# Aromachology Related to Foods, Scientific Lines of Evidence: A Review
## 3 Results and Discussion  
### Revision of Scientific Literature  
Regarding aromachology focused on food, Table 1 shows the scientific manuscripts (reviews and articles) linked with the topic of this review, their main objectives, and findings. Only 18 studies related to aromachology on food were available, most of them on marketing or consumer studies journals, and most of them published within the last 10 years. Therefore, this a new field of scientific studies, with scarce background on the procedures, methodology, and an absence of standardised procedures, as we will discuss below. _What were the main aims of such studies?_ Some published studies reported results from more than one experiment. If we focus on real experiments, a total of 30 were reported. Twelve of the experiments explored food preferences or choices [26; 28; 30; 32; 33; 36]; seven evaluated appetite modulation/effect [27; 34; 35; 36]; three evaluated food sales ([24; 26]; five evaluated odour-emotion mechanisms [26; 28; 29; 31], and one the shopping experience (Table 1). The interest in aromachology comes from different fields, aroma marketing is probably the main field; however, scents as factors affecting appetite are an especially interesting field given that it can be useful to prevent obesity epidemics [26]. _What were the methodologies used in the studies?_ Table 1 shows the main characteristics of the methodologies used in the reviewed studies: number of participants, characteristics of participants, food/non-food used, and type of collected data. 'Non food' means that pictures and slides were used to present food. Uneven details on participants have been provided in different studies; as an example, the number of participants is not given in several studies (unknown), mainly in studies performed in real conditions, when it is difficult to assess real numbers of customers. The number of participants ranged from 19 [28] to up to 900 [26]. Most available studies have been conducted with university students as participants, whereas just three on real restaurant or store customers [22; 26; 35; 38]. Among the experiments reported in the selected papers, only eight were conducted in which real foods were present, i.e., real food choices could be made. In the others, only the scents or some pictures were used to recall the idea of food. Both types of studies are probably useful given that there are two types of scenarios: stores and gastronomic facilities. In some of the experiments, more than one type of data was collected (Table 1). Seventeen experiments collected subjective assessments in questionnaires. Nine of the experiments measured objective real behaviour: time measurement in five studies [22; 23; 25], sales in three studies [24; 26], and food consumption in one study [27]). Finally, five studies measured objective physiological data: salivation in three experiments [27] and neuroimaging in two [28]. As previously commented, most studies relied on students as participants, and although valuable information was obtained from students, it is not clear to which extent a more complex population (diversity of ages, educational level, income level, etc.) will perceive or react to the tested scents in the same way, and therefore, if the results may be translated to market conditions. There are no standardised procedures to set target populations of consumer groups to conduct scent marketing studies, and some studieshave been carried out only in women, mainly those regarding effects on appetite and food choices [23; 35; 36]. It is important to highlight that one of the aspects related to the aroma of an establishment is the number of people in it at any given time. In this, some studies in real conditions included air quality assessment [24] which is somehow related to the influx of visitors, among other factors; however, store influx has not been taken into consideration in the reviewed studies, where only three had been performed in real conditions [24; 25; 26]. In future studies in real conditions, air quality assessment should be considered.