Mold Growth Research Articles

The effect of bioactive film on the shelf life of bread

Relevance. The development of bioactive films is currently relevant due to the need to replace synthetic polymers used in food packaging materials. However, the established positive properties of the films themselves do not always guarantee the predicted effect and do not ensure the preservation of food products during storage. In this regard, for the recommendation of biodegradable films of a specific composition for use as packaging material for a particular type of product, experimental confirmation is required.Methods. The objects of study are samples of wheat bread packaged in alginate films and in polyethylene film as a control. For bread samples after baking and cooling, as well as after 1, and 3 days of storage, sensory characteristics, color characteristics, microbiological indicators, and mass losses were determined.Results. The conducted tests of bread samples revealed the positive effect of the bioactive film based on sodium alginate with the introduction of protein hydrolysate on reducing the growth of bacteria and molds. The research results showed that in alginate films, there is an intensive loss of bread mass — up to 19.27 ± 0.51% (p ≤ 0.05) after 3 days of storage in the film without protein hydrolysate, which is more significant compared to the bread sample in polyethylene film (9.12 ± 0.32%). At the same time, microbiological indicators (total microbial count and mold count) remained more stable in bread samples in alginate films. Thus, the results of microbiological studies confirmed the known data on the antimicrobial properties of protein hydrolysates in the composition of bioactive films. However, when choosing films for bread packaging, it is necessary to consider their vapor permeability to avoid moisture losses during storage..Results. The results of the study showed the need to review the practice of using manure (manure) processing technologies to reduce greenhouse gas emissions

Impact of Sweet Orange Peel Essential Oil on the Nutrient and Oxidative Stability of Aquafeed During the Storage Condition

The main goal of this study was to assess the qualitative composition of essential oil (P), a natural extract produced from wasted orange peels in the citrus processing sector. Additionally, the study aimed to investigate the alterations in fish feeds when this essential oil is incorporated and stored. The essential oil was extracted from the orange peels provided for the study using the hydrodistillation method and the Clevenger apparatus. The study determined the volatile components of the oil with 100% accuracy. The primary constituent was identified as D-limonene, comprising 59.27% of the total composition. Subsequently, experimental feed groups were established by including the essential oil in the feed rations at ratios of ‰0 (P0), ‰0.5 (P5), ‰1 (P10), and ‰3 (P30). Under storage conditions, the feeds were stored in feed sacks for 60 days. Periodic samples were collected during storage and subjected to nutritional, microbiological, structural, and oxidation tests. The results of the study show that P had no protective effect in fish diets against the growth of yeasts, molds, and other mesophilic aerobic bacteria (p > 0.05). It was shown that the nutritional values varied over time during storage. However, this variation was not substantially correlated with the amount of P in the diets (p > 0.05). There was no discernible impact of the addition of P on the structural characteristics of the feed grains. Nevertheless, the inclusion of P substantially impeded the process of lipid oxidation in the diet (p<0.05). After the two-month storage period, it was shown that adding at least 1 ‰ of P to the fish meals prevented the peroxide generated from oxidation in the feed from exceeding acceptable levels.

Quantitative and qualitative assessment of airborne microorganisms during gross anatomical class and the bacterial and fungal load on formalin-embalmed corpses

Mold growth on body donations remains an underreported yet serious issue in anatomical teaching. Bacterial and fungal growth pose health risks to lecturers and students, alongside with ethical and aesthetic concerns. However, limited information exists on the presence of bacteria and fungi on body donations and their underlying causes. To investigate the potential impact of airborne germs on body donation contamination, we conducted indoor air measurements before, during, and after our anatomical dissection course, with outdoor measurements serving as a control. Tissue samples from the dissected body donations were collected to assess the germ load, with qualitative and quantitative microbiological analyses. Air samples from the dissection hall contained no fungi, but various fungal species were identified in the adjacent stairways and outdoors which implies that fungal occurrence in the dissection hall air was independent of lecturers’ and students’ presence. Moreover, our results indicate that adequate ventilation filters can effectively reduce indoor fungal germs during courses, while the bacterial load in room air appears to increase, likely due to the presence of lecturers and students. Additionally, the tissue samples revealed no bacterial or fungal germs which implies that our ethanol-formalin-based embalming solution demonstrates an effective long-term antimicrobial preservation of corpses.

Hygrothermal performance of multilayer wall assemblies incorporating starch/beet pulp in France

This work focuses on the investigation of the hygrothermal performance of four different wall insulation assemblies including starch/beet pulp composite for an office in France under two climatic conditions. Subsequently, a comparative performance analysis is made on all studied assemblies by substituting the Starch/beet pulp composite with hemp concrete (HC). For each design, the overall energy performance, total water content, drying rate and condensation risk were evaluated through hygrothermal simulations using the WUFI® Plus software and mold growth risk assessment was conducted with WUFI®Bio software. Results showed that insulation assemblies based on Starch/Beet pulp exhibited a slightly improved effectiveness in potential energy savings and higher dryness rate while having a higher condensation risk, a lower dynamic thermal performance, and a higher susceptibility to mold growth risk. Moreover, insulation assemblies based on Starch/Beet pulp demonstrated better hygrothermal performance under Nancy’s climate compared to that of Marseille. Wall assemblies based on hemp concrete reduced total energy consumption by up to 35 % in Nancy’s climate and 24.9 % in Marseille’s climate. In comparison, starch/beet pulp concrete achieved reductions of up to 37.5 % and 26 % respectively. However, the mold growth risk for starch/beet pulp was 1.2–7.2 times higher than for hemp concrete. In Marseille’s climate, this risk was 2.3–8.9 times higher for starch/beet pulp and 4.7–17.8 times higher for hemp concrete compared to Nancy’s climate. The findings from these room-scale studies enhance the understanding of the hygrothermal behavior of the Starch/Beet pulp bio-composite material by comparing its performance, under the same conditions, to that of the well-studied hemp concrete material in the literature. Additionally, these studies provide greater insight into the impact of water on the overall energy consumption, service performance of a building and health hazards. Finally, this research also tackles the challenges of integrating innovative materials into the established construction industry.

Indoor mould and population health: estimating the costs in Australia

Indoor mould and population health: estimating the costs in Australia

Boosting mold aerosol reduction and dehumidification performance in liquid desiccant systems using airborne ultrasound: An experimental study

Indoor mold exposure in hot-humid regions poses considerable risks to public health and food security. Ensuring safe, durable, and energy-efficient air disinfection is crucial for the air-conditioning field. While liquid desiccant air-conditioning (LDAC) systems eliminate condensation-related mold proliferation, their capability to combat airborne mold spores is limited due to the spores' robust resistance. This paper explores a novel airborne ultrasound-assisted liquid desiccant air-conditioning (US-LDAC) system. Experiments were conducted using culture-based methods to compare the system's disinfection capacities against Aspergillus niger spores, a desiccant-resistant species, under ventilation, liquid desiccation dehumidification, and airborne ultrasound-assisted liquid desiccant dehumidification modes. Moreover, the viability and morphological changes of mold spores exposed to airborne ultrasound, with and without liquid desiccants, were analyzed to verify the disinfection effectiveness and extrapolate the improving mechanisms. The results show that irradiating low-intensity airborne ultrasound (∼127 W, harmless mechanical waves) into the dehumidifier significantly increased the disinfection efficiency by 50 % and the dehumidification rate by over 90 % when airflow passed through the dehumidifier (∼0.4 s). The enhanced disinfection is attributed to ultrasonic cavitation, which facilitates the rupture of the desiccant-captured spores through microstreaming-induced shear forces. Notably, the improvements were more pronounced in humid air and with dilute desiccant solutions, suggesting that efficiency can be maintained with lowered desiccant concentrations. The US-LDAC system was particularly adept at removing mold aerosols (2.1–3.3 μm) which are easily inhaled. These findings propose a promising avenue for retrofitting existing LDAC systems to effectively reduce airborne molds and enhance dehumidification, thereby protecting indoor air quality.

Hygrothermal risk assessment tool for brick walls in a changing climate

Due to the heritage value of historical buildings, external facades can often not be modified. Therefore, in heritage buildings interior insulation is often considered when undergoing an energy renovation. However, interior retrofitting drastically changes the hygrothermal behaviour of a wall and can potentially cause moisture-related problems. Besides an interior retrofit, a changing climate might also trigger some of these damage mechanisms as parameters such as temperature and precipitation will change over time. Hygrothermal models can provide relevant insights into the risk of deterioration associated with these damage phenomena. However, these Heat, Air and Moisture (HAM) tools are commercially available but rarely used in the building industry to study deterioration risks. Translating research into practical tools and guidelines is a challenge across the whole field of building renovation. This paper aims to tackle that challenge, by means of creating a hygrothermal risk assessment tool based on 48,384 HAM-simulations for the climate of Brussels, Belgium. Seven different performance criteria are addressed and discussed: freeze-thaw damage, mould growth, wood rot, corrosion, moisture accumulation, salt efflorescence and bio-colonisation. Subsequent to a sensitivity analysis, the study further explains how these results can be translated into practice, providing building practitioners the most suitable insights and recommendations. The development of an interactive web tool to assess hygrothermal risks is demonstrated and its use and benefits are further elaborated.

Transformative Nanosized Organic Coatings with Euphorbia Condylocarpa/Poplar Tree Bark/Zircon Silicate Hybrid System for Enhanced Industrial Resilience

This study focused on enhancing the properties of interior coatings by incorporating natural additives to minimize potential health impacts associated with traditional additives. Organic additives such as Euphorbia condylocarpa, poplar tree bark, and zircon silicate were employed by utilizing Design Expert for optimization. The optimized formulation demonstrated impressive attributes including the prevention of bacterial and mold growth, high corrosion resistance, effective coverage and adhesion, and resistance to dirt retention. The recommended optimum formulation, Euphorbia condylocarpa (1%), poplar tree bark (1%), and zircon silicate (1%) by using the 2FI model, exhibited an R2 value of 0.9838, indicating a remarkable predictability of the variability in the experimental data. This result emphasized the effectiveness of the proposed model in optimizing the properties of nanosized organic coatings for various industrial applications. Thermogravimetric and differential thermal analysis (TG-DTA) revealed that the additives contributed to the development of flame-retardant properties as the temperature increased and morphology of coating was obtained with optical microscope and scanning electron microscope (SEM). Specifically, Euphorbia condylocarpa exhibited antibacterial, flame-retardant, and hydrophobic properties. The study concluded that the incorporation of euphorbia plant, poplar tree bark, and zircon silicate substances positively impacted the performance of coatings offering a more health-conscious and technologically advanced alternative.

Hygrothermal assessment of three bio-based insulation systems for internal retrofitting solid masonry walls

The present project investigated the hygrothermal performance and risk of mould growth in solid masonry walls retrofitted internally with three diffusion-open bio-based insulation materials (two loose-fill cellulose and one hemp fibre), installed in test containers with controlled indoor climate. Focus was on bio-based insulation materials, as these are upcoming due to necessary CO2 reductions and because the hygroscopic properties of bio-based materials are different from traditional insulation materials like mineral wool therefore, some manufacturers claim a vapour barrier is unnecessary, even in relatively cold climates. The project was a large experimental study in two reefer containers with reconfigured facades, in which solid masonry walls with embedded wooden elements were constructed. The study focused on the conditions in the masonry/insulation interface and in the embedded wooden elements. The effect of hydrophobization and different indoor moisture loads were also investigated. Moreover, the bio-based insulation systems were compared with a wall insulated with the traditional mineral wool and vapour barrier system. Relative humidity and temperature were measured at several locations in the test walls for 1 year and 9 months. Measurements show that exposed masonry walls retrofitted internally with diffusion-open bio-based insulation materials resulted in unacceptably high moisture levels (>80% RH over longer periods). Lower moisture levels were observed when the internal insulation was combined with hydrophobization against wind-driven rain, but unacceptably high moisture levels still occurred (60%–70% in summer and 95%–100% in winter in the interface). Hydrophobization reduced the moisture levels in the interface and embedded wooden elements only in walls facing southwest, which is the direction with the most wind-driven rain. Mould growth tests showed no growth in the interface in walls insulated with cellulose insulation (mycometer surface value <25). Meanwhile growth was found in all four walls insulated with hemp fibre matts (mycometer surface value >400).

Virtual Restoration of Ancient Mold-Damaged Painting Based on 3D Convolutional Neural Network for Hyperspectral Image

Painted cultural relics hold significant historical value and are crucial in transmitting human culture. However, mold is a common issue for paper or silk-based relics, which not only affects their preservation and longevity but also conceals the texture, patterns, and color information, hindering cultural value and heritage. Currently, the virtual restoration of painting relics primarily involves filling in the RGB based on neighborhood information, which might cause color distortion and other problems. Another approach considers mold as noise and employs maximum noise separation for its removal; however, eliminating the mold components and implementing the inverse transformation often leads to more loss of information. To effectively acquire virtual restoration for mold removal from ancient paintings, the spectral characteristics of mold were analyzed. Based on the spectral features of mold and the cultural relic restoration philosophy of maintaining originality, a 3D CNN artifact restoration network was proposed. This network is capable of learning features in the near-infrared spectrum (NIR) and spatial dimensions to reconstruct the reflectance of visible spectrum, achieving the virtual restoration for mold removal of calligraphic and art relics. Using an ancient painting from the Qing Dynasty as a test subject, the proposed method was compared with the Inpainting, Criminisi, and inverse MNF transformation methods across three regions. Visual analysis, quantitative evaluation (the root mean squared error (RMSE), mean absolute percentage error (MAPE), mean absolute error (MEA), and a classification application were used to assess the restoration accuracy. The visual results and quantitative analyses demonstrated that the proposed 3D CNN method effectively removes or mitigates mold while restoring the artwork to its authentic color in various backgrounds. Furthermore, the color classification results indicated that the images restored with 3D CNN had the highest classification accuracy, with overall accuracies of 89.51%, 92.24%, and 93.63%, and Kappa coefficients of 0.88, 0.91, and 0.93, respectively. This research provides technological support for the digitalization and restoration of cultural artifacts, thereby contributing to the preservation and transmission of cultural heritage.

Stabilization of Fish Protein-Based Adhesive by Reduction of Its Hygroscopicity.

Protein-based fish adhesives have historically been used in various bonding applications; however, due to the protein's high affinity for water absorption, these adhesives become destabilized in high-moisture environments, resulting in reduced bondline strength and early failure. This limitation makes them unsuitable for industrial applications with higher demands. To address this issue, water-insoluble raw powder materials such as iron, copper, or zeolite were incorporated into natural fish adhesives. In this study, the hygroscopicity, dry matter content, thermal analysis (TGA/DSC), FT-IR spectroscopy, surface tension measurements, vapour permeability, and scanning electron microscope (SEM) of the modified adhesives were determined. In addition, the bonding properties of the modified adhesives were evaluated by the tensile shear strength of the lap joints, and mould growth was visually inspected. The resulting modified protein-based adhesives demonstrated improved stability in high humidity environments. Enhancing the hygroscopic properties of protein-based fish adhesives has the potential to unlock new opportunities and applications, providing a healthier and more environmentally sustainable alternative to petroleum-based adhesives.

Exploring a Cheese Ripening Process That Hinders Ochratoxin A Production by Penicillium nordicum and Penicillium verrucosum.

A lack of control of the technological abiotic parameters apparent during cheese manufacture, including temperature and relative humidity, results in this dairy product being prone to mold contamination. Sometimes, inoculant molds are used to obtain the characteristic sensory properties of this type of product. However, during the maturation process, some unwanted molds can colonize the ripening cheese and produce mycotoxins. Mycotoxigenic molds such as Penicillium nordicum and Penicillium verrucosum can colonize ripened cheeses, contaminating them with ochratoxin A (OTA), a nephrotoxic 2B toxin. Thus, the presence of OTA in cheeses could represent a hazard to consumers' health. This study has evaluated the growth and OTA production of P. nordicum and P. verrucosum on a cheese analogue under simulated ripening conditions of 10 and 15 °C and 0.96 water activity (aw). Ecophysiological, molecular, and analytical tools assessed the mold growth, gene expression, and OTA production under these environmental conditions. Both species were able to effectively colonize the cheese under these ripening conditions. However, neither species expressed the otapks and otanps biosynthetic genes or produced phenotypic OTA. Therefore, these results suggest a relatively low risk of exposure to OTA for consumers of this type of cheese product. The conditions used were thus appropriate for cheese ripening to minimize the potential for contamination with such mycotoxins. An appropriate adjustment of the technological ripening parameters during such cheese manufacture could contribute to OTA-free cheeses.

Study on antibacterial characteristics and mechanism of synergistic modification of calcined gypsum from phosphogypsum by inorganic antibacterial materials

Mold on the phosphogypsum wallboard seriously hinders the resource utilization of phosphogypsum, and incorporating inorganic antibacterial materials can effectively inhibit mold growth. In this study, Escherichia coli and wallboard mold were used as experimental strains, and the antibacterial activity of antibacterial material-modified calcined gypsum from phosphogypsum (CPG) was determined using the inhibition zone method and mold surface growth area analysis. Characterization techniques such as XRF, XRD, and SEM were used to study the phase composition and microstructure of the samples, and an antibacterial model was constructed to explore the antibacterial mechanism. The results indicated that using E. coli as an indicator bacterium, ZnO-0.05TiO2-CPG exhibited the best bactericidal effect, while ZnO-CPG exhibited the best bacteriostatic effect. Against mold, ZnO contents of 2.5% or 5% demonstrated strong antibacterial properties, with compressive strengths of 10.1 MPa and 9.95 MPa, respectively, meeting the requirements of ≥3.50 MPa for compressive strength according to the ‘Lightweight Partition Plates for Building’ standard (GB/T 23451 2009). The superior antibacterial performance of ZnO compared to TiO2 is attributed to the slow release of Zn2+, which disrupts cell membranes and the generated reactive oxygen species inhibit cell growth.

Addition of Fresh Herbs to Fresh-Cut Iceberg Lettuce: Impact on Quality and Storability

The aim of this study was to develop ready-to-eat vegetable–herb mixes with high nutritional and sensory values as well as good storability. In this regard, the suitability of fresh herbs (peppermint, oregano, green basil, red basil, and parsley) was tested for their use in mixes with fresh-cut iceberg lettuce. Lettuce–herb mixtures were stored for 6 days at 5 °C. The reason for the decrease in the appearance of the salads was the browning of the cut surface of the lettuce, as well as discoloration on the cut herbs. Comparing the storage abilities of the cut herbs, red basil and parsley retained the best appearance for 6 d at 5 °C. A small addition of herbs to fresh-cut iceberg lettuce caused a significant increase (p < 0.05) in the contents of pro-health ingredients such as chlorophyll, carotenoids, L-ascorbic acid, and polyphenols in the mixes. There were large discrepancies in the sensory quality of the mixes, but the highest quality and consumer acceptance were found for salads with parsley (5% and 10%) and red basil (5%). After harvest, the fresh herbs were more contaminated by molds than the iceberg lettuce. Bacterial, yeast, and mold contamination increased during storage, but the rate of mold growth was much lower in the mixes with parsley compared to lettuce alone. In conclusion, the addition of parsley and mint contributed the most to the health-promoting and microbiological properties of iceberg lettuce salads. However, according to sensory evaluation, parsley and red basil contributed the most to improving the acceptability of the product in terms of best taste and shelf life.

Chitosan-casein blended with condensed tannin and carnauba wax for the fabrication of antibacterial and antioxidant food packing films

In this study, various chitosan-based films such as chitosan (C), chitosan-condensed tannin (CT), chitosan-casein (CC), and chitosan-casein-condensed tannin (CCT) films were prepared for the purpose of food packaging. In order to improve the hydrophobicity of these films, carnauba wax was blended into CCT to produce CCTW film. Properties such as morphology, UV resistance, water solubility, barrier performance, tensile strength, antioxidant, antibacterial and its performance as food packaging were evaluated. Compared with other chitosan-based films, CCTW films exhibited higher UV resistance, tensile strength, thermal stability and hydrophobicity. The addition of both condensed tannin and carnauba wax has significantly decreased the water vapor and oxygen permeability of the CCTW films. The CCTW films were proved capable of repelling most daily consuming liquids. Besides, CCTW films displayed outstanding free radical scavenging rate and antibacterial properties. Meanwhile, bananas wrapped with CCTW films remained fresh for seven days without any mold growth and outperformed other types of films. Apart from that, the CCTW films also showed biodegradable characteristics after exposure to Penicillium sp. These distinguished characteristics made the CCTW films a promising packaging material for long-term food storage.

Optimizing Lactic Acid Bacteria Proportions in Sourdough to Enhance Antifungal Activity and Quality of Partially and Fully Baked Bread.

The organic acids produced by lactic acid bacteria (LAB) during the fermentation of sourdoughs have the ability to reduce the growth of different molds. However, this ability depends on the LAB used. For this reason, in this study, the proportions of different LAB were optimized to obtain aqueous extracts (AEs) from sourdough to reduce fungal growth in vitro, control the acetic acid concentration, and obtain a specific lactic to acetic acid ratio. In addition, the optimized mixtures were used to formulate partially baked bread (PBB) and evaluate the mold growth and bread quality during refrigerated storage. Using a simplex-lattice mixture design, various combinations of Lactiplantibacillus plantarum, Lacticaseibacillus casei, and Lactobacillus acidophilus were evaluated for their ability to produce organic acids and inhibit mold growth. The mixture containing only Lpb. plantarum significantly reduced the growth rates and extended the lag time of Penicillium chrysogenum and P. corylophilum compared with the control. The AEs' pH values ranged from 3.50 to 3.04. Organic acid analysis revealed that using Lpb. plantarum yielded higher acetic acid concentrations than when using mixed LAB. This suggests that LAB-specific interactions significantly influence organic acid production during fermentation. The reduced radial growth rates and extended lag times for both molds compared to the control confirmed the antifungal properties of the AEs from the sourdoughs. Statistical analyses of the mixture design using polynomial models demonstrated a good fit for the analyzed responses. Two optimized LAB mixtures were identified that maximized mold lag time, targeted the desired acetic acid concentration, and balanced the lactic to acetic acid ratio. The addition of sourdough with optimized LAB mixtures to PBB resulted in a longer shelf life (21 days) and adequately maintained product quality characteristics during storage. PBB was subjected to complete baking and sensory evaluation. The overall acceptability was slightly higher in the control without sourdough (7.50), followed by bread formulated with the optimized sourdoughs (ranging from 6.78 to 7.10), but the difference was not statistically significant (p > 0.05). The sensory analysis results indicated that the optimization was used to successfully formulate a sourdough bread with a sensory profile closely resembling that of a nonsupplemented one. The designed LAB mixtures can effectively enhance sourdough bread's antifungal properties and quality, providing a promising approach for extending bread shelf life while maintaining desirable sensory attributes.

Fractional exhaled nitric oxide (FeNO) among school children in Java and Sumatra, Indonesia: associations with respiratory symptoms, house dust mite sensitization and the home environment

Objective To study associations between fractional exhaled nitric oxide (FeNO) and asthma, airway symptoms, sensitization to common allergens, outdoor pollution and home environment among 380 students in eight junior high schools in two areas in Indonesia. Methods Data on health and home were collected by a face-to face interview before measuring FeNO and performing skin prick test against common allergens. Exploratory linear mixed and logistic regression models were employed. Results Geometric mean of FeNO was 17.8 ppb (GSD 2.09) and 139 students (36.6%) had elevated FeNO (>20 ppb). In total, 107 students (28.2%) were sensitized to house dust mite (HDM) (Der p1 or Der f1), 4 (1.1%) to cat and 3 (0.8%) to mold (Cladosporium or Alternaria). Moreover, 20 students (5.3%) had diagnosed asthma, 38 (10.0%) had current wheeze, and 107 (28.2%) had current rhinitis. HDM sensitization, diagnosed asthma, current wheeze, and current rhinitis were associated with FeNO. In total, 281 students (73.9%) had mold or dampness, 232 (61.1%) had environmental tobacco smoke (ETS) and 43 (11.3%) had other odor at home. Indoor mold or dampness and other odor at home were associated with FeNO. ETS was negatively associated with FeNO. Conclusion HDM sensitization and elevated FeNO can be common among children in this part of Indonesia. The high prevalence of elevated FeNO indicate that undiagnosed childhood asthma is common. Dampness, mold and odor at home can be associated with increased FeNO while ETS can be associated with decreased FeNO.

Ozone Treatment as a Sustainable Alternative for Suppressing Blue Mold in Mandarins and Extending Shelf Life

Citrus fruits, particularly mandarins, are highly valued globally for their nutritional benefits and versatile culinary uses. However, the challenge of post-harvest decay, primarily due to blue mold (Penicillium italicum) infections, results in significant food losses and necessitates effective preservation strategies. Traditional methods often rely on fungicides, raising concerns about chemical residues and environmental impact. This study investigates the efficacy of ozone as an alternative approach to controlling blue mold in mandarins. Various gaseous ozone treatments were tested, including single, double, and triple treatments, with durations ranging from 10 to 60 min and concentrations from 3.3 to 20 ppm. Additionally, ozonated water treatments were evaluated with concentrations of 2, 4, and 6 ppm. To simulate a realistic infestation scenario, mandarins were artificially infected with P. italicum spores before undergoing both gaseous ozone and ozonated water treatments. The storage conditions for the mandarins were meticulously controlled, maintaining a humidity level of 50–60% and a temperature range of 10–12 °C. Each fruit was analyzed, and the presence of P. italicum infection was determined two and three weeks after the ozonation. Results indicated that ozone treatments significantly reduced mold growth, with gaseous ozone demonstrating efficacy rates up to 97.5% and ozonated water treatments achieving preservation rates between 95% and 97%. These results underscore ozone’s potential as a safe, efficient, and sustainable alternative to conventional fungicides, offering promising solutions for extending the shelf life of mandarins. Further research is recommended to optimize ozone treatment parameters, assess long-term effects on fruit quality and nutritional content, and refine application techniques to harness ozone’s potential in citrus fruit preservation fully. This approach not only addresses food security challenges but also aligns with global efforts to reduce chemical inputs in agriculture and promote environmentally sustainable practices.

Water Vapour Resistance of Exterior Coatings—Influence on Moisture Conditions in Ventilated Wooden Claddings

Increasing climate fluctuations and extremes due to climate change are particularly concerning for wooden building envelopes, especially in the Nordic region, which has harsh climatic conditions. The exterior coating’s barrier properties are crucial for maintaining building envelopes’ intended lifespans. Hence, it is unfortunate that the vapor resistance of exterior coatings is not openly accessed for commercial products. This study investigates the influence of the water vapour resistance of exterior coatings on the moisture conditions and mould growth risk of ventilated wooden claddings. The sd-value (vapour diffusion-equivalent air layer thickness) is determined for nine free-standing coatings (alkyds, emulsions, and acrylics); in total, 100 specimens are tested with the wet cup method. Additionally, with WUFI Pro, one-dimensional hygrothermal simulations under Nordic climatic conditions investigate how the coatings’ vapour resistance might influence the moisture dynamics of wood. The mould risk is assessed by the add-on WUFI VTT Model. The determined sd-values for the coatings range from 0.453 to 1.350 m (three layers) and from 0.690 to 2.250 m (six layers), showing a strong correlation with the dry film thickness. The vapour resistance of the coatings does not significantly influence the wood moisture content, but lower resistance may cause slightly faster drying. The importance of surface treatment is confirmed. The mould risk is notably higher in a Stavanger climate on a southwest-facing wall compared to Trondheim on a north-facing wall.

Breaking the limits of ambient air conditions in evaporative cooling with vacuum-assisted hollow fiber membrane technology

Conventional direct evaporative cooling systems suffer from persistent issues like air–water cross-contamination, mold growth, and scaling of paddings. Moreover, their widespread application in humid climates is hindered by ambient air conditions. This research presents a promising solution in the form of a vacuum-assisted hollow fiber membrane-based evaporative water cooler (VMEWC). It shifts from relying on air state to vacuum pressure for cold water production. A numerical model was established to reflect the coupled heat and mass transfer characteristics, employing Knudsen diffusion to describe water vapor migration within membrane pores. Experimental tests were performed on the constructed VMEWC system, revealing strong alignment between simulation and measured data, with a 2.2 % error in outlet water temperature predictions. Numerical studies explored the effects of six parameters (inlet water temperature, water velocity, shell-side pressure, fiber length, fiber inner diameter, and overall membrane structure parameter) on VMEWC’s outlet water temperature (Tw2), cooling capacity per unit volume (Qv), and coefficient of performance (COP). The results emphasized that elevated inlet water temperature, reduced shell-side pressure, and a large overall membrane structure parameter effectively enhanced the overall performance of VMEWC. Under specific conditions, Qv and COP reached impressive values of 3753.1 kW/m3 and 13.6, respectively. This work provides a novel and practical perspective, offering references for advancing efficient and sustainable refrigeration technologies.