What Is Fragrance?

Fragrance, or perfume, is a combination of scented oils and other ingredients used to produce a scent. It is worn by both men and women, but has historically been primarily associated with femininity. It has been used in many cultures throughout history, with evidence of its use in some of the earliest human civilizations. The modern perfume industry developed in the late 19th century with the commercial synthesis of aroma compounds such as vanillin and coumarin, enabling perfumers to make scents that could not have been produced using natural aromatic materials alone. Today, the most popular perfumes contain anywhere from tens to hundreds of ingredients. These include (1) essential oils and other extracts of plants or flowers; (2) synthetic aromatic chemicals based on natural aromatic plant components (e.g., alcohols, aldehydes, esters, terpenes and phenols); (3) fixatives to reduce the evaporation rate of the perfume, increase perceived odor strength and improve stability; and (4) solvent solutions such as ethanol.

Perfumes can be classified according to their concentration level, which indicates how strong or weak the scent will be when rubbed on the skin. They can also be designated according to the fragrance family, although these are not necessarily indicative of the scent of the perfume, and a single perfume may have elements from multiple families.

The composition of a perfume can be described in terms of its “notes” or “note pyramid,”[36] which describe the main components of the fragrance, starting with top notes, middle notes, and base notes. Top notes are the first smells to be noticed, usually consisting of small molecules that evaporate quickly and give a “fresh” or “light” impression. Middle notes are a little more complex, and they form the heart of the perfume. Base notes are the last scents to be noticed, and they form the background of a perfume.

A perfumer is an expert on perfume composition, whose job is to turn the concept of a fragrance into a finished product. The perfumer can draw on his or her knowledge of chemistry, the sense of smell and the art of composing a harmony of scents.

Perfumes are both intrinsically and extrinsically a sensory reward; they stimulate the limbic system of the brain, which is associated with pleasure and emotional responses, and they are aesthetically pleasing. In addition, perfumes have the potential to reinforce behaviors by facilitating social acceptance and status. Despite this, there has been very little empirical research into the effects of perfume on humans. In particular, perfume has not been studied as a reinforcement stimulus, and research into its neurobiological properties is lagging far behind that of other sensory rewards such as taste and touch. Nevertheless, anecdotes suggest that perfume can function as a behavioral reward by increasing sexual attractiveness and enhancing cognitive performance. Future innovative research in perfume neuroscience and reward will be a valuable complement to existing research in these areas.