Fragrance Perception

A wide range of factors affect how we perceive a product. If we are to understand the reasons behind why the consumer chooses a product, we need to determine what drives acceptance and how this can be interpreted into information that can be used to develop winning fragrances. 

Sensory analysis is concerned with quantifying human responses to stimuli. It is a precise, descriptive and measuring technique that characterizes the stimulus. In this case, the particular concern is to evaluate the odour of a perfume, perfume ingredient or perfumed product. This is an important process in enabling the perfumer to understand and quantify the sensory characteristics of the product, as only then can they be manipulated in a controlled way as part of the creative process. 

The evaluative and subjective associations made by the consumer must be understood when assessing a product these are measured using market research techniques. If the market is understood, fragrances can be developed to match or enhance the image of a particular product or market segment. Sensory analysis is also an important tool in this process. Using powerful statistical techniques, the odour relationships between different products or perfumes can be characterized and quantified, and the results combined with market research to enable the subjective associations to be interpreted in odour terms. 

Sensory analysis and market research rely on verbal or conscious measurement of an odour or perfumed product by a human respondent. Emotion is another aspect of product perception which is difficult 

A wide range of factors affect how we perceive a product and how we choose one product in preference to another. The human race is inherently variable in its sensitivity to different sensory stimuli, to such an extent that while some of us, for instance, can smell a musky odour quite distinctly while others are completely blind or anosmic to it. Above this, the way that each of us responds to a stimulus depends on our previous experiences and associations so, while one person may find an odour comforting and nostalgic, another person may be completely indifferent to it. 

Sensory Analysis and Market Research are two major disciplines that enable us to measure human responses to sensory stimuli. Both rely on well-researched and rigorous techniques and a fundamental understanding of the difficulties involved in working with human subjects, such as those described above. 

The evaluative and subjective associations made by the consumer can be understood using Market Research techniques. If the market is understood, 

In answering a customer brief such as that from Business Scents Ltd, a perfumer welcomes as much guidance as possible in how to win that brief successfully. The four disciplines mentioned above (Sensory Analysis, Market Research, Statistics and Psychology) together form a powerful analytical and predictive tool, different aspects of which can be used for guidance in perfume creation depending on the requirements of the brief. In the sections that follow in this chapter, a brief outline of the techniques currently used within each of these areas of expertise is given, as are examples of how they could be used to fulfil the Business Scents brief. 

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The phase diagrams are also useful for estimating the decisive elements in the interaction between skin-care formulations and the skin. It is essential to realize that the initial formulation is not important for the action on the skin its influence is limited to the esthetics, the feel, and the fragrance perception at application. These are, of course, decisive for customer selection at the first purchase-, repeat customers depend also on the perceived action on the skin. 

Richardson, A., 1999. Measurement of fragrance perception. In The Chemistry of Fragrances, Chap. 8, D.H. Pybus and C.S. Sell (eds). Cambridge Royal Society of Chemistry. 

Odor perception and description are highly subjective in nature. Nevertheless, there is a generally agreed-upon odor vocabulary that is used to characterize individual ingredients and finished fragrances. Table 1 shows some commonly used odor descriptors grouped into five general classifications. 

A perceptible marker of the olibanum fragrances coming from Somalia, Sudan, or Ethiopia is the aliphatic octyl acetate marked by a distinct acrid smell. Boswellia carterii contains up to 50% of the aliphatic octyl acetate, demonstrated by the strong stinging smell of the fume, whereas Boswellia serrata (its common name in India is salai guggul) contains none or only small amounts of it and, consequentiy, does not have such a harsh smell. 

Sensory information obtained from the interaction of fragrance and flavor molecules with olfactory and taste receptors is processed in defined cerebral areas, resulting in perception. During the past 10 years much research has been done concerning sensory perception and results have been published in, e.g., [2 4b]. 

Since fragrance materials differ in volatility, the odor of a perfume composition changes during evaporation and is divided into the top note, the middle notes or body, and the end note or dry out, which consists mainly of less volatile compounds. Odor perception also depends largely on odor intensity. Therefore, the typical note is not determined only by the most volatile compounds. 

In smelling a complex fragrance, we do not always grasp it in its full complexity. Our perception is dominated by those features that strike us most powerfully, and if we manage to match these features reasonably closely, we may feel that we have come a long way toward matching the perfume. Indeed we may have done so, but someone else whose attention has been struck by other features of the original, which we may have more or less overlooked, may immediately detect discrepancies and be far less impressed by the closeness of our match. 

Another approach, adopted by J. S. Jellinek (1992) in his Map of Perfumes, is to classify perfumes on the basis of consumer perception. Consumer perception in many cases differs considerably from that of either the perfumer or fragrance specialist within the industry. Such a classification is valuable in the positioning of new perfumes being launched onto the market. 

Odor, however, is a very obvious property of any chemical compound, and thus, speculation about the mechanism of perception is very tempting. Experienced fragrance chemists can predict odor type with much better than random accuracy, and a commercial driver exists in terms of design of novel materials for the fragrance industry. Therefore, it is not surprising that many structure/odor correlations and olfaction models have been reported and debated, often very hotly, in the literature. 

Chiral discrimination has been recognized as one of the most important principles in biological activity and also odour perception [1-9]. Besides enantioselective biogenesis, the evaluation of chirality in the origin control of flavourings and fragrances has to be discussed with regard to some fundamental conditions. 

The experiential dimension does not have to stay in the fragrance or color arena. It is expanding to the beads, pearls, and other attractive elements seen in personal care products. A recent example is the Rainett aux Algues Marines LDLD introduced in France by Werner Mertz. This product contains natural marine algae extracts encapsulated in beads. The extracts offer hand care benefits. Pearls or beads can be used as carriers of actives to enhance efficacy or mildness perceptions. 

The softener performance perceived by consumers is the balance between the absolute efficacy determined in the laboratory and the product aesthetics. In other words, the consumer perception of the product performance is heavily influenced by aesthetic attributes such as fragrance and viscosity. Consumer tests indeed show that perfume, and more precisely perfume substantivity on fabrics, is the main reason for preferring one product among several delivering the same softness. Consumers appreciate both the odor of the product itself, which generates the appeal and causes the purchase intent, and the smell of the laundered fabrics, which settles the repurchase intent. 

Those fragrances that are closest together on the map are most similar in odour character, whilst those that are furthest apart are most different. So, for instance, fragrances A59 and C33 are relatively similar in odour character, while A59 and D28 are quite different. To interpret the map and describe the nature of the differences between the odours, a correlation analysis is carried out. This analysis enables us to identify the characteristics that are most important in distinguishing between the fragrances, and the direction of increasing perception of each of these characteristics is indicated on the map with an arrow. So we can tell, for instance, that A59 is perceived to be far more fruity than D28. 

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