Involvement of GPR120 in Perception of Fatty Oral Sensations in Humans

The fatty acid transporter, CD36, and fatty acid receptor, GPR120, have recently been shown to play a role in the gustatory perception of fatty acids in humans. However, limited information is currently available to show that agonists of CD36 and GPR120 evoke fatty oral sensations to dietary fat in humans. Therefore, the involvement of GPR120 agonists in dietary fat perception in humans was investigated herein. An emulsion prepared from vegetable oil evoked a stronger fatty after orosensation, an oily mouth coating sensed 5–10 s after tasting, which is similar sensory characteristics to lastingness in koku, than that prepared from mineral oil; however, the physical properties of both emulsions, such as viscosity, particle distribution, interfacial tension, the contact angle, frictional load, and ζ-electric potential, were similar. The potent GPR120 agonist, TUG-891, enhanced the fatty after orosensation when added to the emulsion prepared from vegetable oil, but not to that from mineral oil. All GPR120 agonists tested enhanced the fatty after orosensation when added to a low-fat food system, whereas they did not evoke any fatty sensation in aqueous solution at the concentrations tested in the food system, and sensory activity positively correlated with GPR120 activity. These results suggest that GPR120 agonists enhanced the fatty after orosensation in humans when added to vegetable oil or a low-fat food system, but did not evoke it by themselves. In addition, to examine the sensory effects of GPR120 agonists on fat-containing foods, changes in the sensory characteristics of normal-fat whipped cream following the addition of the potent GPR120 agonist, TUG-891, were investigated using a descriptive analysis. Trained panelists selected 12 attributes from sensory words collected in evaluations of whipped cream with fat contents of 35 and 47%. The addition of 27.4 μM TUG-891 to normal-fat whipped cream significantly enhanced the intensity of the mouth coating (initial, middle and last, and long-lasting), thickness of taste, and denseness, and also significantly decreased the score for melting speed in the mouth. Sensory scores for these attributes in normal-fat whipped cream were equivalent (mouth coating) or close (thickness of taste, denseness, and melting speed in the mouth) to those of full-fat whipped cream. Therefore, GPR120 agonists appear to possess some of the functions of fat in dairy cream.