Review Articles

Enzymatic refining offers a sustainable alternative to mechanical refining for enhancing the quality of recycled paper fibers. This review examines (a) the benefits and limitations of enzymatic refining and (b) the most commonly used enzymes and their effectiveness. Studies from 2008 to 2023 were systematically analyzed using PRISMA screening to assess enzyme types, energy savings, and paper property improvements. Findings indicate that enzymatic refining reduces energy consumption by up to 20% while improving fiber bonding and drainage. Cellulases and hemicellulases are the most effective enzymes, enhancing mechanical strength and reducing water use. However, enzymatic refining alone is often insufficient, requiring additional mechanical refining for optimal results. Industrial adoption of enzymatic refining remains limited due to challenges in process integration and reaction optimization. This study highlights the role of this kind of refining in advancing circular economy goals and emphasizes future research needs, including enzyme formulation optimization and the development of scalable, one-step refining solutions.

The free drying shrinkage of wood is critical for dimensional stability and industrial applications. This study reviews the influencing factors (drying parameters, environmental conditions, and anatomical structures) and summarizes evaluation indexes and measurement methods. However, current research exhibits significant limitations. Systematic comparisons of free drying shrinkage between softwoods and hardwoods have been lacking, and the mechanism by which internal moisture variations affect shrinkage have remained unclear. Furthermore, existing techniques have failed to simultaneously measure moisture content changes and shrinkage with high accuracy. To address these gaps, future studies should: 1) investigate species-specific free drying shrinkage conditions; 2) elucidate moisture-induced shrinkage mechanisms from macro- and micro-scale perspectives; and 3) develop high-resolution methods for synchronous measurements. Further industrial applications of these findings could optimize wood drying processes and advance wood science and processing technologies.

This article reviews published literature related to the coating of wood surfaces for external applications. Research has shown that a wide range of procedural steps and components in coating formulations can contribute to increasing the effective service life of the coating as well as to maintaining the quality of the coated wood surfaces. Published findings support the idea that the commonly observed service life of painted wood surfaces exposed to outdoor weather can be significantly increased by dedicated application of such measures as optimized sanding, the use of an effective primary coat, the type of resin in the finish coat, increasing the number of layers of the finish coat, and a wide range of issues related to formulation of the finish coat. Even if a majority of contractors and homebuyers continue to prefer such options as vinyl or aluminum siding, the market opportunities remain very large for clients who prefer to rely on coatings and wood products for exterior surfaces of buildings and other exterior wood items.

Nanocellulose, a sustainable and versatile nanomaterial derived from abundant natural resources such as plants and bacteria, has emerged as a promising candidate for advancing eco-friendly food packaging. This review summarizes recent advancements in nanocellulose composites, focusing on their preparation methods, enhanced mechanical and barrier properties, applications in food preservation, safety profiles, and biodegradability. Nanocellulose composites, synthesized via techniques such as solution casting, melt intercalation, layer-by-layer self-assembly, in situ polymerization, coating, and ring-opening polymerization, can exhibit exceptional mechanical strength, oxygen and moisture barrier performance, as well as compatibility with active agents such as antioxidants and antimicrobials. Studies highlight the role of nanocellulose in reducing polymer composite permeability while maintaining biodegradability. Despite these advantages, challenges such as high production costs, energy-intensive methods (e.g., sulfuric acid hydrolysis), and hydrophilic limitations hinder industrial scalability. Emerging strategies, including enzymatic processing and surface modifications (acetylation, oxidation), offer pathways to enhance hydrophobicity, dispersion, and thermal stability. Future research should prioritize scalable, low-cost production technologies and expanded applications in smart and active packaging systems. By addressing these challenges, nanocellulose composites hold significant potential to revolutionize sustainable packaging, aligning with global demands for reduced environmental impact and enhanced food security.

Ruminant farming is a significant contributor to global food production but also a major source of methane emissions. It is responsible for nearly 44% of greenhouse gases from the agricultural sector. The integration of maize and lupine into the diets of ruminants offers a sustainable strategy for improving feed efficiency, reducing methane emissions, and enhancing animal productivity. Fermented maize silage has been shown to lower methane emissions by 10 to 20% compared to conventional high-starch diets. Lupine supplementation can further reduce methane emissions by influencing rumen fermentation. The inclusion of lupine, a nitrogen-fixing legume, additionally enhances soil fertility and reduces the need for synthetic fertilizers, making it an environmentally sustainable alternative to soybean meal. Studies indicate that diets incorporating maize silage and lupine can improve feed conversion efficiency and increase milk yield by up to 5% in dairy cattle. However, large-scale adoption of these feed additives requires further research to optimize fermentation processes, ensure economic feasibility, and overcome regulatory barriers. This study highlights the potential of maize and lupine as viable solutions for enhancing livestock sustainability while mitigating climate impacts.

Plant materials throughout the world, i.e. biomass, can provide annually roughly 18 x 10¹⁵ Watt-hours (6.5 x 10¹³ MJ) of energy, considering just the residues from agriculture and forestry. However, at least part of that amount has higher-valued uses, including being made into durable products, thereby keeping their carbon content from contributing to global warming. This review considers circumstances under which it may be advantageous to use biomass resources, either alone or in combination with other renewable energy technologies – such as solar and wind energy – to meet society’s energy needs, especially for electricity, heating, and transportation. There is a rapidly expanding pool of published research in this area. To slow climate change, rapid maturation of the most promising technologies is needed, followed by their widespread and early implementation. Of particular interest are synergistic combinations of technologies, including the use of solar energy and biomass together in such a way as to provide hydrogen, heating, and electricity. Another need is to use biomass to make high-energy-density liquid fuels, including aviation fuels, diesel, and naphtha. Although some proposed schemes are complicated, biomass is expected to be gradually implemented as a growing component of installed renewable energy capacity in the coming years.

This review article critically examines the integration of Internet of Things (IoT) sensors and wireless technology into polymer composites, highlighting its transformative potential in materials science. The focus is on real-time monitoring of key parameters such as temperature, stress, strain, humidity, and environmental exposure, which are essential for predictive maintenance and performance optimization. This review covers existing research and technological developments in IoT-enabled polymer composites, including sensor technologies, data transmission, cloud-based analysis, and digital twin creation for rapid design optimization and troubleshooting. The scope of this review does not extend to experimental procedures for sensor integration, detailed material property enhancements unrelated to IoT technologies, or the development of new composite materials without IoT integration. Key challenges such as standardization, data security, and system interoperability are discussed, and future research directions are proposed. By defining the scope and boundaries of the discussion, this review provides a comprehensive overview of how IoT integration is advancing the performance, reliability, and sustainability of polymer composites across industries such as aerospace, automotive, and infrastructure.

The growing need for sturdy lumber in many applications has made wood preservation more crucial. Nanoparticles (NPs) have been considered to improve the functionality of wood. This review article focuses on how NPs can be used to enhance the qualities of wood and wood-based products and provide them with anti-microbial protection. The ability of nano-based substances to permeate deeply into wood surfaces, which in turn causes a shift in their exterior chemistry, is the primary driver behind the nanotechnology application in lumber development. The microbial enzymes secreted by microbes is a major factor that can alter the structure of wood, especially during storage before use. This review illustrates various examples of microorganisms which secrete enzymes which impact wood structure through various mechanisms. The increased interface region created by the treatment serves as the reason for any prospective changes in the wood’s characteristics via NPs application. To a certain extent, the NPs change the original characteristics of wood, thus improving its qualities. There are challenges and limitations for using NPs in wood preservation. The potential effect of NPs on human health and the ecosystem should be considered using techniques such as life-cycle evaluations to avoid harmful consequences.

Cellulose and hemicellulose, which are essential structural components of plant cell walls, are key renewable resources for various biotechnological applications. Bacterial enzymes can degrade these polysaccharides and have emerged as efficient, eco-friendly alternatives to chemical methods, offering significant advantages in industrial processes and medical therapies. This review explores bacterial enzymes, such as cellulases and hemicellulases, which break down cellulose and hemicellulose—two major components of plant cell walls—and their mechanisms of action in both industrial and medical applications. These enzymes offer an eco-friendly alternative to chemical processes, contributing significantly to sustainability by reducing chemical usage and improving biofuel yields. Beyond industrial applications, bacterial enzymes contribute to medical innovations such as targeted drug delivery systems and wound healing, with potential for treating chronic diseases like diabetes and inflammatory bowel disorders. These are currently being tested in clinical settings to enhance therapeutic outcomes. Advances in synthetic biology, which involves designing new biological parts and systems, enzyme engineering, the modification of enzymes to improve their function, and microbial consortia design have further enhanced the efficiency and versatility of these enzymes, making them indispensable in modern biotechnology. Future research focusing on optimizing enzyme stability, catalytic efficiency, and substrate specificity will drive innovations in both industrial sustainability and transformative medical applications.

Agave species are increasingly recognized as promising sources of bioactive phytochemicals with therapeutic potential. Among these, β-sitosterol (BSS) and its glucoside (BSSG) have gained attention for their wound-healing, anti-inflammatory, antioxidant, and immunomodulatory properties. In vitro, these compounds enhance fibroblast viability and regulate cytokine production. In vivo, extracts from Agave angustifolia bagasse (BagEE), obtained through microwave-assisted extraction (MAE), significantly accelerate wound closure and re-epithelialization. MAE, particularly when combined with alkaline catalysts, yields higher concentrations of BSS and BSSG compared to conventional methods. However, despite its environmental and efficiency advantages, supercritical fluid extraction remains underutilized for isolating phytosterols from Agave. This review highlights interspecies variation in bioactive profiles, the critical impact of extraction methodology on compound yield and activity, and the potential for valorizing agro-industrial residues. These findings emphasize the value of Agave-derived sterols in the development of sustainable, plant-based therapeutics. Further research is needed to standardize extraction protocols, achieve comprehensive characterization of active metabolites, and evaluate their clinical efficacy—advancing innovation in bioproduct development aligned with circular economy principles.