Mold Growth Research Articles

Multi-objective assessment of the retrofit of traditional walls located in a historical city centre using an urban climate model

Historical city centres face two major challenges in the 21st century: heritage conservation and energy retrofitting. Wall insulation in traditional buildings is at the crossroads of these two issues. When studying the retrofit of the walls, other factors also need to be considered, such as the durability of the walls, the life cycle of the materials used for insulation, the indoor and outdoor comfort in summer. The aim is to propose a method for taking all these objectives into account when choosing the insulation technique for historical walls. To do this, the TEB (Town Energy Balance) urban climate model is used, because it considers the urban microclimate, the energy behaviour of buildings and moisture transfer through walls. A VTT model is integrated into TEB, to include the risk of mold growth. The medieval city centre of Cahors (France) was used as a case study. The retrofit of two types of wall was assessed: “massive” brick walls, and “light” walls with a timber-framed structure, filled with bricks. Six renovation scenarios were studied, including four insulation materials and both internal and external insulation positions. The results obtained underline the need to study the retrofit of the two types of building separately, because the recommendations made for insulation vary depending on the type of wall studied.

Time-varying moisture characteristics and C-S-H gel properties of concrete in dry and hot environments

The construction of deeply buried tunnels has intensified concerns regarding shrinkage cracking and the long-term performance deterioration of lining concrete in dry-hot environments. These issues are related to the dynamic interconversion of internal moisture states, the changing moisture behavior over time, and the evolution of calcium silicate hydrate (C-S-H) properties. However, the mechanisms underlying these phenomena are not fully understood. This study investigates the dynamics of moisture content across different states, the source and composition of evaporated water, as well as the mechanism of change in the microscopic properties of C-S-H in concrete subjected to dry-hot conditions (40℃ and 60℃) and standard curing environments through tests on water loss rates, chemically bound water, and low-field nuclear magnetic resonance. The findings reveal that at 40℃ and 60℃, hydration products were generated rapidly before mold removal, leading to significant increases in chemically bound water, interlayer water, and gel water, while capillary water was notably consumed. After mold removal, the rate of chemically bound water increase slowed, while interlayer water, gel water, and capillary water evaporated significantly, with gel water comprising 87.27 % and 83.51 % of the evaporated water at 40℃ and 60℃, respectively. From day 1 to day 28, interlayer water, gel water, and capillary water contents decreased significantly, with reductions of up to 85.98 % at 60℃. In dry-hot environments, moisture primarily exists as chemically bound water and gel water, contrasting with standard curing conditions where capillary water is also present. The study concludes that drying of C-S-H gels leads to both positive effects, such as interlayer space compression and increased indentation modulus, and negative effects, including increased microporosity and reduced matric densification, ultimately contributing to the deterioration of long-term mechanical properties.

Interventions Implemented to Remediate Mold Identified in Neonatal Intensive Care Unit (NICU) Incubators, 2022-2023

IntroductionNeonatal Intensive Care Units (NICUs) utilize incubators to sustain core temperatures associated with transepidermial water loss. High relative humidity in incubators provide an environment for fungi to grow. In August 2022, mold was identified growing in eleven (85%) NICU incubators. MethodsA team assembled to address mold in incubators. The environment was addressed as a possible source of contamination by consulting an environmental specialist. The air handler, ducts, and environment were terminally cleaned. Specimens were collected from the contaminated incubators and the manufacturer reviewed cleaning practices. Experimental trials were conducted using the incubators to replicate mold growth after interventions. ResultsThe environmental consultant approved when the space could be reoccupied. Incubators introduced to the clean environment did not grow mold. Various fungi and/or yeast were identified in the contaminated incubators. Opportunities to improve cleaning and replacement of parts were identified by the manufacturer. September 2022-February 2023, seven experimental trials were completed after cleaning the incubators. Four (36%) of the eleven contaminated incubators were placed back in use due to no fungal growth. No patient illnesses occurred. ConclusionThe interventions implemented stopped ongoing contamination of incubators and use of previously contaminated incubators.

MONITORING OF BENZOIC ACID LEVELS IN SOFT DRINKS CONSUMED IN ADEN, YEMEN

Benzoic acid is widely used as a food preservative due to its effectiveness in inhibiting the growth of yeast and mold. The undissociated form of benzoic acid is the most potent. In acidic beverages like soft drinks, benzoic acid can react with additives such as ascorbic acid to release benzene, which can pose health concerns. This study aimed to determine the levels of benzoic acid in soft drink samples commonly consumed in Aden, Yemen. Eighteen soft drink samples were analyzed using high-performance liquid chromatography with a UV detector. The highest benzoic acid concentration was found in a FIFA orange sample at 173.87 ppm, while the lowest was 8.40 ppm in a DREAM red sample. Some samples, including MIRINDA orange, FANTA apple, and DILSI red, had no detectable levels of benzoic acid, despite their labels indicating its presence. Overall, the benzoic acid concentrations in all tested samples were within the permissible limits set by local, regional, and international standards.

Effect of Grain Coating by Natural Materials on the Aroma Quality of KDML105 Rice

This study evaluated the effectiveness of different coating formulas in preserving the aroma quality of Khao Dawk Mali 105 (KDML 105) rice grains, particularly focusing on the key aroma compound, 2-acetyl-1-pyrroline (2AP). Initially, thirteen coating formulas were tested, and gum arabic was found to be the most effective in maintaining rice appearance and preventing mold growth during storage. In a subsequent experiment, rice coated with carnauba wax, gum arabic, and a 1:1 mixture of both was analyzed for 2AP content over 10 weeks using SHS-GC, under storage conditions of ambient temperature (25 °C) and 4 °C in polyethylene and laminated bags. The 10% gum arabic coating was the most effective at retaining 2AP after 10 weeks. Additionally, the study included a comparison with a 5% rice gel coating and a mixture of 5% gum arabic and 5% rice gel. The results indicated rice stored at 4 °C in laminated bags exhibited a 2-3% reduction in 2AP content after 6 weeks, while at ambient temperature, a reduction of 44-64% was observed. After 10 weeks, the 2AP contents in the 10% gum arabic coated rice were the highest at an average of 38-40% compared to those of the control group. Furthermore, the rancid compounds, including hexanal, heptanal, octanal, nonanal, and 2-pentylfuran, increased significantly in all coated rice samples at ambient temperature, with the highest hexanal content found in rice coated with a mixture of 5% gum arabic and 5% rice gel, showing approximately 22-55% increase compared with those of the uncoated rice. Overall, gum arabic coating was the most effective in preserving 2AP for at least 10 weeks, and storage at 4 °C provided the best conditions for aroma retention and rancid prevention.

The causes of air movement in hidden indoor micro-environments: measurements in historic bookshelves.

The use of ventilation holes in small micro-environments has been proposed by the National Trust as a mechanism to improve the environmental conditions of moisture and temperature within bookshelves. At one National Trust historic property, this mechanism has been used to encourage air movement behind books as a possible strategy to reduce the risk of mould growth. It is believed that including ventilation holes as a passive design solution to promote airflow within micro-environments could prevent decay from occurring in the archives of historic buildings. This paper investigates the mechanisms that cause airflow behind bookshelves using field measurements in three National Trust historic libraries. The measurements indicate that small but measurable velocities, up to 4 cm/s, can be passively generated behind bookshelves. Air movement in such confined micro-environments is probably caused by a combination of natural convection, caused by temperature differences between the walls and the interior and the exterior of the bookshelf, and forced convection due to drafts in the surrounding environment. While in some cases one mechanism prevailed, both mechanisms may be present simultaneously in most cases. Further research is needed to clarify how surface temperature drives air motion behind shelves.

Performance Evaluation of Low Thermal Bridging Drywall System with Separating Clips for C-Studs

Drywall systems comprising gypsum boards and steel C-studs are widely used due to their lightweight structure, rapid construction, and ease of installation. These systems must meet the required thermal insulation performance for their specific applications. However, metal C-studs penetrate the insulation layer at intervals, leading to additional heat loss, reduced thermal insulation performance, and lower indoor surface temperatures, which can result in condensation and mold growth. To address these issues, this study proposes a drywall system with low thermal bridging studs made up of two small-sized studs and four or five separating clips made of reinforced plastic. These clips separate the studs to minimize heat transfer through metal elements, maintain structural stability despite the spacing between them, and facilitate easy assembly. The results from mock-up tests showed that the proposed system’s thermal transmittance was 0.370 W/m2K, which is 28.8% lower than the 0.52 W/m2K observed with conventional C-studs. The proposed drywall system also met Korean regulations for acoustic insulation level 3 and the 2 h fire resistance criteria, similar to existing drywall systems with conventional C-studs. Moreover, the maximum and residual displacements were within an acceptable range for a horizontal load of 3000 N applied vertically to the non-load-bearing wall. Building energy analysis indicated that using the proposed drywall adjacent to unconditioned spaces could reduce the annual heating and cooling load by 2.5–3.0%, despite a 1.5–1.9% increase in the annual cooling load. The annual heating load decreased by 4.8–5.9% under infiltration rates of 0.5 to 1.5 air changes per hour for adjacent unconditioned spaces, making this drywall system’s improved insulation quality crucial for achieving heating-dominant zero-energy buildings.

Characteristics of Mould Growth in Pine and Spruce Sapwood and Heartwood under Fluctuating Humidity

The importance of maintaining a healthy indoor climate has recently increased, as has the durability of building structures, and for this issue, we need to predict mould growth. To prepare this model under real conditions is challenging, and this work aimed to contribute data to this model. This article presents the findings of a laboratory study investigating the effects of fluctuations in the relative humidity and temperature conditions on mould growth on pine and spruce. The study compared the results to a previous steady-state experiment, demonstrating that fluctuations in relative humidity and temperature prolonged the onset of mould growth. The mould growth observed depended on the type of wood with pine or spruce wood exhibiting different growth patterns compared to heartwood or sapwood. In sapwood, mould growth was found to be almost independent of the direction of the fiber. The first microscopic indications of mould growth on pine sapwood were observed around day 76, with the first macroscopic indications observed around day 90. On the contrary, spruce sapwood demonstrated a limit for mould growth. The mould growth was only visible under the microscope with the first indications observed between the 72nd and 80th day. Furthermore, heartwood was found to be unsuitable for mould growth under fluctuating conditions.

Physico-chemical Characterization of Tofu By-Product Silage Supplemented with Fine Rice Bran and Chestnut Tannin as Silage Additives

This study seeks to evaluate the physico-chemical properties of tofu waste silage with the inclusion of refined rice bran and chestnut tannins as additives. This study employed an experimental method using a completely randomized design, comprising four treatments and five replications. The treatments included are T1: Fresh Tofu Waste (FTW as control), T2: FTW + 5% fine rice bran (DM basis), T3: FTW + 1% chestnut tannin (DM basis), and T4: FTW + 5% fine rice bran + 1% chestnut tannin (DM basis). The variables measured were temperature, humidity, pH, mold growth, aroma, texture, color, and dry matter loss. The data collected were analyzed using analysis of variance (ANOVA), and Duncan's multiple range test was applied at a 5% significance level to assess significant differences between treatments. The findings revealed that the inclusion of fine rice bran and chestnut tannin had a significant impact (P<0.05) on the temperature, humidity, pH, mold growth, aroma, texture, color, and dry matter loss of fresh tofu waste silage. In conclusion, the addition of 5% fine rice bran and 1% chestnut tannin resulted in tofu waste silage with superior physico-chemical quality, as evidenced by the lowest dry matter loss compared to the other treatments.

Limited Effectiveness of Penicillium camemberti in Preventing the Invasion of Contaminating Molds in Camembert Cheese.

Mold-ripened cheese acquires a distinctive aroma and texture from mold cultures that mature on a fresh cheese wheel. Owing to its high moisture content (aw = 0.95) and pliability, soft cheese is prone to contamination. Many contaminating mold species are unable to grow at colder temperatures, and the lactic acid produced by the cheese bacteria inhibits further infiltration. Thus, Camembert cheese is generally well protected against contamination by a wide range of species. In this study, cocultures of Penicillium camemberti and widely distributed mycotoxin-producing mold species were incubated on different types of agars, and purchased Camembert samples were deliberately contaminated with mycotoxin-producing mold species capable of growing at both 25 °C and 4 °C. The production of mycotoxins was then monitored by the extraction of the metabolites and their subsequent measurement by means of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) based targeted metabolite profiling approach. The production of cyclopiazonic acid (CPA) was highly dependent on the species cocultivated with Penicillium camemberti, the temperature and the substrate. Contamination of Camembert cheese with Penicillium chrysogenum, Mucor hiemalis, or Penicillium glabrum induced CPA production at 25 °C. Although mold growth on cheese was not always evident on biofilms for certain cultures, except for Penicillium citrinum, which stained the monosaccharide agar yellow, mycotoxins were detected in many agar and cheese samples, as in all monosaccharide agar samples. In conclusion, cheese should be immediately discarded upon the first appearance of mold.

Biocontrol of Grey Mold on Strawberry Fruit by Bacillus spp. and Study of the Mechanisms Involved

<p>Grey mold, caused by the fungus <em>Botrytis cinerea</em>, is one of the most prevalent diseases affecting strawberry plants (<em>Fragaria ananassa</em>). The objective of this study was to assess the antagonistic effect of 5 bacterial strains belonging to the genus <em>Bacillus </em>spp<em>.</em> (BA1, BF2, BB3, BI3, and BO4) against <em>B. cinerea</em>, tested both <em>in vitro</em> and <em>in vivo</em> on strawberry fruits. The strains exhibited antifungal activity against <em>B. cinerea</em> under <em>in vitro</em> conditions, both through direct confrontations and antibiosis tests, as well as through the effect of organic compounds. Strain BO4 could inhibit mycelial growth by 62.92% through direct confrontation and 64.58% through the secretion of volatile organic compounds. Additionally, the strain BF2 demonstrated a high antibiosis effect (74.64%) compared to the control at a concentration of 25%. Treating fruits with the bacterial suspension and culture filtrate of the 5 studied strains controlled grey mold growth <em>in vivo</em>, as indicated by low severity indices in strawberries treated with strains BI3, BF2, and BA1, marked by percentages of 24.44%, 24.44%, and 37.78%, respectively, for preventive treatment. The difference in the effectiveness of various strains depended on the treatment mode; preventive treatment proved to be more effective compared to curative treatment.</p>

Energy Efficiency in Seasonal Homes: A Study on the Occupancy, Energy Use, and Renovation of Second Homes in Sweden

The escalating utilisation of second homes has led to an extension in heating periods and, to a certain degree, renovations to elevate the standard, resulting in augmented energy and resource consumption. A comprehensive survey was conducted in Sweden, examining user patterns across different seasons, heating systems, and implemented energy efficiency measures. The results indicate that second homes are occupied for extended periods during the summer season and intermittently throughout the year. Over half of the second homes are heated even when unoccupied, with 12% maintaining a temperature above 16 °C. The predominant heating method is direct electricity (32.2%), followed by heat pumps (29.5%) and stoves (17.5%). A variety of renovations are undertaken, primarily to enhance the standard and technical performance, but also to implement energy efficiency measures such as window replacement, additional insulation, or heat pump installation. Based on the reported user and heating patterns, and the energy renovations carried out, the potential energy savings with different energy renovation strategies were estimated for the Swedish second home stock. The results show that though lowering the temperature when a second home is unoccupied emerges as the most efficient measure, both in terms of cost-effectiveness and climate impact, it needs to be complemented with intermittent heating or dehumidification to ensure that the relative humidity is below critical levels, to avoid the risk of damages caused by, for example, mould growth. Installing a heat pump is the second most energy- and cost-effective measure and has the advantage that the indoor temperature can be maintained at rather high levels.

Improving the Storage Quality of Ready-to-Eat Clementine Fruits Using Lemon By-Products

In this study, the effect of the antioxidant extract from lemon by-products (Citrus × Limon L.) integrated into an edible alginate-based coating was evaluated to preserve the storage quality of ready-to-eat Clementine (Citrus × Clementina) fruits. The effects of different coatings (1.5% of alginate and 1.5% of alginate + 2–4% of lemon by-product extract) were assessed by the physical, chemical, microbiological, sensorial, and structural analyses of ready-to-eat Clementine fruits stored for 21 d at 4 °C. Ready-to-eat Clementine fruits coated with alginate and extract from lemon by-products showed greater levels of polyphenols, flavonoids, antioxidant activity, and organic acids. A microbiological analysis revealed the dose-dependent effect of the extract to contrast the growth of mesophilic bacteria, yeast, and molds during storage. A sensory analysis confirmed that the enriched coating improved the visual, structural, and olfactory parameters until the end of storage. The evidence in this study proves that an antioxidant extract from lemon by-products is a great sustainable treatment to preserve ready-to-eat fruits.

How do occupants experience the onset and triggering of building-related symptoms in damp Australian housing? An inductive-deductive content analysis

In recent years, occupants’ time spent in dwellings has increased concurrently with an increase in the duration and intensity of extreme weather events and the worsening of housing conditions. Indoor dampness and or mould (D/M) are risk factors for building-related symptoms (BRS), yet little is known about how symptoms start, thus hindering where to focus indoor air quality measurements and improvements in occupant safety. This study describes perceived symptom initiators, triggers and coinciding factors that explain what and how symptoms occurred from the perspectives of occupants living with indoor D/M. This study uses an inductive/deductive qualitative analysis, with purposive sampling (n = 154) from data collected via an online survey. Deductive content analysis utilises a framework driven by the Determinants of Health (DoH). Themes that emerged from the inductive analysis include: 1) when occupants or others interact with D/M; 2) when indoor D/M conditions change; and 3) a home full of D/M problems. From the deductive analysis, perceived exposure relating to D/M conditions differed between the initial onset of symptoms and the later triggering of symptoms. Additional coinciding factors relating to climate, socioeconomic, policy and individual factors along with a lack of knowledge, attitudes and beliefs, emerged. This study highlights the need to raise occupant awareness, enhance housing and occupancy regulations, and introduce safe work practices to address the lack of health awareness and health significance regarding indoor D/M housing conditions. It also outlines the need for targeted research measuring bioaerosol exposure related to actions, proximity-based exposure, and wet and repeatedly wet conditions.

Transcription Factor VlbZIP14 Inhibits Postharvest Grape Berry Abscission by Directly Activating VlCOMT and Promoting Lignin Biosynthesis.

Sulfur dioxide (SO2) is the most effective preservative for table grapes as it reduces the respiratory intensity of berries and inhibits mold growth. However, excessive SO2 causes berry abscission during storage, resulting in an economic loss postharvest. In this study, grapes were exogenously treated with SO2, SO2 + 1.5% chitosan, SO2 + 1.5% eugenol, and SO2 + eugenol-loaded chitosan nanoparticles (SN). In comparison to SO2 treatment, SN treatment reduced the berries' abscission rate by 74% while maintaining the quality of the berries. Among the treatments, SN treatment most effectively inhibited berry abscission and maintained berry quality. RNA-sequencing (RNA-seq) revealed that SN treatment promoted the expression of genes related to cell wall metabolism. Among these genes, VlCOMT was detected as the central gene, playing a key role in mediating the effects of SN. Dual luciferase and yeast one-hybrid (Y1H) assays demonstrated that VlbZIP14 directly activated VlCOMT by binding to the G-box motif in the latter's promoter, which then participated in lignin synthesis. Our results provide key insights into the molecular mechanisms underlying the SN-mediated inhibition of berry abscission and could be used to improve the commercial value of SO2-treated postharvest table grapes.

Assessment of Storage Structure, Cause of Gran Loss, and Methods Used to Control Storage Losses

Post-harvest losses, leading to substantial grain loss, stem from various factors such as insect infestation, mold growth, rodent damage, adverse weather conditions, and inadequate storage practices. This study investigates the storage structures employed by farmers in Zenzelma Kebele and identifies the primary causes of grain loss. Despite the persistence of traditional storage structures like "Gotera" and "Gota," there is a noticeable lack of adoption of improved storage methods. The research highlights insects and rodents as major contributors to grain loss, both in the field and during storage. Farmers mainly use chemical measures to combat these pests, including fumigation and pesticides like Malathion. Additionally, sun drying remains a widely used traditional method. The study's findings underscore the urgent need for integrated pest management (IPM) strategies and the development of cost-effective, environmentally sustainable solutions to reduce post-harvest losses. Understanding local farming practices is crucial for designing effective interventions that enhance food security and promote economic sustainability in maize production. By focusing on the specific conditions and practices in Zenzelma Kebele, this study provides valuable insights into the challenges and opportunities for improving grain storage and reducing losses. Tailored interventions, informed by local needs and practices, are essential to address these issues effectively. The adoption of improved storage techniques and IPM strategies can significantly reduce grain losses, thereby boosting food security and supporting the livelihoods of farmers. This research advocates for a holistic approach to pest management and storage practices, encouraging collaboration between researchers, policymakers, and farmers. By promoting sustainable agricultural practices and innovative storage solutions, we can work towards a more secure and prosperous future for maize producers in Zenzelma Kebele and beyond.

Microbiological Profile of Phytoestrogen Rich Supplement and Its Impact on Gut-microbiome Composition in Drosophila melanogaster

Phytoestrogen-rich diet alters the composition of gut microbiota by enhancing the growth of beneficial bacteria and decreasing the microbial load of pathogenic organisms. Drosophila is an invertebrate model system used for research studies, as it shares 70% genetic homology with humans. The present study aimed to analyse microbiological profile of phytoestrogen rich supplement and its impact on gut-microbiome composition in Drosophila melanogaster. The phytoestrogen rich supplement was mixed with formula 424 plain and flies were exposed to it. Gut of flies was dissected and cell suspension was prepared. Bacterial colonies were developed by streaking method. Gram staining was performed to differentiate the bacterial cells and further gut microbiome composition (Acetobacteraceae and Lactobacillales taxa) was analysed by 16S rRNA sequencing. The microbiological analysis was carried out to ascertain the microbial load of the developed product for consumption. The total bacterial count and coliform counts of the phytoestrogen rich supplement were <10 CFU/g. Also, the developed supplement exhibited minimal yeast and mold growth (<1 CFU/g). Gram staining showed gram positive (Bacilli and cocci). 16S rRNA sequencing showed significance with mild variation in similarity. It confirmed the presence of Bacillus paramycoids. The developed supplement has showed improved gut microbiome composition in the Drosophila. In future, studies can be extended to humans to analyse the efficacy of the supplement in the gut microbiome composition.

An annotated checklist with a key to the genera of Australian psyllids (Hemiptera: Sternorrhyncha: Psylloidea)

The diversity of the psyllids of Australia reflects that of the plants of this country, with large radiations and ecological dominance of Myrtaceae (e.g., Eucalyptus), Fabaceae (e.g., Acacia), Casuarinaceae (e.g., Allocasuarina, Casuarina) and Scrophulariaceae (e.g., Eremophila, Myoporum). Within Australian ecosystems, psyllids are critical components of food webs, especially with respect to providing energy-rich resources for many species of birds and insects and, historically, humans. Furthermore, in horticulture, agriculture and forestry, some Australian psyllid species are considered pests, causing leaf senescence and ‘dieback’, leaf deformation and inducing growth of sooty mould, with some adventive species capable of acting as vectors of plant pathogens. Several species are considered beneficial, having been introduced as biological control agents of weeds. Additionally, some Australian psyllids have established in other countries, or in regions within Australia that are not within their natural range; while others have such limited geographical ranges that they are of conservation concern. Here we provide an updated checklist of the species of Psylloidea present in Australia and updated a previous key to their genera based on adult morphology. This is the first checklist of the Australian psyllids compiled since the most recent global taxonomic classification, and provides detailed information on biogeographical, ecological and anthropogenic aspects, including global distribution, host plant data, pest status, conservation status, parasitoids, predators, and biological control programs. Our checklist includes information on 66 genera and 450 species, 414 formally described and 36 awaiting descriptions. This represents an increase of almost 20% of species since the last published checklist of 2004, which reported 354 described and 21 undescribed taxa. Additionally, we summarise the available information on more than 150 undescribed taxa. Finally, we reported here more than 60 new records, between distributions and host plant associations.

Long-term mold resistance strategy of laccase-catalyzed eugenol-modified bamboo and its antimicrobial mechanism derived from lignin

Bamboo, which has excellent physical properties and environmental credentials, is widely used in the construction industry and furniture manufacturing. Bamboo is, however, susceptible to attack by molds and bacteria; protection by natural phenolic antimicrobial agents would be a green and environmentally friendly solution to this problem. The application of such protection has, so far, been hampered by poor stability and ease of volatilization of the antimicrobial agent. Here, an innovative strategy that uses the catalytic action of the laccase to chemically attach a natural antimicrobial agent, eugenol (EU), to bamboo, is described. This modification endows bamboo with both long-lasting and extensive mold resistance and antibacterial activity. Laccase-catalyzed covalent bonding of EU to bamboo reduces the volatilization rate of the EU from 1.72 % to 0.29 %. The outstanding mold resistance and antimicrobial activity of bamboo treated using this modified process is retained during a 50-day mold resistance test, with mold growth inhibited by as much as 87.5 %. The treated bamboo is also able to inhibit the growth of both Gram-positive and Gram-negative bacteria. The antimicrobial mechanism results shown that the bamboo lignin is the primary reaction site during laccase-catalyzed EU modification of bamboo, and the long-term mold resistance derived from modified lignin. Furthermore, we analyzed bacterial morphology through SEM, and the results demonstrated that modified enzymatic hydrolysis lignin (EHL) significantly disrupts bacterial morphology, including membrane invagination and collapse. This study provides a new direction for the green development of mold- and bacteria-resistant bamboo, which has potential for use in a wide range of application.

Cordia dichotoma fruit mucilage and flaxseed oil nanoemulsion loaded bioactive film: Synergistic approach to enhance antimicrobial properties and bread shelf-life

Recently, non-conventional sources of mucilage have gained significant attention due to their exceptional techno-functional properties and easy availability. This study aimed to utilize Cordia dichotoma fruit mucilage (CDM) for fabricating bioactive films to evaluate the shelf-life of bread. For the development of nanoemulsion, different concentrations of flaxseed oil (1–5% w/w) were employed. Selection was carried out based on droplet size, encapsulation efficiency, and antimicrobial activity. The selected nanoemulsion (CDM-FO1) was subsequently used to develop CDM-based films with the incorporation of carboxymethyl cellulose (CMC) and sodium alginate (SA). Results revealed that the droplet size of the nanoemulsions was significantly increased from 101.25 ± 4.68 nm to 205.15 ± 7.14 nm with increasing flaxseed oil concentration. However, the addition of CMC and SA improved the tensile strength (13.97 ± 0.34 MPa) of the CDM-F11 film compared to control films CDM (6.98 ± 0.68 MPa) and CDM-FC (7.76 ± 1.65 MPa). The CDM-F11 film exhibited excellent barrier properties compared to the control film. The control film showed higher yeast and mold growth, starting at 0.84 ± 0.57 Log CFU/g on the 3rd day and increased to 3.12 ± 0.39 Log CFU/g by the 9th day. In contrast, the CDM-FC film demonstrated better antimicrobial properties, with microbial growth at 0.52 ± 0.39 Log CFU/g on the 3rd day and 2.84 ± 0.38 Log CFU/g on the 9th day. Overall, CDM film loaded with flaxseed oil nanoemulsion can be effectively used as a sustainable food packaging material with enhanced antimicrobial efficiency for bread preservation.