and not plastic. Yet experience-inducible changes in human taste and olfactory sensitivities have been reported. To test a taste induction hypothesis, we exposed 17 Americans/Europeans to monosodium glutamate (MSG) in food and then compared their ability to identify MSG taste with that of 2 control groups (18 Americans/Europeans without MSG exposure and 18 Japanese). When tested on Day 11 or 12, the Americans/Europeans exposed to MSG were able to identify MSG at significantly lower concentrations than the Americans/Europeans without MSG exposure. Moreover, Japanese subjects who had prior extensive experience with MSG in Japanese food were able to identify MSG at significantly lower concentrations than the two American/European groups. The differences in identification ability between the two American/European groups challenge the notion of taste sensitivity as stable over time and support the hypothesis of an experience-inducible component in human taste.

Glutamate concentration in whole saliva and taste responses to monosodium glutamate in humans

“…Six MSG solutions (0.03, 0.1, 0.3, 1.0, 3.0, 10.0% (w/w); Sigma, Poznan, Poland) were prepared with sterile deionized water (Polfa, Lublin, Poland). The range of MSG concentrations was selected on the basis of previous reports (Yamaguchi 1991, Kobayashi and Kennedy 2002. The lowest concentration used in the present study was above the threshold for MSG (625 -925 mM, 0.01 -0.015%) found in healthy humans (Yamaguchi 1991, Kobayashi andKennedy 2002).…”

“…Thus, these compounds are converted to sodium salts which produce umami taste sensations but also taste slightly salty because of the cation component (Yamaguchi 1991). The sodium salt of Glu, monosodium glutamate (MSG), is a prototypic umami substance used as a flavor enhancer and research tool (Yamaguchi 1991, Yamaguchi and Ninomiya 2000, Kobayashi and Kennedy 2002. The sodium salt of aspartate (monosodium aspartate, AspNa) and disodium salts of certain 5 0 -ribonucleotides (5 0 -guanosine-, 5 0 -adenosine-and 5 0 -inosine-monophosphate) are umami substances which produce umami taste sensations either in combination with Glu or by themselves (Yamaguchi 1991, Chaudhari et al 2000, Halpern 2000.…”

Perceptive maps of dishes varying in glutamate content with professional and naive subjects

“…However, previous studies conducted with western subjects have demonstrated that umami identification ability is plastic, can change with experience (Kobayashi & Kennedy, 2002), and it can be acquired via sensory training (Sinesio, Comendador, Peparaio, & Moneta, 2009). In the West, most people do not identify the umami as such when they find it in their meals, since the 'umami' concept is not yet adopted in their culture as is reflected by the lack of an English word for the taste.…”

Human Taste Thresholds Are Modulated by Serotonin and Noradrenaline

“…This has lead to the concept of "non-tasters" and "supertasters" (Bartoshuk, 2000), in which the taste threshold is linked to the haplotype of specific receptors (Kim et al, 2004). Recent observation of environmental modulation or plasticity within the human taste system are therefore surprising (Kobayashi and Kennedy, 2002;Kobayashi et al, 2006) because this was thought to not occur.…”