Esters

One group of substituted hydrocarbons accounts for the flavors of many foods and the pleasant odor of many flowers. These compounds are known as esters. Esters form when organic acids react with alcohols. The second product of the reaction is water. For example, ethanoic acid can react with methanol to produce methyl ethanoate (methyl acetate). The reaction is reversible.

Esters are used in many processed foods to produce flavors such as strawberry, banana, and grape. Flowers like the roses in Figure 12 produce esters and other compounds with distinctive odors that attract insects for pollination. Sometimes, the compounds produced by the plant mimic compounds produced by the insect.

Figure 12 Many compounds in rose petals contribute to the fragrance of a rose. Some of these compounds are esters, which tend to have pleasant, sweet odors.