Musty Odor Research Articles

Purge and Trap Extraction of Musty Odor Compounds by Thermal Desorption Tube Packed with Polydimethylsiloxane-Coated Macroporous Silica Adsorbent

Purge and Trap Extraction of Musty Odor Compounds by Thermal Desorption Tube Packed with Polydimethylsiloxane-Coated Macroporous Silica Adsorbent

Production and release of 2-MIB in Pseudanabaena: Effects of growth phases on cell characteristics and 2-MIB yield

2-methylisoborneol (2-MIB), a secondary metabolite produced by cyanobacteria, often causes a musty odour in water, threatening the safety of drinking water supplies. This study investigated the effects of the growth phases on the production of 2-MIB by Pseudanabaena. The effects of cell characteristics on the production and release of 2-MIB were also explored. The total 2-MIB concentration increased during the exponential phase and decreased during the declining phase, which was consistent with the changes in cell density. However, the total 2-MIB yield (1.12–1.27 fg cell−1) of Pseudanabaena did not significantly differ throughout the growth cycle (p > 0.05). Meanwhile, the extracellular 2-MIB yield increased significantly from 0.31 fg cell−1 in the exponential phase to 0.76 fg cell−1 in the declining phase (p < 0.05), and the corresponding proportion of extracellular 2-MIB improved from 25.13% to 59.16% (p < 0.05). The surge in extracellular 2-MIB during the declining phase could be attributed to the breaking of the Pseudanabaena filament, as indicated by the decrease in Dmean during cell ageing. The findings of this study contribute to a more inclusive comprehension and management of musty odour issues resulting from cyanobacteria in the water supply.

Analog Astronaut Mission Habitat Bio Contamination Test

The presence of viable particles in materials, devices, people, surfaces, liquids, gases, or air is referred to as bio-contamination. Mold can grow anywhere there is enough moisture or a water problem. Most molds emit musty odors, which are the first indication of a problem. Mold can manifest itself as slightly fuzzy, discolored or slimy patches that expand in size. Mold growth can be significant in hermetically sealed and environmentally controlled environments. The enclosed habitats are well-exemplified by Analog Astronaut Mission Habitats (AAMH). A bio-contamination test was conducted at the AAMH in Poland from November 1 to 10, 2023. Mold was discovered growing in a bio-contamination experiment mixture of wheat flour, tomato powder and sugar. AAMHs should develop a bio-contamination control strategy as well as an internal system to protect the crew and citizens from diseases that the crew may transmit.

Antibiotics in water bodies, cyanobacterial toxicity and odorous compounds release: a review

The present study aimed to propose a new cause of odorous compounds release, i.e., the presence of antibiotics in water bodies and its toxicity to cyanobacteria, known to be the main producer of geosmin (GEO) and 2-methylisoborneol (2-MIB). Therefore, a literature review was carried out regarding the problems caused by antibiotics in aquatic environment, including cyanobacterial blooms and GEO and 2-MIB release. In addition, a bibliometric analysis was performed using the VOSviewer software based on the results obtained from the Web of Science (WOS) database. This review aims to build a scientific understanding of the problem, presenting interesting points that converge with the proposed association. It is worth mentioning that no work has been found in the literature that has proposed this relationship. Thus, based on the bibliographic survey, observations and information acquired in recent years about cyanobacterial blooms and environmental contamination by pharmaceutical drugs, one of the main causes of an earthy and musty flavour and odour in a drinking water supply is the toxicity imposed by the presence of antibiotics in aquatic environments on cyanobacteria.

Particulate Matter (PM2.5) and Mould Characteristics in Selected Classrooms Located in Waikato, New Zealand: Preliminary Results

Small airborne particulate contaminants such as mould spores can harm human health by causing or exacerbating respiratory illnesses. Such particulates tend to be microscopic; however, in the case of moulds, contamination can be associated with visible colonial growth on surfaces and musty odours detectable by occupants of the room. Shared spaces, such as offices and classrooms, represent areas of higher risk due to the larger numbers of people being exposed to airborne particulates. To better appreciate the health risks associated with airborne particulates, it is therefore advantageous to assess the levels of breathable particulates in a room and compare them with the proportion of particulates represented by mould spores. An air image sensor machine was used to collect PM2.5 particulate levels for three urban-campus classrooms and three semi-urban-campus classrooms during different wintertime (August) days in New Zealand. For each room, a settle-plate method was also used to compare background mould levels at breathing height for seated occupants. Three of the classrooms had been recently built or renovated with an adequate ventilation system installed, while the remaining three classrooms were not upgraded and had no evidence of a ventilation system. The results indicated that the classrooms in the new building, located at the semi-urban campus, tended to have lower levels of particulate matter PM2.5 compared with the urban classrooms, which had not been upgraded. However, the semi-urban classrooms tended to have higher mould counts than the urban spaces. Moreover, the building envelope for both new and old classrooms tended to be porous, with indoor PM2.5 readings increasing in step with outdoor PM2.5 readings. This study will assist in identifying new approaches to reduce the risk of particulate-related respiratory issues associated with urban teaching spaces, particularly those buildings requiring more sustainable technologies to purify the air and improve the indoor air quality (IAQ).

Quality of Rainbow Trout (Oncorhynchus mykiss) Reared in Recirculating Aquaculture System and during Depuration Based on Chemical and Sensory Analysis

In recirculating aquaculture systems (RAS), off-flavors can accumulate in fish muscle tissue. They are problematic for consumer acceptance and the reputation of farmed fish products. Although off-flavors are not toxic at low concentrations, they often give fish muscle earthy, muddy, or other unwanted flavors. Traditionally, the study of off-flavors in fish focused on muddy and earthy off-flavors caused by geosmin (GSM) and 2-methylisoborneol (MIB), but other unwanted flavors and compounds have also been identified. In this study, the selected off-flavors were chemically quantified in fish from a RAS-rearing rainbow trout (Oncorhynchus mykiss) and in different stages of depuration. A group of trained panelists with experience in sensory evaluation was specifically trained in analyzing rainbow trout samples. The panelists evaluated the fish with a sensory profile of 29 sensory attributes (12 odor, 5 taste, and 12 flavor properties). Overall, the concentrations of all the studied off-flavor compounds decreased, some to below the limit of detection and others (e.g., octanal, octanoic acid, phenylacetaldehyde, and acetoin) to a certain low level. Moldy, earthy, and musty odors and flavors especially decreased during depuration compared to fish in RAS. This study shows the consistency of the chemical analysis and sensory profiling. It also provides important information about the effects of the depuration period in RAS and on the chemical and sensorial quality of rainbow trout.

Evaluasi Penggunaan Tepung Daun Cengkeh (Syzygium aromaticum) terhadap Kualitas Fisik Jagung Pecah setelah Penyimpanan

The purpose of this research is to find out about the evaluation of using clove leaves powder with different percentages on the physical quality of corngrit that is being stored for two months. This research is done in the Feed Technology and Engineering Laboratory of the animal husbandry department, Faculty of Agriculture, Pattimura University in the period of September to November 2022. This research consists of 4 treatments and 4 repetition, P0 = 1500g corn grit + 0g clove leaves powder (0%); P1 = 1500g corn grit + 225g clove leaves powder (15%); P2 = 1500g corn grit + 450g clove leaves powder (30%); P3 = 1500g corn grit + 675g clove leaves powder (45%). The variables that are being observed in this research include weight, color, smell, lice, and fungus. The result of the research shows that the addition of 30% and 45% clove leaves powder in 1500g of corn grit gives better results to the physical quality of grit because they suppress lice infestation and fungus growth. The treatments also give distinct fragrant clove leaves, instead of the usual musty odor that appears on the corn grit that has been stored for 2 months.

Isolation and Identification of Lactic Acid Bacteria and Their Effects on the Off-odor of Burdocks.

Burdocks have diverse nutritional and pharmacological functions, but their unique odor is unwelcome. Here, the effect and mechanism of lactic acid bacteria fermentation on the off-odor of burdocks were investigated. The sensory evaluation showed that burdocks had earthy, musty, grassy, and pepper odors. 2-Isobutyl-3-methoxypyrazine (IBMP) and 2-secbutyl-3-methoxypyrazine (IPMP) mainly contributed to burdock's unique off-odor and were identified by gas chromatography-mass spectrometry combined with headspace-solid phase microextraction (HS-SPME-GC-MS) and relative odor activity value (ROAV) analysis. Weissella cibaria ZJ-5 from screened strains performed with the strongest ability to remove the off-odor and generate a fragrant odor, as determined by sensory evaluation. When incubated aerobically together with IBMP during fermentation, ZJ-5 degraded IBMP directly from 149.56 ± 0.72 to 71.55 ± 1.81 ng/mL. Additionally, linoleic acid content in fermented burdocks was significantly decreased compared with unfermented burdocks. (E,Z)-2,6-Nonadienal, which mainly contributed to fermented burdock's odor, may have been generated from linoleic acid during ZJ-5 fermentation, through the acid catalysis pathway. It indicated that LAB fermentation could improve burdock odor by degrading off-odor compounds and precursors and by generating new aldehydes.

The effect of drying, cell disruption and storage on the sensory properties of Nannochloropsis sp.

Adding microalgae into food could strongly influence the flavor of the final product which is the key factor for consumer acceptation. To assist food processors in the development of tasteful food products containing microalgae, it is necessary to understand the impact of processing and storage on the flavor of freshly harvested microalgae biomass. In this study, the effect of commonly used drying techniques (freeze-drying, spray drying and thin-layer oven drying) and cell disruption (high pressure homogenization) on the sensory quality of fresh Nannochloropsis sp. biomass was investigated. Furthermore, the impact of storage on the flavor properties of intact (non-disrupted) and disrupted Nannochloropsis paste was examined. Sensory evaluation by a trained panel indicated that the flavor of Nannochloropsis was not affected by freeze-drying. Whereas thin-layer oven drying at 60 °C resulted in a strong bitter taste and a musty odor. This odor is positively correlated with volatile organic compounds (VOCs) including Strecker aldehydes that arise from the Strecker degradation in the course of the Maillard reaction. Spray drying reduced the odor intensity and grassy odor of Nannochloropsis which could be attributed to the loss of several VOCs including esters, saturated alcohols and dimethyl sulfide. Furthermore, cell disruption of Nannochloropsis using high pressure homogenization resulted in intense grassy and fish oil odors features due to high amounts of fatty acid-derived unsaturated aldehydes, ketones and alcohols. Finally, dark storage of fresh intact and disrupted Nannochloropsis paste at ambient temperature strongly impacts the volatile profile due to the rapid formation of several VOCs, which negatively impact the palatability of the Nannochloropsis biomass. Our results provide the basis to be applied in downstream food processing of harvested Nannochloropsis biomass in order to maintain or optimize the flavor properties for specific food products.

Uncorking Haloanisoles in Wine

Haloanisoles in wine have devastating effects on the aroma and quality of the wine. 2,4,6-trichloroanisole (TCA) was discovered and coined as "cork taint" in 1982. However, we now understand that there are many more haloanisoles that contribute to these musty odors, including 2,4,6-Tribromoanisiole (TBA), 2,3,4,6-tetrachloroanisole (TeCA), and pentachloroanisole (PCA). While TCA, TeCA, and PCA can all be traced back to the cork, TBA's phenol precursor is ubiquitous in building material as a fire retardant, making it a much larger vector. All haloanisoles have the ability to aerosolize and resettle onto surfaces in the winery, making this a very difficult problem to eliminate. This literature review will cover the multiple haloanisoles found in wine, their sensory impacts, their effect on wine quality, and current methodologies with regard to their analysis.

An automated micro solid phase extraction gas chromatography–mass spectrometry (μSPE-GC–MS) detection method for geosmin and 2-methylisoborneol in drinking water

Geosmin and 2-methylisoborneol (2-MIB) are amongst the most common earthy and musty taste and odour (T&O) compounds found in drinking water. With low odour threshold detection limits below 10 ng L−1, and the complexity of raw water matrices, these two compounds provide a significant challenge for water companies globally. In this research, for the first time, a novel and fully automated micro-solid phase-extraction (μSPE) method coupled with gas chromatography (GC)–mass spectrometry (MS) has been developed for the detection of geosmin and 2-MIB for drinking water analysis. The new automated method described herein is environmentally friendly requiring low raw water sample volumes, of 25 mL, and only 50 μL of elution solvent. Our μSPE-GC–MS method exhibits excellent linearity for both compounds (R2 > 0.999) and low limits of detection of 2.0 ng L−1 and 4.3 ng L−1 for geosmin and 2-MIB, respectively. The method showed excellent recovery rates (95.1–100.1%) and good precision (RSD < 7%) in raw sample matrices. Our approach is fully automated onto a robotic workstation which can be readily integrated into a laboratory workflow for routine water analysis. Furthermore, the method has excellent potential to be incorporated within a portable system for onsite analysis.

Clinical, genetic, and experimental research of hyperphenylalaninemia.

Hyperphenylalaninemia (HPA) is the most common amino acid metabolism defect in humans. It is an autosomal-recessive disorder of the phenylalanine (Phe) metabolism, in which high Phe concentrations and low tyrosine (Tyr) concentrations in the blood cause phenylketonuria (PKU), brain dysfunction, light pigmentation and musty odor. Newborn screening data of HPA have revealed that the prevalence varies worldwide, with an average of 1:10,000. Most cases of HPA result from phenylalanine hydroxylase (PAH) deficiency, while a small number of HPA are caused by defects in the tetrahydrobiopterin (BH4) metabolism and DnaJ heat shock protein family (Hsp40) member C12 (DNAJC12) deficiency. Currently, the molecular pathophysiology of the neuropathology associated with HPA remains incompletely understood. Dietary restriction of Phe has been highly successful, although outcomes are still suboptimal and patients find it difficult to adhere to the treatment. Pharmacological treatments, such as BH4 and phenylalanine ammonia lyase, are available. Gene therapy for HPA is still in development.

Levels of Two Earthy and Musty Odor Compounds, 2-Methylisoborneol and Geosmin, in Wastewater and Concentration Variations during Treatment

Levels of Two Earthy and Musty Odor Compounds, 2-Methylisoborneol and Geosmin, in Wastewater and Concentration Variations during Treatment

A new method for evaluating nuisance of odorants by chemical and sensory analyses and the assessing of masked odors by olfactometry

The odor threshold concentration and the odor nuisance concentration of the nine persistent odorants at two wastewater treatment facilities were determined by Weber- Fechner curves for each odorant using dynamic olfactometry combined with the odor profile method. The odor threshold concentration results, representing each odorant's concentration at odor intensity of one (I = 1), were within range in the literature. The nuisance concentrations were determined by interpolation along the curves intersecting with the arbitrary odor intensity of three (I = 3). There is no reference that exists in the literature about determining odor nuisance concentrations for a complete set of odorants from any facility. The nuisance concentration results presented here are novel to odor control because they can provide information defining the nuisance odorant's isopleths in modeling and in designing effective odor control systems that avoid public nuisance.Dynamic olfactometry combined with the odor profile method was also used with actual foul air samples from different sources. When analyzed from raw to increased dilution, it was observed that the fecal and sulfur odors initially prominent (with no musty odors detected) gradually changed with increased dilution. Musty odors began to gradually appear while the fecal and sulfur odors became undetectable. We named this observation the “peeling of an onion effect”. It is speculated that this occurs because the musty odors in the concentrated foul air sample are masked by the fecal and the sulfur odors.

Clinical and pathomorphological changes in mycotoxicosis of cows

The defeat of feed by microscopic fungi is a fairly common phenomenon at this stage of the management of the agricultural sector. This is due to weather conditions (high rainfall) and errors in harvesting and storage of grain. Feeding affected feed leads to irreversible processes in the body of cows, reducing their productivity. The aim of the study was to establish marker indicators for the rapid diagnosis of mycotoxicoses in cows. So, when exposed simultaneously to T-2 toxin and toxins of the fungus Aspergillus fumigatus, destructive changes in the skin and mucous membranes were diagnosed, and pathology of the limbs was diagnosed, which was characterized by lameness. The laboratory revealed an increase in the level of leukocytes up to 37.1 g/l and a decrease in the content of hemoglobin in the blood of sick animals. Also, a characteristic feature was the latch of the contents of the rumen at pH 8.0, which in turn leads to a decrease in the number of ciliates. Also a sign of poisoning are changes in the fecal matter: liquid, musty odors and with an increased pH of up to 7.5. At the autopsy of the dead animals, a characteristic sign was: necrosis of the mucous membranes of the oral cavity, esophagus, gastrointestinal tract, protein degeneration in the liver and kidneys, and serous pulmonary edema. Infertility is 67.35 %, which leads to multiple unsuccessful insemination, which is due to destructive changes in the organs of the reproductive system. So, in sick animals, ovarian hypotrophy was diagnosed at the level of 54.09 %, ovarian cysts v in 8.18 %, yellow persistent bodies in the postpartum period – 7.54 %. The prospect of further research will be the development of preventive methods for treating cows and increasing their reproductive function of mycotoxicoses.

Estimation of Hydroxyl Radical Exposure in a three-stage Countercurrent Ozone Contactor – Reduction in Musty Odor Compounds and Formation of Bromate

ABSTRACT The Hanshin Water Supply Authority is the first bulk water supplier in Japan that currently operates two drinking water treatment plants. Both plants employ an ozonation process for the reduction of musty odor compounds, 2-methylisoborneol and geosmin, and trihalomethanes. In this study, we aim to estimate hydroxyl radical (HO∙) exposure in a three-stage countercurrent ozone contactor applied at the Inagawa drinking water treatment plant. We estimated the HO∙ exposure as the product of the ozone exposure multiplied by the RCt value, that is, the ratio of the HO∙ exposure to the ozone exposure. The ozone exposure was estimated by a methodology we developed earlier, and the RCt values were experimentally evaluated in this study. The estimated HO∙ exposure ranged from 0.4 × 10−10 to 6.7 × 10−10 M·s across the contactor during our research period. The highest HO∙ exposure of 6.7 × 10−10 M·s indicated that the reduction ratio of musty odor compounds exceeded 95%. At these exposures, the detected concentration of bromate was 6 µg/L, which is equal to the 60% concentration level of Japan’s water quality standard for drinking water. Further, we attempt to balance the reduction in musty odor compounds with control of bromate formation.

Effects of Harvesting Period and Storage Duration on Volatile Organic Compounds and Nutritive Qualities of Alfalfa

Harvest time and storage time had significant effects on nutrient quality and Volatile Organic Compounds (VOCs) of alfalfa. The objective of this study was to use headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) to analyze alfalfa at different harvest periods (budding stage, early blooming, full blooming), and storage for 0 d, 90 d, 180 d, 270 d, and 360 d, the dynamic changes in VOCs and nutritional quality. Results indicated that ketones, aldehydes, alcohols and esters were the main volatile components of alfalfa VOCs, accounting for 87.41%, 88.57% and 90.85% of the total volatile components at budding stage, early blooming and full blooming, respectively. VOCs and nutrient quality of alfalfa varied significantly in different harvest periods; delayed harvesting significantly reduced alfalfa aldehydes, alcohols, crude protein (CP), and total digestible nutrients (TDN) and significantly increased ketone, dry matter (DM), acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents (p &lt; 0.05). After Comprehensive consideration ofthe yield, nutritional quality and VOCs of alfalfa, the best harvest time was determined to be the budding stage. The VOCs and nutrient quality of alfalfa were significantly different at different storage durations, and ketones, ADF and NDF were significantly increased and significantly reduced DM, CP and TDN (p &lt; 0.05). Ketone content and neutral detergent fiber (NDF) content had a significant positive correlation, (NDF F = 5.5, p = 0.024). Storage 360 d 2-methylbutyraldehyde (musty), 1-octen-3-one (earthy musty odor) content increased. These may be the key compounds that causes the smell of fresh alfalfa to fade away and a musty smell to emerge.

Effect of ozone and hydrogen peroxide on off-flavor compounds and water quality in a recirculating aquaculture system

The recirculating aquaculture system (RAS) is an ever-developing technology for producing fish with a low environmental impact. However, off-flavors can be a major problem in RAS fish production. Off-flavor compounds are of microbial origin and are accumulated in fish flesh. They typically cause a musty and earthy taste and odor, which consumers find unacceptable. Here we hypothesized that oxidizing compounds such as ozone (O3), hydrogen peroxide (H2O2), and their combinations, referred to as advanced oxidation processes (AOP)s, can remove or decrease these compounds in water and prevent their accumulation in fish. In this study, four different oxidative treatments (O3 low (0.4 mg O3 L−1), O3 high (0.8 mg O3 L−1), H2O2 (0.15 µl L−1), AOP (0.4 mg O3 L−1 & H2O2 0.10 µl L−1), and controls were applied to 10 experimental RASs for four months. The results showed that the treatments can reduce dissolved organic carbon (DOC) and the off-flavor compounds (geosmin, GSM and 2-methyl isoborneol, MIB) in circulating water, but they were not able to prevent the accumulated off-flavors in fish flesh below the sensory threshold. There was no significant difference in off-flavor removal between the treatments, which indicates that O3 treatment was ineffective in these conditions. However, H2O2 could still reduce the off-flavor concentrations in water.

Undesirable odour substances (geosmin and 2-methylisoborneol) in water environment: Sources, impacts and removal strategies

Off-flavours in fish products generated from recirculating aquaculture systems (RAS) are a major problem in the fish farming industry affecting the market demand and prices. A particular concern is the muddy or musty odour and taste in fish due to the presence of secondary metabolites geosmin and 2-methylisoborneol (2-MIB), produced by actinobacteria (mainly Streptomyces), myxobacteria and cyanobacteria. Off-flavours have deteriorated the quality of fish, rendering their products unfit for human consumption. The process of odour removal requires purification for several days to weeks in clean water; thus this leads to additional production costs. Geosmin and 2-MIB, detected at extremely low odour thresholds, are the most widespread off-flavour metabolites in aquaculture, entering through fish gills and accumulating in the fish adipose tissues. In this review, we aimed to determine the diversity and identity of geosmin- and 2-MIB-producing bacteria in aquaculture and provide possible strategies for their elimination.

Effect of fungal indoor air pollutant 1-octen-3-ol on levels of reactive oxygen species and nitric oxide as well as dehydrogenases activities in drosophila melanogaster males

ABSTRACT Fungal pollution of indoor environments contributes to several allergic symptoms and represents a public health problem. It is well-established that 1-octen-3-ol, also known as mushroom alcohol, is a fungal volatile organic compound (VOC) commonly found in damp indoor spaces and responsible for the typical musty odor. Previously it was reported that exposure to 1-octen-3-ol induced inflammations and disrupted mitochondrial morphology and bioenergetic rate in Drosophila melanogaster. The aim of this study was to examine the influence of 1-octen-3-ol on dehydrogenase activity, apoptotic biomarkers, levels of nitric oxide (NO) and reactive oxygen species (ROS), as well as antioxidant enzymes activities. D. melanogaster flies were exposed to an atmosphere containing 1-octen-3-ol (2.5 or ∞l/L) for 24 hr. Data demonstrated that 1-octen-3-ol decreased dehydrogenases activity and NO levels but increased ROS levels accompanied by stimulation of glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities without altering caspase 3/7 activation. These findings indicate that adverse mitochondrial activity effects following exposure of D. melanogaster to 1-octen-3-ol, a fungal VOC, may be attributed to oxidant stress. The underlying mechanisms involved in adverse consequences of indoor fungal exposure appear to be related to necrotic but not apoptotic mechanisms. The adverse consequences were sex-dependent with males displaying higher sensitivity to 1-octen-3-ol. Based upon on the fact that the fly genome shares nearly 75% of disease-related genes to human exposure to this fungus may explain the adverse human responses to mold especially for males.