# Aromachology Related to Foods, Scientific Lines of Evidence: A Review
## 3 Results and Discussion
### Revision of Scientific Literature
Mechanisms explaining the appetite for congruent foods have not been elucidated; a theory has been proposed that cephalic phase responses mediated by the vagal nerve that prepare the body for intake and digestion may be involved [36; 40]. It has been reported that the pleasantness of food odours (banana and savoury meat) was reduced during odour exposure, whereas the specific appetite for the congruent food remained unchanged, and hunger/general appetite was unaffected [36], This decreased odour pleasantness may be related to olfactory sensory-specific satiety (SSS), defined by [PERSON] et al. [41] as the decrease in the pleasantness of, or desire to, eat recently consumed foods, relative to uneaten foods, which suggest a lack of appetite for the smelled food; this does not match results obtained by previously cited studies. In this sense, [PERSON] et al. [36; 40] have coined the opposite term: sensory-specific-appetite (SSA), pointing to an enhanced appetite for the congruent food that is possibly explained by the fact that smelling the food anticipates food intake; these authors hypothesise that the extended exposure to the odour stimulates chemical senses and reduces the appeal for the odour but not for the taste, and therefore, different mechanisms would underlie both processed SSS and SSA. It is also hypothesised that the largest changes in food preferences may occur within the first minute to odour exposure; thus, it is of main relevance to study behaviour changes during that first minute. Several authors report that such effect depends on the exposure time to the scent: short times of exposure to sweet scents may enhance appetite for the food, whereas long times decreases the appeal for sweet foods and enhances the appeal for healthy or other choices [26; 36; 41; 42]. This may be caused by cross modal sensory compensation; the scent provides enough reward and reduces the desire for consumption of indulgent foods, such as an olfactory sensory-specific satiety. Another factor to be considered is that the intensity of the scent is either subthreshold or recognisable, as different effects can be reported [20; 43]. Fresh scents are thought to be associated with health care, good hygiene, and cleanliness, rather than being associated with sweets consumption [29; 34]. Most of the published studies only collected and reported craving sensation or appeal, which are not truly food consumption; it needs to be clearly differentiated whether the studies report subjective measurements anticipating food intake (appetite, food choice) or actual food consumption (intake satiety), given that they cannot be directly extrapolated [20]; therefore, more studies are needed in real situations that measure actual consumed food to determine how to use scents to either prevent obesity or ameliorate malnutrition. Reported results have similarities with those reported in non-food stores. Numerous studies have been carried out evaluating the effect of applying scents in non-food store environments [1; 8; 14; 43; 44; 45; 46]. Those studies reported that product sales increased between 14.8% and 15.9%, the time that customers spent in the store also increased by 18.8%, and interest on the purchased products and the request for information also increased [45]. Therefore, scents are used in stores to create a positive shopping environment with the aim of increasing purchase intention or increasing the time spent in the establishment [24]. All these factors are expected to lead to an increase in sales and in the degree of customer satisfaction [6]. Stores that use scents have been reported to give their customers the feeling that they spend less time looking at products and trying them [7; 8; 47]. [PERSON] et al. [47] exhaustively tested 26 individual essences and separated them into the affective dimension and the exciting or activating dimension. They found that the affective dimension explained most of the effects that scent produced in people.