Odor Profiles Research Articles

Applications of electronic nose technology in the tobacco industry: a comprehensive review

Abstract Electronic nose (E-nose) technology has emerged as a promising tool for rapid and objective analysis of complex odor profiles in various industries, including the tobacco sector. This review paper provides a comprehensive overview of the applications of E-noses in the tobacco industry, focusing on their potential for enhancing quality control, optimizing blend formulations, monitoring processing conditions, and assuring the quality of finished products. We discuss the basic principles, working mechanisms, sensor types, and data processing techniques employed in E-noses, as well as the challenges and limitations associated with their adoption in the tobacco industry. These challenges include sensor drift, calibration, interference from environmental factors, the complexity of tobacco aroma and flavor profiles, and regulatory and ethical considerations. The paper concludes by highlighting the need for further research and development in E-nose technology, with an emphasis on addressing technical challenges, refining sensor systems, and fostering collaboration among researchers, industry stakeholders, and regulatory agencies. By overcoming these hurdles, E-nose technology has the potential to revolutionize the tobacco industry, ensuring consistent product quality, and meeting the changing demands of consumers while addressing public health concerns and regulatory requirements.

The Effects of Fresh Hemp Leaf Supplementation (Cannabis sativa) on the Physiological and Carcass Characteristics and Meat Quality in Transported Goats.

Transportation stress adversely affects animal health, productivity, and meat quality. Bioactive plant compounds may alleviate transit stress in livestock. This study evaluated the effects of fresh hemp leaf supplementation on blood metabolites, performance, carcass traits, and meat quality in transported goats. Twenty male goats (15 ± 2.76 kgBW) were investigated, some were given a hemp supplement (n = 10) and the remaining goats were used as a control group (n = 10). The hemp group received 10 g/30 kg body weight of fresh leaves prior to transportation. Blood samples were analyzed before and after the 200 km journey. The goats were slaughtered after transit and the quality of the meat examined. In the controlled group, transportation increased neutrophils and electrolytes, but decreased lymphocytes and hemoglobin. In contrast in the hemp-supplemented group, the hemp maintained this animal blood parameters. Body weight and carcass yield, however, did not differ between the two groups. Hemp reduced meat redness at 1 h postmortem but had minimal effects on its pH, color, water holding capacity, tenderness, and texture after 24 h. However, hemp supplementation did alter the odor profiles between the two groups detected by electronic nose sensors. In conclusion, fresh hemp leaf supplementation maintained blood metabolites and had minor advantageous effects on meat quality in response to transportation stress in goats. Further investigation using hemp supplements shows potential to alleviate transit stress, although higher doses may be required in order to further enhance its benefits.

Exploring the effects of mixture composition factors and perceptual interactions on the perception of icewine odor: An olfactometer-based study.

The perception of food odor, derived from complex mixtures of odorants, remains poorly understood. This study investigated how key odorants of icewine influence odor mixture perception and mixture-induced perceptual interactions. A multichannel olfactometer was used to deliver 90 mixtures to 36 trained participants who used a Rate-All-That-Apply method to rate the odor samples. Results showed that adding odorants to a mixture affected both the characteristic odor of the individual component and other odor characteristics, revealing specific perceptual interactions. Combining up to six odorants with icewine odor influenced a maximum of two odor characteristics in the mixture, regardless of the specific combination. Interestingly, adding odorants had a stronger impact on the overall mixture odor profile than omitting them, particularly when manipulating fewer than three odorants. These findings emphasize the complexity of odor mixture perception and provide new insights into the influence of key odorants on the aroma of wine.

Dimethyl sulphide: The oyster-like odourant of Mertensia maritima

The oyster plant (Britain) or oyster leaf (North America), Mertensia maritima (L.) Gray has a strong oyster-like odour. Headspace volatiles from fresh crushed leaves of this plant were analysed using solid phase microextraction (SPME) and gas chromatography– mass spectrometry (GC–MS). Dimethyl sulphide was detected emanating from the crushed leaves, a compound that is noted for being a major part of the odour profile of raw oysters.

Scent detection of Brucella abortus by African giant pouched rats (Cricetomys ansorgei)

BackgroundBrucellosis is a contagious zoonosis caused by bacteria of the genus Brucella. While the disease has been eradicated in most developed countries, it remains endemic in sub–Saharan Africa where access to reliable diagnostics is limited. African giant pouched rats (Cricetomys ansorgei) have been trained to detect the scent of Mycobacterium tuberculosis to increase case detection in sub-Saharan Africa. Given the similar diagnostic challenges facing brucellosis and tuberculosis, we explored the feasibility of training African giant pouched rats to detect Brucella.ResultsAfter 3 months of training, rats reliably identified cultured Brucella, achieving an average sensitivity of 93.56% (SD = 0.650) and specificity of 97.65% (SD = 0.016). Rats readily generalized to novel, younger Brucella cultures that presumably generated a weaker volatile signal and correctly identified at least one out of three fecal samples spiked with Brucella culture during a final test of feasibility.DiscussionTo our knowledge, these experiments are the first to demonstrate Brucella emits a unique odor profile that scent detection animals can be trained to identify. Importantly, cultured E. coli samples were included throughout training and test to ensure the rats learned to specifically identify Brucella bacteria rather than any bacteria in comparison to bacteria-free culture medium. E. coli controls therefore served a crucial function in determining to what extent Brucella abortus emits a unique odor signature. Further research is needed to determine if a Brucella-specific volatile signature is present within clinical samples. If confirmed, the present results suggest trained rats could serve as a valuable, novel method for the detection of Brucella infection.

Aroma characteristics and odor source analysis of roasted Xinjiang thin-shell walnuts (Juglans regia L.) by using multivariate statistical analysis

Since the correlation between the overall aroma of in-shell walnuts and the volatile compounds existing in both their kernels and shells remained unclear, the odor profiles of roasted in-shell Xinjiang thin-shell walnuts including kernel and shell have been well investigated by sensory analysis, electronic nose, and HS-SPME/GC-MS, while volatile compounds were analyzed by multivariate statistical analysis of PLS-DA, variable importance projection (VIP) values and relative odor activity value (ROAV). Color and sensory evaluations confirmed the walnut shell did not change significantly after roasting, and it may have an odor-shielding effect on the kernel. Electronic nose could effectively distinguish the aroma difference of raw and roasted walnuts by signal intensities. A total of 94 volatile compounds were identified by GC-MS, and 31 odor-active compounds were recognized by further ROAV analysis. Although 2-methyl-furan with a spicy smoky aroma was increased in the roasted shell, benzaldehyde was raised in the roasted kernel with a bitter almond note, which played an important role in the roasted whole in-shell walnut odor. Overall, this study firstly explored the shell contribution to the whole odor of walnuts and illuminated the aromatic characteristics of in-shell roasting walnuts, which will provide a better understanding for the walnut processing and will be beneficial to the quality control for the roasted walnuts.

Method Comparison for the Identification and Characterization of Odorants from Scots Pine (Pinus sylvestris L.) and Oriented Strand Boards (OSB) Made Thereof by GC-MS and GC-FID/O Using Different Headspace Techniques

Volatile organic compounds (VOCs) from wood and wood composites are important contributors to odor profiles of indoor environments and can significantly influence human health and well-being. GC-MS/FID and gas chromatography (GC) with olfactometric detection (GC-O) are employed for the identification and characterization of odorants. Four different sample preparation methods are evaluated on wood strands and isocyanate adhesive–based oriented strand boards (OSBs) made from Pinus sylvestris L.: among these, dynamic headspace extraction thermal desorption ((dynamic) HS-TD), head space solid phase microextraction (HS-SPME), head space solid phase microextraction Arrow (HS-SPME Arrow), and liquid injection of a CH2Cl2 solvent extract. The olfactometric investigation revealed over 30 odor-active substances of cyclic and acyclic monoterpene, monoterpenoid ketone, monoterpenoid aldehyde, monoterpenoid alcohol, monoterpenoid ester, aliphatic aldehyde, alcohol, and acid and phenolic chemistry. Compared to liquid injection, (dynamic) HS-TD was found to result in a similar number of odorants (20 vs. 24), whereas HS SPME Arrow shows good performance with minimal instrumental effort, notably for monoterpene and aldehyde compounds. Native wood vs. OSB showed high concentrations of saturated and unsaturated aldehydes for the wood board sample. These findings demonstrate the capability of headspace methods for odorant detection and their suitability for standardization towards a database for wood and wood composites.

Exploring the visualization of human milk odor profiles: Intuitive characterization and construction of the link between odor compounds and sensory attributes

Studies on odor are not negligible in the human milk (HM) science field because it plays an irreplaceable role in the feeding process of infants. This study aimed to investigate the odor skeleton components (OSCs) in HM and verify and construct an intuitive link between them and the HM odor attributes. A total of 72 odor-active compounds were identified from 32 HMs using the comprehensive two-dimensional gas chromatography–olfactometry-mass spectrometry. Twenty of these compounds were identified as OSCs (average FD ≥ 1 and average OAV ≥ 1), and their actual odor contribution was clarified. Furthermore, the connection of the 20 OSCs with their corresponding eight odor attributes was visualized by constructing a molecular sensory odor wheel. Of them, 2,3-butanedione, (E)-2-decenal, nonanal, (E)-2-nonenal, octanal, 1-octen-3-one, hexanal, methional, and butanoic acid were the most important contributors to dairy-sweet, fishy, dairy-fat, metallic/iron, flour, grassy/green, cooked, and sweaty/rancid odor of HM.

The smell of death. State-of-the-art and future research directions.

The decomposition of a body is inseparably associated with the release of several types of odors. This phenomenon has been used in the training of sniffer dogs for decades. The odor profile associated with decomposition consists of a range of volatile organic compounds (VOCs), chemical composition of which varies over time, temperature, environmental conditions, and the type of microorganisms, and insects colonizing the carcass. Mercaptans are responsible for the bad smell associated with corpses; however, there are no unified recommendations for conducting forensic analysis based on the detectable odor of revealed corpses and previous research on VOCs shows differing results. The aim of this review is to systematize the current knowledge on the type of volatile organic compounds related to the decomposition process, depending on a few variables. This knowledge will improve the methods of VOCs detection and analysis to be used in modern forensic diagnostics and improve the methods of training dogs for forensic applications.

Sensory evaluation of axillary odour samples of younger and older adults by a trained panel

AbstractIt has been reported that a distinct ‘old person smell’ can develop with advancing age, however, this odour has not yet been sufficiently described in previous research. Sensory evaluation by a trained panel might be useful to describe alterations with age in body odour (BO). To evaluate the alterations and achieve first insights into the ‘old person smell’, this pilot study determined the odour profiles of BO samples from both a younger and an older age group with a trained panel. In addition, we aimed to assess whether the panellists can recognize the age group based on the smell of the BO samples. Eight younger (20–28 years) and eight older (80–83 years) participants sampled their BO by wearing a cotton T‐shirt for one night. The samples were sensorially evaluated by a trained panel, including ratings of total intensity and pleasantness. Additionally, an age labelling task was performed as a forced‐choice decision. Results revealed that the odour profiles of the BO samples were very similar for both age groups. Nevertheless, trained panellists were able to predict the age group with significantly higher accuracy (p = .042) than expected by chance (61% mean accuracy over all panellists). Furthermore, a linear support vector machine (SVM) classifier achieved an average accuracy of 69%. This finding indicates that the age of a person affects the BO, though it is not reflected in significantly distinct odour profiles.

A principal odor map unifies diverse tasks in olfactory perception.

Mapping molecular structure to odor perception is a key challenge in olfaction. We used graph neural networks to generate a principal odor map (POM) that preserves perceptual relationships and enables odor quality prediction for previously uncharacterized odorants. The model was as reliable as a human in describing odor quality: On a prospective validation set of 400 out-of-sample odorants, the model-generated odor profile more closely matched the trained panel mean than did the median panelist. By applying simple, interpretable, theoretically rooted transformations, the POM outperformed chemoinformatic models on several other odor prediction tasks, indicating that the POM successfully encoded a generalized map of structure-odor relationships. This approach broadly enables odor prediction and paves the way toward digitizing odors.

Production of restructured beef jerky using blood plasma solutions activated by non-thermal atmospheric plasma

Abstract The effect of blood plasma powder (2.5, 5, and 7.5% w/w in water) activated using non-thermal atmospheric plasma (T1, T2, and T3, respectively) was investigated as a nitrite source in the production of restructured beef jerky. A group without a nitrite source (NC) and a group cured with 100 ppm of sodium nitrite (PC) were used as negative control and positive control groups, respectively. The nitrite content of the plasma-activated solutions was adjusted to match that of the positive control by calculating the required plasma treatment time, based on previous studies. The obtained results showed that addition of treated solutions with nonthermal plasma for a 70 min, at a level of 20% in relation to the meat, can have beneficial effects on nitrosylhemochrome content, redness, and TBARS values of restructured jerky. These effects were statistically comparable (p≥0.05) to sodium nitrite-cured samples. Furthermore, compared to the PC group, the T1, T2, and T3 treatments exhibited significantly lower water activity and higher protein content (p<0.05). The T2 and T3 treatments also showed increased lightness and shear force values (p<0.05) compared to the control groups (NC and PC). It should be noted that the T3 group had the highest (p<0.05) residual nitrite content among all the samples. However, a sensory analysis is necessary to assess consumer acceptance with regard to differences in the odor profile of the treatments, according to the Principal Components Analysis (PCA).

Applying the COM-B behaviour change model to a pilot study delivering volatile pyrethroid spatial repellents and insecticide-treated clothing to forest-exposed populations in Mondulkiri Province, Cambodia

BackgroundSoutheast Asia is making tremendous progress towards their 2030 malaria elimination goal but needs new interventions to stop forest malaria. This study trials two new vector control tools, a volatile pyrethroid spatial repellent (VPSR) and insecticide-treated clothing (ITC), amongst forest-exposed populations in Mondulkiri Province Cambodia to inform their potential use for eliminating forest malaria.Methods21 forest-exposed individuals were given a questionnaire on their perceptions of malaria and preventive practices used, after which they trialed two products sequentially. Clothes was treated with ITC by the study team. Mixed methods were used to understand their experience, attitudes, and preferences regarding the products trialed. Quantitative data was summarized and qualitative insights were analysed using thematic analysis, applying the Capability, Opportunity, and Motivation Behaviour Change (COM-B) model and Behaviour Change Wheel Framework to identify intervention functions to support tailored product rollout amongst these populations.ResultsStudy participants reported a need for protection from mosquito bites in outdoor and forest-exposed settings and perceived both products trialed to be effective for this purpose. The VPSR product was preferred when travel was not required, whereas ITC was preferred for ease of use when going to the forest, especially in rainy conditions. COM-B analysis identified that key enablers for use of both products included their perceived efficacy and ease of use, which required no skill or preparation. For barriers to use, the odour of ITC was sometimes perceived as being toxic, as well as its inability to protect uncovered skin from mosquito bites, while the perceived usefulness of the VPSR product trialed was limited by its water sensitivity in rainy forest settings. Intervention components to encourage appropriate and sustained use of these products include education about how to use these products and what to expect, persuasion to use them from community leaders and targeted channels, and enablement to facilitate convenient and affordable access.ConclusionThe rollout of VPSRs and ITC amongst forest-exposed populations can be useful for eliminating malaria in Southeast Asia. Study findings can be applied to increase product uptake among forest exposed populations in Cambodia, while manufacturers can aim to develop products that are rainproof, easy to use in forest settings, and have favourable odour profiles to target users.

Changes in the Physical Properties and Volatile Odor Characteristics of Shiitake Mushrooms (Lentinula edodes) in Far Infrared Radiation Drying.

The effects of far infrared radiation drying (FID) on physical properties (drying kinetics, color, shrinkage ratio, rehydration ratio, and microstructural characterization) and volatile odor characteristics (volatile odor profile distinction and volatile compounds) of shiitake mushrooms were evaluated in this study. During the FID, the drying time decreased with the increase in drying temperature, and it had a less significant effect in the lower temperature range. The increase in drying temperature led to increasing shrinkage and collapse in the microstructure, resulting in a decreased rehydration rate and highlighting the influence of microstructure characteristics on macroscopic properties. Higher drying temperatures employed in the FID process were found to be associated with a decreasing L* value and an increasing ΔE value. The application of principal component analysis can effectively distinguish the significant effect of FID on the volatile odor profiles of shiitake mushrooms. Compared to raw shiitake mushrooms, FID treatment has endowed samples with a greater variety of volatile compounds. After processing with FID, there have been increases in volatile components such as sulfur compounds, acids, nitrogen compounds, and aldehydes, while volatile components like alcohols, ketones, and hydrocarbons have shown decreases.

Effect of Conventional and Microwave Heating on Protein and Odor Profile in Soymilk Powder

Soymilk contained serine protease enzymes with inhibitory activity against trypsin, causing a negative effect on nutritional absorption. This project aimed to investigate the effects of conventional heating (100 °C/20 min) and microwave heating (360–900 W/1–6 min) on trypsin inhibitor, protein digestibility, and odor profiles. Soymilk contained 46–47% protein, regardless of heating conditions. Using scanning electron microscopy, it can be seen that the conventionally heated sample had a smooth surface and a porous structure, whereas microwave-heated samples contained a protein matrix in clusters with rough surfaces. The molecular weight of proteins in SDS-PAGE was reduced to 19 kDa and <16 kDa after conventional and microwave heating, respectively, resulting in the reduction of trypsin inhibitor from 36.66 to 0.91 and 0.56–0.66 mg/g, respectively. Protein digestibility was significantly improved when either the conventional heating at 100 °C for 20 min or the microwave heating at 900 W for 6 min was applied. From e-nose analysis, the beany flavor was reduced after the microwave heating for 3–6 min, and the highest intensity of the sweet odor compounds were observed after the microwave heating at 600 W for 1 min. Due to the short processing time, microwave heating was then recommended for inhibition of trypsin inhibitors and improving protein digestibility.

Effect of relative humidity on the desorption of odour-active volatile organic compounds from paper and board: sensory evaluation and migration to Tenax®

Paper and board are used for packaging of moist as well as dry food. According to Regulation (EC) No. 1935/2004, food contact materials (FCM) must not bring about a deterioration in the organoleptic characteristics of foodstuffs. For testing the transfer of off-flavour (taint) from packaging to food via the gas phase (DIN EN 1230-2), relative humidity (rH) has to be adjusted. In contrast, rH is neither taken into account when testing the odour (DIN EN 1230-1), nor in chemical migration of volatile organic substances (VOC) onto the adsorbent Tenax® (DIN EN 14338). In this work, effect of different rHs on the desorption of VOC from paper and board was investigated by GC-MS analysis as well as by human sensory tests. Raising humidity led to an increase in VOC transfer, which was observed by increasing peak areas as well as the detection of more substances in GC-MS. Analytical results were in line with human sensory tests. The odour profile of the paper at 33 and 58% rH was described as cardboard-like, sweet and smoky. Impact substances for these olfactory impressions were (E)-2-nonenal, vanillin and 2-methoxyphenol as identified by GC with an olfactory detection port (GC-ODP). The increase to 75 and 100% rH resulted in the additional perception of cheesy/sweaty and fatty/rancid impressions, which were primarily caused by short-chain fatty acids and di-unsaturated aldehydes.

Effect of amino compounds on the volatile compounds and antioxidant activity of Maillard reaction products of enzymatic hydrolyzed cabbage leaves

Different Maillard reaction model mixtures based on hydrolyzed cabbage leaves waste protein supplemented with different amino compounds (cysteine, thiamine and / or alanine) were used to explore the effect of each amino compound on the characteristics of the generated Maillard reaction products (MRPs). A comparative study was carried out between MRPs of the model mixtures in terms of odour sensory characteristics, SPME-GC–MS analysis of the headspace volatiles, browning intensity and antioxidant activity. The results revealed that omission of one amino compound from the model mixtures led to significant variations in the volatile compounds, browning intensity and odour profile of the MRPs. Omission of cysteine resulted in 25.00% and 30.83% decrease in the thiol containing compounds and antioxidant activity, respectively. While, omission of alanine led to a significant decrease in pyrazines and furans (75% and 100%, respectively), browning intensity and an increase in content of the thiol compounds and antioxidant activity of MRPs.

Continuous odor profile monitoring to study olfactory navigation in small animals.

Olfactory navigation is observed across species and plays a crucial role in locating resources for survival. In the laboratory, understanding the behavioral strategies and neural circuits underlying odor-taxis requires a detailed understanding of the animal's sensory environment. For small model organisms like Caenorhabditis elegans and larval Drosophila melanogaster, controlling and measuring the odor environment experienced by the animal can be challenging, especially for airborne odors, which are subject to subtle effects from airflow, temperature variation, and from the odor's adhesion, adsorption, or reemission. Here, we present a method to control and measure airborne odor concentration in an arena compatible with an agar substrate. Our method allows continuous controlling and monitoring of the odor profile while imaging animal behavior. We construct stationary chemical landscapes in an odor flow chamber through spatially patterned odorized air. The odor concentration is measured with a spatially distributed array of digital gas sensors. Careful placement of the sensors allows the odor concentration across the arena to be continuously inferred in space and monitored through time. We use this approach to measure the odor concentration that each animal experiences as it undergoes chemotaxis behavior and report chemotaxis strategies for C. elegans and D. melanogaster larvae populations as they navigate spatial odor landscapes.

Multivariate regression modelling for gender prediction using volatile organic compounds from hand odor profiles via HS-SPME-GC-MS.

The efficacy of using human volatile organic compounds (VOCs) as a form of forensic evidence has been well demonstrated with canines for crime scene response, suspect identification, and location checking. Although the use of human scent evidence in the field is well established, the laboratory evaluation of human VOC profiles has been limited. This study used Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) to analyze human hand odor samples collected from 60 individuals (30 Females and 30 Males). The human volatiles collected from the palm surfaces of each subject were interpreted for classification and prediction of gender. The volatile organic compound (VOC) signatures from subjects' hand odor profiles were evaluated with supervised dimensional reduction techniques: Partial Least Squares-Discriminant Analysis (PLS-DA), Orthogonal-Projections to Latent Structures Discriminant Analysis (OPLS-DA), and Linear Discriminant Analysis (LDA). The PLS-DA 2D model demonstrated clustering amongst male and female subjects. The addition of a third component to the PLS-DA model revealed clustering and minimal separation of male and female subjects in the 3D PLS-DA model. The OPLS-DA model displayed discrimination and clustering amongst gender groups with leave one out cross validation (LOOCV) and 95% confidence regions surrounding clustered groups without overlap. The LDA had a 96.67% accuracy rate for female and male subjects. The culminating knowledge establishes a working model for the prediction of donor class characteristics using human scent hand odor profiles.

Odor profile characterization and variety identification of brown lactobacillus beverage based on untargeted metabolomics

Odor profile characterization and variety identification of brown lactobacillus beverage based on untargeted metabolomics