Odor Reduction Research Articles

Effect of rosemary extract on volatile flavor profile and flavor source of skipjack tuna

A fishy odor can significantly hinder the development of products made from nutritious skipjack tuna. To address this issue, rosemary extract (RE) was used as a deodorizing agent for skipjack tuna. Multi-omics techniques, including e-nose, e-tongue, gas chromatography-ion mobility mass spectrometry (GC-IMS), and gas chromatography-mass spectrometry (GC-MS), were employed to analyze the volatile flavor compounds in the skipjack tuna meat before and after deodorization. The main fishy odors found in the skipjack tuna were identified as nonanal, heptanal, hexanal, and 1-octen-3-ol, primarily resulting from lipid oxidation. Treatment with RE solutions at concentrations of 0.8% and 1.0% completely removed nonanal, hexanal, and heptanal from the skipjack tuna meat, while the level of 1-octen-3-ol was significantly reduced by 67.21% (p < 0.05). The GC-MS analysis of the impregnated solution indicated a 31% increase in 1-octen-3-ol content at a concentration of 0.2% (p < 0.05). Additionally, skipjack tuna meat treated with 0.8% and 1.0% RE showed lower peroxide values and thiobarbituric acid reactive substances values (p < 0.05). The reduction of fishy odor by RE was directly linked to decreased lipid oxidation. Quantitative analysis of phenolics revealed that the relative content of phenolics in RE was 52.54%, with the main phenolics being chlorogenic acid, caffeic acid, and luteolin. Thus, RE shows promise in eliminating fishy odors and minimizing lipid oxidation in skipjack tuna.

Emission and odour reduction in bitumen at high temperature: A comprehensive assessment of 18 functional additives using HS-GC-MS

Bitumen additives that can reduce emissions in bitumen and asphalt are desirable for managing or mitigating harmful or odorous emissions during infrastructure projects. Assessing and comparing the relative performance of different additive classes is crucial for determining their significance in emission reduction. In this study, a range of additive classes were investigated, including commercial additives, natural products, synthetic chemicals, biomolecules, and solid adsorbents. Headspace gas chromatography-mass spectrometry (HS-GC-MS) was used to measure the release of volatile organic compounds (VOCs) from bitumen after the incorporation of these additives. Among the additives investigated, solid adsorbents such as biochar materials were the most effective in mitigating the emissions of the monitored VOCs by up to 50%. These results suggest that biochar, may be prioritized for managing VOC emissions in asphalt-related projects.

Effects of different reheating methods on lipid oxidation in frozen silver carp fish cakes

SummaryThis study investigated the effect of five different reheating methods (boiling water, steaming, low‐heat microwave at 120 W, medium‐heat microwave at 400 W, high‐heat microwave at 800 W) on lipid oxidation of silver carp fish cake. The changes of lipid content, thiobarbituric acid (TBA) value, acid value (AV), peroxide value (POV), volatile flavour components and fatty acid composition were detected. The results indicated that products reheated with medium‐heat microwave had higher lipid content, lower TBA, AV and POV value. The medium‐heat and high‐heat microwave reheated group had larger variety of volatile flavour substances. Moreover, the relative content of hexanal and heptanal related to unpleasant “overcooked taste” was less, and the relative content of 2‐heptanone, which contributed to the reduction of fishy odour, was more in medium‐heated microwave group. The content of monounsaturated fatty acids in the medium‐heat microwave group was higher than other reheating methods, so as the ratio of unsaturated to saturated fatty acids. Considering all indicators, medium‐heat microwave reheating is more recommended due to its inhibition of fat oxidation.

Tracing the odor source of crumb rubber modified asphalt emissions and evaluating the deodorization effect of attapulgite

Crumb rubber modified asphalt (CRMA) is widely used in road construction due to its excellent performance. However, it generates significant odorous gases during paving. To analyze the odor contribution, both untreated crumb rubber and desulfurized rubber were involved in this study to prepare CRMA and desulfurized rubber modified asphalt (DRMA). Attapulgite was selected as an emission reduction agent to reduce the odorous emissions released from CRMA and DRMA. An indoor fume collection system and gas chromatography-mass spectrometry (GC-MS) analysis were used to trace the odor source and quantify the odorous emissions. A comprehensive olfactory thresholds database for CRMA emissions was further established to evaluate the odor level of various rubberized asphalt binders by using three-point comparative odor bag method, along with known olfactory thresholds of certain compounds reported in the literature. Dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), bending beam rheometer (BBR) and Brookfield viscosity tests were used to analyze the effect of attapulgite on rheological properties of CRMA and DRMA. Results indicated that odor emission rate of CRMA containing 1 %, 3 %, and 5 % attapulgite was decreased by 42.62 %, 63.29 %, and 71.06 %, respectively. Benzothiazole, derived from tire rubber vulcanization accelerator, can be reduced by 60.25 % with 1 % attapulgite, demonstrating excellent performance in terms of reducing target odor emissions. Although DRMA has a lower emission rate than that of conventional CRMA, the addition of 1 % attapulgite can further reduce the odor emission rate of DRMA by 37.92 %. The addition of attapulgite has less impact on the overall performance of CRMA and DRMA. Besides, it was found that attapulgite can reduce the viscosity of rubberized asphalt binders, which is beneficial for rubberized asphalt mixture paving and compaction. Considering odor reduction, performance, and economic factors, the optimal attapulgite content was determined to be 5 % for CRMA and 1 % for DRMA. This approach successfully reduces odorous emissions while maintaining the desirable properties of CRMA, making it a viable solution for environmentally friendly road construction.

Bio-enriched composite materials derived from waste cooking oil for selective reduction of odour intensity

Currently, pathogenic microorganisms are becoming more active in public utility areas like parking lots and waste shelters due to the accumulation of organic waste. This uncontrolled waste leads to decay, altering its composition and presenting a microbiological risk to public health. Additionally, it emits unpleasant odors containing chemicals that irritate the mucous membranes, causing discomfort in the nose, throat, and eyes by stimulating the trigeminal nerve. These odors can have various negative effects on both quality of life and public health. The study investigated the physicochemical properties of oil composites enriched with natural additives and determined their effectiveness in reducing the intensity of nuisance odours. The research showed over 82% reduction in decaying meat odour and almost 65% reduction in ammonia odour. A higher impact of the given composites on reducing the odour from decaying meat than from ammonia was observed. This may be due to the biocidal properties of the additives used (turmeric, thymol, salicylic acid, hops and curly sorrel) and the higher intensity of ammonia odor compared to meat-derived odour. Despite the non-porous nature of the solids tested (with similar specific surface areas ranging from 0.66 to 0.88 m2/g), they were capable of sorbing NH3.

The Smell of Progress in the Circular Plastics Economy – Odor Characterization and Reduction in Polymer Recyclates and HDPE‐Lignin Blends

The Smell of Progress in the Circular Plastics Economy – Odor Characterization and Reduction in Polymer Recyclates and HDPE‐Lignin Blends

Mitigation of ammonia and hydrogen sulfide emissions during aerobic composting of laying hen waste through NaOH-modified biochar

The impact of NaOH-modified biochar on the release of NH3 and H2S from laying hens' manure was examined for 44 days, using a small-scale simulated aerobic composting system. The findings revealed that the NaOH-modified biochar reduced NH3 and H2S emissions by 40.63% and 77.78%, respectively, compared to the control group. Moreover, the emissions of H2S were significantly lower than those of the unmodified biochar group (p < 0.05). The increased specific surface area and microporous structure of the biochar, as well as the higher content of alkaline and oxygenated functional groups, were found to facilitate the adsorption of NH3 and H2S. This enhanced adsorption capability was the primary reason for the significant reduction in NH3 emissions. Furthermore, during the high-temperature phase of composting, there was a notable alteration in the microbial community. The abundance of Limnochordaceae, Savagea, and IMCC26207 increased significantly which aided in the conversion of H2S to stable sulfate. These microorganisms also influenced the abundance of functional genes involved in sulfur metabolism, thereby inhibiting cysteine synthesis, along with the decomposition and conversion of sulfate to sulfite. This led to a significant decrease in H2S emissions. This study provides valuable data for the selection of deodorizers in the composting process of egg-laying hens. The results have significant implications for the application of NaOH-modified biochar for odor reduction in aerobic composting processes.

Septage treatment using the First Stage of French Vertical Flow Constructed Wetlands: From the beginning to the closure of the system

The First Stage of French Vertical Flow Constructed Wetlands (FS-FVFCW) offers a sustainable solution for treating septage. The system operates through distinct phases: start-up, full operation and final rest. During full operation, factors such as feeding duration, rest periods and percolate impounding significantly affect performance. This study assessed the performance of a pilot-scale Modified FS-FVFCW in Northern Tropical Andes, from start-up to closure stages under three operational scenarios. These scenarios varied in planted/unplanted conditions and percolate drainage/impounding. A four-month start-up phase proved adequate for vegetation growth and adaptation, achieving over 50% COD removal efficiency. Percolate retention (impounding) during operation notably improved COD and TS removal, increasing efficiencies from 49% to approximately 90% for COD and from 39% to around 70% for TS. Plant presence contributed to mosquito control and odour reduction but had minimal impact on removal efficiencies. The pilot demonstrated significant dewatering potential, with sludge deposit samples showing water content below 76% across all scenarios after 24 h; and a 10% reduction in VS/TS ratio during the operational resting period. After a 5-month closure, the sludge deposit layer exhibited organic matter content similar to long-rested sludge, albeit with persistent faecal contamination.

Deodorant Efficacy of Xylityl Sesquicaprylate Vehiculated into Roll-on and Stick Prototype Formulations

Given the burgeoning global market for deodorant products, it is paramount to develop novel, safe, and efficacious molecules that align with the cosmetic industry’s trend toward active compounds sourced from natural, sustainable, and renewable sources. In this context, we in vitro and in vivo investigated the deodorant potential of xylityl sesquicaprylate, a compound that, besides other functions, has antimicrobial activity. We performed the time–kill test to challenge the xylityl sesquicaprylate against Staphylococcus epidermidis, Staphylococcus aureus, and Corynebacterium xerosis and in vivo trial efficacy was established through a sniff test using two deodorant prototype formulations containing xylityl sesquicaprylate at 0.35% (w/w). The xylityl sesquicaprylate at 0.35% (w/w) in glycerin presented in vitro deodorant activity through a bactericide/bacteriostatic profile against S. epidermidis, S. aureus, and C. xerosis. The in vivo efficacy trial performed by the sniffers through a single application of the roll-on and the stick prototype formulations added to the developed active compound deodorant’s effectiveness with a reduction in axillary bad odor, in comparison to the respective blank sample, for 2, 4, 8, and 12 h. When the deodorant efficacy was evaluated subjectively by the participants, there was always no difference between the stick sample and the blank; however, the roll-on deodorant was perceived as effective after 4 and 8 h of a single application of the sample, as established by the volunteers.

Odor-Active Compounds in Flexible Polyurethane Materials

Flexible polyurethane (PU) materials find extensive use in upholstery, mattresses, and automobiles, yet the molecular background of their odor is still inadequately understood. To address this gap, we aimed at identifying major odorants in fifteen samples representing eight common types of flexible PU materials. The volatiles isolated from the samples were subjected to activity-guided screening via gas chromatography-olfactometry. Structures were assigned by comparing odor, retention data, and mass spectra to those of authentic reference compounds. This approach led to the identification of 50 odorants, 39 of which had not previously been described in PU. The odorants belonged to a wide range of compound classes, including tertiary amines, fatty acid oxidation products, short-chain aldehydes, trioxocanes, pyrazines, aromatic hydrocarbons and heterocycles, chlorinated compounds, phenol derivatives, fragrance compounds, and nitriles. For some odorants, further insights were gained into their origins and release behavior. For example, the odorous 1,4-dimethylpiperazine had been used as a catalyst, and propanal was shown to be not only a PU odorant but also the precursor of an odor-active trioxocane. Additionally, the quantitation of acetaldehyde and propanal suggested their continuous regeneration from the samples. While the sources of other compounds still have to be clarified, the data obtained in this study could pave the way for odor reduction strategies in the production of PU materials, ultimately resulting in an improved odor and consumer experience.

Long-term pilot study on advanced treatment of lake water by ultrafiltration / nanofiltration

Advanced water treatment technologies, including ozone biologically activated carbon adsorption (O3-BAC), ultrafiltration (UF), and nanofiltration (NF), are essential for enhancing drinking water quality. O3-BAC and UF excel in pathogen, virus, and by-product removal, while NF promises enhanced contaminant elimination for high-quality water. However, the implementation of combined UF/NF dual-membrane treatment processes in large-scale water treatment facilities using surface water sources like lakes remains relatively novel. The lack of long-term operational data is the main reason for the limited widespread adoption. To address this, two pilot systems were established: one comprising ‘O3-BAC + pressure-driven UF(I) + NF(I) (Route 1 at 6.4m3/h)’, and the other ‘immersed UF(II) + NF(II) (Route 2 at 3.2m3/h)’, undergoing a year-long evaluation. The trials showed that the dual-membrane systems were effective and resistant to interference. Notably, they achieved removal efficiencies exceeding 98 % for turbidity, UV254 absorbance, fluorescence substances, and algae, alongside significant reductions in odor (80 %) and total dissolved solids (TDS) by 30 %. Both membrane systems display promising performance and O3-BAC is recommended as a pretreatment process. Analysis revealed that the primary constituents of membrane fouling on the NF membranes are aluminum silicate, SiO2, CaCO3 particles, and organic pollutants, which are typically formed through interactions between calcium ions and dissolved organic matter (DOM). The most effective cleaning protocol involves acidic-alkaline treatments. This study provides valuable operational insights into advanced treatment processes using dual-membrane combinations for water treatment plants that rely on lake water sources.

Enhancement of Physical Appearance, Skin Permeation, and Odor Reduction Using Liposome of Hydrolyzed Salmon Collagen for Cosmetic Products.

Hydrolyzed collagen (HC) derived from salmon (Oncorhynchus nerka) skin possesses properties that can nourish the skin, and it is one of the active ingredients used in cosmeceutical products for moisturizing the facial skin. However, HC solution gives off a fishy odor and it is gray in color that makes the product unacceptable for cosmetic purposes. This study aimed to use liposome-encapsulated hydrolyzed salmon collagen to improve its physical appearance, skin permeation, and eliminate the fishy odor. Two percent of HC and vitamin B3 (VitB3) were used as active ingredients to incorporate into liposomes. Phosphatidylcholine, cholesterol, and Tween 80 at a suitable weight ratio of 8 : 2 : 1 produced nano-sized vesicles (170.6 ± 0.70 nm) with the highest percentage of entrapment efficiency (95.72 ± 2.00%) of VitB3 and (49.63 ± 1.74%) of HC. Skin permeation and odor detection of the HC-VitB3 liposome were studied using Franz's diffusion cell and gas chromatography, respectively, and compared with HC-VitB3 solution. Subsequently, facial serums were formulated using HC-VitB3 liposomes and HC-VitB3 solutions, and a product satisfaction test was conducted with 100 volunteers to determine their preferred product. The results of the studies of HC-VitB3 liposome serum showed improved formulation appearance, enhanced skin permeation, and better odor elimination compared to the HC-VitB3 serum. Furthermore, seventy-three volunteers in the product satisfaction test preferred and selected the liposomal serum for its superior scent. From all the experimental results, it could be seen that liposomes can help increase skin penetration, and undesirable odors and colors can be masked by the appropriate lipid bilayer structure of liposomes.

Odor reduction efficiency through exhaust fan operating rate with spraying inside Bio-curtain

Odor reduction efficiency through exhaust fan operating rate with spraying inside Bio-curtain

Closed-House Biofilter Design and Performance Evaluation for Mitigating Environmental Odor Disturbances

Broiler-closed houses typically lack reduction technology, leading to environmental issues, namely odor. Processing technology can be used, namely biofilters. This study aims to design and construct a closed-house biofilter and perform a test on the biofilter to reduce odors. Odors are measured by the odor gas concentration (ammonia and hydrogen sulfide) and hedonic scale by the panel method. The biofilter consisted of an odor source (closed house), a humidifier, and a biofilter reactor. Factors that influence the size of the biofilter reactor from gas removal activities include air flow rate, retention time, and air volume. The proposed biofilter can reduce the odor from the broiler. Reactor temperature, relative humidity, and bacterial activity affect odor reduction. This successful implementation of a biofilter significantly mitigates odors in a closed-house broiler, addressing a critical environmental concern.

Deodorisation of Ventilated Air from a Fat-Processing Plant Using Different Types of Biofilter Fillings and Membranes

The aim of the research is to assess changes in odour concentration in the ventilated air of a production hall, using different types of biofilter fillings and different types of membranes. Deodorisation was carried out using a mobile combined biofilter at a plant producing lard and liquid oils. Ventilated air from the hall contained organic and inorganic pollutants. Two types of fillings were used for technological tests: stumpwood chips mixed with pine bark and a mix of stumpwood chips with pine bark and green waste compost. Two types of membranes were also used, differing in thickness, permeability, and water resistance. The subjects of the research were the air supplied to the filter, lifted directly from the bed, and the air above the membranes. The deodorisation efficiency—the percentage reduction in the odour concentration value as a result of air flow through the bed and membranes—was calculated. The filtration methods used allowed the selection of the most advantageous technological variant from the point of view of deodorisation effectiveness: a mix of stumpwood chips with pine bark and the Pro Eko Tex UV membrane. It has a total odour reduction efficiency of 99.3–99.9% and has been added to full-scale implementation works.

Stabilization of biomass in manure effluent using the thermophilic-aerobic process

Aerobic-thermophilic stabilization of biomass is crucial in improving the processing processes of manure. This method makes it possible to achieve effective and stable processing of organic materials contained in manure using aerobic microorganisms and elevated temperatures. The aerobic-thermophilic process includes the action of oxygen and high temperature, which contribute to the active decomposition of organic substances in manure runoff. The increased temperature helps to create optimal conditions for the action of thermophilic bacteria, which accelerates the process of biological decomposition. Studies show that aerobic-thermophilic treatment of manure effluents helps to reduce the concentration of pathogenic microorganisms and ammonia. This contributes to obtaining cleaner and environmentally safe manure suitable for use in agriculture. Advantages of aerobic-thermophilic stabilization: Faster recycling process compared to traditional methods. Reduction of odors and risk of pathogen contamination. High quality and efficiency of produced manure. Aerobic-thermophilic stabilization of biomass in manure processing is a promising direction in improving modern waste treatment technologies. Its implementation contributes to improving the quality and safety of manure and the effective use of these resources in agriculture. Research and development of this method are essential for achieving sustainable and ecologically clean agricultural production. It has been established that liquid manure of enterprises with intensive milk and pork production technologies with hydraulic manure removal systems with a humidity of 92–96 % should be subjected to aerobic fermentation in an auto thermal mode, as a result of which products are obtained that are safe from a sanitary and hygienic point of view. In addition, the loss of nutrients is reduced. which determines the quality of organic fertilizers. Established that liquid manure businesses for technology-intensive milk production and pig manure removal by hydraulic systems with humidity 92–96 % of it are advisable to expose aerobic biofermentatsiyi in autothermal mode, which allows you to get the products in a safe sanitary and hygienic attitude and reduce the loss of nutrients that determine the quality of organic fertilizers.

Best practices for managing malodorous and infected wounds in advanced cervical cancer.

This cross-sectional study was conducted to examine the most effective strategies for managing malodorous and infected wounds in patients who have been diagnosed with advanced cervical cancer. The research was conducted in Liupanshui, China. The study specifically examined demographic profiles, wound characteristics and effectiveness of wound management approaches. The study incorporated the heterogeneous sample of 289 participants who fulfilled the inclusion criteria. Data collection was conducted via structured questionnaires and medical record evaluations. Descriptive statistics and statistical analyses, such as regression analysis, were utilized to evaluate demographic attributes, wound profiles and effects of different approaches to wound management. The findings unveiled the heterogeneous demographic composition of patients, encompassing differences in socioeconomic standing, educational attainment and age. A wide range of wound characteristics were observed, as 65.7% of lesions during the acute phase with diameter between 2 and 5 centimetres, while 41.5% of lesions had this range. The most prevalent types of infections were those caused by fungi (48.4%), followed by bacterial infections lacking resistance (38.1%). A moderate degree of odour intensity was prevalent, affecting 45.0% of the cases. With maximal odour reduction of 80%, a mean healing time of 25 days and patient satisfaction rating of 4.5 out of 5, Negative Pressure Wound Therapy demonstrated itself to be the most efficacious treatment method. Additional approaches, such as photodynamic therapy and topical antibiotic therapy, demonstrated significant effectiveness, as evidenced by odour reductions of 70% and 75%, respectively, and patient satisfaction ratings of 4.3 and 4.2. Thus, the study determined challenges associated with management of malodorous and infected lesions among patients with advanced cervical cancer. The results underscored the significance of individualized care approaches, drew attention to efficacious wound management techniques and identified critical determinants that impacted patient recuperation. The findings of this study hold potential for advancing palliative care for individuals diagnosed with advanced cervical cancer.

Environmental Odor Analysis in West and East Java’s Ambient Air and Odor Reduction Using Biofilter Model

The odor affects both one’s health and quality of life. This study measures and analyzes odor concentration and odor sources in ambient air, the correlation between odor gas concentration and the hedonic scale, and the design of an odor-reduction instrument. The research commenced from February to May 2022 in the small industrial area (SIA) of Magetan Regency and compost bins of Bogor City. Data was collected through chemical analysis, and the hedonic scale was measured at four points divided into radii one and two. The concentration of odor parameters in Magetan and Bogor City is below the quality standard, while the correlation between ammonia gas concentration and the hedonic scale is low. Regarding the biofilter, its odor reduction efficiency is 35% for rotten fish, 70% for goat manure, 82% for compost waste, and 47% for chicken carcasses.

Botulinum toxin A versus microwave thermolysis for primary axillary hyperhidrosis: A randomized controlled trial

Botulinum toxin A (BTX) and microwave thermolysis (MWT) represent 2 treatment modalities for axillary hyperhidrosis with different procedural and efficacy profiles. To compare long-term outcomes following BTX vs MWT treatment of axillary hyperhidrosis. A prospective, randomized, within-patient, controlled trial, treating axillary hyperhidrosis with contralateral BTX and MWT. Objective sweat measurement and patient-reported outcome measures for sweat and odor were collected at baseline, 6-month and 1-year follow-up (6M/1YFU). Hair reduction and patient treatment preference was also assessed. Sweat reduction was significant (all P <.01) for both interventions throughout the study. Objectively, sweat reduction was equal at 1-year FU (ΔP =.4282), but greater for BTX than MWT at 6-month FU (ΔP =.0053). Subjective sweat assessment presented comparable efficacy (6MFU: ΔP =.4142, 1YFU: ΔP =.1025). Odor reduction was significant (all P <.01) following both interventions, whereas only sustaining for MWT (6MFU: ΔP =.6826, 1YFU: ΔP =.0098). Long-term, hair reduction was visible after MWT, but not BTX (ΔP ≤.0001), and MWT was preferred by the majority of patients (76%). The intrinsic challenges in efficacy assessment. This study exhibited BTX and MWT with similar sweat reduction, but distinguishable odor and hair reduction at 1-year FU. These findings support individualized treatment approaches for axillary hyperhidrosis based on patient-specific symptoms and preferences.

Odour reduction of kraft lignin by wet oxidation

This study assesses wet oxidation of partially concentrated Kraft black liquor (40% dry matter) as a method for odour reduction of the lignin obtained from it by acid precipitation. To this end, and for the first time ever, the effects of wet oxidation temperature (120–150 ºC) and pressure (10–50 bar) on the odour profile of both the black liquor and the acid precipitated lignin were analysed. 2-methoxyphenol, dimethyl disulphide and dimethyl trisulphide were the main responsible compounds of the black liquor odour and, in the case of the precipitated lignin, aldehydes and organic acids also contributed. The most odourless lignin was the one precipitated from Kraft black liquor oxidised at the most severe conditions tested (150 °C and 50 bar for 2 h). However, these also caused a reduction in the lignin yield, as well as significant compositional and appearance changes, thus limiting its use in certain fields.