Human Sweet and Umami Taste Receptor Variants

The complexity of taste discrimination (salty, sour, sweet, umami and bitter) varies between human individuals and populations. Sweet and umami (the taste of glutamate) tastes play a major role in the perception of calorically-rich and essential nutrients and there are well-documented differences in individual perception of sweet and umami flavorings, many of which appear to be genetic in origin. Studies of individuals within and between populations that vary in any of the taste receptors should be of direct interest to the multi-billion dollar food and flavoring industry as the characterization of such variants could be used to aid in the development of a variety of taste improvements in foods and orally administered medications. NIH researchers previously characterized bitter taste receptor variants in world wide populations [Human Mutation 26, 199-204; HHS Ref. No. E-222-2003/0] and have now extended their studies to the sweet and umami receptors in global populations.

The group of Dr. Dennis Drayna at NIDCD have now discovered novel coding sequence polymorphisms in the human TAS1R genes. These genes encode dimeric receptors that sense sweet taste (as TAS1R2+TAS1R3) and the taste of umami (as TAS1R1+TAS1R3). To achieve maximum genetic diversity, TAS1R receptors from a panel of 30 Europeans, 20 East Asian, 10 Native Americans, 8 South Asians and 20 sub-Saharan Africans were sequenced. Approximately 60% of the identified SNPs caused an amino acid substitution in the encoded receptor protein. This variation may account for individual preferences in sweet and umami tastes in foods and could be of use in the understanding and control of dietary preferences that lead to obesity and diabetes.

These novel variants and methods of use are available for licensing and should be of particular use to those using sensorial analysis in the food and flavoring industry where the use of taster panels in the development of flavors and flavor enhancers for different foods is key to the development of new food products and taste masking compounds. The ability, for example, to genetically match taster individuals employed by industry with the target consumer populations can both guide improved formulations and marketing decisions as well as reducing the total sample size in the testing of new products in this highly competitive industry.