How food odorants are represented in flavor perception and how perception determine behavior
CALS Impact Statement
This sensory representation of the external chemical world in the brain is a translation of stimulus features into a neural sensory map. It is the nature of this sensory map—how it is established by stimulant patterns, how it varies in a population, and ultimately how it modulates other brain functions, e.g. emotions (joy) or behavior (buying wine)—that is the goal of our research.
Sustainable food production is more successful with value-added products than commodities. Fine wines associated with a terroir are the best examples. Because such food products usually express their value through their unique flavor, understanding the biology of flavor perception and the flavorants that produce them is central to enhancing their value. This research is intended to increase the profitability of New York food production through a better understanding of the unique features of foods that motivate consumers to pay more for them. Farmers care because higher prices give them better lives and the income to be better land stewards.
We have developed a database, called the Flavornet, of all the odorants in foods and put it on the Web at http://www.flavornet.org/. Flavornet is a compilation of aroma compounds found in human odor space. A seemingly infinite number of perceptions are invoked by the fewer than 1,000 odorants that make up this space. Those chemicals with mass lower than 300 Daltons bind to proteins on the olfactory receptor neurons (ORNs) at the surface of the olfactory epithelium. Excitation of ORNs generates a topographic map of sensory information in the brain that is a representation of the stimulating chemical features of the external world. The Flavornet lists only those odorants that have been found in a human odor space at supra-threshold levels, i.e. at levels likely to stimulate ORNs.
We have developed a selective and sensitive bioassay, called CharmAnalysis, for smell based on gas chromatography-olfactometry (GCO) that, along with other forms of chromatography, spectrometry, and sensory analysis, is used to study food quality. Using GCO and an odorant probe composed of stimulants that produce a broad range of perceptions, odorant-specific sensory deficits in human subjects were quantitatively measured as variations in odor detection thresholds.
The GCO technology is being modified to the study of odor mixtures. The new technology is based on Pedestal Olfactometry (GCPO) uses pulses of odor mixtures at fixed concentrations to which GC effluents are added. Presently in development, GCPO will ultimately be used to understand how odor mixtures are perceived.
Understanding the relationship between stimulant composition and perception is therefore central to understanding the representation of chemical information in the brain and the impact of genetic diversity on the perception of food. Results from this research will help consummers understand their perceptions and cultivate unique food choices that enhance their pleasure, health, and safety while sustaining profitable use of New York land.