RESUMO
PURPOSE: The detection of fat taste in humans requires the delivery of hydrophobic stimuli to the oral cavity. Due to their low solubility in water, these fat taste stimuli are difficult to administer to test subjects by means of aqueous solutions or dispersions. These hydrophobic stimuli are also difficult to prepare in sufficient amounts to generate an appreciable chemosensory response. METHODS: An improved procedure for preparing thin edible strips that contain 18-carbon fatty acids as representative fat taste stimuli is described. This protocol includes the addition of low amounts of the dispersing agent xanthan gum and high drying temperature during film formation. These edible strips can be prepared in 4-5 h, are highly flexible, and evenly disperse long-chain fatty acids at micromole amounts. Due to the rapid dissolving time of these strips in the oral cavity, this delivery method generates minimal tactile responses. RESULTS: Psychophysical studies with edible strips indicate that nearly all individuals detected linoleic acid, with intensity responses in the weak to moderate range. Fewer individuals perceived stearic acid, with most intensity responses in the barely detectable range. Both fatty acids caused a fatty/oily or bitter taste response in the majority of test subjects. Finally, these intensity responses allowed the development of edible circles for regional testing of the tongue. CONCLUSION: This novel delivery method for hydrophobic stimuli should be useful for examining human fat taste perception, characterizing variations in fat taste perception, and identifying the emerging role of fat taste in human health.
