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Odor perception of aromatherapy essential oils with different chemical types: Influence of gender and two cultural characteristics

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Olfactory perception, and especially affective responses of odors, is highly flexible, but some mechanisms involved in this flexibility remain to be elucidated. This study investigated the odor perceptions of several essential oils used in aromatherapy with emotion regulation functions among college students. The influences of people’s characteristics including gender, hometown region, and fragrance usage habit on odor perception were further discussed. Odor perception of nine essential oils, which can be divided into the ester-alcohol type (e.g., lavender oil) and terpene type (e.g., lemon oil) were evaluated under three odor concentrations. The results indicated that chemical type, but not concentration, significantly influenced the odor perception and there was no interaction between the two factors in this study. The arousal and emotional perception scores of odors with terpene-type oil were significantly higher than odors with ester-alcohol type. In terms of people’s characteristics, participants from the southern Yangtze river gave a higher familiarity rating to almost all of these odors. The habits of fragrance usage also significantly influenced some of the odors’ subjective intensity and emotional perception ratings. However, there were no significant gender differences in most of the odor perceptions. In addition, familiarity and pleasantness were positively correlated, and emotional perception and subjective intensity also showed a weak correlation. These results suggested that users’ cultural characteristics could be considered to be important factors that affect the essential oil’s odor perception in aromatherapy.
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Frontiers in Psychology 01 frontiersin.org
Odor perception of
aromatherapy essential oils with
dierent chemical types:
Influence of gender and two
cultural characteristics
Jie Chen
1,2, Nan Zhang
1,2*, Shichun Pei
1,2 and Lei Yao
1,2*
1 School of Design, Shanghai Jiao Tong University, Shanghai, China, 2 Aromatic Plant R&D Center,
Shanghai Jiao Tong University, Shanghai, China
Olfactory perception, and especially aective responses of odors, is highly
flexible, but some mechanisms involved in this flexibility remain to beelucidated.
This study investigated the odor perceptions of several essential oils used in
aromatherapy with emotion regulation functions among college students. The
influences of people’s characteristics including gender, hometown region,
and fragrance usage habit on odor perception were further discussed. Odor
perception of nine essential oils, which can bedivided into the ester-alcohol
type (e.g., lavender oil) and terpene type (e.g., lemon oil) were evaluated
under three odor concentrations. The results indicated that chemical type,
but not concentration, significantly influenced the odor perception and there
was no interaction between the two factors in this study. The arousal and
emotional perception scores of odors with terpene-type oil were significantly
higher than odors with ester-alcohol type. In terms of people’s characteristics,
participants from the southern Yangtze river gave a higher familiarity rating
to almost all of these odors. The habits of fragrance usage also significantly
influenced some of the odors’ subjective intensity and emotional perception
ratings. However, there were no significant gender dierences in most of the
odor perceptions. In addition, familiarity and pleasantness were positively
correlated, and emotional perception and subjective intensity also showed a
weak correlation. These results suggested that users’ cultural characteristics
could beconsidered to beimportant factors that aect the essential oil’s odor
perception in aromatherapy.
KEYWORDS
odor perception, aective responses, aromatherapy essential oils, characteristics,
region, fragrance usage habits
Introduction
Olfactory perception is known to behighly exible and is related to the age, gender,
cultural background of the perceiver, the environment in which the odor is perceived or
the characteristics of the odorant itself like its chemical composition or its concentration.
e olfactory (Delplanque etal., 2008) environments inuence people’s emotions and the
TYPE Original Research
PUBLISHED 10 November 2022
DOI 10.3389/fpsyg.2022.998612
OPEN ACCESS
EDITED BY
Per Møller,
University of Copenhagen,
Denmark
REVIEWED BY
Monique A. Smeets,
Utrecht University,
Netherlands
Ilja Croijmans,
Radboud University,
Netherlands
Paul Alan Arkin Alvarado Garcia,
Cesar Vallejo University, Peru
*CORRESPONDENCE
Nan Zhang
fxzwzhangnan@sjtu.edu.cn
Lei Yao
yaolei@sjtu.edu.cn
SPECIALTY SECTION
This article was submitted
to Emotion Science,
a section of the journal
Frontiers in Psychology
RECEIVED 20 July 2022
ACCEPTED 25 October 2022
PUBLISHED 10 November 2022
CITATION
Chen J, Zhang N, Pei S and Yao L (2022)
Odor perception of aromatherapy essential
oils with dierent chemical types: Influence
of gender and two cultural characteristics.
Front. Psychol. 13:998612.
doi: 10.3389/fpsyg.2022.998612
COPYRIGHT
© 2022 Chen, Zhang, Pei and Yao. This is
an open-access article distributed under
the terms of the Creative Commons
Attribution License (CC BY). The use,
distribution or reproduction in other
forums is permitted, provided the original
author(s) and the copyright owner(s) are
credited and that the original publication in
this journal is cited, in accordance with
accepted academic practice. No use,
distribution or reproduction is permitted
which does not comply with these terms.
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 02 frontiersin.org
connection between olfaction and emotion is particularly close.
In the olfactory process, odor molecules enter the nasal cavity and
attach to the cilia of olfactory receptors in the olfactory epithelium
(Mackay-Sim etal., 2006). en the guanine nucleotide-binding
protein (G-protein) coupled receptors are activated and electrical
signals are generated. Electrical signals are then transmitted to the
brain via the olfactory bulb and higher olfactory cortex by
olfactory sensory neurons (Sell, 2006; Angelucci etal., 2014).
ese electrical signals further aect the limbic system, which is
closely related to emotion regulation (Laurent and Gilles, 2002).
erefore, essential oils, perfumes and incenses have been used
for self-adornment, and modication of the living environment
since ancient times.
In recent years, essential oils have been increasingly used to
improve people’s olfactory environment for their naturalness and
possible ecacy in improving mood. A study of older adults
found that aer inhaling drops of 1.5% lavender oils for 30 nights,
statistically signicant improvement occurred in the scores of
depression, anxiety, and stress-scale (Ebrahimi et al., 2021).
Inhalation of bergamot oil was also found to reduce the salivary
alpha-amylase level and scores on the state–trait anxiety
inventory (Watanabe et al., 2015). However, aromachology
research has found that odor subjective perception was relevant
to the possible impact of odor (Herz, 2009). For example, the
degree of odor pleasantness would aect the emotional changes
of the subjects (Villemure et al., 2003; Burnett etal., 2004).
Essential oils are composed of various volatile chemical
components, which are mainly classied as terpenes, esters,
alcohols, etc. e constituent dierences lead to the aroma type
dierences. Meanwhile, due to individual dierences, people have
dierent perceptions of odors, which may inuence the potential
eects of those functional odors.
Many factors can aect odor sensory evaluation. In terms of
the odor itself, both type and concentration are important. Odor
classication relies mainly on the classication of objects as
odorant sources (Dubois, 2000), such as oral odor, fruit odor,
peppermint odor, etc. Ba etal. (Ba and Kang, 2019) found that the
mean scores of olfactory comfort and odor familiarity for food
odors were higher than those for plant odors, and both elevated
with increased concentration. However, the scores of the
subjective intensity of dierent odors at three concentrations did
not dier signicantly in this study. Odors can also beclassied
according to their chemical composition. As weall know, most of
the odors in the environment are made up of various monomeric
compounds, with terpenes, esters, and alcohols being the main
categories. Of the ten most common single compounds in oral
odor identied so far, ve are terpenes (limonene, etc.), three are
alcohols (linalool, etc.), and one is an ester (methyl salicylate;
Knudsen et al., 2006). e terpene-type odors and the ester-
alcohol type odors also play an important role in food odors,
which seem to comprise a category of particular importance to
humans. A study on the odorant hedonic value of 23 monomeric
compounds found that isoamyl acetate and geraniol had higher
pleasantness and familiarity scores than limonene, while limonene
had a relatively low score of subjective intensity among all
compounds (Chalencon etal., 2022).
e odor information like verbal labels also inuences people’s
judgment of odors (Sorokowska etal., 2015a), negative labels had
no eect on intensity ratings but would aect the subject’s
preference for the odors (Zellner etal., 2014). Some studies have
conrmed the existence of the halo eect of natural ingredient
claims (Apaolaza etal., 2014). In addition, the pleasantness ratings
of odors were found to bemodulated by the knowledge of their
identity due to prior experience and this relationship might
be more evident in unpleasant odors (Martinec Novakova
etal., 2015).
In terms of individual dierences, biological makeup, personal
experience, and the environment have also been shown to
inuence odor sensory evaluation (Majid etal., 2017). ere is
tremendous variation within and between populations in olfactory
receptor genes. Some specic genes may belinked to the olfactory
ability associated with particular odors (Li et al., 2022). In
addition, gender is an important determinant of the ability to
identify odors (Bontempi et al., 2021). Women are oen
considered to have better olfactory abilities than men (Larsson
etal., 2003; Greenberg etal., 2013) and they are generally more
attentive to odors (Ferdenzi etal., 2008). However, it has also been
suggested that the superiority of women in odor detection ability
may beonly for specic odors. For example, riel etal. found
only the odor thresholds of trimethylamine were signicantly
aected by gender, while all other odor thresholds were not
aected (Van riel etal., 2008). Some studies have even shown
that men are better at detecting specic odors (Olsson and Laska,
2010). Personal experiences such as age, mere exposure to odors
(Schriever et al., 2014), etc. were also associated with odor
identication abilities. Most studies show that human olfactory
function peaks in adulthood and declines with age (Sorokowska
etal., 2015b). It was discovered that seniors had the same ability
to identify unpleasant odors, whereas the identication of pleasant
odors was decreased among seniors when compared to young
adults (Joussain etal., 2013). In addition to the factors mentioned
above, there appear to bevariances in odor perception among
people in dierent environments, as environmental dierences
bring with them a range of dierences in climate, vegetation
conditions, dietary habits, and culture. Factors such as ethnic
background (Ayabe-Kanamura etal., 1998; Sorokowska et al.,
2015c) were also associated with odor identication abilities. But
ethnicity did not seem to inuence the evaluation of odor intensity
or the distribution of mood responses. A study comparing the
ability of subjects from Japan and the Netherlands to detect
m-xylene odors reported a 10-fold dierence in chemical
identication between the groups (Hoshika etal., 1993). Jin etal.
found that Caucasian participants preferred cinnamaldehyde
more than East Asian participants (Jin etal., 2018). At present, the
research objects of related research mainly focus on food odor or
monomeric compound odor, and there is relatively little research
on the sensory evaluation of functional odor combined with
chemical types.
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 03 frontiersin.org
erefore, the aims of this study were: (1) to understand the
aective responses of essential oil odors with healthy function at
dierent concentrations, (2) to understand the inuence of
participants’ characteristics on odor sensory evaluation, and (3)
to understand the correlation between the odor evaluation
indexes. According to the chemical constituent and function, six
essential oil odors which were commonly used in the mainstream
aromatherapy market for anxiolytic or antidepressant treatment
and their compound odors were used in this study, and young
healthy adults with dierent gender, regional culture, and living
habits were selected to evaluate the odor subjective indexes.
Materials and methods
Participants
A priori power analysis was selected from the F test family in
G*Power 3.1.7 soware (Heinrich Heine, Universität Düsseldorf)
for sample size estimation. e eect size was assumed to be0.25,
α err prob. to 0.01, and power (1- β err prob) to 0.95, and the total
sample required was estimated to be at least 28. Fiy healthy
students (25 females and 25 males) including 40% undergraduates,
56% postgraduates, and 4% doctoral students, with an average age
of 22 (SD = 2.6; Min = 18; Max = 29), with self-reported normal
olfaction, no mental illness, no rhinitis or other olfactory disorders
and not pregnant, were recruited for the experiment. e study
was performed in accordance with the Declaration of Helsinki on
Biomedical Research involving human subjects and approved by
the Research and Ethics Oces of the Shanghai Jiao Tong
University (NO.H2022015I). All participants were recruited from
Shanghai Jiao Tong University through networking contacts. e
privacy rights of participants always beobserved.
Odor preparation
Nine essential oils were used for the preparation of the odor
samples, including six essential oils [lavender oil (Lavandula
angustifolia, LVO), clary sage oil (Salvia sclarea, CSO), bergamot
oil (Citrus × bergamia, BGO), lemon oil (Citrus × limon, LMO),
rosemary oil (Rosmarinus ocinalis, RMO), copaiba oil (Copaifera
ocinalis, CPO)], and three blend essential oils. e essential oils
used in this study were sourced from the Aromatic Plant Research
and Development Centre at Shanghai Jiao Tong University.
Blended oil-I (blended-I) was prepared from the six essential oils
mentioned above according to the volume ratio of 1:1:1:1:1:1;
blended oil-II (blended-II) was composed of LMO, RMO, and
CPO according to the volume ratio of 1:1:1; blended oil-III
(blended-III) was composed of LVO, CSO, and BGO according to
the volume ratio of 1:1:1. ese essential oils have been selected
based on both chemical constituents and ecacy. Firstly, the main
constituents of LVO, CSO, and BGO are esters and alcohols; the
main constituents of LMO, RMO, and CPO are terpenes. Secondly,
the selected oils have a range of bioactive properties (e.g.,
antibacterial (Wang etal., 2012; Ojeda-Sana etal., 2013; Ontas
etal., 2016), anti-inammatory (Lucca etal., 2018; Pandur etal.,
2021), etc.), and also have been proved to alleviate emotional
disorders (Yoshizawa etal., 2015; Samadi etal., 2021), so they have
a broad application prospect.
An aromatherapy machine that using air pressurized
atomization technology was used to atomize the essential oil into
the 500 ml olfactory bottle to prepare the odor sample for
evaluation. e odor samples were set to low, medium, and high
intensity groups, in which the essential oils were atomized into the
bottle for 3, 15, and 75 s, respectively. According to the
measurement results, at low concentration, the essential oil
content in the olfactory bottle is 0.33–0.43 mg, and the gas mass
concentration is 0.66–0.86 g/m3; at the medium concentration, the
essential oil content in the olfactory bottle is 1.72–2.15 mg, and the
gas mass concentration is 3.54–4.30 g/m
3
; at high concentration,
the essential oil content in the olfactory bottle is 8.25–10.70 mg
and the gas mass concentration is 16.50–21.40 g/m
3
. e ratio of
essential oil content at low, medium, and high concentrations is
about 1:5:25. An additional olfactory bottle without any odorant
was added to the selection as a control.
Chemical constituent analysis
e chemical constituents of essential oils were analyzed by
gas chromatography–mass spectrometry (GC–MS, Agilent
7890B-5977A). A DB-WAX column (30 m × 0.25 mm × 0.25 μm)
was utilized as a stationary phase. e GC conditions were as
follows: helium was utilized as a mobile phase (1 ml/min); the
splitting ratio was 30:1; the injector temperatures were held at
260°C; the oven temperature was programmed from 50°C to
120°C at 4°C/min, then held isothermally for 10 min and nally
raised to 220°C at 2°C/min. e MS conditions were as follows:
mass spectra were recorded with ionization energy of 70 eV and
ion source temperature of 230°C.
e identication of the oil constituents was made by
matching their recorded mass spectra with those stored in the
NIST 14 mass spectral library of the GC–MS data system (Milman
and Zhurkovich, 2016; Zhou etal., 2022).
Questionnaire design
During the test, a questionnaire was used to investigate
subjects ‘evaluation of odor, with ve evaluation indicators of odor
perception: pleasantness, familiarity, subjective intensity,
emotional arousal and emotional perception, as shown in Figure1.
A pleasantness scale of 10 to 10 levels represents the pleasantness
caused by odor from “very unpleasant” to “very pleasant.” A
familiarity scale of 10 to 10 levels represents the pleasantness
caused by odor from “very unfamiliar” to “very familiar.” For the
subjective intensity, scores of 1–6, respectively, represent “no
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 04 frontiersin.org
odor,” “almost imperceptible odor,” “slightly perceptible odor,
“easily perceptible odor,” “strong odor,” and “very strong odor.” An
emotional perception scale of 10 to 10 levels represents the
emotional perception caused by odor from “very relaxed” to “very
energetic.” An arousal scale of 10 to 10 levels represents the
arousal caused by odor from very weak to very strong. Among
them, pleasantness and arousal are thought of as two independent
dimensions of emotions (Russell, 1980; Feldman Barrett and
Russell, 1998). Pleasantness reects the pleasant-unpleasant
properties of emotional stimuli, whereas emotional arousal
reects the degree of emotions evoked by the odor, and emotional
perception reects the attribute categories of emotions evoked by
the odor.
Experimental procedure
e experiments were performed with the subjects sitting
position in an air-conditioned (temperature 23 ± 2°C) room. e
test room was well ventilated, no perfume, smoking, or other
factors aected the results.
Participants need to evaluate three groups of odors in order:
low, medium, and high. Each odor group consisted of a total of 10
inhalation bottles including six essential oil odor samples, three
blended essential oil odor samples, and one blank odor sample.
e interval between each group trial was at least 10 min. To avoid
the inuence of olfactory sequence on odor evaluation, the
olfactory sequences varied between the groups and the olfactory
sequences would change again aer every ten participants
completed the experiment. Each odor sample was newly prepared
for dierent subjects. Participants were instructed to remove the
screw cap from each sample in turn, sni odor 1 cm away from the
opening of the bottle for 2–3 s, then immediately tighten the cap
and ll in the questionnaire to do the odor evaluation. ey could
re-sni the samples if they wished. e sning interval for each
of the two odor samples was 60 s. When the participants nished
evaluating a set of odor samples, they needed to leave the test
room for 20 min for a rest, while the room was ventilated
for 20 min.
Statistical method
IBM SPSS Statistics 22.0 was used to establish a database with all
results. All scale data are reported as means ± standard error of the
mean (SEM). Two-factor repeated analyses of variance (ANOVAs)
were run to analyze the eects of odor type and concentration on the
sensory evaluation, and a post hoc Bonferroni test was used. At low,
middle, and high concentrations, two-factor mixed analyses of
variance (ANOVAs) were used to further analyze whether the
correlation between odor sensory evaluation and type was inuenced
by gender, regional culture, or fragrance usage habits. Pearson’s
correlation coecients were used to assess relationships between ve
evaluation indexes of odor perception: pleasantness, familiarity,
emotional perception, arousal, and subjective intensity.
Results
Participants’ characteristics
Basic information about participants’ age, hometown, and
fragrance usage habits was collected and kept strictly condential
(Table 1). Based on the geographical location of the participants’
hometowns, the participants were divided into two categories:
southern Yangtze (n = 25, hometowns located south of the Yangtze
River in China) and northern Yangtze (n = 25, hometowns located
north of the Yangtze River in China). In terms of fragrance usage
habits, 24 participants selected “yes” to the question of whether they
had fragrance usage habits, and they all use fragrance products
(including essential oils, perfumes, scented candles, reed diusers,
etc.) more than 2–3 times a month. e 24 participants were divided
FIGURE1
Contents of the questionnaire and specific evaluation index scores. The corresponding score range was shown in parentheses.
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 05 frontiersin.org
into groups with fragrance usage habits, while the other 26
participants were divided into groups without fragrance usage habits.
Chemical constituents of essential oils
e analysis of the essential oil constituents was carried out by
GC–MS with the peak area normalization method to clarify the
relative content of each component (Figure 2). e main
constituents of each essential oil were listed in Table2 and a more
detailed chemical constituent table can be found in
Supplementary Tables S1–S9.
Nine essential oils could beclassied into three types. One
includes LVO, CSO, BGO, and blended-III, of which esters and
alcohols were the main constituents. In LVO, esters accounted for
41.92%, alcohols 39.38%, and terpenes 14.99%. In CSO, esters
accounted for 57.69%, alcohols 37.86%, and terpenes 2.28%. In
BGO, esters accounted for 40.55%, alcohols 22.84%, and terpenes
35.45%. In blended-III, esters accounted for 31.52% and alcohols
46.4%. Linalool and linalyl acetate were the representative
constituents of these essential oils. e second includes LMO,
RMO, CPO, and blended-II, of which terpenes were the main
constituents. e terpenes in LMO accounted for 95.78%, the
highest content of which was limonene (62.37%); the terpenes in
RMO accounted for 55.33%, the highest content of which was
α-pinene (26.81%); the terpenes in CPO accounted for 99.60%,
the highest content of which was caryophyllene (55.93%); and the
main constituents in blended-II were also terpenes (84.07%), the
higher content of which was limonene (20.41%) and caryophyllene
(19.47%). e third group includes blended-I with a more average
percentage of the three compounds, with 21.00% of esters, 19.23%
of alcohols, and 55.65% of terpenoids.
Eect of odor type and concentration on
odor sensory evaluation
e main eect of odor types on odor sensory evaluation was
signicant (all p<0.05), while the main eect of concentration
was not (all p>0.05). e interactive eects of odor types and
TABLE1 Basic information of participants.
Basic information Number
Gender Male 25
Female 25
Hometowns Southern Yangtze 25
Northern Yangtze 25
Fragrance usage habits Ye s 24
No 26
FIGURE2
Distribution characteristics of compound types in dierent odors.
Chen et al. 10.3389/fpsyg.2022.998612
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TABLE2 The essential oil used in the study and their main constituents.
Essential oil Chemical type Main constituents
Lavender oil Ester + Alcohol-type Linalyl acetate (33.59%), Linalool (31.76%)
Clary sage oil Ester + Alcohol-type Linalyl acetate (50.46%), Linalool (26.20%), α-Terpineol (7.02%)
Bergamot oil Ester + Alcohol-type Linalyl acetate (40.55%), Limonene (33.31%), Linalool (20.88%)
Lemon oil Terpene-type Limonene (62.37%), β-Pinene (14.40%), γ-Terpinene (11.20%)
Rosemary oil Terpene-type α-Pinene (26.81%), Eucalyptol (25.99%), Camphene (7.88%), Camphor (6.11%)
Copaiba oil Terpene-type Caryophyllene (55.93%), α-Copaene (10.41%), trans-α-Bergamotene (6.81%), Humulene (5.459%)
Blended oil-I Blended type Linalyl acetate (19.33%), Limonene (17.39%), Caryophyllene (11.95%), Linalool (11.23%), Pinene (7.36%)
Blended oil-II Terpene-type Limonene (20.41%), Caryophyllene (19.67%), α-Pinene (12.24%), Eucalyptol (8.09%)
Blended oil-III Ester + Alcohol-type Linalyl acetate (41.43%), Linalool (25.81%), Limonene (12.10%)
Terpene-type, the main constituents of essential oil were terpene; Ester + Alcohol-type, the main constituents of essential oil were ester and alcohol. Blended type, the main constituents of
essential oil were balanced. Main constituents: chemical constituents with a relative percent age over 5% in oil.
TABLE3 The significance of the indicators under main eect and interaction.
Source Pleasantness Familiarity Subjective intensity Emotional arousal Emotional
perception
Odor type 0.000*0.000*0.000*0.000*0.000*
Concentration 0.694 0.898 0.155 0.605 0.086
Odor type×Concentration 0.207 0.101 0.321 0.458 0.504
*represents signicant dierence (p < 0.05).
intensity on pleasantness, familiarity, subjective intensity,
emotional arousal, and emotional perception were not statistically
signicant (all p>0.05; Table3).
As the concentration increased, the mean scores of odor
pleasantness and familiarity decreased, and the mean score of
emotional perception increased, indicating that the perception of
odors shied to exciting energized. e mean score of arousal and
subjective intensity also showed an increasing shi. However,
those changes did not reach statistical signicance, and none of
the main eects of the concentration factors on odor sensory
evaluation were statistically signicant (Table3). It was worth
mentioning that the subjective intensity scores of the blank group
were signicantly lower than those of the experimental groups at
all three concentrations (all p < 0.001). e detailed gure can
befound in Supplementary Figure S1.
Average scores of odor sensory evaluation and further post hoc
comparison results between the nine odors were shown in Table4.
In terms of odor pleasantness, the scores of dierent essential oil
odors varied signicantly [F (8, 392) = 18.407, p < 0.001]. LMO
odor scored the highest, followed by odors of CPO, blended-II,
BGO, RMO, blended-I, blended-III, and LVO. CSO odor scored
lower than all other odors (all p < 0.05). Signicant dierences in
familiarity were observed across odor samples [F (8, 392) =13.249,
p < 0.001]. e familiarity score of LMO odor was signicantly
higher than those of other essential oils (all p < 0.001), while the
familiarity score of LVO was the lowest.
e type of oil odor also inuenced participants’ judgments of
odor intensity [F (8, 392) =9.746, p < 0.001]. CPO and blended-II
odors were perceived as the least concentrated odors (both
p<0.05), while participants rated the highest odor intensity for the
CSO odor. e emotional perception varied with the type of
essential oil odor [F (8, 392) =2.490, p < 0.05]. Among them, LMO
odor was rated as the most stimulating odor, only blended-II odor
and CPO scored negatively, with their emotional perception being
more inclined to calm and relax. In terms of arousal, LMO odor
scored signicantly higher than other oil odors (all p < 0.001),
while blended-II odor scored lowest.
When the main constituent of the odors was considered
instead of the specic type, the results were shown in Table5. e
analysis suggested that the terpene-type odors brought more
energetic perception (p < 0.01) and higher emotional arousal
(p < 0.001) than the other two odors. However, there was no
signicant dierence in odor pleasantness, familiarity, and
subjective intensity among the three.
According to the Pearson correlation analysis results (Table6),
there was a positive correlation between familiarity and
pleasantness (r = 0.531, p < 0.001). e higher the familiarity with
the odor, the more popular it will be. In addition, there was a
weaker positive correlation between emotional perception and
subjective intensity (r = 0.328, p < 0.001). e analysis did not
reveal any signicant correlations between arousal and other
subjective rating indicators.
Eect of participants’ characteristics on
odor sensory evaluation
Influence of gender
e analysis results were shown in Table7 and further post hoc
comparison results were displayed in Figure3. e interaction of
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 07 frontiersin.org
TABLE4 Sensory evaluation of dierent oil odor.
Essential oil odor Pleasantness Familiarity Subjective intensity Emotional arousal Emotional
perception
Blended-I 1.24±0.43c2.86±0.55b4.69±0.10ab 2.79±0.36bc 0.41±0.42bc
Blended-II 2.01±0.42bc 2.76±0.47b4.35±0.10c2.35±0.36c0.17±0.43c
Blended-III 1.15±0.47c2.54±0.53b4.72±0.11ab 2.90±0.35bc 0.56±0.47bc
LVO 0.86±0.44cd 1.71±0.56b4.75±0.09ab 2.53±0.45bc 0.29±0.43bc
CSO 0.35±0.50d2.27±0.54bc 4.80±0.08a3.07±0.41b0.79±0.39b
BGO 1.84±0.48bc 2.83±0.51b4.57±0.10b3.23±0.34b0.53±0.45b
LMO 5.31±0.43a5.79±0.46a4.57±0.10b5.28±0.37a2.19±0.54a
RMO 1.30±0.47c2.82±0.55b4.68±0.11ab 3.20±0.50b1.03±0.44ab
CPO 2.31±0.39b2.99±0.55b4.36±0.09c2.73±0.37bc 0.09±0.42c
Mean ratings (±standard error of the mean, n = 50) of dierent odors at three concentrations on pleasantness, familiarity, subjective intensity, emotional arousal, and emotional
perception. Values followed by dierent or same lowercase letters indicate signicant dierences (p < 0.05) or no signicant dierence (p > 0.05) between groups. Data were analyzed by
main eects analysis with two-way repeated ANOVAs, a post hoc Bonferroni test was used.
TABLE5 Sensory evaluation of dierent odor types.
Odor type Pleasantness Familiarity Subjective intensity Emotional arousal Emotional
perception
Blended type 1.95±0.48a2.86±0.55a4.69±0.10a2.79±0.36b0.41±0.42b
Ester+Alcohol-type 1.30±0.45a2.54±0.53a4.75±0.09a2.52±0.45b0.29±0.43b
Terpene-type 1.14±0.40a2.76±0.47a4.57±0.10a5.28±0.37a2.19±0.54a
Mean ratings (± standard error of the mean, n = 50) of dierent odor types at three concentrations on pleasantness, familiarity, subjective intensity, emotional arousal, and emotional
perception. Values followed by dierent or same lowercase letters indicate signicant dierences (p < 0.05) or no signicant dierence (p> 0.05) between groups. Data were analyzed by
main eects analysis with two-way repeated ANOVAs, a post hoc Bonferroni test was used.
TABLE6 Correlation between sensory evaluation indexes.
PCCS Pleasantness Familiarity Subjective intensity Emotional arousal Emotional
perception
Pleasantness 10.531*** 0.267*** 0.217*** 0.190***
Familiarity 0.531*** 10.007 0.290*** 0.900***
Subjective intensity 0.267*** 0.007 1 0.211*** 0.328***
Emotional arousal 0.217*** 0.290*** 0.211*** 1 0.190***
Emotional perception 0.190*** 0.090*** 0.328*** 0.190*** 1
Pearson’s correlation coecients (PCCS) were used to assess relationships between ve evaluation indicators. ***p<0.001 represents that the condence level of the results was more
than 99.9%.
TABLE7 The significance of the indicators under main eect and interaction of gender and type.
Odor
concentration
Source Pleasantness Familiarity Subjective
intensity
Emotional
arousal
Emotional
perception
Low Odor type 0.000*0.000*0.006*0.000*0.080*
Gender 0.160 0.408 0.727 0.431 0.851
Odor typ e × Gender 0.871 0.331 0.411 0.052 0.210
Middle Odor type 0.000*0.000*0.000*0.000*0.024*
Gender 0.412 0.680 0.852 0.088 0.692
Odor typ e × Gender 0.655 0.221 0.739 0.193 0.476
High Odor type 0.000*0.000*0.222 0.001*0.014*
Gender 0.095 0.595 1.000 0.450 0.531
Odor typ e × Gender 0.074 0.582 0.055 0.612 0.487
Data represents the value of p, * signicant dierence at 0.05 level.
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gender and types had no signicant eect on the odor sensory
evaluation at three concentrations, respectively. At low
concentrations, females scored higher than males on pleasantness
for all odors [F (1, 48) =2.041, p>0.05] and the mean pleasantness
scores of females were all positive at three concentrations while
the male participants scored negatively for LVO and CSO odor at
high concentrations. In addition, the females scored higher than
males on average at three concentrations on odor familiarity [Low:
F (1, 48) =0.697, Mid: F (1, 48) =0.173, High: F (1, 48) =0.286, all
p>0.05] and arousal [Low: F (1, 48) =0.632, Mid: F (1, 48) =3.038,
High: F (1, 48) =0.580, all p>0.05], and scored lower in emotional
perception[F (1, 48) =0.036, Mid: F (1, 48) =0.158, High: F (1, 48)
=0.398, all p>0.05], indicating that their emotional perception was
more inclined to calm and relax. However, those dierences did
not reach statistical signicance and the main eect of gender was
not signicant on odor sensory evaluation.
Further post hoc comparisons showed that at medium
concentrations, the familiarity (6.76 ± 0.58 vs. 4.44 ± 0.88, p < 0.05)
and arousal (6.24 ± 0.51 vs. 4.12 ± 0.68, p < 0.05) scores of LMO in
female were signicantly higher than those in male, and signicant
dierences in arousal were also observed in blended-I (3.44 ± 0.58
vs. 1.68 ± 0.64, p < 0.05) and blended-II (3.36 ± 0.62 vs. 1.12 ± 0.75,
p < 0.05). At high concentration, females scored signicantly
higher for pleasantness of LVO (2.71 ± 0.68 vs. 0.80 ± 0.72,
p < 0.001) and BGO (3.92 ± 0.66 vs. 1.48 ± 0.72, p < 0.05) than
males, and females were more familiar with LMO (7.08 ± 0.60 vs.
4.96 ± 0.60, p < 0.05).
Influence of regional culture
e analysis results were shown in Table 8 and the average
ratings were obtained and further post hoc comparisons results were
displayed in Figure4. Similar to gender, the interaction between
regional culture and type had no signicant eect on odor sensory
evaluation. e dierences caused by regional culture were mainly
reected in odor familiarity. Participants’ ratings of odor familiarity
varied signicantly between regions at three concentrations [Low: F
(1, 48) = 4.791, Mid: F (1, 48) =6.198, High: F (1, 48) = 4.613, all
p < 0.05], with participants from the southern Yangtze giving higher
rating (Low:1.92 ± 0.69 vs. 0.69 ± 0.30, Mid: 4.06 ± 0.59 vs. 4.00 ± 0.59,
High: 3.79 ± 0.58 vs. 2.01 ± 0.59, all p < 0.05). Signicant dierences
in familiarity were observed in LVO, RMO, CPO, blended-II, and
blended-III, with the familiarity scores of CPO in participants from
the southern Yangtze were all signicantly higher than in participants
from the northern Yangtze at three concentrations (Low:5.62 ± 0.50
vs. 1.60 ± 1.18, Mid: 3.60 ± 0.68 vs. 1.00 ± 1.00, High: 4.52 ± 0.50 vs.
1.56 ± 1.01, all p < 0.05).
In terms of odor pleasantness, subjective intensity, emotional
perception, and arousal, the average scores at three concentrations
of participants from the southern Yangtze were all higher than those
from the northern Yangtze. e signicant dierences in arousal
between the two groups were observed in LVO (2.80 ± 0.78 vs.
0.40 ± 0.78, p < 0.05), blended-II (3.40 ± 0.65 vs. 1.08 ± 0.72, p < 0.05),
and CPO (3.76 ± 0.59 vs. 0.92 ± 0.84, p < 0.01) at low, medium, and
high concentrations, respectively. However, the main eects of these
factors were not signicant on odor sensory evaluation.
FIGURE3
Sensory evaluation of odor between male and female. Mean ratings (n = 25) on pleasantness, familiarity, subjective intensity, emotional arousal, and
emotional perception at low (L), mid-range (M), and high (H) concentrations between male and female. M: male, F: female. The asterisk indicates
that the odor evaluation results of the two groups show significant dierences. *p < 0.05, **p < 0.01, ***p < 0.001. Data were analyzed by main eects
analysis with two-way mixed ANOVAs, a post hoc Bonferroni test was used.
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 09 frontiersin.org
Influence of fragrance usage habits
e inuence of fragrance usage habits on odor sensory
evaluation was shown in Table9 and the average ratings were
obtained and further post hoc comparisons results were displayed
in Figure5. e main eects of fragrance usage habits on odor
sensory evaluation were not signicant at low and middle
concentrations. At high concentrations, the interaction of
fragrance usage habits and type had a signicant eect on
emotional perception [F (8, 384) =5.335, p<0.001] and subjective
intensity [F (8, 384) =3.277, p<0.01].
Further simple eects analysis revealed that participants
with fragrance usage habits believed that the emotional
perception caused by LVO odor, BGO odor, and blended-II odor
was more inclined to calm and relax (all p < 0.05), while t hose
without fragrance usage habits were the opposite. But the
contrary dierence was shown between the two groups for RMO
odor, participants with fragrance usage habits perceived that the
emotional perception was more inclined to encourage
(2.83 ± 0.92 vs. 0.00 ± 0.75, p < 0.01). In terms of subjective
intensity, participants with fragrance usage habits scored
signicantly higher for RMO odor (5.13 ± 0.19 vs. 4.35 ± 0.18,
p < 0.01). In terms of odor pleasantness and familiarity, the
average scores at three concentrations of participants with
fragrance usage habits were all higher than participants without
fragrance usage habits but those dierences did not reach
statistical signicance.
TABLE8 The significance of the indicators under main eect and interaction of region and type.
Odor
concentration Source Pleasantness Familiarity Subjective
intensity
Emotional
arousal
Emotional
perception
Low Odor type 0.019*0.000*0.006 *0.000*0.058
Region 0.615 0.034*0.292 0.186 0.315
Odor typ e × Region 0.407 0.338 0.170 0.543 0.835
Middle Odor type 0.000*0.000*0.000*0.000*0.025*
Region 0.791 0.016*0.350 0.262 0.165
Odor typ e × Region 0.377 0.278 0.941 0.209 0.780
High Odor type 0.000*0.000*0.322 0.000*0.015*
Region 0.176 0.037*0.682 0.152 0.312
Odor typ e × Region 0.321 0.314 0.411 0.064 0.98
Data represents the value of p, * signicant dierence at 0.05 level.
FIGURE4
Eect of regional culture on sensory evaluation of odor. Mean ratings (n = 25) at three concentrations on pleasantness, familiarity, subjective
intensity, emotional arousal, and emotional perception at low (L), mid-range (M), and high (H) concentration of the participants from the northern
Yangtze and the southern Yangtze. N: participants from the northern Yangtze, S: participants from the southern Yangtze. The asterisk indicates
that the odor evaluation results of the two groups show significant dierences. * p < 0.05, ** p < 0.01. Data were analyzed by main eects analysis
with two-way mixed ANOVAs, a post hoc Bonferroni test was used.
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e results of the correlation analysis showed that there was
no signicant correlation between the three factors of gender,
region, and fragrance use habits, and a more detailed table can
befound in Supplementary Table S10.
Discussion
In this study, according to the constituent and function, nine
essential oil odors with health function were selected for the
sensory evaluation experiment at low, medium, and high
concentrations, respectively. e evaluation indexes included
pleasantness, familiarity, emotional perception, arousal, and
subjective intensity. e eects of odor types, concentration, and
their interactions were explored. Gender, hometown (regional
culture), and fragrance habits factors were chosen to better
understand how participants’ characteristics might impact the
responses to odors.
e results showed that the odor type signicantly aected
the evaluation results, while concentration did not, and there
was no interaction between the two factors. Essential oils are
composed of various small molecular volatile chemical
TABLE9 The significances of the indicators under main eect and interaction of habits and type.
Odor
concentration Source Pleasantness Familiarity Subjective
intensity
Emotional
arousal
Emotional
perception
Low Odor type 0.000*0.000*0.015*0.000*0.083
Fragrance usage habits 0.136 0.325 0.434 0.732 0.623
Odor type × Fragrance usage habits 0.419 0.686 0.229 0.302 0.497
Middle Odor type 0.000*0.000*0.000*0.000*0.018*
Fragrance usage habits 0.101 0.221 0.924 0.506 0.991
Odor type × Fragrance usage habits 0.386 0.245 0.120 0.497 0.127
High Odor type 0.000*0.000*0.250 0.000*0.002*
Fragrance usage habits 0.701 0.339 0.569 0.714 0.610
Odor type × Fragrance usage habits 0.747 0.453 0.001 *0.126 0.000*
Data represents the value of p, * signicant dierence at 0.05 level.
FIGURE5
Eect of fragrance usage habits on sensory evaluation of odor. Mean ratings (n = 24–26) at three concentrations on pleasantness, familiarity,
subjective intensity, emotional arousal, emotional perception and at low (L), mid-range (M), and high (H) concentration of the participants without
fragrance usage habits and the participants with fragrance usage habits. N: participants without fragrance usage habits, Y: participants with
fragrance usage habits. The asterisk indicates that the odor evaluation results of the two groups show significant dierences. *p < 0.05, **p < 0.01.
Data were analyzed by two-way mixed ANOVAs, a post hoc Bonferroni test was used.
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Frontiers in Psychology 11 frontiersin.org
components, which also dier in sensory evaluation. A study on
the odorant hedonic value of 23 monomeric compounds found
that isoamyl acetate and geraniol had higher preference and
familiarity scores than limonene, while limonene had a relatively
low score of subjective intensity among all compounds
(Chalencon et al., 2022). e results of the present study
suggested that the terpene-type odors brought more inspiring
perception and higher emotional arousal than the other two
odors. e nding is consistent with prior literature that shows
an eect of emotional perception triggered by chemical
composition dierences (Kaneda etal., 2011). One study found
that strawberry odor had a relaxing eect, while lemon odor had
a stimulating eect. is dierence may also berelated to the
chemical composition, since the compositions of strawberry
odor are mainly esters and alcohols while that of lemon odor is
dominated by terpenes (Baccarani etal., 2021b). However, LMO,
CPO, and blended-II were all terpene-type odors. LMO odor
received the highest ratings for emotional perception and
arousal, while CPO odor and blended-II odor received the
lowest ratings with negative values, which showed a more
calming and relaxing perception. It indicates that oil odors with
similar major constituents may dier signicantly in their taste,
ingredient type was not the primary predictor of odor
sensory evaluation.
In this experiment, odor concentration did not signicantly
aect the odor sensory evaluation. While the concentration
increased, the participants’ subjective intensity remained between
the levels of “easily perceptible odor” and “strong odor.” e
subjective intensity scores of the blank group were signicantly
lower than those of the experimental groups at all three
concentrations, indicating that the participants without olfactory
training were able to correctly discriminate between the presence
or absence of odors, but not well enough to discriminate the
changes in odor concentration. It was noteworthy that there were
signicant dierences in subjective intensities between the
dierent odors, with the highest subjective intensity score for CSO
odor and the lowest subjective intensity score for the CPO odor
and blended II odor, which may berelated to the nasal pungency
of the dierent odors. One previous study showed that pungency
contributed to overall aroma intensity (Jin etal., 2018), which was
also reected by the highest subjective intensity score for CSO
odor in this experiment. However, in another study, the subjective
intensity scores of dierent odors were very close (Ba and Kang,
2019). is inconsistency of results might becaused by dierent
odor types and experimental tasks design.
People’s characteristics inuenced odor sensory evaluation to
some extent. Gender dierences in the ability to detect,
discriminate, and identify odors are still a matter of debate.
Previous studies have shown that females possess higher olfactory
sensitivity than males and there were signicant gender dierences
for the hedonic estimate (uerauf etal., 2009; Greenberg etal.,
2013). However, in the present study, signicant dierences were
observed only in some oil odor such as LMO, the main eect of
gender was not signicant on odor sensory evaluation, which is in
agreement with past studies (Van riel etal., 2008; Nováková
etal., 2014), and there was no interaction between the gender
and type.
China’s Yangtze River is known as the mother river of the
Chinese nation, which ows from west to east to debouch into the
East China Sea. It has served as an important link between nature
and people. e results of this study showed that the dierences
in odor sensory evaluation between participants from the
southern Yangtze and the northern Yangtze were mainly reected
in familiarity. At three concentrations, participants from the
southern Yangtze were more familiar with the odor than
participants from the northern Yangtze. ese dierences
presumably reected vegetation dierences caused by climates.
e climate in the region south of the Yangtze River is dominated
by a subtropical monsoon climate with ample light and heat
resources, which is suitable for the growth of lavender, rosemary,
bergamot, and lemon. Both lemon and bergamot are cold-
intolerant and rarely cultivated in the northern Yangtze, which is
presumably related to the dierence between the two groups in
odor sensory evaluation.
Fragrance usage habits also inuenced people’s odor
evaluation. People with fragrance usage habits showed a higher
level of pleasantness and familiarity with essential oil odors than
those without fragrance usage habits, but those dierences did not
reach statistical signicance. is may berelated to the dierence
in odor between essential oils and perfumes. Previous studies
reported that exposure to relatively high concentrations of
chemicals aected sensitivity to that particular odorant (Zibrowski
and Robertson, 2006; Sorokowska etal., 2013), but our study
showed that the fragrance usage habits did not signicantly aect
subjective intensity. It may be related to the concentration
dierence. In daily life, people perceive a relatively lower
concentration of fragrance indoors compared to the chemicals. In
addition, at high concentrations, participants with fragrance usage
habits perceived the emotional perception associated with LVO
odor, BGO odor, and blended-II odor as more calming and
relaxing, while the perception associated with RMO odor was
more motivating and inspiring, but those without fragrance usage
habit were the opposite. ose dierences may berelated to the
prior experience of participants with fragrance usage habits. Once
participants identied the type of odor, their emotional perception
of the odor may have been potentially inuenced by pre-existing
understanding. e ndings in this study are helpful to the eld
of aromatherapy for more personalized treatments can
beperformed. In addition to considering the possible ecacy of
essential oil odor, factors such as chemical type, gender,
hometown, and fragrance usage habits should be taken into
comprehensive consideration in the selection of oil odor, which
may improve people’s experience in aromatherapy and better help
people improve their mood.
Subjective odor perception is oen investigated with the help
of several dimensions, such as pleasantness, familiarity, intensity,
emotional perception, and arousal. Studies have demonstrated
that these dimensions are not independent, especially between
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 12 frontiersin.org
familiarity and pleasantness. Studies have generally found that the
more familiar an odor, the more pleasant it is judged (Knaapila
etal., 2017). However, it had also been suggested that the relation
between pleasantness and familiarity was specic to pleasant
odors (Delplanque etal. 2008). In this study, the mean pleasantness
scores for all odors were positive and those odors could
beconsidered not to beunpleasant odors. And the correlation
analysis revealed that there was a positive correlation between
familiarity and pleasantness, which agrees with the univariate
analyses. In addition, there was a weaker positive correlation
between emotional perception and subjective intensity, implying
that the odor properties of inspiring were associated with higher
subjective intensity, in line with the previous ndings (Baccarani
etal., 2021a).
However, this study has potential limitations. Many studies
have shown that age aects odor perception. In this experiment,
the odor sensory evaluation test was conducted for young
adults, so it is unclear whether age will aect the oil odor
evaluation results. Age factor can be added as a variable in
future research. On the other hand, the odor sensory evaluations
were obtained based on participants’ short-term sning in this
experiment. Although participants were allowed to sni
repeatedly if they wished, it is still unclear whether the
evaluation changed aer long-term sning. A comparison
between short-term sensory evaluation and long-term sensory
evaluation could bediscussed in future studies. Meanwhile, the
sample size of this study was limited, which may aect the
statistical signicance of the results.
Conclusion
Essential oils are widely used as functional fragrances to
improve people’s olfactory environment and regulate emotions. In
this study, nine oil odors were selected based on chemical
composition and function. e eects of odor conditions,
participants’ characteristics on odor sensory evaluation, and the
interactions between dierent evaluation indexes
were investigated.
Chemical type, but not the concentration, signicantly
inuenced the evaluation. ere was no interaction between the
two factors. e terpene-type odors brought more inspiring
perception and higher emotional arousal than the ester+alcohol-
type odors and the blended odors, but signicant dierences also
existed between odors with the same main constituent, indicating
that constituent type was not the primary predictor of odor
sensory evaluation.
Signicant geographical dierences for odor familiarity
existed, with participants from the southern Yangtze scoring
signicantly higher than participants from the northern Yangtze.
Fragrance usage habits signicantly inuenced the subjective
intensity and emotional perception ratings of some odors. ere
was no signicant gender dierence in odor sensory evaluation;
In addition, familiarity and pleasantness were positively correlated,
and emotional perception and subjective intensity also showed a
weak correlation.
Data availability statement
e original contributions presented in the study are included
in the article/Supplementary material, further inquiries can
bedirected to the corresponding authors.
Ethics statement
e studies involving human participants were reviewed and
approved by the Research and Ethics Oces of the Shanghai Jiao
Tong University. e patients/participants provided their written
informed consent to participate in this study.
Author contributions
JC: methodology, investigation, project administration, formal
analysis, and writing original dra. NZ: investigation, formal
analysis, project administration, supervision, and funding
acquisition. SP: investigation and formal analysis. LY:
conceptualization, supervision and funding acquisition. All authors
contributed to the article and approved the submitted version.
Funding
is work was supported by the National Key Research and
Development Program of China (grant number:
2019YFA0706200), Shanghai Sailing Program (grant number:
20YF1421700), and National Natural Science Foundation of
China (grant number: 52078291).
Acknowledgments
Authors deeply thank volunteers for their participation
and cooperation.
Conflict of interest
e authors declare that the research was conducted in the
absence of any commercial or nancial relationships that could be
construed as a potential conict of interest.
Publisher’s note
All claims expressed in this article are solely those
of the authors and do not necessarily represent those of their
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 13 frontiersin.org
aliated organizations, or those of the publisher,
the editors and the reviewers. Any product that may be
evaluated in this article, or claim that may be made by its
manufacturer, is not guaranteed or endorsed by the
publisher.
Supplementary material
e Supplementary material for this article can befound online
at: https://www.frontiersin.org/articles/10.3389/fpsyg.2022.998612/
full#supplementary-material
References
Angelucci, F., Silva, V., Dal Pizzol, C., Spir, L., Praes, C., and Maibach, H. (2014).
Physiological eect of olfactory stimuli inhalation in humans: an overview. Int. J.
Cosmet. Sci. 36, 117–123. doi: 10.1111/ics.12096
Apaolaza, V., Hartmann, P., López, C., Barrutia, J. M., and Echebarria, C. (2014).
Natural ingredients claim’s halo eect on hedonic sensory experiences of perfumes.
Food Qual. Prefer. 36, 81–86. doi: 10.1016/j.foodqual.2014.03.004
Ayabe-Kanamura, S., Schicker, I., Laska, M., Hudson, R., Distel, H., Kobayakawa, T.,
et al. (1998). Dierences in perception of everyday odors: a Japanese-German cross-
cultural study. Chem. Senses 23, 31–38. doi: 10.1093/chemse/23.1.31
Ba, M., and Kang, J. (2019). A laboratory study of the sound-odour interaction in
urban environments. Build. Environ. 147, 314–326. doi: 10.1016/j.
buildenv.2018.10.019
Baccarani, A., Brand, G., Dacremont, C., Valentin, D., and Brochard, R. (2021a).
e inuence of stimulus concentration and odor intensity on relaxing and
stimulating perceived properties of odors. Food Qual. Prefer. 87:104030. doi:
10.1016/j.foodqual.2020.104030
Baccarani, A., Grondin, S., Laamme, V., and Brochard, R. (2021b). Relaxing and
stimulating eects of odors on time perception and their modulation by expectancy.
Atten. Percept. Psychophys. 83, 448–462. doi: 10.3758/s13414-020-02182-0
Bontempi, C., Jacquot, L., and Brand, G. (2021). Sex dierences in odor hedonic
perception: an overview. Front. Neurosci. 15:764520. doi: 10.3389/fnins.2021.764520
Burnett, K. M., Solterbeck, L. A., and Strapp, C. M. (2004). Scent and mood state
following an anxiety-provoking task. Psychol. Rep. 95, 707–722. doi: 10.2466/
pr0.95.2.707-722
Chalencon, L., evenet, M., Noury, N., Bensa, M., and Mandairon, N. (2022).
Identication of new behavioral parameters to assess odorant hedonic value in
humans: a naturalistic approach. J. Neurosci. Methods 366:109422. doi: 10.1016/j.
jneumeth.2021.109422
Delplanque, S., Grandjean, D., Chrea, C., Aymard, L., Cayeux, I., Le Calve, B., et al.
(2008). Emotional processing of odors: evidence for a nonlinear relation between
pleasantness and familiarity evaluations. Chem. Senses 33, 469–479. doi: 10.1093/
chemse/bjn014
Dubois, D. (2000). Categories as acts of meaning: the case of categories in
olfaction and audition. Cogn. Sci. Q. 1, 35–68.
Ebrahimi, H., Mardani, A., Basirinezhad, M. H., Hamidzadeh, A., and
Eskandari, F. (2021). e eects of lavender and chamomile essential oil inhalation
aromatherapy on depression, anxiety and stress in older community-dwelling
people: a randomized controlled trial. Explore (NY) 18, 272–278. doi: 10.1016/j.
explore.2020.12.012
Feldman Barrett, L., and Russell, J. A. (1998). Independence and bipolarity in the
structure of current aect. J. Pers. Soc. Psychol. 74, 967–984. doi:
10.1037/0022-3514.74.4.967
Ferdenzi, C., Coureaud, G., Camos, V., and Schaal, B. (2008). Human awareness
and uses of odor cues in everyday life: results from a questionnaire study in children.
Int. J. Behav. Dev. 32, 422–431. doi: 10.1177/0165025408093661
Greenberg, M. I., Curtis, J. A., and Vearrier, D. (2013). e perception of odor is
not a surrogate marker for chemical exposure: a review of factors inuencing human
odor perception. Clin. Toxicol. 51, 70–76. doi: 10.3109/15563650.2013.767908
Herz, R. S. (2009). Aromatherapy facts and ctions: a scientic analysis of
olfactory eects on mood, physiology and behavior. Int. J. Neurosci. 119, 263–290.
doi: 10.1080/00207450802333953
Hoshika, Y., Imamura, T., Muto, G., Van Gemert, L. J., Don, J. A., and Walpot, J. I.
(1993). International comparison of odor threshold values of several odorants in
Japan and in the Netherlands. Environ. Res. 61, 78–83. doi: 10.1006/enrs.1993.1051
Jin, L., Haviland-Jones, J., Simon, J. E., and Tepper, B. J. (2018). Inuence of aroma
intensity and nasal pungency on the ‘mood signature’ of common aroma compounds
in a mixed ethnic population. Food Qual. Prefer. 65, 164–174. doi: 10.1016/j.
foodqual.2017.10.017
Joussain, P., evenet, M., Rouby, C., and Bensa, M. (2013). Eect of aging on
hedonic appreciation of pleasant and unpleasant odors. PLoS One 8:e61376. doi:
10.1371/journal.pone.0061376
Kaneda, H., Kojima, H., and Watari, J. (2011). Novel psychological and
neurophysiological signicance of beer aromas. Part I: measurement of changes in
human emotions during the smelling of hop and ester aromas using a measurement
system for brainwaves. J. Am. Soc. Brew. Chem. 69, 67–74. doi: 10.1094/
ASBCJ-2011-0328-01
Knaapila, A., Laaksonen, O., Virtanen, M., Yang, B., Lagstrom, H., and Sandell, M.
(2017). Pleasantness, familiarity, and identication of spice odors are interrelated
and enhanced by consumption of herbs and food neophilia. Appetite 109, 190–200.
doi: 10.1016/j.appet.2016.11.025
Knudsen, J. T., Eriksson, R., Gershenzon, J., and Ståhl, B. (2006). Diversity and
distribution of oral scent. Bot . Re v. 72, 1–120. doi: 10.1663/0006-8101(2006)72[1:DA
DOFS]2.0.CO;2
Larsson, M., Lövdén, M., and Nilsson, L.-G. (2003). Sex dierences in recollective
experience for olfactory and verbal information. Acta Psychol. 112, 89–103. doi:
10.1016/S0001-6918(02)00092-6
Laurent & Gilles (2002). Olfactory network dynamics and the coding of
multidimensional signals. Nat. Rev. Neurosci. 3, 884–895. doi: 10.1038/nrn964
Li, B., Kamarck, M. L., Peng, Q., Lim, F.-L., Keller, A., Smeets, M. A., et al. (2022).
From musk to body odor: decoding olfaction through genetic variation. PLoS Genet.
18:e1009564. doi: 10.1371/journal.pgen.1009564
Lucca, L. G., De Matos, S. P., Kreutz, T., Teixeira, H. F., Veiga, V. F. Jr., De
Araujo, B. V., et al. (2018). Anti-inammatory eect from a hydrogel containing
Nanoemulsied copaiba oil (Copaifera multijuga Hayne). AAPS PharmSciTech 19,
522–530. doi: 10.1208/s12249-017-0862-6
Mackay-Sim, A., Royet, J.-P., and Universitybrisbane, G. 2006. e olfactory
system. Cambridge University Press Cambridge, United Kingdom.
Majid, A., Speed, L., Croijmans, I., and Arshamian, A. (2017). What makes a
better smeller? Perception 46, 406–430. doi: 10.1177/0301006616688224
Martinec Novakova, L., Plotena, D., Rober ts, S. C., and Havlicek, J. (2015). Positive
relationship between odor identication and aective responses of negatively
valenced odors. Front. Psychol. 6:607. doi: 10.3389/fpsyg.2015.00607
Milman, B. L., and Zhurkovich, I. K. (2016). Mass spectral libraries: a statistical
review of the visible use. TrAC Trends Anal. Chem. 80, 636–640. doi: 10.1016/j.
trac.2016.04.024
Nováková, L., Varella Valentova, J., and Havlíček, J. (2014). Engagement in olfaction-
related activities is associated with the ability of odor identication and odor awareness.
Chemosens. Percept. 7, 56–67. doi: 10.1007/s12078-014-9167-2
Ojeda-Sana, A. M., Van Baren, C. M., Elechosa, M. A., Juarez, M. A., and
Moreno, S. (2013). New insights into antibacterial and antioxidant activities of
rosemary essential oils and their main components. Food Control 31, 189–195. doi:
10.1016/j.foodcont.2012.09.022
Olsson, P., and Laska, M. (2010). Human male superiority in olfactory sensitivity
to the sperm attractant odorant bourgeonal. Chem. Senses 35, 427–432. doi: 10.1093/
chemse/bjq030
Ontas, C., Baba, E., Kaplaner, E., Kucukaydin, S., Ozturk, M., and Ercan, M. D.
(2016). Antibacterial activity of Citrus Limon Peel essential oil and Argania spinosa
oil against sh pathogenic bacteria. Kaas Universitesi Veteriner Fakultesi Dergisi
22, 741–749. doi: 10.9775/kvfd.2016.15311
Pandur, E., Balatinácz, A., Micalizzi, G., Mondello, L., Horváth, A., Sipos, K., et al.
(2021). Anti-inammatory eect of lavender (Lavandula angustifolia mill.) essential
oil prepared during dierent plant phenophases on THP-1 macrophages. BMC
Complement. Med. er. 21, 1–17. doi: 10.1186/s12906-021-03461-5
Russell, J. A. (1980). A circumplex model of aect. J. Pers. Soc. Psychol. 39,
1161–1178. doi: 10.1037/h0077714
Samadi, Z., Jannati, Y., Hamidia, A., Mohammadpour, R . A., and Hes amzadeh, A.
(2021). e eect of aromatherapy with lavender essential oil on sleep quality in
patients with major depression. J. Nurs. Midwifery Sci. 8, 67–73. doi: 10.4103/jnms.
Jnms_26_20
Schriever, V. A., Lehmann, S., Prange, J., and Hummel, T. (2014). Preventing
olfactory deterioration: olfactory training may beof help in older people. J. Am.
Geriatr. Soc. 62, 384–386. doi: 10.1111/jgs.12669
Chen et al. 10.3389/fpsyg.2022.998612
Frontiers in Psychology 14 frontiersin.org
Sell, C. S. 2006. e Chemistry of Fragrances: From Perfumer to Consumer,
London, UnitedKingdom: Royal Society of Chemistry.
Sorokowska, A., Albrecht, E., and Hummel, T. (2015a). Reading rst or smelling
rst? Eects of presentation order on odor identication. Atten. Percept. Psychophys.
77, 731–736. doi: 10.3758/s13414-014-0811-3
Sorokowska, A., Schriever, V. A., Gudziol, V., Hummel, C., Hähner, A., Iannilli, E.,
et al. (2015b). Changes of olfactory abilities in relation to age: odor identication in
more than 1400 people aged 4 to 80 years. Eur. Arch. Otorhinolaryngol. 272,
1937–1944. doi: 10.1007/s00405-014-3263-4
Sorokowska, A., Sorokowski, P., and Frackowiak, T. (2015c). Determinants of
human olfactory performance: a cross-cultural study. Sci. Total Environ. 506,
196–200. doi: 10.1016/j.scitotenv.2014.11.027
Sorokowska, A., Sorokowski, P., Hummel, T., and Huanca, T. (2013). Olfaction
and environment: Tsimane’of Bolivian rainforest have lower threshold of odor
detection than industrialized German people. PLoS One 8:e69203. doi: 10.1371/
journal.pone.0069203
uerauf, N., Reulbach, U., Lunkenheimer, J., Lunkenheimer, B.,
Spannenberger, R., Gossler, A., et al. (2009). Emotional reactivity to odors: olfactory
sensitivity and the span of emotional evaluation separate the genders. Neurosci. Lett.
456, 74–79. doi: 10.1016/j.neulet.2009.03.096
Van riel, C., Kiesswetter, E., Schäper, M., Juran, S. A., Blaszkewicz, M., and
Kleinbeck, S. (2008). Odor annoyance of environmental chemicals: sensory and
cognitive inuences. J. Toxic. Environ. Health A 71, 776–785. doi: 10.1080/
15287390801985596
Villemure, C., Slotnick, B. M., and Bushnell, M. C. (2003). Eects of odors on pain
perception: deciphering the roles of emotion and attention. Pain 106, 101–108. doi:
10.1016/S0304-3959(03)00297-5
Wang, W., Li, N., Luo, M., Zu, Y. G., and Eerth, T. (2012). Antibacterial activity
and anticancer activity of Rosmarinus ocinalis L. essential oil compared to that of
its Main components. Molecules 17, 2704–2713. doi: 10.3390/molecules17032704
Watanabe, E., Kuchta, K., Kimura, M., Rauwald, H. W., Kamei, T., and Imanishi, J.
(2015). Eects of bergamot (Citrus bergamia (Risso) Wright & Arn.) essential oil
aromatherapy on mood states, parasympathetic nervous system activity, and salivary
cortisol levels in 41 healthy females. Complementary Medicine Research 22, 43–49.
doi: 10.1159/000380989
Yoshizawa, T., Tani, Y., Yamaguchi, T., and Sawa, M. (2015). Eects of inhaled the
Cyperi rhizoma and Perillae herba essential oil on emotional states, autonomic
nervous system and salivary biomarker. Health 07, 533–541. doi: 10.4236/
health.2015.75063
Zellner, D. A., Hoer, K., and Feldman, J. (2014). Labels aect both liking and
preference: the better the stimuli, the bigger the preference. Atten. Percept.
Psychophys. 76, 2189–2192. doi: 10.3758/s13414-014-0768-2
Zhou, Y., He, L., Zhang, N., Ma, L., and Yao, L. (2022). Photoprotective eect of
Artemisia sieversiana Ehrhart essential oil against UVB-induced Photoaging in
mice. Photochem. Photobiol. 98, 958–968. doi: 10.1111/php.13561
Zibrowski, E. M., and Robertson, J. M. (2006). Olfactory sensitivity in medical
laboratory workers occupationally exposed to organic solvent mixtures. Occup. Med.
56, 51–54. doi: 10.1093/occmed/kqi190
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