Pleasant Odor Research Articles

Endogenous mood state and hedonic responses to pleasant odors

AbstractResponses to olfactory cues hold significant practical implications. For instance, emerging research reveals that strategic administration of pleasant olfactory cues can support positive health and well‐being outcomes. The underlying assumption is that pleasantness of odor perception stimulates various downstream benefits. However, olfactory responses vary across individuals and identifying who is most receptive to positive olfactory effects remains an important objective. One key factor may be the perceiver's mood. This study evaluated the association between natural mood state and subjective pleasantness ratings to normatively positive odors. In two experimental sessions, 232 participants with intact olfactory function rated their current mood and the pleasantness of six odorants. Across sessions, individuals with more positive baseline moods rated the odors as being more pleasant than did those with lower baseline mood scores. These findings suggest that individual differences in natural occurring mood should be considered in research examining the positive effects of olfactory cues.Practical ApplicationsPleasant olfactory cues show great potential for interventional research design within sensory science; however, there is little research examining how individual differences may impact the perception and effectiveness of odors. Our data demonstrate that baseline mood state is directly associated with the hedonic perception of pleasant odors. These findings illustrate that individual mood state may be essential to consider for basic research, applied, and consumer sensory panel testing of odor hedonics, and further suggest that inherent mood may influence the degree to which smelling normatively pleasant odors may enhance mental and physical health outcomes.

Conventional water bath heating on undried brewer's spent grain: Functionality, fatty acids, volatiles, polyphenolic and antioxidant properties

Brewers' spent grain (BSG) contains bioactive compounds. It was hypothesized that heating treatments using conventional water bath heating (CWH) on brewers' spent grain (BSG) would modify the functionality, chemical constituents and antioxidant activities of BSG. Different temperatures and time exposures (80, 90 and 100 °C at 15, 30 and 60 min) were applied on fresh undried BSG. CWH at 80 °C increased the amount of flavan-3-ols, while 100 °C at 30 and 60 min improved the ABTS (2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) value. CWH significantly declined saturated fatty acid and enhanced the poly-unsaturated fatty acid. Moreover, CWH discharged pungent, floral, spice and mushroom odor perceptions and formed fruity, sweet and pleasant odor perceptions, as well as essential-oil-related compounds. Additionally, CWH improved water-holding and oil-holding capacities. In conclusion, CWH as a low-cost treatment improved the functionality, fatty acid composition and aromatic profile of BSG.

Increased sensitivity to unpleasant odor following acute psychological stress

Previous studies have reported increased sensitivity to malodor after acute stress in humans. However, it is unclear whether stress-related “hypersensitivity” to odors depends on odor pleasantness. Forty participants (mean age 19.13 ± 1.14 years, 21 men and 19 women) completed a stress (Trier Social Stress Test, TSST) and a control session in randomized order. Detection threshold to three odors varying in pleasantness (pleasant: β-Citronellol; neutral: 2-Heptanol; unpleasant: 4-Methylpentanoic acid), odor discrimination, odor identification, sensitivity to trigeminal odor, and suprathreshold odor perception were assessed after participants' completion of the stress or the control tasks. Salivary cortisol, subjective stress, and heart rate were assessed throughout the experiment. After TSST, participants showed an increased sensitivity for the unpleasant odor. Moreover, there were correlations between stress-related salivary cortisol and the increased sensitivity for the unpleasant odor (r = 0.32, p = 0.05) and the neutral odor (r = 0.34, p < 0.05). Besides, salivary cortisol response was correlated to the increased odor discrimination performance (Δ stress - control) (r = 0.34, p < 0.05). The post-TSST perceived stress was correlated with decreased odor identification and decreased sensitivity to the unpleasant odor. After stress, participants rated lower pleasantness for β-Citronellol than the control condition. Overall, these results suggest the impact of acute psychological stress on odor sensitivity depends on the odor valence, and that the stress-related cortisol responses may play an important role in this effect.

Olfactory training reduces pain sensitivity in children and adolescents with primary headaches.

Headache prevalence among children and adolescents has increased over the last few years. Evidence-based treatment options for pediatric headaches remain limited. Research suggests a positive influence of odors on pain and mood. We investigated the effect of repeated exposure to odors on pain perception, headache-related disability, and olfactory function in children and adolescents with primary headaches. Eighty patients with migraine or tension-type headache (mean 13.1 ± 3.29 years) participated, of whom 40 underwent daily olfactory training with individually selected pleasant odors for 3 months and 40 received state-of-the-art outpatient therapy as a control group. At baseline and after a 3-month follow-up, olfactory function [odor threshold; odor discrimination; odor identification; comprehensive Threshold, Discrimination, Identification (TDI) score], mechanical detection and pain threshold (quantitative sensory testing), electrical pain threshold, patient-reported outcomes on headache-related disability [Pediatric Migraine Disability Assessment (PedMIDAS)], pain disability [Pediatric Pain Disability Index (P-PDI)], and headache frequency were assessed. Training with odors significantly increased the electrical pain threshold compared to the control group (U = 470.000; z = -3.177; p = 0.001). Additionally, olfactory training significantly increased the olfactory function (TDI score [t(39) = -2.851; p = 0.007], in particular, olfactory threshold, compared to controls (U = 530.500; z = -2.647; p = 0.008). Headache frequency, PedMIDAS, and P-PDI decreased significantly in both groups without a group difference. Exposure to odors has a positive effect on olfactory function and pain threshold in children and adolescents with primary headaches. Increased electrical pain thresholds might reduce sensitization for pain in patients with frequent headaches. The additional favorable effect on headache disability without relevant side effects underlines the potential of olfactory training as valuable nonpharmacological therapy in pediatric headaches.

Comparison of Three Different Extraction Methods on Osmanthus Volatile Oil: Aroma and Biological Activity.

The osmanthus volatile oil was welcomed by consumers even if the high price since the unique and pleasant odor. Meanwhile, the low yield of osmanthus volatile oil restricts industrial production. In this work, an osmanthus volatile oil was obtained by means of a novel ultrasonic-assisted flash extraction method and was compared with the oil from hydrodistillation and supercritical fluid extraction on yield, aroma, and biological activities. The volatile oil obtained from the ultrasonic-assisted flash extraction was obtained with the petroleum ether and got a high yield at 3.51 % within a 40-min process, an increase of nearly 81 % from the single solvent extraction. This oil also showed a high aroma intensity and aroma compound concentration. Meanwhile, the oil also has the highest antioxidant ability but lower antibacterial activity against oil from hydrodistillation. It was considered that this work was helpful for the optimization of the extraction method of osmanthus volatile oil.

Monitoring the Aroma Compound Profiles in the Microbial Fermentation of Seaweeds and Their Effects on Sensory Perception

Seaweeds have a variety of biological activities, and their aromatic characteristics could play an important role in consumer acceptance. Here, changes in aroma compounds were monitored during microbial fermentation, and those most likely to affect sensory perception were identified. Ulva sp. and Laminaria sp. were fermented and generally recognized as safe microorganisms, and the profile of volatile compounds in the fermented seaweeds was investigated using headspace solid-phase microextraction with gas chromatography–mass spectrometry. Volatile compounds, including ketones, aldehydes, alcohols, and acids, were identified during seaweed fermentation. Compared with lactic acid bacteria fermentation, Bacillus subtilis fermentation could enhance the total ketone amount in seaweeds. Saccharomyces cerevisiae fermentation could also enhance the alcohol content in seaweeds. Principal component analysis of volatile compounds revealed that fermenting seaweeds with B. subtilis or S. cerevisiae could reduce aldehyde contents and boost ketone and alcohol contents, respectively, as expected. The odor of the fermented seaweeds was described by using GC–olfactometry, and B. subtilis and S. cerevisiae fermentations could enhance pleasant odors and reduce unpleasant odors. These results can support the capability of fermentation to improve the aromatic profile of seaweeds.

АКТУАЛЬНЫЕ ВОПРОСЫ ОЦЕНКИ КАЧЕСТВА ПОЛИКОМПОНЕНТНОГО ГЕЛЯ РЕПАРАТИВНОГО ДЕЙСТВИЯ

The domestic pharmaceutical market still lacks reparative drugs, which determines research on their creation as an urgent theoretical and applied task. In this regard, the expediency of developing the composition and technology for obtaining a polycomponent gel with a predictable positive effect on wound healing processes based on dermal biopolymers and a complex of biologically active substances of corn columns with stigmas is substantiated. The complex of technological studies carried out made it possible to establish the optimal composition and technology for obtaining a polycomponent gel. At the next necessary stage of pharmaceutical development, it was necessary to solve the issues of assessing the quality of the proposed composition of the polycomponent gel. The purpose of this study was to determine the criteria and methods for monitoring the quality indicators of a multicomponent reparative gel. The object of the study was experimental samples of a multicomponent gel obtained by introducing a thick extract of corn columns with stigmas into a collagen base. The quality of the polycomponent gel was assessed in accordance with the requirements of GPM.1.4.1.0008.15 "Ointments" of the State Pharmacopoeia IV edition according to the following criteria: "Description", pH, "Microbiological purity", authenticity and quantitative content of active substances. The indicator "Description" was evaluated organoleptically. The determination of the pH of the gel was carried out potentiometrically using a pH meter (Mettler Toledo, USA) according to GPM.1.2.1.0004.15 "Ionometry" directly in the gel sample. Microbiological purity was studied by the agar plate method in accordance with GPM.1.2.4.0002.15. The presence and quantitative determination of flavonoids in the developed gel was determined spectrophotometrically on a UV-1800 SHIMADZU spectrophotometer, Japan. As a result of the studies carried out, the criteria for the quality of a multicomponent gel of reparative action were studied and proposed. According to the "Description" indicator, the polycomponent gel is a homogeneous mass of light brown color with a pleasant fruity odor without impurities. It has been established that the polycomponent gel is characterized by a slightly alkaline pH value, which creates optimal conditions for the healing phase of the wound process. It is shown that the use of the method of differential spectrophotometry makes it possible to carry out a statistically significant qualitative and quantitative assessment of the content of flavonoids in the composition of a polycomponent gel.

Metabolic and molecular mechanisms underlying the foliar Zn application induced increase of 2-acetyl-1-pyrroline conferring the 'taro-like' aroma in pumpkin leaves.

Fresh pumpkin leaf is popular vegetable for its rich nutrition. The pleasant taro-like odour is important aroma quality of crops, and mostly contributed by 2-acetyl-1-pyrroline in pumpkin. Element Zn can impact metabolite biosynthesis in plants, including aroma formation. However, Zn-induced biochemical responses, especially 2-acetyl-1-pyrroline formation in pumpkin, haven't been elucidated. This study integrated metabolome and transcriptome to explore molecular fluctuations in pumpkin leaves at different time intervals after foliar Zntreatment. We first identified more than one thousand metabolites from pumpkin leaves by integrating different mass spectrometry methods according to the form in which a metabolite exists. Comparative metabolomic analysis revealed there were separately 25 out of 50 and 286 out of 963 metabolites that were respectively identified by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry, differentially regulated by Zn treatment. Our findings revealed that 50mg/L of Zn significantly enhanced 2-acetyl-1-pyrroline production by more than 38%, which was contributed by increased biosynthesis of its precursors, including ornithine and proline. The following transcriptome analysis discovered 30,574 genes, including 953 novel genes. Zn treatment induced the differential expression of 41.6% of identified genes which were supposed to regulate the downstream metabolite changes in a time-dependent manner. Pathway analysis indicated that alternations in primary metabolism, including carbon metabolism and biosynthesis of amino acids, were vital to the fluctuated aromatic compound generation. Phytohormones and transcription factors may regulate the expression of gene P5CS and proline biosynthesis, which, therefore, affect 2-acetyl-1-pyrroline production. This research reveals molecular mechanisms of 2-acetyl-1-pyrroline formation in pumpkin, which will provide the molecular basis for desired aroma compound production through metabolite engineering.

Bioactive Chemical Constituents of Matthiola longipetala Extract Showed Antioxidant, Antibacterial, and Cytotoxic Potency

The exploration of bioactive compounds from natural resources attracts the attention of researchers and scientists worldwide. M. longipetala is an annual aromatic herb that emits a pleasant odor during the night. Regarding the chemical composition and biological characteristics, M. longipetala extracts are poorly studied. The current study aimed to characterize the chemical composition of M. longipetala methanol extract using GC-MS and determine its biological potencies, including its capacity for cytotoxicity and antioxidant and antibacterial activities. In this approach, 37 components were identified, representing 99.98% of the total mass. The major chemical components can be classified as oxygenated hydrocarbons (19.15%), carbohydrates (10.21%), amines (4.85%), terpenoids (12.71%), fatty acids and lipids (50.8%), and steroids (2.26%). The major identified compounds were ascaridole epoxide (monoterpene, 12.71%) and methyl (E)-octadec-11-enoate (ester of fatty acid, 12.21%). The extract of M. longipetala showed substantial antioxidant activity. Based on the DPPH and ABTS scavenging, the antioxidant activity of the extracted components of M. longipetala revealed that leaf extract is the most effective with IC50 values of 31.47 and 28.94 mg/L, respectively. On the other hand, the extracted plant showed low antibacterial activities against diverse bacterial species, viz., Escherichia coli, Klebsiella pneumonia, Staphylococcus epidermidis, S. haemolyticus, and S. aureus. The most potent antibacterial results were documented for leaf and flower extracts against E. coli and S. aureus. Additionally, the extract’s effectiveness against HepG2 cells was evaluated in vitro using the measures of MTT, DNA fragmentation, and cell proliferation cycle, where it showed considerable activity. Therefore, we can conclude that M. longipetala extract displayed improvement in cytocompatibility and cell migration properties. In conclusion, M. longipetala could be considered a potential candidate for various bioactive compounds with promising biological activities. However, further characterization of the identified compounds, particularly the major compounds, is recommended to evaluate their efficacy, modes of action, and safety.

Classification of pleasant and unpleasant odor imagery EEG signals

Classification of pleasant and unpleasant odor imagery EEG signals

Pharmacognostical Standardization of Balamulachurna- Root Powder of Sida rhombifolia subsp. retusa (L.) Borssum

Pharmacognosy Research,2023,15,1,155-162.DOI:10.5530/097484900224Published:December 2022Type:Original ArticleAuthors:Thota Jyostna Kumari, Goli Penchala Prasad, Goli Penchala Pratap, Mohd Kashif Husain, and Padamata Sai Sudhakar Author(s) affiliations:Thota Jyostna Kumari1, Goli Penchala Prasad2, Goli Penchala Pratap3,*, Mohd Kashif Husain3, Padamata Sai Sudhakar1 1Dr. NRS Govt. Ayurvedic Medical College, Vijayawada, Andhra Pradesh, INDIA. 2National Institute of Indian Medical Heritage, Hyderabad, Telangana, INDIA. 3Survey of Medicinal Plants Unit, National Research Institute of Unani Medicine for Skin Disorders, Hyderabad, Telangana, INDIA. Abstract:Background: Ksheerabala tailam is well known Ayurvedic herbal formulation which is used in inflammations, pains and neurological disorders. The primary botanical source for Ksheerabala tailam is Balamulachurna. The literature refers to Balamulachurna as either of the root powders of Sida cordifolia, Sida acuta, Sida cordata or Sida rhombifolia subsp. retusa. To accomplish the clinical efficacy of Ksheerabala tailam, standardization of Balamulachurna is necessary. Objectives: The study is aimed to establish pharmacognostic standards of Balamulachurna with respect to Sida rhombifolia subsp. retusa root powder. Materials and Methods: Pharmacognostical standardization was carried out by focusing on organoleptic, macroscopic, microscopic, preliminary phytochemical evaluation, heavy metal assessments, fluorescence and HPTLC studies. Results: The roots macroscopic features were noticed as; an elongated taproot with few lateral roots, thick, woody, brown-coloured and bitter to taste. Organoleptic characteristics revealed the nature of the root powder as cream in colour with a pleasant odour and slightly bitter taste. The powder microscopic study specified the presence of fibres, fibre–sclereids, tracheids, vessel elements and calcium oxalate crystals. Physicochemical studies assessed total ash (7.5%), water-soluble ash (4.46%), alkalinity of water-soluble ash (0.4 ml) and acid-insoluble ash (3.3%). The preliminary phytochemical analyses revealed the presence of glycosides, alkaloids, phenols, flavonoids, tannins, terpenoids, and quinones. The HPTLC analyses exhibited various Rf values with the diversity of multiple phytoconstituents. Conclusion: The scientific data generated by the study is beneficial for adequately identifying and establishing standards for using Sida rhombifolia subsp. retusa as a primary drug for maintaining the quality and purity of the Ksheerabala tailam, an Ayurvedic formulation. Keywords:Balamulachurna, Ksheerabala tailam, Pharmacognosy, Sida rhombifolia subsp. retusa, StandardizationView:PDF (594.85 KB)

CHEMICAL CONSTITUENTS AND ANTIBACTERIAL PROPERTIES OF KITAGAWIA BAICALENSIS (REDOW. EX WILLD.) PIMENOV ESSENTIAL OILS

Kitagawia baicalensis (Redow. ex Willd.) Pimenov (Umbelliferae) is a perennial monocarpic plant with Siberian-Mongolian type of habitats. Decoction of flowers and roots has been used in Tibetan medicine for intoxication and as diuretic agent to treat edema. The essential oils of the aerial part of K. baicalensis growing within the territory of the Republic of Buryatia were obtained by steam distillation method. The isolated essential oils were yellow oily liquids, lighter than water, with characteristic pleasant odour. The qualitative composition and quantitative content of the components of essential oils were determined by GC/MS. 26 compounds with aromatic, mono- and sesquiterpenoid structures were identified in the composition of essential oils. The main components of the essential oils of the aerial part of the Kitagawia baicalensis from Buryatia were limonene (34.40%), β-myrcene (21.10%), γ-terpinene (12.60%), β-elemen (5.70%), sabinene (5.30%), germacren B (3.20%) and germacrene D (3.10%). Monoterpenoids (83.00%) predominated in general composition of essential oils. The content of compounds with sesquiterpenoid structure was 14.70%. The group of aromatic compounds was represented only by p-cymene (2.30%). Bactericidal and bacteriostatic activities of essential oils against Bacillus cereus, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Aspergillus niger, Candida albicans were determined in this paper. The most pronounced antibacterial effect of essential oils was found against Streptococcus pyogenes (1 : 64 dilution).

Efficient removal of acetaldehyde from ethanol by template-free synthesized mesoporous SiO2-based solid acid catalyst with high surface silicon exposure

In the absence of any template, mesoporous silica-based solid acid owing a high surface area (380.2 m2/g), big average pore size (5.6 nm), and moderate acid amount (1.33 mmol/g) was synthesized through a one-step reverse-phase microemulsion method. The introduction of 3-sulfopropyl as the acidic sites by this method increased the surface silicon exposure to a high value of 74.1 %, which enabled plenty of active groups to be available on the surface. As the main impurity in ethanol and has the potential to cause the serious damage for people’s health, acetaldehyde was removed with high removal (above 99.99 %) from ethanol through a novel strategy of “waste to value” with the present acid catalyst at the ambient temperature, in which acetaldehyde was converted to a much safer chemical of acetal that owns a pleasant odor and is permitted to be used as the fragrance in food. The remaining acetaldehyde could be controlled to a very low and much safer level of below 0.01 ppm with a wide range of initial concentration.

Pleasantness Recognition Induced by Different Odor Concentrations Using Olfactory Electroencephalogram Signals.

Olfactory-induced emotion plays an important role in communication, decision-making, multimedia, and disorder treatment. Using electroencephalogram (EEG) technology, this paper focuses on (1) exploring the possibility of recognizing pleasantness induced by different concentrations of odors, (2) finding the EEG rhythm wave that is most suitable for the recognition of different odor concentrations, (3) analyzing recognition accuracies with concentration changes, and (4) selecting a suitable classifier for this classification task. To explore these issues, first, emotions induced by five different concentrations of rose or rotten odors are divided into five kinds of pleasantness by averaging subjective evaluation scores. Then, the power spectral density features of EEG signals and support vector machine (SVM) are used for classification tasks. Classification results on the EEG signals collected from 13 participants show that for pleasantness recognition induced by pleasant or disgusting odor concentrations, considerable average classification accuracies of 93.5% or 92.2% are obtained, respectively. The results indicate that (1) using EEG technology, pleasantness recognition induced by different odor concentrations is possible; (2) gamma frequency band outperformed other EEG rhythm-based frequency bands in terms of classification accuracy, and as the maximum frequency of the EEG spectrum increases, the pleasantness classification accuracy gradually increases; (3) for both rose and rotten odors, the highest concentration obtains the best classification accuracy, followed by the lowest concentration.

Impact of Hedonics and Magnitude Upon Validated Psychophysical Olfactory Tests and Olfactory-Specific Quality of Life.

Patients often describe the olfactory loss as either the inability to detect unpleasant odors (eg, smoke or spoiled food) or noticeable impairment in enjoying pleasant odors (eg, food and fragrances). This complex relationship between the hedonics of various odors, their perceived magnitude in odor strength, and the impact on patient quality of life is not well understood. Sixty-five subjects underwent testing with the Henkin olfaction test which assesses hedonics and magnitude for odors traditionally deemed unpleasant (pyridine/dead fish and thiophene/gasoline) and pleasant (amyl acetate/banana and nitrobenzene/almond). Subjects also completed Smell Identification Test-40 (SIT-40), Sniffin' Sticks (Sniffin' Sticks), and Snap & Sniffin' Sticks (Snap) Olfactory Tests, as well as the 17-item Questionnaire for Olfactory Disorders Negative Statements (QODNS) and olfactory symptom visual analog scale (VAS). Spearman's rank correlations were conducted between various olfactory domains, QODNS and VAS. Mean age was 52.1 years (range: 28-86), with 63.1% females. Magnitude estimation was greatest for pyridine. Most people rated thiophene (75.4%) and pyridine (92.3%) as "unpleasant." Although most people rated amyl acetate (47.7%) and nitrobenzene (56.9%) as "pleasant," many rated amyl acetate (52.3%) and nitrobenzene (43.1%) as "neutral" or "unpleasant" scents. Hedonics for unpleasant odors correlated with each other (rs = 0.60), but not with hedonics for pleasant odors. Hedonics for unpleasant odors also correlated with magnitude estimation and other psychophysical tests. These findings were not seen for hedonics of pleasant odors. The use of unpleasant odors in Henkin testing showed unique relationship patterns with patient-reported outcome measures and validated olfactory tests, which may provide utility in characterizing olfactory dysfunction. The incorporation of more unpleasant odors in current psychophysical olfactory testing may provide enhanced information regarding the patient impact of olfactory dysfunction.

The different aspects of attractive toxic baits containing fipronil for control of the German cockroach (Blattella germanica).

The use of Attractive Toxic Baits (ATBs) is considered to be a low-risk practical method for controlling cockroaches. This study evaluates the attractiveness of a lab-made, fipronil-containing bait, and its effect on the food consumption and mortality of the German cockroach Blattella germanica, under field and laboratory conditions. Different developmental stages of the cockroach were used to determine their preferred carbohydrate/protein rich foods and examine the effectiveness of lab-made baits. The analysis of variance (ANOVA) with Tukey's Test was determined using SAS 9.1 and GraphPad Prism software programs. The significance level was considered at p<0.05. The most-consumed foods were carbohydrate-rich foods (biscuit and banana powder) and food consumption rate was highest in non-gravid females. The most attractive bait ingredients were 20% roasted peanut butter, 50% biscuit and 30% banana powder. The highest lethality was recorded from the baits containing 0.02% fipronil under laboratory conditions, while infested houses baited with the lab-made bait showed 76.5% and 100% decline, respectively, in cockroach numbers in the first- and fourth-week post-baiting. In conclusion, palatable foods with a pleasant odour, like biscuit powder, banana powder and peanut butter were the most effective ingredients for the ATBs. The ATBs impregnated with 0.02% fipronil provide a promising approach for control of the German cockroach. However, there is a need to evaluate the potentials of the lab-made baits, under laboratory and field conditions, in the control of other health-important cockroaches.

Stimulus responsive microcapsules and their aromatic applications

Fragrances and essential oils are promising for a wide range of applications due to their pleasant odors and diverse effects. However, direct addition to consumer products has the disadvantages of short retention time and easy deterioration of odor. At the same time, releasing a large amount of odor in a short time may be an unpleasant experience, which severely limits the practical application of aromatic substances. Microencapsulation perfectly solves these problems. Stimuli-responsive microcapsules, which combine environmental stimulation with microencapsulation, can not only effectively prevent the rapid decomposition and evaporation of aroma components, but also realize the "on-off" intelligent release of aroma substances to environmental changes, which have great promise in the field of fragrances. In this review, the application of stimuli-responsive microcapsules in fragrances is highlighted. Firstly, various encapsulation materials used to prepare stimuli-responsive aromatic microcapsules are described, mainly including some natural polymers, synthetic polymers, and inorganic materials. Subsequently, there is a detailed description of the common release mechanisms of stimuli-responsive aromatic microcapsules are described in detail. Finally, the application and future research directions are given for stimuli-responsive aromatic microcapsules in new textiles, food, paper, and leather.

Odor Pleasantness Modulates Functional Connectivity in the Olfactory Hedonic Processing Network.

Olfactory hedonic evaluation is the primary dimension of olfactory perception and thus central to our sense of smell. It involves complex interactions between brain regions associated with sensory, affective and reward processing. Despite a recent increase in interest, several aspects of olfactory hedonic evaluation remain ambiguous: uncertainty surrounds the communication between, and interaction among, brain areas during hedonic evaluation of olfactory stimuli with different levels of pleasantness, as well as the corresponding supporting oscillatory mechanisms. In our study we investigated changes in functional interactions among brain areas in response to odor stimuli using electroencephalography (EEG). To this goal, functional connectivity networks were estimated based on phase synchronization between EEG signals using the weighted phase lag index (wPLI). Graph theoretic metrics were subsequently used to quantify the resulting changes in functional connectivity of relevant brain regions involved in olfactory hedonic evaluation. Our results indicate that odor stimuli of different hedonic values evoke significantly different interaction patterns among brain regions within the olfactory cortex, as well as in the anterior cingulate and orbitofrontal cortices. Furthermore, significant hemispheric laterality effects have been observed in the prefrontal and anterior cingulate cortices, specifically in the beta ((13–30) Hz) and gamma ((30–40) Hz) frequency bands.

Odour hedonics and the ubiquitous appeal of vanilla.

Our food choices and consumption behaviours are often influenced by odour hedonics, especially in the case of those orthonasally experienced aromas (that is, those odours that are food-related). The origins of odour hedonics remain one of the most intriguing puzzles in olfactory science and, over the years, several fundamentally different accounts have been put forwards to try and explain the varying hedonic responses that people have to a wide range of odorants. Associative learning, innate and molecular accounts of odour pleasantness have all been suggested. Here the origins of the hedonic response to vanilla, which is one of the most liked smells cross-culturally, are explored. The history of vanilla's use in food and medicine is outlined, with a focus on its neurocognitive appeal. While vanilla is one of the most widely liked aromas, it is also rated as smelling sweet to most people. Food scientists are becoming increasingly interested in the possibility that such 'sweet smells' could be used to help maintain the sweetness of commercial food products while, at the same time, reducing the use of calorific sweeteners. Such an approach is likely to be facilitated by the low cost of artificial vanilla flavouring (when compared with the high and fluctuating price of natural vanilla pods).

Effects of odors on posture

AbstractEvidence suggests that postural stability may benefit from olfactory exposure, but whether this effect is different for hyposmic and healthy subjects remains unknown and little attention has been paid to the hedonic valence of odors in this context. Forty‐five participants aged between 23 and 64 years were invited to this study, of whom 32 had normal olfactory function 13 exhibited olfactory deficits. Movement measurements were performed with the “Unterberger stepping test.” Participants walked in place with stretched arms for 8 periods of 30 s each, separated by intervals of approximately 15 s. During each of these 30‐s blocks one of the three odor conditions was presented to them: (a) pleasant odor, (b) unpleasant odor, and (c) odorless control. Both participants with normosmia and impaired olfaction moved to the left and right sides more when exposed to the unpleasant odor as compared to pleasant odor exposure or no odor. When smelling pleasant odors, participants presented shorter maximal anterior/posterior sway than during no odor exposure, but it was similar when smelling unpleasant odor. The study demonstrated strong effects of odors on postural stability with pleasant odors limiting and unpleasant enhancing postural sways.Practical ApplicationsOdors affect postural stability. Although we fail to demonstrate that postural stability measurements can be applied as a supporting method in smell dysfunction diagnosis, the current study opens prospects for further explorations of the relationship between olfactory and vestibular systems. These efforts may eventually lead to practical solutions supporting postural balance in patients suffering from conditions adversely affecting the vestibular system.