Olfactory Evaluation Research Articles

Late olfactory bulb involvement in COVID19.

Transient or persistent hypo-anosmia is common in SARS‑CoV‑2 infection but olfactory pathway late-term morphometric changes are still under investigation. We evaluated late olfactory bulb (OB) imaging changes and their correlates with the olfactory function in otherwise neurologically asymptomatic COVID-19 patients. Eighty-three subjects (mean-age 43±14 years; 54 females; time-interval infection/MRI: 129±68 days) affected by asymptomatic to mild COVID19 in 2020 and 25 healthy controls (mean-age 40±13 years; 9 females) underwent 3T-MRI and olfactory function evaluation through anamnestic questionnaire and Sniffin' Sticks. Exclusion criteria were intensive care treatment or neurological involvement other than olfaction. Maximal OB area was measured blindly on high-resolution coronal T2w images by two observers. Patients were subdivided into: i) persistently hypo/anosmic, ii) recovered normosmic and iii) never complaining smell dysfunction with proven normal olfactory function. No significant differences were observed among patients' subgroups (p=0.76). Intra-observer and inter-observer reliability were high.(r=0.96 and 0.86). Former COVID19 patients had decreased mean maximal OB area than controls (6.52±1.11mm2 vs 7.26±1.17mm2, p=0.008) even when considering persistently hypo-anosmic (6.46±0.90, p=0.006) or normosmic patients at MRI (6.57±1.25, p=0.04). SARS-CoV-2 infection is associated with mid/late-term morphological changes on the olfactory bulbs, regardless of presence or persistence of olfactory dysfunction. The long-term consequences on olfactory aging need to be further investigated including possible links with neurodegenerative disorders.

Regional aroma characteristics of spontaneously fermented Cabernet Sauvignon wines produced from seven sub-regions in Shangri-La of China.

Shangri-La is a promising wine region in China, which has great potential for producing high-quality wines with distinctive regional characteristics. In this work, the aroma properties of spontaneously fermented Cabernet Sauvignon wines produced from seven sub-regions of Shangri-La (Adong, Liutongjiang, Sinong, Xidang, and Nitong from Lancang River basin; Benzilan and Dari from Jinsha River Basin) were comprehensively analyzed using the headspace micro-extraction with gas chromatography-mass spectrometry, odor activity values, and olfactory evaluation. Results showed that a total of 59 volatiles belonging to seven groups were identified and quantified in all regional wines, with alcohols constituting the most abundant group, followed by esters and volatile fatty acids. Based on their odor activity values, six alcohols, seven esters, two terpenes, one C13-norisoprenoids, and three volatile fatty acids were identified as key volatiles which significantly contribute to the aroma of these wines. Principal component analysis showed the distinct compositions of these 19 key volatiles among the seven regional wines. Olfactory evaluation revealed certain differences in aroma profiles, particularly "Tropical fruit", "Dried fruit", "Vegetal", and "Sweet" among them. This study enhances our understanding on the unique terroir flavors of Shangri-La wines and is helpful for further producing high-quality wines with regional characteristics.

Effect of Roasting Level on the Development of Key Aroma-Active Compounds in Coffee

Coffee roasting is considered the most critical process in the development of sensory characteristics. During this stage, a substantial number of compounds are generated. Nevertheless, only a limited number of these compounds are responsible for the aroma, referred to as key aroma-active compounds. This study aimed to assess the impact of roasting levels on the formation of these compounds. Coffee was roasted at four different levels: very light (RL85), light (RL75), medium (RL55), and extremely dark (RL25), according to the Specialty Coffee Association (SCA) guidelines. The extraction, olfactory evaluation, and identification of compounds were performed using solid-phase microextraction (SPME), gas chromatography–olfactometry (GC-O), and gas chromatography–mass spectrometry (GC-MS), respectively. A total of 74 compounds were successfully identified, of which 25 were classified as aroma-active compounds. RL75 and RL85 displayed similar aromatic profiles. RL55 was characterized by pleasant notes such as sweet, toasted hazelnut, and caramel. In contrast, RL25 was marked by undesirable odors including burnt notes, putrid, and sulfurous scents. This study is the first to identify key odorant compounds in coffee based on SCA roasting standards.

Identification of a higher C-S lyase activity of Staphylococcus hominis in volunteers with unpleasant axillary odour.

Excessive and unpleasant odours that emanate from the skin can induce bromhidrosis and substantially impair a person's quality of life. Enzymatic pathways generating unpleasant odours are well detailed, and among them, the C-S lyase is one of the enzymes involved in the conversion of non-volatile precursors into thiol-type malodorous volatile molecules such as 3M3SH. This study aimed to investigate the variation of axillary odour intensity correlated with Staphylococcus (S.) hominis C-S lyase activity within a group of volunteers after a physical activity. First, a group of 24 volunteers from the same ethnicity with standardized hygienic and alimentary practices participated in a supervised indoor cycling activity. Following this session, worn T-shirts were recovered to enable the olfactory evaluation of axillary odours by qualified experts. To go further, the microbiota from the axillary zone of each volunteer was sampled and the bacterial relative abundance was investigated by using 16S rRNA metasequencing. Then, S. hominis isolates were obtained by culturomics from these microbiota samples and the C-S lyase activity was measured by spectrofluorometry in protein crude extracts. The evaluation of the odour intensity revealed that within the panel, two groups were significantly distinct. A non-odorous group and a malodorous one with volunteers having unpleasant odours. The 16S rRNA metasequencing reveals differences in bacterial communities between the two groups with a significant increase in the relative abundance of S. hominis in the malodorous group compared with the non-odorous one. The C-S lyase activities measured on S. hominis sampled on volunteers from the two groups demonstrate that for an equivalent quantity of protein, this enzymatic activity is significantly higher for the samples originating from the malodorous group. Hence, this study demonstrates that beyond the increase of S. hominis relative abundance, the C-S lyase enzymatic activity of this bacteria is also higher in volunteers with unpleasant axillary odours.

Paper based analytical devices for ions determination in nasal secretions demonstrating association with olfactory function

Nasal ions environment plays a crucial role in maintaining nasal physiology and supports olfactory transmission. Addressing the limited research on nasal ion levels and their association with olfactory function, paper-based sensors were developed for determination of sodium, potassium, calcium and chloride in the nasal mucus of healthy volunteers and patients with olfactory dysfunction. Multi-walled carbon nanotubes and carbon quantum dots from beetroot were incorporated into paper substrate where sensors were designed with ion association complexes for sodium, potassium, calcium and chloride enhancing the recognition sensing capabilities. The sensors composition was optimized, including ion-exchange materials and plasticizers, to enhance sensitivity and selectivity. The performance of the sensors is evaluated based on Nernstian slope, dynamic range, detection limit and response time. Selectivity of the sensors was tested and the results demonstrated high selectivity for the target ions. The sensors were successfully determined sodium, potassium, calcium and chloride levels in nasal mucus of healthy volunteers and patients with olfactory dysfunction. The results revealed elevated calcium levels in patients with olfactory dysfunction, highlighting associated diagnostic implications. This suggests that the proposed sensors could serve as a diagnostic tool for olfactory evaluation, particularly in resource-constrained settings where access to advanced diagnostic tools is limited.

Efficacy of the nasal airflow-inducing maneuver in the olfactory rehabilitation of laryngectomy patients: A systematic review and meta-analysis.

This is the first systematic review and meta-analysis to investigate the effectiveness of the nasal airflow-inducing maneuver (NAIM) in olfactory rehabilitation for total laryngectomy (TL) patients. We conducted a systematic literature search following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The inclusion criteria required that patients must have undergone a TL with subsequent NAIM training for at least 2weeks and olfactory evaluation. The impact of NAIM on olfactory outcomes compared to that at baseline was measured. Olfactory measures included the Sniffin' Sticks Test, Smell Disk Test, Scandinavian Odor Identification Test, and Quick Odor Detection Test. The primary outcome measures were the proportion of patients with normosmia at baseline and after intervention. Seven studies from 2000 to 2023 comprising a total of 290 TL patients met the inclusion criteria. The meta-analysis revealed that prior to intervention, the pooled proportion of patients with normosmia was 0.16 (95% confidence interval [CI]: 0.09‒0.27, p=0.01). After intervention, the same proportion increased to 0.55 (95% CI: 0.45‒0.68, p=0.001). Among the included patients, 88.3% were initially anosmic or hyposmic, which was reduced to 48.9% after NAIM practice, with 51.1% achieving normosmia. The percent improvement was not found to be significantly associated with the timing of intervention post-TL (p=0.18). NAIM increased the proportion of patients who achieved normosmia in TL patients. NAIM stands out as a safe, easily teachable maneuver with promising results. Further efforts are warranted to provide specific recommendations and guidelines for the use of NAIM in clinical practice.

The association between olfactory subdomains and frailty: A prospective case‒control study investigation.

Amidst the rise of frailty among a globally aging population, olfactory decline has emerged as a harbinger of frailty and mortality in population-level studies. However, the relationships between frailty and the olfactory subdomains of identification (OI), discrimination (OD), and threshold (OT) remain unexplored. This study prospectively examined the association between olfactory subdomains and the physical frailty phenotype (PFP) to investigate olfactory evaluation as a means of frailty screening. A case‒control study of 45 frail and 45 non-frail individuals matched by age and sex. OT, OD, OI (range 0‒16), and composite sum (threshold, discrimination, and identification scores [TDI], range 0‒48) were measured with Sniffin' Sticks. PFP was defined by presence of three or more criteria: physical inactivity, self-reported exhaustion, muscle weakness, slow gait, and unintentional weight loss. Conditional logistic regression evaluated associations between olfactory subdomains and frailty. Ninety individuals with mean age of 83.1±4.9 years, 60% female (n=54), and 87.8% white (n=79) were included. Olfactory scores were significantly lower in the frail group for OI (9.2vs. 12.1, p<0.001), OD (8.1vs. 11.6, p<0.001), OT (4.4vs. 8.5, p<0.001), and TDI (21.7vs. 32.2, p<0.001) than in the non-frail group. A single-point decrease in olfactory score was associated with increased odds of frailty in OT (odds ratio [OR]: 2.21, 95% confidence interval: [1.22, 3.98]), OD (OR: 2.19, 95% CI: [1.32, 3.65]), OI (OR: 2.29, 95% CI: [1.19, 4.39]), and TDI (OR: 1.54, 95% CI: [1.14, 2.08]). The robust association between olfactory subdomain scores and frailty suggests that olfaction may be an accessible signifier of frailty. Future studies should investigate this relationship longitudinally to assess predictive relationships.

Research on digital-visual evaluation method of down fibers odor

Down is often used as a natural filler for warm clothing, but the odor of down is one of the issues that affects the performance of warm clothing applications. At present, the evaluation of down odor mostly uses the human olfactory evaluation method, which has low reproducibility and accuracy. This article first uses the method of activated carbon gas extraction/gas chromatography–mass spectrometry to identify five down odor compounds that can be detected in a stable way, as representative compounds of down odor. Then, a simple direct impregnate extraction/gas chromatography–mass spectrometry method was used to determine the exact concentration of odor compounds in down fibers. Finally, an odor level radar chart was constructed by analyzing the concentration of odor representative compounds of levels 1–5 in down. The digital visual evaluation method was composed of direct impregnate extraction combined with radar chart to judge the down odor level and compared to the human olfactory method. The results indicate that the radar chart evaluation has relatively accurate evaluation results and is more objective and accurate than the human olfactory method. This method for evaluating the odor level of down is simple and reliable, and has certain promotion and application prospects in the down production industry.

Hemp Flour as a Functional Ingredient for the Partial Replacement of Nitrites in a Minced Meat Model: Effect on Nutrient Composition, Antioxidant Profile and Sensory Characteristics

Consumers are becoming increasingly concerned about synthetic preservatives like nitrites in meat, prompting the meat industry to explore alternatives in order to lower nitrite levels. This study investigated the effects of incorporating hemp flour on the chemical and shelf-life characteristics of minced meat products with reduced nitrite content. Three types of products were prepared: HF0 (control) (0% hemp flour, 30 mg/kg NaNO2), HF4 (4% hemp flour, 15 mg/kg NaNO2), and HF6 (6% hemp flour, 15 mg/kg NaNO2). Analyses were conducted on proximate composition, fatty acid composition, antioxidant properties, lipid oxidation, colour, texture, and sensory characteristics. The addition of hemp flour at 6% reduced moisture content and influenced ash and sodium chloride levels in minced meat products. Despite the favorable fatty acid profile of hemp flour, its inclusion did not significantly alter the composition of the products. However, it did lead to significantly lower levels of lipid oxidation and modified the antioxidant capacity. Colour attributes were affected, with a higher hemp flour content resulting in colour deterioration. Cooking loss increased with a higher hemp flour content, and the minced meat products were significantly harder. Visual and olfactory sensory evaluation indicated that there were no significant differences in most traits, suggesting consumer acceptance of hemp-flour-enriched minced meat products. Overall, this study highlights the potential of hemp as a functional ingredient in minced meat products, also exhibiting the ability to reduce lipid oxidation.

Enhancing Odor Analysis with Gas Chromatography-Olfactometry (GC-O): Recent Breakthroughs and Challenges.

Gas chromatography-olfactometry (GC-O) has made significant advancements in recent years, with breakthroughs in its applications and the identification of its limitations. This technology is widely used for analyzing complex odor patterns. The review begins by explaining the principles of GC-O, including sample preparation, separation methods, and olfactory evaluation techniques. It then explores the diverse range of applications where GC-O has found success, such as food and beverage industries, environmental monitoring, perfume and aroma development, and forensic analysis. One of the major breakthroughs in GC-O analysis is the improvement in separation power and resolution of odorants. Techniques like rapid GC, comprehensive two-dimensional GC, and multidimensional GC have enhanced the identification and quantification of odor-active chemicals. However, GC-O also has limitations. These include the challenges in detecting and quantifying trace odorants, dealing with matrix effects, and ensuring the repeatability and consistency of results across laboratories. The review examines these limitations closely and discusses potential solutions and future directions for improvement in GC-O analysis. Overall, this review presents a comprehensive overview of the recent advances in GC-O, covering breakthroughs, applications, and limitations. It aims to promote the wider usage of GC-O analysis in odor analysis and related industries. Researchers, practitioners, and anyone interested in leveraging the capabilities of GC-O in analyzing complex odor patterns will find this review a valuable resource. The article highlights the potential of GC-O and encourages further research and development in the field.

Study of Gender and Age Differences in Olfaction and Olfactory Evaluation —Focusing on Olfactory Experience and Preference—

Study of Gender and Age Differences in Olfaction and Olfactory Evaluation —Focusing on Olfactory Experience and Preference—

Design, synthesis, olfactory evaluation and molecular docking study of Isoxazoline carboxylate derivatives as fragrance molecules

AbstractIn this research, a wide range of aldoxime derivatives with aromatic and aliphatic substituents were synthesized as precursors to nitrile oxide in cycloaddition reactions. The aldoximes were synthesized with good to high yields and showed a lack of diastereoselectivity, as confirmed by 1H NMR measurements. These aldoximes were then utilized as precursors of nitrile oxide in 1,3‐dipolar cycloaddition reactions and were treated with dipolarophilic reagents, namely methyl methacrylate (MMA) and glycidyl methacrylate (GMA), to produce isoxazoline carboxylate derivatives with high regioselectivity. The obtained compounds were characterized using various techniques, including NMR, FT‐IR, GC–MS and TOF‐LCMS analyses. The study also targets the molecular docking analysis, using Autodock 4.2.6 software, targeting the OR51E2 protein. This protein has drawn recent attention, with the hypothesis that propionic acid activates OR51E2, making it a suitable candidate for the carboxylate group within the obtained isoxazoline skeleton. Through these multifaceted investigations, this research contributes to the design and development of fragrant molecules with potential applications in the fragrance industry, offering a promising avenue for future olfactory innovations.

Validation of Korean Olfactory Questionnaire for Perioperative Olfactory Assessment in Endoscopic Endonasal Skull Base Surgery.

Objective: To analyze changes in olfactory function after endoscopic endonasal skull base surgery and compare performance of the olfactory questionnaire with those of conventional psychophysical tests. Methods: Patients were classified into 5 categories for olfactory function evaluation (normal, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia) based on a self-assessment. Patients also underwent the butanol threshold test (BTT), Cross-Cultural Smell Identification Test (CCSIT), and 11-item olfactory questionnaire. Subjects with normosmia preoperatively and who were followed up at least 6 months after surgery were analyzed. Receiver operating characteristic curves and confusion matrix analysis were performed for BTT, CCSIT, and olfactory questionnaire to compare their diagnostic abilities. The effects of age, preoperative olfaction, septal flap, tumor pathology, and tumor size on postoperative olfaction were evaluated using multivariate linear regression analysis. Results: Data from 108 patients were analyzed. Postoperative changes in the olfactory questionnaire were significantly associated with changes in the BTT and CCSIT. The area under the curve for postoperative self-olfactory function classification was highest for olfactory questionnaire (0.894), followed by BTT (0.767) and CCSIT (0.688). Patient age at the time of surgery and preoperative BTT score were significantly related to postoperative olfactory outcomes. Conclusion: The olfactory questionnaire correlated well with conventional psychosomatic olfactory function tests. In combination with clinical parameters and preoperative psychosomatic olfactory function tests, the olfactory questionnaire is suitable for assessing subjective olfactory function after endoscopic endonasal skull base surgery.

Impact of post-COVID-19 olfactory disorders on quality of life, hedonic experiences and psychiatric dimensions in general population

Background and objectiveOlfactory disorders in COVID-19 impact quality of life and may lead to psychological impairments. Prevalence ranges from 8 to 85%, persisting in about 30% of cases. This study aimed to evaluate the 6-month post-COVID-19 impact on quality of life, hedonic experiences, anxiety and depression due to olfactory disorders. Additionally, it sought to compare psychophysical tests and self-perceived olfactory evaluations.MethodsA prospective, longitudinal study was conducted over baseline (T0) and 6 months (T1) on individuals with persistent olfactory disorders post-COVID-19 for more than 6 weeks. Psychophysical tests employed the Sniffin’ Sticks Test® (TDI score), and self-perceived olfactory evaluation used a Visual Analogue Scale. Quality of life was assessed with an Olfactive Disorder Questionnaire and the French version of the Quality of Life and Diet Questionnaire. Hedonic experiences were gauged using the Snaith-Hamilton Pleasure Scale, while anxiety and depression dimensions were measured by The State-Trait Anxiety Inventory, The Post Traumatic Stress Checklist Scale, and Hamilton Rating Scale for Depression. Participants were classified into the “normosmic group” (NG) and the “olfactory disorders group” (ODG) at T0 and T1 based on the TDI score.ResultsWere included 56 participants (58.93% women, 41.07% men) with a mean age of 39.04 years and a mean duration of post-COVID-19 olfactory disorders of 5.32 months. At T1, ODG had a significantly lower quality of life and hedonic experiences than NG. No significant differences in anxiety and depression dimensions were observed between groups. At T0, psychophysical tests and self-perceived olfactory evaluations were significantly correlated with quality of life and hedonic experiences in both groups. At T1, self-perceived olfactory evaluation in NG correlated significantly with quality of life, hedonic experiences, anxiety and depression dimensions, whereas ODG only correlated with hedonic experiences.ConclusionIndividuals with persistent post-COVID-19 olfactory disorders after six months demonstrated compromised quality of life and hedonic experiences. Self-perceived olfactory evaluation played a more significant role in influencing quality of life and the dimension of anxiety and depression than the psychophysical presence of olfactory disorders. These findings emphasize the importance of considering patients’ perceptions to comprehensively assess the impact of olfactory disorders on their well-being.Trial registrationClinicalTrials.gov number (ID: NCT04799977).

Olfactory Evaluation of Geisha Coffee from Panama Using Electronic Nose

Geisha arabica coffee from Panama is featured in the world specialty coffee market. Its quality is assessed by sensory analysis with a panel of experts over several days. However, there is a risk of commercial fraud where cheaper coffees are mixed with pure specialty coffees. For these reasons, having an electronic nose (EN) device proves advantageous in supporting the cupping panel. It allows a greater number of fragrance and aroma analyses to be conducted per day, providing more objective results. In this study, an experimental EN equipped with a metal oxide semiconductor (MOS) gas sensor array was used. Olfactory evaluation of ground and infused Geisha coffee of different roast levels, brewing process, and purity was studied by EN, sensory analysis and chromatography. The sensory analysis perceived significant differences in fragrance and aromas in the light and dark roast levels of the samples. A total of 57 volatile organic compounds (VOC) were studied by gas chromatography. The EN data were analyzed chemometrically with principal component analysis (PCA) and predictive partial least squares (PLS). The data variances for two components were explained with values greater than 82%. The EN demonstrated its ability to differentiate the three levels of roasting, two production processes, and adulteration in the analyzed samples.

Discrimination analysis of wines made from four species of blueberry through their olfactory signatures using an E-nose

Blueberries are rich in polyphenols, anthocyanins and vitamins. Products such as fermented beverages are viable, as these fruits have a short shelf life and are difficult to preserve. During the fermentation process, many volatile and phenolic compounds are released, which will define the quality of the product, bringing detectable aromas and flavors. Some product evaluations can be performed through laboratory analyses, which are not always available, are often expensive and time-consuming. Other analyses can be carried out through olfactory evaluation, work carried out by experienced people such as sommeliers. From this perspective, this work presents an initial assessment of the volatile organic compounds (VOCs) of fermented samples of four blueberry varieties over two seasons, using an electronic nose to collect the volatile compounds. Subsequently, six classifiers are then used to evaluate the collected data. The results showed hits of over 99.7% in all cases, indicating the e-nose's ability to differentiate the by-products of different blueberries and to present itself as an auxiliary method to standard laboratory tests in the evaluation of beverages, allowing comparative evaluations.

Discrimination rancidity degree of infant formula rice flour based on Headspace Solid-Phase Microextraction combined with Gas Chromatography–Mass Spectrometry as an alternative to sensory evaluation

To mitigating the serious threat of harmful volatile substances to the health of infants, an alternative method of odor evaluation were proposed based on Headspace solid-phase microextraction (HS-SPME) combined with Gas Chromatography–Mass Spectrometry (GC–MS) to discriminate the degree of rancidity of infant formula rice flour (IFRF). Inspectors can simply calculate the rancidity degree of infant formula rice flour according to the regression equation based on the concentration of rancidity markers. The results showed that the joint application of OPLS-DA, molecular sensory experiments, and unsaturated fatty acids (UFAs) degradation experiments could successfully recognize the rancidity markers without collinearity in multiple linear regression analysis. The rancidity markers curve fitting was helpful for the establishment of multivariate regression model of rancidity grading. The model had an accuracy of more than 92.90% by the verification of odor evaluation. The application of the model to investigate the market IFRF samples showed that about 3% of the samples collected in the experiment were unsuitable for infant feeding. Therefore, the established model was considered to be a robust and less workload method to replace the olfactory evaluation method for discriminating the rancidity degree of IFRF.

Real-time emission characteristics, health risks, and olfactory effects of VOCs released from soil disturbance during the remediation of an abandoned chemical pesticide industrial site.

Volatile organic compounds (VOCs) released along with soil disturbance during the remediation of abandoned industrial sites have attracted great attention due to their possible toxicity and odour. However, the real-time emission characteristics of these VOCs and their subsequent effects on health and olfaction are less understood. In this study, the gaseous VOCs released from soil disturbance by excavators and drilling rigs at an abandoned chemical pesticide plant were monitored online with a laboratory-built single photoionization time-of-flight mass spectrometer (SPI-TOFMS). Twelve main VOCs with total mean concentrations ranging from 2350 to 3410 μg m-3 were observed, with dichloromethane (DCM) having a significant contribution. The total concentrations of the remaining 11 VOCs increased substantially during soil disturbance, with the total mean concentrations increasing from 18.65-39.05 to 37.95-297.94 μg m-3 and those of peak concentrations increasing from 28.46-58.97 to 88.38-839.13 μg m-3. This increase in VOC concentrations during soil disturbance leads to an enhanced heath risk for on-site workers. The distinctive difference between the mean and peak concentrations of VOCs indicates the importance of using mean and peak concentrations, respectively, for risk and olfactory evaluation due to the rapid response of the human nose to odours. As a result, the cumulative noncarcinogenic risk at the relatively high pollutant plot was higher than the occupational safety limit, while the total carcinogenic risks at all monitored scenarios exceeded the acceptable limit. Among the VOCs investigated, DCM and trichloroethylene (TCE) were determined to be crucial pollutants for both noncarcinogenic and carcinogenic risks of VOCs. With regard to olfactory effects, organic sulphides, including dimethyl disulphide (DMDS), dimethyl sulphide (DMS), and dimethyl trisulphide (DMTS) were identified as dominant odour contributors (78.28-92.11%) during soil disturbance.

An Integrated Audio-Visual-Olfactory Virtual Reality False Feeding Device: Research, Development, and Design

To resolve the problem of the lack of sensory stimulation from the colors and aromas of food when patients are given enteral nutrition support by tube feeding or simple oral administration, an immersive virtual reality (VR) sham feeding device integrating audio, visual, and olfactory sense perceptions was developed independently and the usability of the device was tested. Relying on the multidisciplinary cooperation of nursing, mechanical engineering, and computer science and using as a reference the characteristics of gastric tube and oxygen tube placement in clinical patients, we carried out 3D modeling and printing of the exterior framework of the odor box. Unity 3d.5.x, a mainstream virtual engine tool, was used to create scenarios. The device could create visual stimulation through 3 VR dining scenarios, 23 kinds of food, and comfortable dining environment. The sound of chewing was played to simulate the dining process and provide auditory stimulation. Through the independently researched and developed olfactory odor box, corresponding food aromas were sprayed out for olfactory stimulation. After the equipment prototype was created, 10 patients were recruited to perform users' subjective evaluation of the usability of the equipment. A VR sham feeding device integrating audio-visual-olfactory stimulation was successfully developed. In the visual effect evaluation, all users commented that the vision was clear and unimpeded, and that the menu program could follow their rotation movement. Eight people considered the scenes to be rather realistic. In the auditory effect evaluation, all users stated that the volume of the sound was appropriate, and that they would hear a chewing sound being played when the food was approaching. In the olfactory effect evaluation, 9 people stated that they smelled the food aromas when the food was approaching, and that they thought the odor was real or partially real. On the whole, the equipment was convenient to use and all users thought that the equipment had clear presentation and could run stably and smoothly. No adverse reactions, such as dizziness, occurred in any users. Successfully presenting visual, auditory, and olfactory stimuli, the prototype device passed the subjective usability test. The prototype device effectively expands the application prospects of VR in the medical field. In the future, it will be applied to patient populations, including surgical patients, patients with eating disorders, obesity, and loss of appetite, and other patients who cannot take in food through their mouths. The prototype device provides new ideas for promoting enhanced recovery after surgery and improving patient experience.

Could olfactory identification be a prognostic factor in detecting cognitive impairment risk in the elderly?

Aging contributes to the deterioration of the olfactory system in humans. Several studies indicate that the olfactory identification test alone may function as a screening test for olfactory dysfunction and they are more feasible to apply in clinical practice. Olfactory identification may be a predictor for cognitive impairment. Multiple studies have considered the use of odor identification as a measure to identify the conversion from normality to mild cognitive impairment or dementia. The objectives were (i) to elucidate the associations between cognitive status and olfactory identification performance in aging; (ii) understand the predictive value of olfactory capacity in identifying subjects with cognitive impairment risk; and (iii) to study how cognitive status and olfactory identification relate with other variables of wellness in aging, such as functional capabilities and clinical measures. For this purpose, a group of 149 participants (77.15 ± 7.29 years; 73 women of 76.7 ± 8 years and 76 men of 77.6 ± 6.52 years) were recruited and were subjected to a sociodemographic questionnaire, a psychological screening tool of general cognitive status, an olfactory identification evaluation, and clinical measures. The participants were divided into groups based on their cutoff scores of previous scientific reports about the Spanish version of Montreal Cognitive Assessment. Our results indicate an age-associated decline in olfactory identification ability and intensity of odor perception. The predictive ability of olfactory identification scores for the risk of mild and severe impairment is around 80%. Olfactory identification decreases with cognitive function. Performance in odor identification is associated with impairment of episodic memory and executive functions. These findings further our current understanding of the association between cognition and olfaction, and support olfactory assessment in screening those at higher risk of dementia.