Olfactory Evaluation Research Articles

Gender-Related Differences in the Correlation between Odor Threshold, Discrimination, Identification, and Cognitive Reserve Index in Healthy Subjects.

Many studies suggested that olfactory function could be associated with semantic memory, executive function, and verbal fluency. However, the gender-related association between olfactory function and the cognitive domain is not well investigated. The aim of this study was to estimate gender-related differences in the relationship between olfactory function and each specific cognitive domain of the Cognitive Reserve Index (CRI) questionnaire, such as education, working activity, and leisure time in healthy subjects. Two hundred and sixty-nine participants were recruited (158 women and 111 men), with a mean age of 48.1 ± 18.6 years. The CRI questionnaire and Sniffin' Sticks test were used to evaluate the cognitive reserve and the olfactory function, respectively. In all subjects, significant associations between the odor threshold versus CRI-Education, between the odor discrimina-tion and identification versus CRI-Working activity and CRI-Leisure Time, were found. In women, odor threshold, discrimination, and identification were associated with CRI-Leisure Time, while in men, only a significant association between odor threshold and CRI-Education was observed. Our data, showing significant gender-related associations between olfactory function and CRI scores, suggested the use of olfactory evaluation and cognitive reserve as an important screening tool for the early detection of mild cognitive impairment.

Mutational Spectrum, Ocular and Olfactory Phenotypes of CNGB1-Related RP-Olfactory Dysfunction Syndrome in a Multiethnic Cohort.

CNGB1 gene mutations are a well-known cause of autosomal recessive retinitis pigmentosa (RP), which was recently associated with olfactory dysfunction. The purpose of this study was to report the molecular spectrum and the ocular and olfactory phenotypes of a multiethnic cohort with CNGB1-associated RP. A cross-sectional case series was conducted at two ophthalmic genetics referral centers. Consecutive patients with molecularly confirmed CNGB1-related RP were included. All patients underwent a complete ophthalmological examination complemented by psychophysical olfactory evaluation. Fifteen patients (10 families: 8 Portuguese, 1 French, and 1 Turkish), mean aged 57.13 ± 15.37 years old (yo), were enrolled. Seven disease-causing variants were identified, two of which are reported for the first time: c.2565_2566del and c.2285G > T. Although 11/15 patients reported onset of nyctalopia before age 10, diagnosis was only established after 30 yo in 9/15. Despite widespread retinal degeneration being present in 14/15 probands, a relatively preserved visual acuity was observed throughout follow-up. Olfactory function was preserved in only 4/15 patients, all of whom carried at least one missense variant. Our study supports previous reports of an autosomal recessive RP-olfactory dysfunction syndrome in association with certain disease-causing variants in the CNGB1 gene and expands the mutational spectrum of CNGB1-related disease by reporting two novel variants.

Olfactory function in laryngectomised patients: tracheo-oesophageal versus oesophageal speech.

This study aimed to evaluate olfactory function in patients rehabilitated with oesophageal (ES) voice or tracheo-oesophageal (TES) prosthesis to further verify whether there were differences in smell alterations depending on voice rehabilitation modality. A total of 40 patients who had undergone total laryngectomy participated in the study. Speech rehabilitation was achieved through TES in 20 patients (Group A) or ES in 20 patients (Group B). Olfactory function was evaluated using the Sniffin' Sticks test. At olfactory evaluation, in Group A, 4/20 patients (20%) were anosmic, whereas 16/20 patients (80%) were hyposmic; in Group B, 11/20 patients (55%) were anosmic whereas 9/20 patients (45%) were hyposmic. A significant difference (p = 0.04) was found at global objective evaluation. The study shows that the rehabilitation with TES contributes to maintaining a functioning, albeit limited, sense of smell.

Differences in Methods for Olfactory Evaluation in Postoperative Eosinophilic Chronic Rhinosinusitis

嗅覚検査法として本邦ではT&Tオルファクトメーター（T&T）を用いた基準嗅力検査が一般的である。オープンエッセンス（OE）や日常のにおいアンケート票（SAOQ）による嗅覚評価では基準嗅力検査との相関性は高いとされている。手術加療を行った好酸球性副鼻腔炎（ECRS）105例を対象とし手術前および術後3か月で施行された各検査間の相関性，治療効果判定結果について検討を行った。T&T平均認知域値（T&T値）とOE，SAOQの相関係数は−0.81，−0.74であり強い相関を認めた。T&T値を基に回帰分析を行い，OE，SAOQの治療効果判定基準を設定し，症例ごとにT&T値，OE，SAOQそれぞれで治癒・軽快・不変・増悪の判定を行うと，OEおよびSAOQではT&T値に比べ治癒判定が多く軽快判定が減少する傾向を認めた。治癒・軽快（改善）と不変・増悪（非改善）に大別して各検査法での判定を行うと改善率はT&T値71.4％，OE 69.7％，SAOQ 62.2％となった。T&T値とOEでは改善／非改善の結果が不一致であったものは16例（16.2％），T&T値とSAOQでは23例（23.5％）であった。OEによる検査やSAOQを用いた自覚的評価はT&Tの結果をある程度反映しうるが，各検査間では結果に乖離が生じる場合があることに留意する必要がある。

1404. Factors Associated to Decrease in Quality of Life After Mild-Moderate COVID-19: A Cross-Sectional Study.

Abstract Background Post-COVID-19 alterations have been recognized even after mild disease. We aimed to assess which factors are the main contributors to a decrease in quality of life(QOL) of patients with different times elapsed from the COVID-19 diagnosis. Methods A cross-sectional study from January 2021 to April 2021 in a Referral Center in Mexico City. Patients were invited for a follow-up visit in which a structured questionnaire about symptoms, the EQ-5D-5L QOL for QOL, and an objective olfactory evaluation with The Sniffin’ Sticks Screening 12 test. Results We included 179 patients, 64% were female with a median age of 33 years. The median time since COVID-19 diagnosis until the evaluation was 219 days (IQR, 94-255). Persistent symptoms were present up to in 158/179 (88%), fatigue, pain/discomfort and cognitive alterations were present in 61%, the median EQ-5D-5L index value preCOVID-19 was 1 (IQR, 0.94-1) and post- COVID-19 was 0.87 (IQR, 0.80-0.94), P< 0.001. There were 101/179 (56%) patients with decreased QOL; In the multivariate analysis, post-COVID-19 pain (aOR, 2.5; P= 0.01), anxiety (aOR, 13; P= 0.03), and the persistence of three or more symptoms (aOR, 2.6; P= 0.05) were factors associated with decreased QOL. Conclusion Within the post- COVID-19 alterations, psychological and physical factors such as Pain/discomfort, anxiety, and persistent symptoms explained the decreased QOL in the post-COVID-19 patient. These alterations were present as early as 30 days to more than eight months. Disclosures All Authors: No reported disclosures.

Olfactory Evaluation in Clinical Medical Practice.

The subjective and demanding nature of olfactory testing means that it is often neglected in clinic despite loss of smell leading to significant limitations in everyday life. The list of diseases associated with loss of olfaction far exceeds the field of otorhinolaryngology and can also be seen in neurodegenerative disorders. Knowledge of possible clinical testing is essential to determine a proper differential diagnosis for the loss of olfactory sense. Causes of olfactory impairment can be divided into either failure in transferring odour to the organ of perception or damage to the olfactory pathway structure itself. Examination should therefore include methods evaluating cross-sectional area and patency of the nasal cavity as well as subjective or objective assessment of olfactory function. In this report we summarize several articles, studies, and our own experiences to provide a comprehensive review of their current clinical usage including their benefits, limitations, and possible outcomes. We also discuss the mechanism of olfaction step by step to provide a full understanding of the possible errors depending on the localization in the pathway and the methods designed for their detection. We discuss the correlation of the microbiome in nasal polyposis and chronic rhinitis with olfactory impairment using objective olfactometry. The topic of objective olfactometry and the examination of olfactory event-related potentials (OERP) is commented upon in detail.

Anosmia/hyposmia differences between severe acute respiratory syndrome coronavirus 2 variants; objective olfactory function evaluation

Objectives: This study aimed to investigate whether the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants cause more or less loss of smell than the wild type variant as a clinical finding that may guide physicians in addition to the increased mortality feature. Patients and Methods: In the prospective study, Connecticut Chemosensory Clinical Research Center (CCCRC) odor testing was performed on patients hospitalized for coronavirus disease 2019 (COVID-19) between May 2021 and December 2021, and variants of SARS-CoV-2 isolated from patients were analyzed. A total of 51 patients (30 males and 21 females; mean age 59.3±14.2 years; range, 29 to 88 years) were included in the study. Age, sex, and COVID-19 vaccine status of the patients were recorded. The patients were asked whether they had new-onset odor or taste complaints and whether they differently perceived smells they knew. Results: The delta variant was detected in 14 patients, the alpha variant was detected in 20 patients, and no variant of concern was detected in 17 patients. Odor disorders were present in 79.4% of all patients (13.73% anosmia, 15.69% severe hyposmia, 13.7% moderate hyposmia, and 37.2% mild hyposmia). There was no statistically significant difference between sex, age, smoking habits, presence of parosmia, degree of smell disorder, and Vicks definition results according to the variants (p>0.05). A statistically significant difference was found between alpha and delta variants in terms of patients' complaints of decreased smell and taste, mean olfactory threshold value, and mean olfactory score variables (p<0.05). There was no difference in terms of age and identification score. The complaints of smell and taste disorders, the mean threshold value of odor, and the mean odor score were found to be significantly lower in the delta variant than in the alpha variant. Conclusion: SARS-CoV-2 variants differ significantly in olfactory dysfunction. Future clinical and laboratory studies may show the diagnostic, clinical, and prognostic significance of olfactory nerve injury.

The novice nose knows: How olfactory knowledge shapes evaluation confidence

Prior consumer knowledge research compares differences between experts and novices within a product category, implicitly assuming that novices are similar across categories. Relying on the differences between incidental and intentional learning, as well as on the unique physiological characteristics of olfaction processing, we examine this assumption, comparing novice consumers between olfactory and non-olfactory categories and suggesting that olfactory novices are unique. Using electronic word-of-mouth (eWOM) analysis and experiments, we find that olfactory novices are more familiar with technical terms than non-olfactory novices in their product category. Thus, when exposed to technical olfactory product descriptions, olfactory novices are more confident in evaluating products by gaining a higher sense of understanding. This cross-category novice comparison and the underlying cognitive mechanism are new to the literature. The research highlights the theoretical importance of how olfactory novices are unique and shows how eWOM and experimental data can be combined in sensory marketing. Practically, we suggest scented product managers to provide more technical product descriptions for olfactory novices, especially when product trial is not feasible (e.g., online purchases).

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.

Microwave-assisted synthesis and odor characteristics of some new isoxazolidines

We describe herein the design and synthesis of new isoxazolidin-5-carboxylates by microwave-assisted 1,3-dipolar cycloadditions of aldonitrones, derived from five fragrant aldehydes, with methacrylate esters. The reaction proceeded regioselectively providing mostly endo- diastereomers and in some cases an inseparable mixture of endo-exo products. The structures of target compounds were identified on the basis of IR, NMR, and TOF-MS measurements. Besides, both aldonitrone and isoxazolidine derivatives were subjected to olfactory evaluation by an expert nose. Diverse fragrance notes were observed in each series of isoxazolidines bearing different groups from aldonitrones. However, their odor ranges were found as animalic, medical, waxy, and ozonic undertones in common.

The diagnostic value of the olfactory evaluation for congenital hypogonadotropic hypogonadism

ObjectiveThe aim of this study was to evaluate the diagnostic accuracy of different olfactory evaluation tools in congenital hypogonadotropic hypogonadism (CHH) patients.MethodsSeventy-one CHH patients were prospectively recruited at Peking Union Medical College Hospital between November 2020 and July 2021. The Chinese Olfactory Function Test (COFT) and Self-reported Olfactory Scale (SROS) were adapted as the subjective tools for the evaluation of olfactory function, and magnetic resonance imaging of olfactory apparatus (MRI-OA) was the objective tool. The olfactory bulb volume (OBV) and the olfactory sulcus depth (OSD) were quantified.ResultsBased on the COFT, 36 patients were categorized as having normosmic CHH (nCHH), and the other 35 patients were categorized as having Kallmann syndrome (KS). Among nCHH patients, 35 patients were classified as having normal olfaction and 1 patient had abnormal olfaction by SROS. For KS patients, there were 30 patients grouped into abnormal olfaction, while 5 patients had normal olfaction by SROS. For MRI-OA, 67% (18/27) of nCHH patients showed normal olfactory apparatus, and 33% (9/27) showed bilateral or unilateral olfactory bulb aplasia or hypoplasia. Among KS patients, 96% (27/28) of patients showed bilateral olfactory bulb hypoplasia or aplasia, and 4% (1/28) of patients showed normal olfactory apparatus. All six patients with unilateral olfactory bulb aplasia and three patients with bilateral olfactory bulb aplasia showed normal olfactory function. The accuracy of the SROS in the diagnosis of nCHH and KS was 91.5%, with a sensitivity of 0.857 and a specificity of 0.972, while the accuracy of MRI-OA is 92.7%, with a sensitivity of 0.964 and a specificity of 0.889.ConclusionSROS and MRI-OA both showed high accuracy to distinguish between KS and nCHH. The abnormal structure of the olfactory apparatus was relatively common in nCHH patients. CHH patients with unilateral olfactory bulb aplasia dysplasia usually had normal olfaction. Normal olfaction without apparent olfactory bulbs is rare but occurred in male CHH patients.

Evaluation of the complete Sniffin Sticks Test versus its subtests in differentiating Parkinson's disease patients from healthy controls.

Hyposmia is one of the most common, as well as the first nonmotor condition in Parkinson disease (PD). The sniffin sticks test (SST) evaluates three different aspects of olfactory function: threshold (T), discrimination (D), and identification (I). The sum of the scores of these three subtests produce a global score of olfaction, the Threshold-Discrimination-Identification (TDI) score. The aim of this study was to investigate if the TDI score or one of its subtests is better to discriminate PD patients from controls. We recruited 27 PD patients and 17 healthy age-matched controls (HC) who were evaluated through a clinical interview, the Montreal Cognitive Assessment and Movement Disorders Society - Unified Parkinson Disease Rating Scale. The olfaction was assessed using the complete SST. The performance of PD patients on the olfactory test was significantly worse when compared with the HC (T: 3.0 vs. 6.5, p < 0.001; D: 8.1 vs. 11.2, p < 0.001; I: 7.3 vs. 11.7, p < 0.001; TDI: 18.8 vs. 29.9, p < 0.001). The prevalence of olfaction impairment in our study (PD: 100%, and HC: 56%) was greater than that found in the literature. Cognition influenced the performance on TDI. The olfactory subtests were impaired proportionally between patients and controls. Furthermore, D and I were correlated, but only in PD patients. The TDI showed a tendency to better discriminate PD patients from HC, when compared with its subtests. Although the complete olfactory evaluation is time consuming, it seems to be a superior tool to identify olfaction impairment in PD patients, when compared with the isolated subtests.

Electrochemical Signal Amplification Strategies and Their Use in Olfactory and Taste Evaluation.

Biosensors are powerful analytical tools used to identify and detect target molecules. Electrochemical biosensors, which combine biosensing with electrochemical analysis techniques, are efficient analytical instruments that translate concentration signals into electrical signals, enabling the quantitative and qualitative analysis of target molecules. Electrochemical biosensors have been widely used in various fields of detection and analysis due to their high sensitivity, superior selectivity, quick reaction time, and inexpensive cost. However, the signal changes caused by interactions between a biological probe and a target molecule are very weak and difficult to capture directly by using detection instruments. Therefore, various signal amplification strategies have been proposed and developed to increase the accuracy and sensitivity of detection systems. This review serves as a reference for biosensor and detector research, as it introduces the research progress of electrochemical signal amplification strategies in olfactory and taste evaluation. It also discusses the latest signal amplification strategies currently being employed in electrochemical biosensors for nanomaterial development, enzyme labeling, and nucleic acid amplification techniques, and highlights the most recent work in using cell tissues as biosensitive elements.

PH-responsive citral microcapsules with tannic acid-FeIII coordination complexes

Citral is one of the most important aromatic ingredients in foods and beverages for its distinct lemon-like odor. However, the fast evaporation and oxidation limit these applications. Herein, citral microcapsules were constructed by tannic acid-FeIII coordination complexes (citral@TA-FeIII). The morphologies, structure, citral loading amount, pH responsiveness, oxidative stability and olfactory sensory evaluation were investigated. The obtained citral@TA-FeIII microcapsules presented core–shell structure with the average size of 528.16 nm. Citral loading amount was 12.79 %. Citral release exhibited pH-responsiveness with a sustained release rate at neutral pH and a fast release under acidic condition. Citral microcapsules retained excellent sensory profile due to the antioxidant capsule shells. Citral@TA-FeIII microcapsules efficiently inhibited bacteria (S. aureus and E. coli) growth, and the performance is enhanced under acidic condition by citral pH-responsive release. This work may open a new path for hydrophobic unsaturated aroma compounds encapsulation, widening their applications with multifunctionalities.

Dual stabilization of Pickering emulsion with epigallocatechin gallate loaded mesoporous silica nanoparticles

Oxidation in food emulsions remains challenging to keep food quality and shelf-life. In this paper, a dual stabilization to both oil phase and antioxidant in Pickering emulsion is presented. Mesoporous silica nanospheres (MSN) were prepared to incorporate epigallocatechin gallate (EGCG), a typical plant-based antioxidant. EGCG loaded MSN were used to emulsify Litsea cubeba essential oil, a model oil, with olfactory investigation of the chemical stability. The emulsions improved the physical and chemical stabilization. The emulsions were uniformly stable with various parameters with one-month observation. Olfactory evaluation and GC–MS-O investigation reveal that the odors and odorous compounds of essential oil were well preserved in Pickering emulsions and much better than those in conventional emulsion with Tween 80. EGCG loaded MSN Pickering emulsion efficiently protect essential oil from oxidation. EGCG was also well retained in Pickering emulsion. This strategy could inspire new designs for food functional Pickering emulsions with efficient protective effect.

Parosmia assessment with structured questions and its functional impact in patients with long-term COVID-19-related olfactory dysfunction.

Parosmia assessment with structured questions and its functional impact in patients with long-term COVID-19-related olfactory dysfunction.

Olfactory Evaluation in Alzheimer's Disease Model Mice.

Olfactory dysfunction is considered a pre-cognitive biomarker of Alzheimer’s disease (AD). Because the olfactory system is highly conserved across species, mouse models corresponding to various AD etiologies have been bred and used in numerous studies on olfactory disorders. The olfactory behavior test is a method required for early olfactory dysfunction detection in AD model mice. Here, we review the olfactory evaluation of AD model mice, focusing on traditional olfactory detection methods, olfactory behavior involving the olfactory cortex, and the results of olfactory behavior in AD model mice, aiming to provide some inspiration for further development of olfactory detection methods in AD model mice.

Measured and self-reported olfactory function in voluntary Norwegian adults

PurposeThe lack of epidemiological data on the proportion of olfactory dysfunction (OD) using comprehensive olfactory assessment in healthy adults in Scandinavia motivated to the present study which aimed to explore the proportion of OD in voluntary healthy Norwegian adults, assessed by Sniffin’ Sticks, and its correlation to self-reported olfactory function. Furthermore, sociodemographic and clinical factors associated with olfactory function were analysed.MethodsThe sample included 405 Norwegian participants, aged 18–78 years, 273 women and 132 men, who underwent olfactory testing with extensive Sniffin’ Sticks test, allergy testing, clinical examination with nasal endoscopy and completed a self-administered questionnaire, including self-evaluation of olfactory function on a 100 mm Visual Analogue Scale.ResultsWe found that 37% had OD, of which 1.2% had anosmia assessed with extensive Sniffin’ Sticks test. The proportion of hyposmia and anosmia increased with age. Men and participants with low education had poorer olfactory function scores. Allergy, smoking status, general health and endoscopic findings were not associated with measured olfactory function. We found no correlation between self-reported and measured olfactory function.ConclusionsThis study has identified that a large proportion of our sample of voluntary healthy Norwegian adults have OD, considerably more common in older adults and somewhat more common in men and individuals with low education. The lack of correlation between self-reported and measured olfactory function highlights the importance of using validated tests for a reliable olfactory evaluation.

Support for local wines in The Netherlands: opportunities for the hospitality industry

ABSTRACT This article reports on a research project to measure the current intrinsic competitive value of Dutch wine in comparison to wines from renowned wine countries based on a taste and olfactory evaluation, and to explore the sustainable benefits that local Dutch wine can offer and wines made from fungus-resistant grape varieties (FRG). Both factors aim to measure the unique selling point of Dutch wine and explore if adoption in The Netherlands can be strengthened in the future. A blind tasting experiment with four different tasting groups (n = 54) was conducted. Participants evaluated (blind) two Dutch wines (white and red), a New Zealand wine (white) and a Bordeaux blend (red), which were matched according to their flavour components and popularity in The Netherlands. The outcome of this research shows no significant difference in overall scores between groups when comparing Dutch wine to wines from renowned wine-producing countries when tasted blind. However, the Dutch white wine was significantly more likely to be purchased according to participants. Results show that the competitiveness of Dutch wine in comparison to other renowned wine regions is evident. Dutch wine has increased in quality over the last years, therefore it is more likely to be purchased now. This offers opportunities in marketing and sales to increase efforts towards a more sustainable food and beverage programme among restaurateurs in The Netherlands.

A hami melon flavor creation

Hami melon fruit is highly appreciated for its unique flavor. How to simulate Hami melon flavor has rarely been reported. If the Hami melon flavor is developed, it can be widely used in food, beverages, and other products. Thus, Hami melon flavor creation is of great interests. This study dealt with Hami melon flavor creation in the light of note method. The notes for construction of a Hami melon flavor were obtained by tasting and smelling Hami melon fruity. Green note, sweety note, melon fruity note, other fruity note, winey note, and special note together form Hami melon flavor. Based on these notes, a series of aroma materials were selected to construct Hami melon flavor formula. After olfactory evaluation, numerous adjustments and modifications were made until a desired Hami melon flavor formula was obtained. The flavor blended based on the formula has the typical characteristic odor of natural Hami melon fruit. It has a fresh, sweet, harmonious Hami melon aroma.