Odour Impact Research Articles

Combined assessment of health hazard and odour impact of soils at a contaminated site: a case study on a defunct pharmaceuticals factory in China.

Surveys and assessments of contaminated sites primarily focus on hazardous pollutants in the soil with less attention paid to odorants. This makes the management of contaminated sites difficult. In this study, hazardous and odorous pollutants in the soil were assessed for a large site that was previously used for production of pharmaceuticals to determine the degree and characteristics of soil contamination at pharmaceutical production sites, for undertaking rational remediation measures. The main hazardous pollutants at the study site were triethylamine, n-butyric acid, benzo(a)pyrene (BaP), N-nitrosodimethylamine (NDMA), dibenzo(a,h)anthracene (DBA), total petroleum hydrocarbons (C10-C40) (TPH), and 1,2-dichloroethane; TEA, BA, and isovaleric acid (IC) were the main odorants. As the type and distribution of hazardous and odorous pollutants differ, it is necessary to separately assess the impact of these pollutants at a contaminated site. Soils in the surface layer pose significant non-carcinogenic (HI = 68.30) and carcinogenic risks (RT = 3.56E-5), whereas those in the lower layer only pose non-carcinogenic risks (HI > 7.43). Odorants were found at considerable concentrations both in the surface and lower layers, with the maximum concentrations being 29,309.91 and 41.27, respectively. The findings of this study should improve our understanding of soil contamination at former pharmaceutical production sites and should inform the assessment of the risks posed by contaminated sites, with problems associated with odour, and possible remediation strategies.

Impact of human milk odor on respiratory distress and oxygen saturation in preterm neonates

Backgroundand purpose: Human milk is the most typical and accessible way of improving a neonate's respiratory status. The present study was conducted to examine the impact of human milk odor on respiratory distress and oxygen saturation in preterm neonates in the intensive care unit. MethodsThis clinical trial included 96 premature neonates divided into three groups, including human milk odor, formula odor, and a control group. The human milk group received 3 ml of human milk at 8 a.m. and 12 p.m. on a daily basis for four days. The human milk and formula were prepared and used under the same conditions. The control group did not receive any interventions. The research instruments were a demographic questionnaire and the Downes score that was completed daily by the researcher. ResultsThe results indicated no significant differences in the blood oxygen saturation and respiratory distress between the human milk odor, formula odor, and the control group (P > 0.05). It was also found that preterm neonates in the human milk group show less respiratory distress compared to the control group on the third day. In addition, the heart and respiratory rates did not show any significant difference between the study groups. However, the heart rate decreased more in the human milk group compared to the other two groups. Implication for practice and researchIt seems that oxygen saturation increased from the third day in the human milk group. It is suggested that the duration of aromatherapy increase in future studies to evaluate its possible effects more accurately.

Malodorous volatile organic compounds (MVOCs) formation after dewatering of wastewater sludge: Correlation with the extracellular polymeric substances (EPS) and microbial communities

Malodorous volatile organic compounds (MVOCs) are often the key odorants in determining sludge odor character and odor impact. However, the emission characterization and generation mechanisms of MVOCs from various dewatered sludge have not been sufficiently understood partly due to the diverse and complex composition and low concentration of odorants. In this study, waste activated sludge (WAS) was collected to examine the variation of MVOC emission from sludge after different dewatering treatment in lab-scale trials. The MVOCs were measured using the electronic nose (eNose), headspace gas chromatography-coupled ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC–MS). The results showed that centrifugation treatment promoted the generation of various odorous volatiles. The identified key odorants included dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), geosmin, and p-cresol according to their odor activity values (OAVs). The effects of the enhanced dewatering on volatile production were greater than thickening, however, the key odorants of dewatered sludge using gravity thickening varied more greatly than sludges from centrifuge thickening. The distribution of extracellular polymeric substances (EPS) and variation of microbial community showed correlations with the production of key odorants. Tryptophan-like substances in the inner layer of EPS (LB-EPS and TB-EPS) were better correlated with the key odorants. The bound EPS released by centrifugation may play the role of precursor for odorous microbial volatiles. According to the predicted functions of differential microbial genera, Desulfobulbus (Desulfobacterota), Gordonia (Actinobacteriota), and Hyphomicrobium (Proteobacteria) were associated with the production of DMS, DMDS, and DMTS, while Gordonia and Hyphomicrobium were related to p-cresol production.

Assessment of Odour and Ammonia Impacts for a Novel Fattening Piggery Tailored for Animal Welfare and Low Emission Rates

According to the European Commission, Austria is obliged to reduce ammonia emissions by 12% between 2005 and 2030. Agriculture, in particular livestock buildings and the spreading of manure, is the predominant source of ammonia in most countries, calling for stringent mitigation measures in this area. This study investigated a combination of measures implemented in a newly constructed fattening piggery in Styria (Austria) for reducing ammonia, particulate matter (not subject of this publication), and odour emissions. Additionally, the livestock building should meet standards to enhance animal welfare as well. Based on observed ammonia concentrations at several locations in the vicinity of the farm as well as field inspections for odour according to EN 16841-1, corresponding emission factors were derived using the Lagrangian particle model GRAL and in situ measurements of meteorology. The resulting emission factor for ammonia was found to be 80% lower compared to the standard emission factor of 3.64 kg a−1 for fattening piggeries according to the German guideline VDI 3894-1. Moreover, the emission factor for odour was 95% lower than the standard factor of 0.180 ouE kg−1 s−1 used in Styria for conventional fattening piggeries without any reduction techniques.

Odour impact assessment using kinetics and optimization: case studies on removal of multiple volatile organo-sulphur compounds from sewage wastewater using porous functional materials.

Expanding industries and booming population have led to the increase in the installation of wastewater and sewer systems, even in close proximity to residential areas. Emissions from these installations particularly volatile organo-sulphur compounds (VOSCs) such as methyl mercaptan (CH3SH), ethyl mercaptan (C2H5SH), dimethyl sulphide (CH3SCH3) and carbon disulphide (CS2) are a nuisance to people even when present in small concentration. Strategies for removal involve addition of chemicals or other chemical processes which are generally expensive. Biofilters, on the other hand, consume large amount of energy and wash waters. Hence keeping commercialization in mind, it is important to develop a strategy which would be cost-effective and at the same time be effective to remove most of the odorous compounds present in these systems. In the present research work, granular activated carbons (GAC) are functionalized with alkali solution to improve the adsorption capacity. Liquid phase batch adsorption is performed with GAC and various functionalized activated carbons (FACs) with the help of raw sewage water from a local sewage water treatment plant. Concentration of odour was evaluated by two methods-olfactometry-based analysis for sensory measurement and GCMS-based analysis for analytical estimation of a specific odorous compound. The adsorption capacities of the functionalized GACs are higher primarily because of complex formation at the surface of modified GACs. Pseudo-second-order kinetic model agreed well with experimental results with the rate constant being 0.0191mg/l min and 0.0153mg/l min for methyl and ethyl mercaptan adsorption onto FAC-NH3. Boyd's film diffusion along with rate kinetic model supported that chemical adsorption forms the rate-limiting step. Response surface methodology (RSM) was used to optimize the removal of VOSCs with respect to different process parameters like adsorbent amount and time. The olfactometry removal of overall odour was also optimized taking 6 factors in the Box Behnken design. Variance of analysis results indicated that all the models displayed considerable goodness of fit with R2 values close to 1. Methyl mercaptan turned out to be the highest contributor to the overall odour as confirmed both from experimental and optimization study. The optimized olfactometry odour removal (77.4%) along with CH3SH removal (80.34%), C2H5SH removal (59.16%), CH3SCH3 removal (63.21%) and CS2 removal (71.95%) was found at optimum process conditions, with amount of adsorbent of 10.29g, adsorption time of 2.92h. This result indicates that methyl mercaptan (CH3SH) is the highest odour contributing component out of the studied VOSCs. The results show promising potential for the use of activated carbon as an adsorbent for removal of odorous compounds from STPs.

Relationship between the dynamics of volatile aroma compounds and microbial succession during the ripening of raw ewe milk-derived Idiazabal cheese

Cheese microbiota contributes to various biochemical processes that lead to the formation of volatile compounds and the development of flavour during ripening. Nonetheless, the role of these microorganisms in volatile aroma compounds production is little understood. This work reports for the first time the dynamics and odour impact of volatile compounds, and their relationship to microbial shifts during the ripening of a raw ewe milk-derived cheese (Idiazabal). By means of SPME-GC-MS, 81 volatile compounds were identified, among which acids predominated, followed by esters, ketones and alcohols. The ripening time influenced the abundance of most volatile compounds, thus the moments of greatest abundance were determined (such as 30–60 days for acids). Through Odour Impact Ratio (OIR) values, esters and acids were reported as the predominant odour-active chemical families, while individually, ethyl hexanoate, ethyl 3-methyl butanoate, ethyl butanoate, butanoic acid or 3-methyl butanal were notable odorants, which would provide fruity, rancid, cheesy or malt odour notes. Using a bidirectional orthogonal partial least squares (O2PLS) approach with Spearman's correlations, 12 bacterial genera were reported as key bacteria for the volatile and aromatic composition of Idiazabal cheese, namely Psychrobacter, Enterococcus, Brevibacterium, Streptococcus, Leuconostoc, Chromohalobacter, Chryseobacterium, Carnobacterium, Lactococcus, Obesumbacterium, Stenotrophomonas and Flavobacterium. Non-starter lactic acid bacteria (NSLAB) were highly related to the formation of certain acids, esters and alcohols, such as 3-hexenoic acid, ethyl butanoate or 1-butanol. On the other hand, the starter LAB (SLAB) was related to particular ketones production, specifically 3-hydroxy-2-butanone; and environmental and/or non-desirable bacteria to certain ketones, hydrocarbons and sulphur compounds formation, such as 2-propanone, t-3-octene and dimethyl sulphone. Additionally, the SLAB Lactococcus and Psychrobacter, Brevibacterium and Chromohalobacter were described as having a negative effect on aroma development caused by NSLAB and vice versa. These results provide novel knowledge to help understand the aroma formation in a raw ewe milk-derived cheese.

International experience of air pollution assessment in areas where enterprises with odorous emissions are located (literature review)

The article provides a review of literature data on approaches to the ambient air pollution assessment in the areas where enterprises - sources of odour are located. According to the analysis, international practice in the field of odour management in the atmosphere includes a variety of methods of the odour impact assessing. The considered approaches, both predictive and observational (empirical), have their advantages and disadvantages. Thus, atmospheric dispersion modelling is a very valuable predictive tool and plays an important role in assessing ambient odours. However, the models, although based on rigorous quantitative calculations, are a simplification of the real situation. The accuracy of this method is significantly reduced in cases of unpredictable, unplanned or accidental releases. An easier-to-use tool is a qualitative (descriptive) risk-based odour assessment (source-pathway-receptor concept). Empirical approaches (field olfactometry, sniff tests) make it possible to assess odour exposure in given real conditions, while more objective assessment requires long-term studies. The use of instrumental methods is limited by the fact that odours in the air are mainly due to complex multicomponent mixtures of substances with an unknown nature of the combined action, with levels below the detection limits, etc. When developing an odour assessment strategy, it is necessary to select the tools that are most appropriate in each case. According to many authors, to improve the quality and reliability of this assessment in areas where enterprises and other facilities are located, it is advisable to use all available empirical approaches together with modelling, in combination with community surveys and other methods of analyzing the health status of the population. The data obtained as a result of such a comprehensive assessment will make it possible to substantiate measures to reduce air pollution by odorous substances. The literature search was carried out in the English-language text databases PubMed, Scopus, Web of Science and in the scientific electronic library eLIBRARY.ru. (RSCI)

Emission of odor pollutants and variation in microbial community during the initial decomposition stage of municipal biowaste

Odor pollution often occurs in the initial decomposition stage of municipal biowaste, including throwing/collection and transportation. However, this aspect of odor impact from municipal biowaste has not been well studied. In this study, a practical dustbin (120 L) equipped with flux chamber and filled with three types of municipal biowaste was used to simulate garbage storage conditions. The result indicated that the emission rate of odor pollutants for uncooked food waste (UFW) represented a nearly linear growth trend, reaching the maximum (3963 ± 149 μg kg−1 DM h−1) at 72 h. Cooked food waste (CFW) increased rapidly from 8 h to 24 h, and then remain fluctuated, reached the maximum (2026 ± 77 μg kg−1 DM h−1) at 72 h. Comparatively, household kitchen waste (HKW) reached the maximum emission rate (10,396 ± 363 μg kg−1 DM h−1) at 16 h. Sulfide and aldehydes ketones were identified as dominant odor contributor to UFW and CFW, respectively. While aldehydes ketones and sulfides were both dominant odor contributor to HKW. Moreover, the microbial diversity analysis suggests that Acinetobacter was the dominant genus in UFW, and Lactobacillus was the dominant genus in CFW and HKW. In addition, it was evident that each odorous pollutant was significantly associated with two or more bacterial genera, and most bacterial genera such as Acinetobacter, were also significantly associated with multiple odorous pollutants. The variation of odorants composition kept consistent with microbial composition. The present study could provide essential evidence for a comprehensive understanding of odorant generation in the initial decomposition stage of municipal biowaste. It could contribute to setting out strategies for odor control and abatement in municipal biowaste management systems.

Investigation of odor emissions from coating products: Key factors and key odorants

Coating products are widely used for the interior decoration of residential property. However, there is growing concern regarding their odor emissions and their impact on indoor air quality (IAQ). Most manufacturers and government agencies set odor intensity limits to control the odor of coating products, including their raw materials. However, it is difficult to determine product performance by means of their odor intensity index. Although evaluating odor intensity requires odor assessors to distinguish between different intensity levels, low consensus and reproducibility represent challenges that are difficult to avoid. As the odor concentration index only requires odor assessors to ascertain whether the odor is felt or not, the reproducibility of the evaluation results is relatively better. Moreover, suitable methodologies for determining odor concentrations in volatile coating product emissions have rarely been reported. Therefore, establishing an evaluation method for odor concentration of coating products and exploring its key influencing factors should bridge this gap. We examined the influence of the airbag material on the recovery rate of typical volatile organic compounds (VOCs) using direct injection by GC-MS and established that their adsorption effects were in the order: PET > PVF > PTFE. We then explored the influences of the sample curing and odor emission times on odor concentration. The solvent-based and water-based coatings reached equilibrium after 8 h and 16 h curing, respectively, and after 8 h and 12 h odor emission, respectively. The odor concentrations of real coating samples were measured and compared against their odor intensities. The odor concentration method more accurately and reliably discriminated coating products than the odor intensity approach. Thus, to assist manufacturers in improving coating formulations to reduce the odor impact of coating products, we used headspace gas chromatography to determine the odor substances in water- and solvent-based coatings and analyzed the odor contribution of various volatile compounds using the odor activity value (OAV) method. Butyl acetate, ethylbenzene, and 1-methoxy-2-propyl acetate were the key odorants in solvent-based coatings while 1-butanol, ethylbenzene, and butyl acetate were the key odorants in water-based coatings.

Impact of bad odors from the wastewater treatment plant on the well-being of the population of M’rirt (Morocco)

In the city of M’rirt, the odour nuisance caused by the wastewater treatment plant (WWTP) has led to numerous complaints from residents whose quality of life has been affected by these odours. Therefore, the objective of our study is to evaluate, in the field, the “real” impact of bad odours emanating from the WWTP with the help of a questionnaire during a period of 6 months. Our study sample composed of 1473 respondents chosen in a simple random way from the two municipalities surrounding the said odour source. The survey results revealed that among the 1473 respondents 71 (n=1040) confirmed “yes” the odour of the WWTP presents a real olfactory annoyance and 29% said “no” and that several factors are involved in its prediction. The statistical analysis of our study confirmed the negative impact of WWTP odours on the well-being of the city’s population, its spatial and temporal distribution with the establishment of a map of the olfactory discomfort in the city.

Limitations of FIDOL Factors for Odour Impact Assessment: Potential Ways of Improvements

Limitations of FIDOL Factors for Odour Impact Assessment: Potential Ways of Improvements

Smart instrumental Odour Monitoring Station for the efficient odour emission management and control in wastewater treatment plants

Odour emission assessment in wastewater treatment plants (WWTP) is a key aspect that needs to be improved in the plant management to avoid complaints and guarantee a sustainable environment. The research presents a smart instrumental odour monitoring station (SiOMS) composed of an advanced instrumental odour monitoring system (IOMS) integrated with other measurement units, for the continuous characterization and measurement of the odour emissions, with the aim of managing the potential odour annoyance causes in real time, in order to avoid negative effects. The application and on-site validation procedure of the trained IOMS is discussed. Experimental studies have been conducted at a large-scale WWTP. Fingerprint analysis has been applied to analyze and identify the principal gaseous compounds responsible for the odour annoyance. The artificial neural network has been adopted to elaborate and dynamically update the odour monitoring classification and quantification models (OMMs) of the IOMS. The results highlight the usefulness of a real-time measurement and control system to provide continuous and different information to the plant operators, thus allowing the identification of the odour sources and the most appropriate mitigation actions to be implemented. The paper provides important information for WWTP operators, as well as for the regulating bodies, authorities, manufacturers and end-users of odour monitoring systems involved in environmental odour impact management.

Quantifying odour impacts from aged organic waste to be considered as a priority constraint in route optimization for waste collection trucks.

Route optimization has been used for years to plan the routes for municipal solid waste (MSW) collection trucks to achieve cost reductions. Historically, optimized routes had overlooked a number of aspects and parameters in their design. This study aims to consider MSW odour detection as a performance indicator and a priority constraint in the optimization process by quantifying the impact of objectionable odours from uncollected aged MSW that contains a high percentage of food waste (typically called wet garbage). Odours from 48 aged food waste samples were rated on a scale from 0 to 3 to mark the beginning of the critical time of objectionable odour detection. The critical time was found to take place approximately at the hour 13.6, which was then used, along with the estimated food waste weight in the bin, to define the beginning of a time window that puts the bin on a high priority status for collection over the other, less odoriferous bins. Three optimization scenarios for collection of 100 MSW bins in the city of Madaba, Jordan, were conducted under different constraints: least travelled distance, maximum collected volume and least odour impact. Without the application of the odour consideration, a total travelled distance of 143 km was the shortest travelled distance achieved, with 53 bins emitting odours and leaving 81 m3 of uncollected waste. However, when odour impact was the main routing constraint, a total travelled distance of 161 km was needed and 13 m3 of waste was left uncollected.

Odour concentrations prediction based on odorants concentrations from biosolid emissions

Biosolids storage areas are a significant contributor to wastewater treatment plant (WWTPs) odour emissions which can cause sensorial impact to surrounding communities. Most odour impact regulations are based on odour concentration (COD) measurements determined by dynamic olfactometry. Understanding the relationship between odorants concentrations and COD in the biosolids emission is important to identify how the measurement and monitoring can be conducted using analytical rather than sensorial techniques. Some of the odorants are unknown in biosolid emissions, increasing the uncertainty in predicting COD. In this study, emissions from 56 biosolid samples collected from two WWTPs located in Sydney, Australia, were analysed by analytical and sensorial methods, including olfactory detection port (ODP) and dynamic olfactometry. Concentrations of 25 odorants and two ordinal variables represented odour events detected by ODP assessors were linked to COD values. Bayesian Model Averaging and Variable Selection with Bayesian Adaptive Sampling were applied to model the relation between COD and odorants concentrations. Results indicate the usability of the probabilistic methods and nonlinear transformations in modelling the odour concentrations based on odorants concentrations from biosolids emission and the accuracy of a small dataset.

Methodology for assessment the impact of environmental odours on the population according to questionnaire surveys (literature review)

This article contains the review of methodological approaches to assessment of the perception by the population odours from industrial and other sources, and studying the relationship between the perception of odours with the both the health status and quality of resident’s life, the degree of odour annoyance, using questionnaires. The literature search was carried out using Pubmed, Scopus, Web of Science, MedLine, Global Health, RSCI databases. The long-term practice of surveys of the population living in areas, where sources of emissions of odourous substances are located, has shown annoyance with odours to be a complex reaction, including emotional, behavioral, and somatic aspects. In addition to the direct impact of the odour, it is important to take into account contextual and personal factors that can weaken or strengthen the annoyance. Personal factors include the socio-demographic characteristics of the respondents, “environmental worry”, ways of responding to the situation and the subjective assessment of their own health. Contextual factors include the socio-economic conditions of the population and other indicators of the environmental state. These factors form the blocks included in the model of the relationship between odour impact, odour perception and odour annoyance, which is the basis of a standard questionnaire for a population survey. The questionnaire consists of basic and additional questions combined in several modules. The questions of the main module, which are obligatory and asked in all cases, devoted to the living conditions of the respondents, environmental factors (for example, noise and odours) that, in their opinion, can cause annoyance, have a negative impact on health. The questions of the additional modules (“Health”, “Behavioral changes”, “Environmental worry”) are asked depending on the context and specific objectives of the study. Using this methodology, numerous studies have been conducted abroad, which have shown the presence of correlations between the annoyance of odours, the occurrence of stress and the appearance of symptoms of various diseases. In different countries, the proportion of residents who are “significantly annoyed” by odours, is a criterion for authorities and enterprises to make certain management decisions to reduce emissions. The use of questionnaires can be implemented in the Russian Federation, where enterprises being sources of odours are located, in particular, if there is a problem with odours in the atmospheric air, while complying with the current sanitary legislation.

Application of Field Olfactometry to Monitor the Odour Impact of a Municipal Sewage System

Odorant emissions are associated with, among other things, wastewater transport in sewer networks; they contribute to air pollution and result in complaints from residents living close to emission sources. The critical location in terms of the formation of unpleasant odour compounds is the pressure line that connects the pumping station and the expansion well; this is where they are released into the atmosphere. This paper presents comprehensive results of olfactometric and chromatographic tests in the Polish city of Białystok using portable devices that allow for multiple determinations and instant results. The study attempts to investigate the relationship between odour and odorant concentrations and check the suitability of field olfactometry as a tool for the ongoing monitoring of the emission of noxious odours and for verifying complaints submitted by residents. Statistical analysis shows a very high correlation coefficient between cod and the concentrations of individual odorants, ranging from 0.82 to 0.91. This olfactometric research, mainly conducted in situ, can be an appropriate method for the ad hoc monitoring of processes in sewage networks. This method allows the detection of unwanted emissions of odours at individual points in the network in concentrations that are not detected by standard sensors but that nevertheless cause odour nuisances, complaints, and social conflict. The research results provide evidence in favour of the energetic usage of wastewater, which is in line with circular economy conception, since odour nuisance is one of its indicators.

Odor Identification by Parkinson's Disease Patients Tested by Using Sniffin' Sticks versus Natural Spices.

Introduction Hyposmia is a frequent symptom of Parkinson's disease (PD), which greatly impacts patients' flavor perception and their quality of life. However, PD patients recognize some odors better than others. Identifying which food odors are still recognized by PD patients may be useful for flavor enhancement. Our aim was to evaluate the olfactory identification of Sniffin' Sticks and spice odorants in PD patients and healthy controls (HC), to identify the impact of synthetic odorants compared with real-life food and the impact of odor familiarity and pleasantness on odorant identification in PD patients. Methods Sniffin' Sticks odorant identification was evaluated in 80 PD patients and 105 age-matched HC. In a subset, the spice odorant identification was evaluated. Results The mean total score was higher for the Sniffin' Sticks than for the spice odor identification test in all participants (55.4% versus 22.5%). Sniffin' Sticks orange, peppermint, rose, and fish odorants were best correctly identified by PD patients, by 62.5, 53.8, 52.9, and 57.5%, respectively. Of the spice odor identification test, garlic and “no stimulus” were best correctly identified by PD patients, by, respectively, 38.2 and 67.6%. HC identified most Sniffin' Sticks odorants and spices better than PD patients. Odorant familiarity determined real-life food odorant identification. Conclusion This study demonstrates that some food odorants, both the commercial Sniffin' Sticks as natural odorants, are still recognized by PD patients. Sniffin' Sticks were better recognized compared with real-life odorants, by both HC and PD patients. Odorant familiarity determined PD patients' odorant identification; therefore, familiar food odorants may have potential for a future flavor enhancement. Implications. This is the first study, to our knowledge, to evaluate real-life food odor identification in PD patients. Our results provide a first step towards patient-appropriate flavor enhancement strategies in PD.

Characterization of volatile compounds of cooked wild Iberian red deer meat extracted with solid phase microextraction and analysed by capillary gas chromatography - mass spectrometry

Wild Iberian red deer meat demand and interest are increasing and, therefore, an in-depth characterization of meat quality is needed to meet consumer demands. The objective of the present work was to assess, for the first time, the volatile profile of cooked wild sport-hunted Iberian red deer meat. Twenty-three loin samples from male red deer (Cervus elaphus hispanicus) were cooked and the volatile profile was analysed using solid phase microextraction, followed by capillary gas chromatography-mass spectrometry. Fifty-five volatile compounds were found. The major ones in number and relative abundance were aldehydes (84%), followed by alcohols (11%), hydrocarbons (2.4%), ketones (1.7%), furans (0.34%) and sulphur compounds (0.18%). Hexadecanal was the major compound and other long-chain compounds such as (E)-2-tetradecen-1-ol or 2-pentadecanone were also reported in considerable abundance. Several compounds related to grass-based diets were identified (2,3-octanedione, hexadecane or 1-pentadecanol). Odour impact ratio of volatile compounds was calculated and dimethyl trisulphide, (E,E)-2,4-decadienal, decanal and dodecanal were the most odorant compounds affecting the flavour of the cooked deer meat.

Assessing the contribution of odor-active compounds in icewine considering odor mixture-induced interactions through gas chromatography–olfactometry and Olfactoscan

The sensory impact of odor-active compounds on icewine aroma could be influenced by perceptual interactions with other odor-active compounds. The aim of this study was to establish an approach to evaluate the contribution of odor-active compounds found in icewine considering mixture-induced perceptual interactions. By comparing the impact of key odorants detected in icewine following a gas chromatography–olfactometry approach with an Olfactoscan-based methodology using a background odor of icewine, 69 odor zones were detected, and their related compounds were further identified. The results revealed that icewine background odor could exert odor masking or enhancement on key odorants when they are considered in the complex wine aroma buffer. Several compounds can induce qualitative changes in the overall wine aroma. This study underlined the efficiency of Olfactoscan-like approaches to screen for the real impact of key odorants and to pinpoint specific compounds that could be highly influential once embedded in the aroma buffer.

Activated sludge process versus rotating biological contactors in WWTPs: Evaluating the influence of operation and sludge bacterial content on their odor impact

Two municipal wastewater treatment plants (WWTPs), based on activated sludge process (ASP) and rotating biological contactors (RBC) as biological treatments, were comparatively evaluated in terms of their operational conditions, bacterial content and physicochemical characteristics of their derived sludge (SL) to determine their influence on odor impact. The average values of influent wastewater flow, inlet chemical oxygen demand (COD) and COD removal efficiency were (ASP-WWTP vs. RBC-WWTP): 447 vs. 689 m3/d, 300 vs. 423 mg/L and 88.28 vs. 83.17%, respectively. Regarding the global odor emissions, ASP-WWTP and RBC-WWTP had a similar odor emission rate (11,177 ouE/s and 12,784 ouE/s, respectively), with sludge thickening and dewatering being the major sources of odor in both facilities. Proteobacteria, Bacteroidetes and Firmicutes were the three predominant phyla in both WWTPs, representing the 83% in ASP-SL and the 97% in RBC-SL. RBC-SL showed lower bacterial biodiversity than ASP-SL. The higher odor concentration from the sludge handling activities in RBC-WWTP were linked to the significative increments in the abundance of Porphyromonadaceae, Clostridiales, Lachnospiraceae (obligate anaerobe) and Moraxellaceae (aerobic) families compared to ASP-WWTP. However, when odor emissions were evaluated per equivalent inhabitant (EI), a higher value was obtained for ASP-WWTP (16.22 ouE/s·EI) compared to RBC-WWTP (6.84 ouE/s·EI).