Introduction

Practical cooking skills accompanied by knowledge about food preparation have been described as food literacy (Truman et al., 2017). These competencies are formally taught in educational institutions like culinary vocational schools. The goal of culinary vocational schools is to help students develop a set of skills relevant to food preparation and prepare them to undertake the role of a chef. The knowledge and skills which culinary students gain are related for instance to technical processes and procedures, customer service, and understanding of the occupational environment (Heusdens et al., 2018). To determine whether students have gained the knowledge and skills required to become a chef, students undertake vocational exams during and at the end of their course. Sociodemographic characteristics are among other factors likely to predict students’ educational and academic achievements (Azhar et al., 2014; Rodríguez-Hernández et al., 2020). In the specific context of vocational education, Cerda-Navarro et al. (2019) found parental education, financial situation, and students’ previous educational experiences predict academic engagement and may lead to greater achievement (Lei et al., 2018). These sociodemographic factors predict students’ performance in vocational education in various vocational programs (Cerda-Navarro et al., 2019).

Olfactory ability may also play a role in the successful completion of culinary vocational education. However, this has not been investigated. Available data demonstrated clearly that olfaction plays a critical role in food perception (Croy et al., 2014; Demattè et al., 2014; Groyecka et al., 2018) and shapes dietary habits (Gopinath et al., 2016; Stevenson et al., 2020). The link between smell and professional functioning has also been demonstrated in sommeliers who show greater odor identification skills than amateurs (Mariño-Sanchez et al., 2010). Additionally, sommelier training has been found to increase olfactory sensitivity (Tempere et al., 2012) and improve the ability to discriminate between odors (Wang et al., 2021). To date, it has not been established if olfaction ability is also relevant in culinary vocational education. Therefore, in the current study we aimed to explore whether olfactory ability may predict scores on the theoretical and/or practical parts of a culinary vocational exam. Additionally, we aimed to investigate whether olfactory ability may predict scores in the culinary vocational exam beyond what is explained by sociodemographic factors.

Culinary Vocational Exam

Students in culinary vocational schools undergo training in order to gain skills required for a career as a chef. Their competencies cover multiple facets of the cooking process including knowledge about culinary procedures and food products, abilities to prepare dishes according to a recipe as well as serving the product in a way that will be enjoyable for a consumer. Mastering these abilities is essential to gain advanced competencies like creating new recipes and introducing new culinary concepts (Peng et al., 2013). Such complex processes of food preparation and serving as well as proposing new culinary ideas require a combination of professional knowledge and practical skills that are interchangeably used (Heusdens et al., 2019; Suhairom et al., 2019).

Both these aspects – culinary knowledge and practical cooking and serving skills – are tested during culinary vocational exams. The theoretical part of such exams tests knowledge regarding different culinary procedures, food nutritional values, or knowledge about food and spice combinations forming appealing recipes. The dominant cognitive processes required for effective performance during the theoretical exam are semantic and episodic memory. These types of memory store relevant information about relationships between different concepts (semantic memory) or memory of specific events (episodic memory) (Menon et al., 2002). For example, culinary vocational students may retrieve information on cooking procedures from the semantic memory system. Additionally, semantic knowledge may be supported by episodic memories of specific events. For example, when students prepare some of the trained recipes or execute the procedure under supervision.

The practical part of the vocational exam relates to applying knowledge in a specific setting (Heusdens et al., 2019). Thus, the semantic aspect of culinary knowledge tested in the theoretical exam is still necessary for successful performance but must be accompanied by procedural cooking and serving skills. These competences are based on perceptual-motor skills, behavioral habits and established sequences of actions (Heusdens et al., 2019; Suhairom et al., 2019). As such, the practical part of the culinary vocational exam verifies students’ abilities in a real-life scenario, making the testing procedure similar to the role of a chef.

Sociodemographic Factors Shaping Educational Achievements

Educational achievements are at least partially dependent on social and demographic factors. This effect has been systematically demonstrated across students of different ages and in different populations. The findings consistently report that children of higher-educated parents score higher in measures of educational achievements as compared with children of lower-educated parents (Azhar et al., 2014; Idris et al., 2020; Sirin, 2005; Spera et al., 2009; Su et al., 2015; Zabel & Kopf, 2018). There are two main explanations of this effect. First, higher-educated parents have either more competences or resources to support their children during education. The second is that higher-educated parents are more aware of the importance of their children’s education for their future social position and motivate their children to pursue academic achievements. The second explanation is less likely given previous research showing parents have equally-high educational aspirations for their children, regarding of their own educational attainment (Spera et al., 2009). Moreover, research on educational achievements indicated that the educational background of both parents should be considered as omitting one of them increases estimation bias (Korupp et al., 2002).

Another factor related to parental educational attainment is the financial status of the familial household. Congruent with the idea that parents with higher education might have more resources to help their children pursue educational achievements, households with higher incomes offer more opportunities to support children which in turn leads to greater educational achievements (Duncan et al., 2010, 2011; Siegler et al., 2012). A similar relationship is observed when financial situation of a household is rated subjectively, for example, children who perceive their social situation as unfavorable and report more concerns about their financial status have lower educational achievements (Mistry & Elenbaas, 2021).

Although the abovementioned studies focused on the impact of sociodemographic factors on educational achievements in general education, there are also reports showing a similar pattern in vocational education. For example, research with Spanish vocational students found parental education, students’ educational background, and perceived financial situation predicted a students’ engagement and risk of dropping out from the vocational program (Cerda-Navarro et al., 2019; Cerdà-Navarro et al., 2022) that corroborates findings from the general population of non-vocational students (Duncan et al., 2010; Spera et al., 2009). In the current study, we measured parental and students educational background as well as perceived financial situation to investigate how these variables may predict performance on the practical and theoretical parts of culinary vocational exams.

Significance of Olfaction in Food Preparation

The major functions of the sense of smell are to regulate food intake behavior and avoid environmental hazards (Stevenson, 2010) and both these functions affect food preparation. The smell of food may serve as a cue to product’s freshness as odors present in spoiled food will elicit a disgust response and inhibit ingestion (Stevenson, 2010). Food odors might also serve as indicators of a product’s nutritional value, which has been demonstrated in studies where odors of energy-dense food activated intense physiological (salivation) and behavioral (food intake) responses (Proserpio et al., 2017, 2019).

The contribution of olfaction to food-related behavior might be also understood from the perspective of people with olfactory dysfunction (Croy et al., 2012). For example, people with olfactory loss report increased prevalence of ingesting spoiled food and overall problems with cooking when being unable to perceive food odors (Croy et al., 2014). Additionally, olfactory disorders alter dietary choices (Seo & Hummel, 2009) and may lead to higher intake of sweet and fat products and lower preference for nutritious food (Rolls, 1999; cf. Stevenson et al., 2020). Changes in the diet composition caused by olfactory disorders may elevate the risk of nutritional deficiencies (Gunzer, 2017).

The interplay between olfactory sensitivity and cooking might be dynamic in nature as repeated daily exposures to odors enhance individual’s olfactory functioning (Pieniak et al., 2022; Sorokowska et al., 2017). For example, professionals working in odorous environments (i.e., perfume shop) better discriminate odors than their counterparts working in non-odorous environments (Hummel et al., 2004). Sommelier training has been reported to impact different dimensions of olfactory performance, specifically; increased odor identification ability (Mariño-Sanchez et al., 2010; Poupon et al., 2019), lowered olfactory detection threshold (Tempere et al., 2012), and improved ability to discriminate odors (Wang et al., 2021). Importantly, changes induced by sommelier training are not only observed on the behavioral level but are also reflected in the brain structure, evidenced by an increased olfactory bulb volume and altered cortical thickness of different brain regions (Filiz et al., 2022). The impact of working in an odorous environment on brain functions has been additionally demonstrated for perfumers. A functional magnetic resonance imaging study demonstrated that activation of olfactory brain regions (i.e., piriform cortex, hippocampus, orbitofrontal cortex) during smells imagery was correlated with professional experience of perfumers (Plailly et al., 2012) suggesting that professional training might lead to functional brain reorganization. Taken together, these findings suggest high plasticity of the olfactory system and its responsiveness to environmental odors, highlighting the possibility of observing increased olfactory abilities in students of culinary vocational schools.

Culinary knowledge and cooking skills of culinary vocational students may be related to different olfactory abilities. For example, higher olfactory sensitivity could allow for perceiving spoiled food products and therefore not including them in recipes. One’s olfactory sensitivity may impact perceived odor intensity and shape the selection and amount of spice used in a recipe. As odor identification is related to semantic knowledge (Hedner et al., 2010), it may help with designing new recipes based on information acquired during vocational training.

Besides objective olfactory ability, the relative importance of olfaction to individuals is also likely to play an important role in shaping culinary behaviors and interests. People vary in the degree to which they rely on odorous cues while making cooking decisions or food-related choices and the relative importance of olfaction to individuals reflects the extent to which odors in the environment affect one’s cognition, emotion and behavior (Croy et al., 2010). Thus, the extent to which odors influence one’s memories and behavior could be one of the factors predicting culinary students’ performance. For example, those who believe olfactory ability is very important to them may demonstrated elevated learning abilities of smell-related knowledge (e.g., food recipes) and greater dependence on smell cues in food-related choices (e.g., choosing specific products while cooking).

Current Research

The aim of the current study was to investigate which factors may predict scores in both practical and theoretical parts of a culinary vocational exam. The current study included sociodemographic variables that have been shown to be relevant for vocational students’ engagement into studies – parental education level, previous educational attainment, and perceived financial situation of the household (Cerda-Navarro et al., 2019). Additionally, we measured students’ olfactory ability which might be a domain-specific predictor of scores of culinary students. It was hypothesized that sociodemographic factors will partially explain the relationship between both practical and theoretical parts of the culinary vocational exam. Additionally, we predicted that olfactory abilities and the individual importance of olfaction would predict exam performance beyond that explained by the sociodemographic factors.

The influence of olfaction ability on culinary performance may highlight the role of human chemosensory perception in vocational education. If olfactory perception was relevant for culinary practice, it would be worth including odor-related subjects into culinary schools curricula. This would enable students to consciously use their olfactory abilities in their professional work. Additionally, exploring the sociodemographic predictors of the culinary exam results may allow the early identification of students who may need additional educational support.

Materials and Methods

Ethical Approval

The investigation was conducted in accordance with the Declaration of Helsinki on Biomedical Studies Involving Human Subjects. All participants provided informed, written consent.

Participants

Sixty-four culinary school students (6 females) participated in the study. The participants’ age ranged from 16 to 40 years (M = 20.1 ± 4.06 years). Of 64 participants, 60 were German and 4 were of different nationality (Bulgarian, Russian, Nepali, Urdu). All participants were fluent German speakers. The participants were students at the vocational school center for hospitality industry in Germany. The culinary training program lasts three years and has an intermediate vocational examination during the second year of the training. The study sample included second-year students who had already passed the intermediate vocational examination. According to the vocational training statistics, sixty-four culinary school students equaled 18% of all apprentices at the second year of training as chefs in the state of Saxony. Female culinary school students were under-represented – the proportion of female apprentices varied from 28 to 30% (STLA, 2017) in the state of Saxony, whereas female participants constituted 9% of the study sample.

Materials

Olfactory functions were measured using the “Sniffin’ Sticks” test battery (Hummel et al., 1997). The battery consists of 3 subtests: odor threshold, odor discrimination, and odor identification. It is widely used in the assessment of sensory functioning in otorhinolaryngological practice (Hummel et al., 2017). Odors are delivered in felt-tip pens filled with odorants.

Olfactory sensitivity was measured with the olfactory threshold task. In this task participants are presented with three pens – one pen containing target odorant (phenyl ethyl alcohol – a rose odor), two containing odorless solvent (propylene glycol) – and are asked to indicate the pen with the odorant. The target odor is prepared in sixteen dilutions – the highest concentration is 4% which is further diluted in 1:2 ratio in propylene glycol until 16 dilutions are obtained. The procedure starts with the lowest concentration. If participants fails to recognize the target odorant from the odorless pens, a higher concentration of the odorant is presented. This continues until participants recognize the target odorant twice in a row for the same concentration level. After two correct recognitions the presentation reverses and participants are again presented with lower concentrations until they make the first mistake. This procedure called reversed-staircase method is repeated until seven reversal-points are obtained. The olfactory threshold is indicated as the mean of the last four reversal points. The possible score ranges from 1 to 16 points where higher score indicates lower olfactory threshold (i.e., greater sensitivity of the sense of smell).

The odor discrimination task of the “Sniffin’ Sticks” battery employs sixteen pen triplets – two pens with the same odorant, one pen with a different odorant. The participants’ task is to determine which pen contains an odorant different from the other two. The sum of all correct answers is the results of this subtest. The participants can score from 0 to 16 points with higher score indicating greater odor discrimination abilities.

In the odor identification task participants are presented with an odor and are supposed to identify it. Participants are aided with four possible visual and verbal descriptors – one correct, three false. Identification subtest includes common odors that are familiar for German population (e.g., orange, cloves, leather, rose). The test consists of 16 odors and the number of correctly identified odors is the result of this subtest. The possible score ranges from 0 to 16 points with higher score indicating greater odor identification abilities.

The sum of points obtained in Threshold, Discrimination, and Identification subtests is called a ‘TDI’ score and it ranges from 1 to 48 points.

The individual importance of olfaction was measured with the ‘Individual Significance of Olfaction Questionnaire’ (ISOQ) (Croy et al., 2010). The scale consists of 18 items which are categorized into three subscales. The ‘Association’ subscale reflects emotions and memories triggered by odors (e.g. ‘Certain smells immediately activate numerous memories.’), the ‘Application’ subscale indicates the degree to which a person uses their sense of smell on a daily basis (e.g. ‘When I buy tomatoes, I pay attention to their odor.’) and the ‘Consequence’ subscale refers to how the odors influence person’s daily decisions and impressions (e.g. ‘I try to locate the odor, when I smell something.’). The participants answer on a 4-point Likert type scale ranging from 1 (‘I totally disagree) to 4 (‘I totally agree’). The possible score in each subscale ranges from 1 to 4 (a mean value of all answers provided for a given subscale).

Sociodemographic variables were measured with a questionnaire that participants filled in individually. Participants were asked to choose their educational background (‘What is the highest school degree that you have obtained?’ with possible answers being (1) elementary school, (2) lower secondary school, (3) secondary school, or (4) vocational high school). They also provided information on their parents’ educational history (‘What is the highest school degree that your mother/father has obtained?’ with possible answers being (1) elementary school, (2) lower secondary school), (3) vocational high school, (4) high school, or (5) university degree). Additionally, participants rated their subjective financial situation on an scale ranging from 1 (‘I always need to be careful about my expenses’) to 3 (‘I usually have enough money’). The question about financial situation has been adopted from another study focusing on vocational school students (Cerda-Navarro et al., 2019).

The intermediate vocational exam is a compulsory stage of culinary education and consists of a theoretical and a practical part. Each part is scored separately, and the possible scores range from 0 to 100 points which are further transformed into grades ranging from 1 to 6 (which are not analyzed in the current study). In the statistical analyses we used the raw scores obtained in each part of the exam where higher scores mean better performance.

In the theoretical part of the exam (theoretical exam), the participants’ knowledge of food preparation procedures and recipes is examined. Fifity points can be received for answering questions related to the curriculum of the teaching program. Up to 20 points are awarded for preparing the participants’ own recipe where the correct structure of the recipe and usage of appropriate ingredients is evaluated. The final 30 points are awarded for detailed instruction on the recipe preparation. The participants’ task is to describe a step-by-step procedure of preparing the recipe and the quality of the instruction (logical flow of commands, attention to detail) is assessed.

In the practical part of the exam (practical exam), the participants are asked to prepare and serve a requested dish. Different aspects of the students’ performance are evaluated including preparation of the work station and cleanliness (5 points each), methods and use of appropriate materials (30 points), the appearance of the dish and its taste (30 points), table covering, orientation towards guest, and professional presentation (10 points each). The examination committee awards points based on the participants’ written answers (theoretical part) and performance (practical part) in a consensus-based manner. The committee included the same examiners for all of the study participants.

Procedure

Participants were tested individually in standardized conditions, in the well-ventilated classroom that the culinary school provisioned for the purpose of this study. After providing written informed consent, participants filled in the ‘Individual Significance of Olfaction Questionnaire’, answered sociodemographic questions and declared their scores in theoretical and practical parts of the exam. Consequently, olfactory functions were measured with the ‘Sniffin’ Sticks’ test. The entire procedure lasted around 50 min per participant.

Statistical Approach

All the statistical analyses were performed with jamovi 2.3.18 software (The jamovi project, Sydney, Australia) for Windows™. Descriptive statistics are presented for all variables. Additionally, we ran a series of Spearman’s correlations to investigate if the variables included in the subsequent analyses are not too highly correlated to avoid multicollinearity. Spearman’s correlation were used instead of Pearson’s because some variables were measured on an ordinal scale. We assumed multicollinearity assumption to be violated with correlation between predictors being at least r = .80 as suggested by Field (2013).

To test whether olfactory functions, individual significance of olfaction or sociodemographic variables may predict the results of vocational exam in the culinary school we used hierarchical regression models. We ran two analogous models. In the first tested model the depended variable were scores from the practical exam. The second model concerned scores from the theoretical exam. In both models we entered the independent variables (sociodemographic factors, olfactory ability, importance of olfaction) in two steps. In the first step we introduced the all sociodemographic variables that has been previously shown to be related to school performance (educational background of the student and parents, perceived financial situation). In the second step we entered the measures of olfactory ability (Threshold, Discrimination, Identification) and scores in the ISOQ questionnaire, separately for each subscale (Association, Application, Consequence). Although the sociodemographic variables were measured on an ordinal scale, we treated them in the analyses as continuous variables. Such analytical decision was also motivated by recommendations by Pasta (2009) and Moses et al. (1984) who demonstrated that such approach does not lead to significantly increased inferential bias and by the lack of widely used non-parametric equivalent of hierarchical regression (unlike it is with Pearson’s and Spearman’s correlation analyses).

Results

Descriptive Statistics

The descriptive statistics are presented in Table 1. On average, participants received more than 50% of the possible points in both practical and theoretical parts of the exam. Scores obtained in Sniffin’ Sticks battery (Threshold M = 8.63, Discrimination M = 12.51, Identification M = 13.31) show that most participants had an intact olfactory ability as group average scores are similar to scores of the general population (differences between sample scores and normative data are lower than 1 point in each test (Oleszkiewicz et al., 2019b). However, the minimum values of Sniffin’ Sticks subtests suggest that some of the participants were exhibiting decreased olfactory functions (hyposmia).

Table 1 Descriptive statistics of the tested variables
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Spearman’s Correlations

Spearman’s correlation coefficients are presented in Table 2. The analyses revealed positive moderate correlation between participants’ educational background and scores in the theoretical exam (r = .40, p = .014). Participants’ educational background was negatively correlated with their olfactory threshold score (r=-.30, p = .024). The distribution of scores in the theoretical exam and in the olfactory threshold task across participants with different educational background is presented in Fig. 1.

Table 2 Spearman’s correlations (r) for the relationships between dependent variables and tested predictors
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Fig. 1
figure 1

Boxplots presenting statistically significant relationships between participants’ educational background, exam scores in the theoretical part, and olfactory threshold

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Additionally, a positive correlation has been found between the mother’s and father’s educational backgrounds (r = .34, p = .033). In the olfactory domain, we found a positive correlation between odor discrimination ability and the declared tendency to have one’s actions and decisions influenced by odors (ISOQ Consequence scale; r = .32, p = .013). Additionally, three subscales of ISOQ questionnaire were also positively correlated (r ranging between 0.38 and 0.56; all p values ≤ 0.002). As none of the correlations was greater than r = .80, according to Field’s (2013) guidelines, the collinearity assumption required for the linear regression analyses was not violated. The scatterplots of all aforementioned significant correlations are presented in Fig. 2.

Fig. 2
figure 2

Scatterplots presenting Spearman’s correlations between parental educational background, odor discrimination ability, and scores obtained in Individuals Significance of Olfaction Questionnaire subscales. Regression lines are presented with statistical error bands

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Hierarchical Regressions

The first hierarchical regression model concerned scores obtained in the practical exam. None of the sociodemographic predictors entered in the first step was statistically significant. The adjusted R2 value suggested that the model could not explain any of part of the variance in the scores in the practical part of the vocational exam and the model did not fit the data, F(4, 16) = 0.41, p = .80. In the second step we entered into the model all the predictors related to olfactory functions and the individual significance of olfaction. The amount of variance explained by the model did not change significantly after entering this set of predictors, F(6, 10) = 0.67, p = .68, and the model did not fit the data, F(10, 10) = 0.55, p = .82. Therefore, the current study failed to find determinants of scores of the practical exam in the culinary school. The model summary is presented in Table 3.

Table 3 Summary of hierarchical multiple regressions for practical exam score predicated by sociodemographic variables, olfactory functions, and individual significance of olfaction
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The second model concerned results of the theoretical exam. In the first step, we entered all the sociodemographic predictors. The model fit the data, F(4, 15) = 3.76, p = .026. The educational background of the participants was a significant positive predictor of the score in the theoretical exam (B = 24.01, p = .009; see Fig. 1, panel A). Entering the set of olfactory predictors in the second step did not lead to a significant increase in explained variance, F(6, 9) = 1.72, p = .22. Combining sociodemographic and olfactory predictors, the tested model explained more variance in the scores in the theoretical exam and fit the data on a trend level, F(10, 9) = 2.97, p = .058. In the second step, the participant’s educational background became a non-significant predictor whereas odor discrimination ability and subjective tendency to have one’s emotions and memories triggered by odors (ISOQ Association scale) tended to be positive predictors of the score (p values on trend-level < 0.1). Model summary is presented in Table 4.

Table 4 Summary of hierarchical multiple regressions for theoretical exam score predicated by sociodemographic variables, olfactory functions, and individual significance of olfaction
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Discussion

This study investigated the predictive value of olfactory ability, individual significance of odors, and sociodemographic factors on the vocational exam results in culinary school students. We explored whether performance on the practical or theoretical part of the vocational culinary exam predicted by olfactory abilities (odor detection threshold, odor discrimination, odor identification, subjective significance of olfaction), or demographic factors (parents’ and students’ educational history, household financial situation). Our results indicated that the theoretical exam score was predicted by students’ educational history but not their olfactory ability and other demographic factors. The current study did not identify predictors for the practical exam results.

We found that students who had completed more advanced education previously scored higher in the theoretical exam. It is likely that these high performing students may have had higher aspirations before entering the culinary vocational school, which is a more difficult educational track in the German schooling system. These aspirations could lead to greater engagement in the learning process and/or preparation to the vocational exam. Alternatively, experience in schools with more complex curricula is beneficial for performance in vocational exams as the experience of participating in exams and tests might improve learning (Rowland, 2014).

We found no support for the impact of parents’ education level and perceived financial situation on the vocational exam scores. One of the explanation for this finding may relate to the mechanism through which parents’ education level and financial situation contribute to students’ educational achievements. If these sociodemographic factors lead to greater support of the students during difficult times, the offered support needs to be adequate to the current needs of the students. For example, students facing difficulties learning algebra might ask their educated parents for help or pursue some additional private lessons. In contrast, vocational exams focus on very technical and specific tasks that might be not easily learned from parents or may not available as private lessons.

We also found a trend-level relationship between the theoretical exam scores and subjective feeling of association between memories, emotions and odors (ISOQ Association scale), which may reflect the neural processing of odor stimuli. This could be due to the fact that odors activate neurons in the olfactory epithelium and this activation is further projected to limbic areas (e.g., amygdala and hippocampus) involved in emotional and cognitive processing (Royet & Plailly, 2004). Stronger activation in the hippocampus during learning phases correlates positively with the subsequent strength of the memory trace (Shrager et al., 2008). Hence, memories acquired in the presence of olfactory stimuli might be stronger and easier to retrieve than memories acquired in non-odorous settings (Sorokowska et al., 2022). Memories connected with olfactory cues are also more emotional and vivid than memories recalled by visual or auditory stimuli (Larsson et al., 2014).

This relationship between olfaction and memory might partly explain why individuals who declare that their memories are easily triggered by their sense of smell scored higher in the theoretical part of the vocational exam. Even in the absence of an initial odorous cue, if the information required for the vocational exam is learned in the odorous setting of the culinary school, it may create more established memory traces that are easily accessible during the exam. This result is consistent with findings from studies on autobiographical and episodic memory (Larsson et al., 2014; Sorokowska et al., 2022). Further studies in a laboratory setting are needed to verify whether previous findings on autobiographical memory are also applicable for semantic memory.

Another trend-level effect we found showed that odor discrimination ability was a positive predictor of the theoretical exam. Odor discrimination is, along with odor identification, a higher order olfactory function that is based on semantic knowledge (Hedner et al., 2010). Thus, it relies on the same memory systems as professional culinary knowledge. A positive relationship between these variables may arise from efficient functioning of brain memory circuits that are contributing to both correct odor discrimination ability and effective learning processes, which in turn lead to higher scores in the theoretical exam. Importantly, the relationship of individual significance of olfaction and odor discrimination with the scores in the theoretical exam did not reach the conventional level of statistical significance. Thus, these findings should be verified in further studies employing greater number of participants.

We did not find any significant predictors of the practical exam, likely due to the highly complex nature of the tasks used in this part of the exam. Students must demonstrate that they can use their semantic knowledge in a practical setting and perform a range of different culinary procedures. Thus, the influence of olfactory cues on learning such behavioral procedures may be weaker than its influence on establishing strong semantic memories accessed during the theoretical part of the vocational exam.

There are several limitations to the current study. Multiple factors may influence educational outcomes besides the sociodemographic and olfactory variables we tested in this study, such as a participant’s motivation, self-efficacy, interests, intelligence or creativity, which can impact educational achievements (Dubeau et al., 2017, 2021; Gajda et al., 2017; Kriegbaum et al., 2018). Additionally, in the context of culinary vocational education, there is a unique set of familial factors related to the cross-generational transfer of food-preparation knowledge and techniques. Studies have demonstrated that across cultures, some young adults (especially women) prepare food based on knowledge and skills they obtained from their family members (De Backer, 2013; Engler-Stringer, 2010; Nor et al., 2012). We did not investigate whether and to what extent participants in our study used family-shared knowledge about food preparation during their exam (e.g., while designing their own recipes). To provide a comprehensive overview of the predictors of success in culinary vocational education, sociodemographic and olfactory measures should be employed along the psychological factors and information about family social practices in future research.

Although the most commonly used measure of olfactory ability was employed in the current study, the Sniffin’ sticks is designed to identifying those with broad levels of olfactory function (Hummel et al., 1997), so subtle differences between healthy individuals may not be detected. Additionally, the Sniffin’ Sticks battery includes both food-related and non-food related odors, so it is possible that the sensitivity for or recognition of food related odors was not fully captured, which is important given context. Furthermore, food-related odors may reach the olfactory epithelium via orthonasal (i.e., the nose) or retronasal (i.e., the mouth) routes (Bojanowski & Hummel, 2012). Retronasal olfaction is highly involved in flavor perception (Rozin, 1982) and it is related to well-being of patients with smell loss (Oleszkiewicz, Park et al., 2019a). Thus, the differential role of food-related and non-food-related odors as well as the route of odor administration should be explored further in future studies.

A recent study demonstrated that besides olfactory threshold, discrimination, and identification abilities there is a fourth component of olfactory functions, specifically, ability to sort different concentrations of the same odor (Lötsch et al., 2022). Measuring this ability would shed more light on the relationship between olfactory functions and culinary performance as sorting odor concentrations is ecologically valid within the context of food preparation. For instance, to determine the optimal amount of seasoning and spice added to a dish it might be necessary to differentiate subtle differences in the intensity of an odor. How this specific olfactory ability contributes to food preparation awaits further empirical investigation.

No association was found between culinary vocational exam results and the degree to which a person uses their sense of smell in daily tasks or how their decisions are influenced by odors. However, it requires noting that these two aspect of the importance of olfaction were measured with ISOQ subscales that had rather low internal reliability in our sample (Cronbach’s α < 0.50) so these results should be interpreted cautiously. Despite the low internal reliability of these two subscales, the correlation matrix between three components of ISOQ scale obtained in the presented study is similar to the one reported when this ISOQ was firstly introduced (Croy et al., 2010). The low internal reliability might arise either from potential differences between the culinary vocational students population and the population used for the validation of the questionnaire (general population) or from the low number of participants in our study as Cronbach’s α is affected by sample size (Rouquette & Falissard, 2011). We assume that the second explanation is more likely considering that ISOQ has been successfully employed in different populations (Bentz et al., 2017; Seo et al., 2013).

Conclusions

Taken together, our results showed that performance on the theoretical culinary vocational exam was predicted by students’ educational background. Sociodemographic factors and olfactory ability did not predictor performance on the practical culinary vocational exam. The latter finding is probably related to the more complex nature of the tasks employed in the practical examination.