Volume 21 Issue 4

Published findings are reviewed related to the recovery and recycling, as well as the biodegradability, of single-use food packaging materials that include waterborne barrier coating layers. Such layers can replace petroleum-based plastics, such as polyethylene, which tend to build up in the environment and contribute to microplastics issues. Barrier layers, of either type, can block the transport of oxygen, water vapor, liquid water, grease, contaminants, and flavors in and out of such packaging systems.  Key concerns include whether such layers can be readily dispersed in water, thereby allowing the packaging material to be used again in subsequent generations of recycled paper products. The process efficiency, including the yield of recovered materials, is also of concern. Because single-use food packaging products, in most regions, are not yet routinely routed to paper recycling, this review also considers findings related to biodegradability and compostability of waterborne barrier layers. Based on the reported findings, there are numerous waterborne formulations that can meet practical needs in terms of biodegradability and repulpability, leading to relatively high yields in paper recycling operations. Chemical components of future waterborne coating formulations need to be considered on a case-by-case basis regarding their contributions to toxicity, compostability, general biodegradability, and circular systems of recovery and reuse.

Tannic acid has attracted considerable attention as a natural inhibitor of fungi. The antifungal activity of tannic acid was evaluated by assessing fungal growth and the activities of polygalacturonase and pectin methylesterase. Fungal growth was stimulated at 200 μg mL⁻¹ (112.6%), but significantly reduced at higher concentrations, reaching 12.4% at 1000 μg mL⁻¹ (87.6% inhibition) of tannic acid. In vivo, tannic acid effectively controlled postharvest soft rot in muskmelon, achieving up to 81.4% disease control. Enzyme activities in the culture medium declined markedly, reduced to 15.3% for polygalacturonase and 20.1% for pectin methylesterase. However, it should be noted that this reduction may result from either direct inhibition of enzyme catalytic activity or reduced enzyme secretion due to suppressed fungal growth, or a combination of both. Molecular docking was performed using heterologous protein structures (endopolygalacturonase from Fusarium verticillioides, PDB: 1HG8; pectin methylesterase from Daucus carota, PDB: 1GQ8) as representative models. Because these proteins are not from R. stolonifer, the docking results have no direct biological relevance to the target pathogen and cannot be used to infer binding to R. stolonifer enzymes. Thus, the experimental data demonstrate that tannic acid reduces extracellular pectin-degrading enzyme activity in fungal cultures, but the mechanism remains unresolved.

Bamboo (subfamily Bambusoideae, Poaceae) represents one of the most taxonomically complex and evolutionarily dynamic lineages within grasses due to irregular flowering cycles, extensive morphological plasticity, frequent hybridization, and widespread polyploidy. These characteristics have historically complicated species delimitation and phylogenetic reconstruction. This review synthesizes recent advances in integrative bamboo systematics, emphasizing the roles of phylogenomics, molecular cytogenetics, DNA barcoding, multi-locus sequencing, and computational morphological analytics in resolving bamboo diversity and evolutionary relationships. Genome-wide sequencing approaches have enabled the detection of hybridization events and reticulate evolutionary histories that were previously difficult to resolve using morphology or single-locus markers. These advances have improved phylogenetic resolution, particularly among closely related bamboo taxa. Nevertheless, incongruence between nuclear and plastid datasets, incomplete lineage sorting, and polyploid genome complexity continue to constrain full phylogenetic resolution. Integrative systematic approaches provide an essential framework for improving taxonomic stability, biodiversity conservation, and sustainable management within Bambusoideae.

To evaluate the long-term durability of environmentally friendly biomass composites under hydrothermal conditions, this study investigated the degradation behavior of wood-fiber-reinforced magnesium oxysulfate (MOS) panels subjected to accelerated hydrothermal cycling with alternating immersion at 60 and 20 °C. The results showed non-monotonic changes in mechanical properties and microstructure. After 7 cycles, the diffraction peak associated with the 517-phase (5Mg(OH)₂·MgSO₄·7H₂O) weakened, while residual MgO continued to hydrate. Meanwhile, the porosity increased to 23.1%, and the modulus of rupture (MOR) decreased from 25.3 to 15.4 MPa. At 14 cycles, the porosity decreased slightly to 21.1%, while the MOR increased numerically to 16.3 MPa, indicating a temporary stabilization tendency associated with continued hydration and evolution of MOS hydration products. After 21 cycles, the diffraction features of the 517-phase weakened further, MgCO₃-related peaks became more pronounced, and the porosity increased to 33.9%. Interfacial deterioration was also observed, accompanied by a decrease in MOR to 14.8 MPa. Taken together, the hydrothermal durability of the composites was closely associated with the degradation of MOS hydration products, continued hydration of residual reactive components, and pore-structure evolution. These findings provide useful evidence for improving the hydrothermal durability of MOS-based biomass composites.

During the production of fuel ethanol, biogas, and organic fertilizer from whole grains, mycotoxins in the feedstock raise complex issues regarding product safely. In fuel ethanol production, processes such as grinding, liquefaction, and fermentation can cause structural transformations or reductions in the levels of certain toxins (such as zearalenone and vomitoxin); however, degradation products may remain in the distillers’ grains protein feed, affecting the safety of the byproduct. During the biogas fermentation stage, anaerobic microbial communities can further degrade some toxins through enzymatic reactions and metabolic processes. The degradation efficiency is significantly influenced by feedstock characteristics, process parameters, and toxin types, and small amounts of toxins or their transformation products may still remain in the digested liquid. In the subsequent organic fertilizer production process, the high-temperature phase of composting helps reduce residual toxins, and the synergistic action of aerobic microorganisms enhances degradation. However, certain mycotoxins may not be completely degraded or may generate unknown metabolites, posing potential ecological and health risks after application to farmland. Elucidating the degradation mechanisms, transformation pathways, and product safety of mycotoxins during multi-stage sequential treatment is important for ensuring pollution control across the entire industrial chain and the safe utilization of resource-recycled products.

The sensitivity of an optical device was evaluated when determining the mass concentration of inhalable wood dust under conditions where workers’ exposure was below 0.25 mg/m³. Samples were collected during the processing of oak wood using a belt sander (BS) and thermally modified (TM) ash wood using a four-sided planer (4SP). The Split2 (SKC) optical device, operated in active mode, consists of an optical sensor and an inlet component with an Institute of Occupational Medicine (IOM) filter holder for inhalable dust. Gravimetric determination of respirable and inhalable dust mass concentrations was performed using a Higgins-Dewell respirable dust cyclone and an IOM inhalable dust sampler. Measured exposure levels for the inhalable fraction near the BS and 4SP machines ranged from 0.02 to 0.219 mg/m³ (N = 18). The Split2 optical device significantly overestimated the inhalable dust concentration during the belt sanding operation (p = 0.02). This overestimation may be related to the high average proportion of the respirable fraction (70.3%). However, no statistically significant overestimation was found for the four-sided planer operation (p = 0.13). Based on the ratio of gravimetric to photometric mass concentrations, two specific photometric correction factors are recommended for the Split2 optical device under these specific working conditions: 0.24 for the belt sander and 0.48 for the four-sided planer.

Medical beds designed for institutional care often do not fully meet the functional, aesthetic, and environmental requirements of home-based care. This study therefore focused on wooden care beds for home use and examined the coexistence of functional redundancy and insufficient core functions in this product category. Older adults with full or partial functional limitations and their family caregivers were selected as respondents. Satisfaction with 23 nursing-bed functions was evaluated under two scenarios: function availability and function absence, using a five-point scale. A total of 312 valid responses were collected through online questionnaires and field visits. Based on Kano theory, an I-Kano quantitative framework was used to classify functional requirements, while Better–Worse coefficients were introduced to measure satisfaction gains from function availability and dissatisfaction risks from function absence. The results identified 10 must-be attributes, mainly related to safety and basic usability, including pressure ulcer prevention, fall prevention, backrest adjustment, and power-off emergency support; 8 one-dimensional attributes, related to comfort and care efficiency; 3 attractive attributes, such as bed–chair conversion and remote/voice control; and 2 indifferent attributes. These findings provide a quantitative basis for functional configuration and product positioning of wooden home care beds.

This study investigated the prediction of lignin removal from mixed-species wood chips (oak and pine) containing bark. A two-stage pretreatment consisting of steam explosion (SE) and alkaline (NaOH) treatment was employed, and a dataset was constructed by systematically varying severity factors, bark inclusion, chemical concentration, and pretreatment time. Four predictive models—Random Forest (RF), Extra Trees (ET), Extreme Gradient Boosting (XGBoost), and polynomial regression (PR)—were developed and evaluated using five repeated random 80:20 sample-level splits. XGBoost showed the highest mean test R² (0.9848), the lowest mean test RMSE (0.2984), and the highest mean cross-validation R² (0.9361), significantly outperforming conventional polynomial regression (R² = 0.5145). SHAP analysis identified NaOH concentration as the most influential predictor, followed by severity factor and bark inclusion. Finally, a web-based graphical user interface (GUI) was developed using Streamlit to provide real-time lignin removal predictions. These results showed that ensemble machine learning, particularly XGBoost, can effectively optimize pretreatment processes for heterogeneous biomass feedstocks in industrial biorefinery applications. These results support the use of ensemble machine learning for this heterogeneous feedstock, while indicating sensitivity to the sample-level partition and the need for future condition-level validation.

Electrospun nanofibers have gained attention for biomedical applications due to their high surface area and extracellular matrix-like structure. In this study, polyvinyl alcohol (PVOH)-based electrospun nanofibers with keratin and curcumin were fabricated and characterized. The effects of keratin and different curcumin concentrations on morphology, chemical structure, thermal stability, wettability, and mechanical properties of the nanofibers were investigated. Field emission scanning electron microscopy (FESEM) showed that keratin incorporation noticeably reduced the fiber diameter from 453 nm to 254 nm, while increasing curcumin concentration further decreased the average fiber size from 330 nm to 282 nm. Fourier transform infrared spectroscopy (FTIR) confirmed the successful incorporation of keratin and curcumin into the nanofibers through the presence of characteristic functional groups. X-ray diffraction (XRD) analysis indicated that the nanofibers remained predominantly amorphous with the presence of crystalline curcumin domains. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) demonstrated improved thermal stability after the incorporation of keratin and curcumin. Water contact angle measurements revealed that all nanofibers were hydrophilic, with keratin substantially enhancing wettability. Mechanical analysis showed that keratin improved nanofiber flexibility, while curcumin influenced the balance between strength and elongation. The developed PVOH/keratin/curcumin nanofibers exhibited promising physicochemical and mechanical properties for biomedical applications.

Spent coffee grounds (SCG) are an abundant lignocellulosic biomass rich in galactomannan and cellulose, rendering them a promising feedstock for biorefinery, especially for the production of manno-oligosaccharides (MOS) as high-value prebiotics. This study investigated the role of α-galactosidase (α-G) in the enzymatic hydrolysis of ammonia-pretreated SCG, with particular emphasis on MOS production and cellulose hydrolysis. Enzymatic hydrolysis was conducted at 50 °C and pH 5.0, and the resulting sugars and MOS were quantified by HPLC. Supplementation with α-G effectively removed α-1,6-linked galactose side groups from galactomannan and increased MOS yield. Notably, the addition of α-G enabled a 50% reduction in mannanase dosage without compromising MOS production, indicating its potential to improve galactomannan conversion efficiency. However, α-G treatment altered the properties of the resulting MOS and was associated with stronger inhibition in MOS-containing cellulase systems. Under the tested conditions, α-G supplementation in MOS-containing systems was associated with additional numerical reductions in glucose yield of 15.8% for CBHI and 8.1% for EGII, whereas little numerical change was observed in the βG system. These results reveal a trade-off associated with α-G supplementation: although it promotes MOS generation, stronger inhibition was observed in MOS-containing cellulase systems, which may impair downstream cellulose hydrolysis.