Smell is an elementary parameter in the food valuation. Aroma (or smell or odor) is the sensation perceived when volatile compounds are sniffed through the nose.
What is a volatile compound? A small molecule which has a high tendency to evaporate. Volatiles are naturally produced by plants (flowers, fruits, vegetables, herbs…) and animals. They can also be made artificially (by chemical reactions designed for their production).
Food aroma is felt by sense of taste and smell by awaking the receptors of taste on the tongue and by smell receptors in the nasal cavity, that send information to the central nervous system and give a flavor sensation.
A natural aroma, smell or odor is typically made up of tens or sometimes hundreds of different volatile compounds. In general, the aroma of a food consists of many volatile compounds, only a few of which are sensorially relevant. A first essential step in aroma analysis is the distinction of the more potent odorants from volatiles having low or no aroma activity.
Typically, food aroma is an equilibrium mixture of aroma compounds. All aroma compounds are relatively small (400 Da), usually organic compounds. A vast array of compounds may be responsible for the aroma of the food products, such as alcohols, aldehydes, esters, dicarbonyls, short to medium-chain free fatty acids, methyl ketones, lactones, phenolic compounds and sulphur compounds.
The release of aroma compounds from foods is determined by the partition coefficient between the air phase and food matrix and, in the retronasal case, by the partition coefficient between the water phase (saliva) and the food matrix.
Food aroma is very sensitive to the processing and storage conditions. Flavor loss as well as off-flavor development is a problem for the food industry, and could be limited by the encapsulation of the volatile ingredients prior to their use.
Of the major food constituents, carbohydrates have generally the greatest influence on aroma compound release and retention. Carbohydrates are widely used in the food industry as sweetener, thickeners, stabilizers and gelling agents in products such as ice cream, beverages, jellies and sauces.
Food aroma: sense by taste and smell
