Sensory perception hedonics

Much of our present day knowledge of sweetness intensity, both at the threshold level, where taste begins, and above the threshold level, derives from the application of psychophysical techniques. It is now evident that the psychophysical procedure used measure separate aspects of sweetness perception. Hedonic responses cannot be predicted from intensity of discrimination data, and vice versa. The taste-panel evaluation of sweetness is of fundamental importance in the development of worthwhile structure-taste relationships. Therefore, it is vital that the appropriate psychophysical method and experimental procedure be adopted for a particular objective of investigation. Otherwise, false conclusions, or improper inferences, or both, result. This situation results from the failure to recognize that individual tests measure separate parameters of sensory behavior. It is not uncommon that the advocates of a specific method or procedure seldom... 

Although these two types of data - sensory profiles and hedonic ratings for the same set of products - contain valuable information for product developers, they are not very actionable in isolation. However, once combined, this information becomes really powerful. If product developers gain insight into how the sensory perception relates to the appreciation of the products, they can try to apply this information to improve the products (Moskowitz and Sidel, 1971 Moskowitz et al, 1977). More particularly, if one can tell product developers which sensory characteristics (and at which intensity) are influencing consumers appreciation, or why some products are more liked than others in terms of sensory attributes, R D can start to create new potentially successful products (product development), or improve existing products (product optimization). 

They have a huge influence on car design, because they are not only responsible for the sensory and hedonic aspects, but also for the safety of the car. Therefore, their judgements are decisive. These experts use their own words to define the sensations, with their own test procedures, and score their perceptions according to a scale that has been developed inside the company for that specific purpose. Sensory scientists have to take into account their expertise and skills. 

Children have a different approach to products from adults. Even teenagers have a different perception of product quaUty from their parents (Bech-Larsen and Jensen, 2011). Children s basic sensory perceptions are likely to differ from those of adults (Ganchrow and Mennella, 2003 Nicklaus et al 2005), which results in different perceptions of food products and, ultimately, in different hedonic evaluations and different optimal product formulation (Hough et ai, 1997). Diminished sensitivity may be specifically true for boys when simple food stimuli are concerned (James et al., 1997), but not in more complex matrices (James et al, 1999). 

It has been shown quite clearly that children s sensory preferences may differ from those of adults (e.g., Zandstra and de Graaf, 1998), and that growing from childhood into adulthood may alter preferences, in particular for sweet tastes (Desor and Beauchamp, 1987). Children s sensory perceptions may also differ from those of adults, especially when intensity scaling is used (Zandstra and de Graaf, 1998), and to a lesser extent when pair comparisons are used (MenneUa et al., 2003). However, the extent of differences in terms of perceptions between children and adults, or between children from various age groups, is often inferred from hedonic judgements, making a true comparison of children s and adults sensory abilities difficult. One cannot rule out the possibility that children differ more from adults in terms of affective responses than of perceptual abilities. 

The aroma of fmit, the taste of candy, and the texture of bread are examples of flavor perception. In each case, physical and chemical stmctures ia these foods stimulate receptors ia the nose and mouth. Impulses from these receptors are then processed iato perceptions of flavor by the brain. Attention, emotion, memory, cognition, and other brain functions combine with these perceptions to cause behavior, eg, a sense of pleasure, a memory, an idea, a fantasy, a purchase. These are psychological processes and as such have all the complexities of the human mind. Flavor characterization attempts to define what causes flavor and to determine if human response to flavor can be predicted. The ways ia which simple flavor active substances, flavorants, produce perceptions are described both ia terms of the physiology, ie, transduction, and psychophysics, ie, dose-response relationships, of flavor (1,2). Progress has been made ia understanding how perceptions of simple flavorants are processed iato hedonic behavior, ie, degree of liking, or concept formation, eg, crispy or umami (savory) (3,4). However, it is unclear how complex mixtures of flavorants are perceived or what behavior they cause. Flavor characterization involves the chemical measurement of iadividual flavorants and the use of sensory tests to determine their impact on behavior. 

CATA questions have been recently introduced to sensory and consumer science to obtain information about consumers perception of products (Adams et al., 2007). Although the method has been previously used with trained assessors (Campo et al., 2010 Le Fur et al., 2003 McCloskey et al., 1996), its popularity has markedly increased for product sensory characterization with consumers (Varela and Ares, 2012). In this approach, consumers are presented with a set of products and a CATA question to characterize them. Consumers are asked to try the products and to answer the CATA question by selecting all the terms that they consider appropriate to describe each of the samples, without any constraint on the number of attributes that can be selected. The list of words or phrases in the CATA question usually include exclusively sensory characteristics of the product (Fig. 11.1a) but can also include hedonic terms, as well as terms related to non-sensory characteristics, such as usage occasions, product positioning and emotions (Fig. 11.1b) (Ares and Jaeger, 2013 Parente et al., 2011 Piqueras-Fiszman and Jaeger, 2014 Plaehn, 2012). 

When it is necessary to know the spontaneous reasoning behind consumers (or untrained panels ) perceptions of the sensory, hedonic and/or emotional differences or similarities between products. In this case, the researcher would not only want to measure how the participants perceive the products, but also to collect the genuine reasons for these perceptual differences, which will differ from one person to another. 

Consumers are consistent from a sensory point of view if they rate their ideal product with similar sensory characteristics to the product they like most. The evaluation of sensory consistency (at the panel level) is done by evaluating whether the ideal information provided is making the link between the perception and the appreciation of the products. Such evaluation is done by double projection as supplementary of the sensory profiles (supplementary entities) and the hedonic scores (supplementary variables) within the ideal space (Fig. 14.3). 

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