title: Humans are more sensitive to the taste of linoleic and α-linolenic than oleic acid.
abstract: Health concerns have led to recommendations to replace saturated fats with unsaturated fats. However, addition of unsaturated fatty acids may lead to changes in the way foods are perceived in the oral cavity. This study tested the taste sensitivity to and emulsion characteristics of oleic, linoleic, and α-linolenic acids. The hypothesis tested was that oral sensitivity to nonesterified fatty acids would increase with degree of unsaturation but that in vitro viscosities and particle sizes of these emulsions would not differ. Oral taste thresholds were obtained using the three-alternative, forced-choice, ascending method. Each participant was tested on each fat 7 times, for a total of 21 study visits, to account for learning effects. Viscosities were obtained for the blank solutions and all three emulsions. Results indicate lower oral thresholds to linoleic and α-linolenic than oleic acid. At higher shear rates, 5% oleic and linoleic acid were more viscous than other samples. More-dilute emulsions showed no significant differences in viscosity. Particle sizes of the emulsions increased very slightly with increasing unsaturation. Together, the emulsion characteristics and oral sensitivity data support a taste mechanism for nonesterified fatty acid detection.
authors.affiliation: Department of Food Science, Purdue University, West Lafayette, Indiana; and.
authors.forename: Cordelia A
authors.initials: CA
authors.lastname: Running
authors.affiliation: Department of Nutrition Science, Purdue University, West Lafayette, Indiana mattes@purdue.edu.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Mattes
mesh_terms: D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D004655:Emulsions / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D006801:Humans; D019787:Linoleic Acid / Q000737:chemistry / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000187:drug effects; D019301:Oleic Acid / Q000737:chemistry / Q000494:pharmacology*; D011897:Random Allocation; D012684:Sensory Thresholds; D013649:Taste / Q000502:physiology*; D017962:alpha-Linolenic Acid / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D004655:Emulsions; D017962:alpha-Linolenic Acid; D019301:Oleic Acid; D019787:Linoleic Acid
keywords: fat detection; fat taste; nonesterified fatty acids; unsaturation