Search Results (59)

Yak horn represents a valuable resource for fabricating keratin-derived materials; however, its dense, highly cross-linked protein network resists efficient processing via conventional extraction methods. This study introduces a single-step steam flash explosion (SFE) approach to produce keratin nanoparticles (KNPs) from yak horn. The impact of SFE operating pressure (0–1.6 MPa) on KNP morphology, protein secondary/tertiary structures, thermal behavior, and in vitro biocompatibility was systematically investigated. Morphological evaluations revealed that SFE pressure successfully regulates particle dimensions, yielding optimal uniformity with a minimum average particle height of 11.5 nm at 1.45 MPa. Structural characterization indicated that high-pressure treatment induced a shift in disulfide bonds from stable gauche-gauche-gauche (g-g-g) states (515 cm⁻¹) toward higher-energy trans-gauche-trans (t-g-t) arrangements (540 cm⁻¹). This structural deconstruction led to a decrease in thermal degradation temperatures (from 321.9 °C at 0 MPa to <300 °C at 1.6 MPa) but significantly enhanced dehydration efficiency (ΔH = −470.44 J/g at 1.6 MPa). In vitro biocompatibility assessments demonstrated that the prepared KNPs maintain excellent cytocompatibility, supporting L929 and HaCaT cell viabilities above 95%. These findings demonstrated the versatility and effectiveness of SFE as a sustainable strategy for tuning KNP properties, highlighting its great potential in biomedical applications and green material processing. Full article

In response to the increasing needs for environmentally friendly products, lignocellulosic natural fibers have been of interest as potential replacements for synthetic reinforcement materials in textiles, composites, and related applications. Among these resources, bast fibers derived from plant stems (flax, hemp, nettle, jute, hop), which contain a high cellulose content, have good mechanical properties, low density, and are renewable, are highly promising. Steam explosion has emerged as a green fiber extraction, defibrillation, and surface modification pretreatment technology. Despite the growing number of studies on steam-exploded natural fibers, a comprehensive understanding of the relationships between processing conditions, fiber modifications, mechanisms, and end-use performance remains limited. This review investigates the structural, chemical, and morphological influences of steam explosion on bast fibers. Specifically, it focuses on the mechanism of steam explosion including the solubilization of hemicellulose, partial lignin redistribution or removal, fiber individualization, and cellulose enrichment. The literature indicates that steam explosion can improve fiber separation, fineness, surface morphology, and interfacial adhesion of the composite materials and reduce the use of hazardous chemicals compared with conventional extraction methods. Nonetheless, conflicting results have also been documented, where the same steam explosion conditions can yield distinct fiber characteristics according to biomass type, composition of biomass, moisture concentration, and the amount of processing involved. Excessive treatment severity may lead to fiber shortening, cellulose degradation, and deterioration of fiber quality, particularly for textile applications requiring long fibers. This review highlights current knowledge gaps regarding the optimization of processing conditions, the understanding of steam explosion mechanisms, and the scale-up of the technology for industrial applications. Full article

Steam Explosion (SE) is a relatively newly developed physicochemical pretreatment method that has received increasing attention since it can effectively upgrade biomass for further utilization. During SE, biomass is first exposed to high-temperature, high-pressure steam and then rapidly depressurized. This process efficiently breaks down the lignocellulosic structure, reduces moisture content, and increases fixed carbon and calorific value. It also enhances biomass grindability and densification, making it more suitable as a renewable solid fuel. This review carefully discusses the fundamental principles of SE and its effects on particle characteristics. Then, the types of SE reactors (mainly composed of batch reactors and continuous reactors) are systematically compared, and the challenges in scaling up and commercialization are discussed. Also, the characteristics of pyrolysis or gasification of biomass pretreated by SE are described in detail. Studies indicate that SE is beneficial for the enhancement of product quality. Finally, the prospects and future challenges in the development of SE (including superheated steam explosion, reaction kinetics improvement, and heat and mass transfer intensification) are presented and discussed. Full article

In China, antibiotic fermentation residue has been listed as a “hazardous waste” due to its high residual concentrations of antibiotics. There are many ways to deal with antibiotic fermentation residue; however, effective methods are still lacking. In the present work, steam explosion (SE), thermal, and aerobic composting treatments were performed to investigate the resource utilization of cephalosporin C fermentation residue (CFR). The results show that 0 mg/kg, 50.2 mg/kg and 150.5 mg/kg cephalosporin C (CEPC) remained after the SE, composting, and thermal treatments. The total abundance of antibiotic resistance genes (ARGs) decreased by 62.2% and 47.2% after the SE and thermal treatments and increased by 1.4 times in the samples subjected to composting. Nitrogen analysis showed that the nitrogen loss (N loss) was only 1.9% in the SE-treated samples. The antibiotic inhibition zone was reduced by 80.3%, 71.2% and 40.8% in the samples subjected to SE, composting, and thermal treatments. LC/MS showed that the β-lactam ring and dihydrothiazine ring of CEPC were largely destroyed via SE. These results suggest that the SE treatment not only decreased the residual cephalosporin and ARG levels and antimicrobial activity but also preserved most of the nitrogen. SE is therefore a feasible treatment that can be used to deal with CFR. Full article

Mycelium-based composites (MBCs) have emerged as promising biofabricated materials that align with circular economy and clean technology goals by utilizing fungal networks to transform lignocellulosic residues into functional, biodegradable composites. Despite the MBC’s potentials, the intrinsic nature of the fungal strain, substrate physico-chemical composition and engineering property variability remain significant hurdles that should be critically surmounted. Substrate treatment is central to determining growth kinetics, microstructural uniformity, and mechanical performance in MBC production. This review highlights recent advancements in physical, chemical, biological, and hybrid pretreatment methods, including comminution, pasteurization, alkali hydrolysis, enzymatic conditioning, microwave-assisted hydrolysis, ultrasound pretreatment, steam explosion, plasma activation, and irradiation. These technologies collectively enhance substrate digestibility, aeration, and permeability while reducing contamination. Optimization parameters—temperature, pH, C:N ratio, moisture content, particle size, porosity, and aeration—are examined as critical process levers influencing hyphal density, bonding efficiency, and composite uniformity. Evidence suggests that properly engineered substrate treatments accelerate colonization, strengthen hyphal networks, and significantly improve compressive, tensile, and flexural material properties. The review discusses emerging process control tools such as AI-assisted modeling, micro-CT porosity analysis, and sensor-integrated bioreactors that enable reproducible and energy-efficient fabrication. Collectively, the findings position substrate engineering as a foundational technology for scaling high-performance mycelium composites and advancing sustainable material innovation. Full article

This review highlights recent progress in the sustainable extraction, production and application of plant fiber-reinforced biopolymer composites. The review mainly focuses on properties of these materials—mechanical, thermal, and interfacial—and explores how factors such as fiber type, extraction methods, and surface treatments (e.g., enzymatic retting, deep eutectic solvents, steam explosion) affect fiber morphology and bonding with the polymer matrix. The work also discusses strategies to select and modify biopolymer matrices (e.g., PLA, PHA) for better compatibility, recyclability, and long-term performance, addressing challenges like fire resistance and environmental impact. Special attention is given to cellulose surface modification, which improves wettability and interfacial adhesion, while highlighting alternatives to conventional chemical treatments due to cellulose’s high crystallinity and strong hydrogen bonding. Despite advances in surface treatments and manufacturing, persistent challenges include moisture sensitivity, processing reproducibility, and standardization. Future research should prioritize application-tailored extraction, scalable eco-friendly modifications, and standardized testing to optimize durability and circular economy alignment. These fiber-reinforced biopolymer composites offer a viable path to fossil-free, high-performance materials. Overall, this review provides a comprehensive perspective that bridges sustainability and industrial applicability, offering practical guidance for developing high-performance, eco-friendly composites. Full article

The resource utilization of keratin waste has garnered significant attention, yet the processing of yak hair keratin in underdeveloped regions such as Tibet and Qinghai in China remains challenging. This study addresses these concerns by carbonizing yak hair keratin waste using a steam flash explosion (SFE) technique for 150 s, which is followed by activation with KOH at various ratios and subsequent to produce activated carbon (AC) samples. The AC was then combined with sodium alginate (Alg) at different ratios, pH and applied voltage to yield AC−Alg gel microbeads using an electrospinning method. The characterization of the AC and AC–Alg gel microbeads was conducted using SEM, BET, TG, and FT-IR analysis. In adsorption studies, AC−Alg_0.5U gel microbeads prepared with optimized conditions (pH 7, 11 kV, 19 G needle) were used to remove dyes (methylene blue (MB) and methyl orange (MO)) and antibiotic minocycline hydrochloride (MH). Various parameters such as temperature, pH, and adsorbent dose were optimized to obtain the maximum adsorption performance under model concentrations. The experimental results showed that the AC−Alg_0.5U gel microbeads can effectively adsorb MB and MO with adsorption capacities of 1038.9 mg/g and 206.2 mg/g, respectively. Moreover, the microbeads had the best adsorption performance for MH (1694.2 mg/g), with the kinetics most accurately represented by the pseudo-second-order kinetic model (R² = 0.999), and the isotherm followed the Langmuir model (R² = 0.984). The microbeads maintained a high adsorption capacity of 75% after six cycles. The composite gel microbeads not only utilize yak hair keratin waste but also will be used as durable and favorable adsorbents for the removal of pollutants. Full article

In modern agriculture, small peptide fertilizers (SPFs) have emerged as a promising tool to enhance crop growth, yield, and stress resilience. However, the influence of raw materials and innovative preparation methods on SPF characteristics and agronomic performance remains underexplored. This study introduces instant catapult steam explosion (ICSE), a novel thermomechanical technology, for synthesizing SPFs from fish, soybean meal, and sheepskin. The molecular, chemical, and nutritional properties of the SPFs were then characterized using methods including gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and HPLC/LC-MS. The research aims to characterize the molecular, chemical, and nutritional profiles of resulting SPFs and evaluate their effects on rice and rapeseed growth, yield, and nitrogen use efficiency (NUE). ICSE-generated SPFs exhibited distinct properties based on raw materials. Fish-derived SPF1 had a narrow molecular weight distribution, high small peptide content (573 mg g⁻¹), and free amino acids (0.478 mg g⁻¹), while sheepskin-derived SPF3 showed the lowest values (386 mg g⁻¹ and 0.366 mg g⁻¹, respectively). Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of peptide bonds and functional groups, with variations in peak intensities reflecting differences in raw materials. Field trials revealed that SPF1 significantly improved rice and rapeseed growth parameters, including plant height, SPAD values, and flag leaf area, compared to controls. Yield increases of 10.36% (rice) and 11.74% (rapeseed) were observed for SPF1, alongside the highest NUE (42.3–43.4%). Soybean meal-derived SPF2 showed moderate performance, while SPF3 had minimal effects. These findings validate ICSE for sustainable SPF production and emphasize the importance of selecting raw materials to optimize fertilizer outcomes and enhance crop productivity. Full article

Spices play a crucial role in shaping the characteristic flavor of marinated meat products. This study systematically compared the effects of physical crushing, vacuum nano-collision, and steam explosion on the physical and flavor characteristics of star anise and cinnamon. The vacuum nano-collision treatment effectively reduced particle size to below 15 nm, promoting faster flavor release and improving both moisture retention and solubility. Hydrocarbons, alcohols, and aldehydes were identified as the dominant volatile compounds. Among the non-volatile components, crushed cinnamon contained the highest shikimic acid concentration (1510.1 ± 25.45 μg/kg), while star anise treated with vacuum nano-collision reached the highest level of shikimic acid (893.10 ± 23.99 μg/kg). However, the main active components of these two spices did not show significant differences between the two treatment methods. Steam explosion treatment resulted in the lowest levels of both volatile and non-volatile compounds. Flavor profiling and electronic tongue analyses further revealed that the flavor characteristics of the crushed and nano-collision groups were similar, but distinctly different from those obtained with steam explosion. Overall, these results provide new insights into the development of efficient spice processing technologies and offer practical guidance for optimizing flavor quality in marinated meat products. Full article

The aim of this study was to check the content of metal inhibitors before and after the pre-treatment of fast-growing poplar wood using steam explosion (SE) at selected temperatures (160, 175, 190 and 205 °C). An X-ray fluorescence spectrometer (XRF) was used for the analysis. The material was analysed after pre-treatment and in its native form in two variants: incinerated wood chips and incinerated wood chips dissolved in nitric acid. The analysis was intended to show the difference in the content of metals inhibiting biological processes, including enzymatic hydrolysis and fermentation (i.e., chromium, manganese, iron, nickel, copper and zinc). The study aimed to identify changes in the content of metallic inhibitors depending on the SE temperature and to demonstrate differences depending on the methodology used to measure metals in the tested material. The greatest change in metal content in the material after pre-treatment was observed for pre-treatment at 175 °C, regardless of the determination method used. Both methods allow the trend in changes in metal content in wood material to be determined. However, due to the heterogeneous structure of wood, the methods give different results, especially for iron. Full article

Nowadays, insects are reared for food and feed. This idea includes the rearing of yellow mealworm (Tenebrio molitor L.). The study aimed to assess the effect of pretreatment of lignocellulosic materials on the growth, survival, and chemical composition of mealworm larvae. The main factor in the experiment was the type of feed. The components of the experimental mixed diets were wheat bran (control feed), enzymatically hydrolysed wheat straw pretreated with steam explosion (WES), enzymatically hydrolysed wheat straw pretreated by the organosolv method (WEO), and enzymatically hydrolysed cup plant pretreated by the organosolv method (CEO) in different combinations with wheat bran. Larval development and survival were monitored and measured. In the final bioassay, larval growth on all feeds containing 10% of pretreated lignocellulosic feed was similar to that of insects reared on the control diet. The specific growth rate of larvae reared on the WEO10 diet was significantly the highest (10.1%). The diet used to feed the insects had a significant effect on the crude protein and crude fat content in their biomass. The highest protein content was found in insects fed wheat bran and fed the CEO10 diet. Protein digestibility averaged 40.7% and did not differ statistically among diets. In conclusion, a moderate inclusion of processed lignocellulosic biomass can be used as a feed component for insect diets. Moreover, insect rearing on such substrates not only enables the utilisation of agricultural residues but also converts them into high-quality protein and fat, which can find applications in the feed, cosmetic, or food industries. Full article

Cellulosic raw materials are the most common source of carbon on Earth and are in great demand for the production of high-value-added products. Cellulosic feedstocks represent a strong matrix consisting of cellulose, lignin, and hemicelluloses. The efficient transformation of cellulosic raw materials into fermentable sugars requires the use of effective pretreatment strategies. The methods employed for pretreatment should be efficient, have low operating costs, and exhibit lower environmental impact. The present review describes pretreatment methods like liquid hot water (LHW) and steam explosion (SE) and highlights peculiar features, benefits and disadvantages of these processes. The effectiveness of these pretreatment methods and their effect on cellulosic raw materials strongly depends on the type of feedstock (component composition), pretreatment method, and pretreatment conditions (pressure, temperature, time, etc.). The LHW pretreatment requires neither addition of chemicals and catalysts nor grinding stage, but requires high energy inputs. The SE pretreatment is regarded as environmentally friendly and requires lower energy inputs, but contributes to the formation of toxic compounds. The life cycle assessment approach demonstrated that the SE pretreatment outperforms dilute acid pretreatment methods and allows the reduction of energy inputs, thereby improving the environmental performance of the process, while the LHW method improves long-term energy security and creates a greener future. Full article

Herein, a novel super-hygroscopic material, steam-exploded modified corn stalk pith (SE-CSP), was developed from corn stalk pith (CSP) via the steam explosion (SE) method, and its hygroscopic properties and mechanisms were evaluated. The results confirmed that SE effectively removed lignin and hemicellulose, disrupted the thin cell walls of natural CSP, and formed an aligned porous structure with capillary channels. SE changed the bonding distribution and surface morphology, and enhanced the crystallinity and thermal stability of CSP. The equilibrium hygroscopic percentage of SE-CSP (62.50%) was higher than that of CSP (44.01%) at 25 °C and 80% relative humidity (RH), indicating significantly greater hygroscopicity. The hygroscopic process of SE-CSP followed a Type III isotherm and fitted the Guggenheim–Anderson–de Boer (GAB), Peleg, and pseudo-first-order kinetic models. This process exhibited multi-layer adsorption with enthalpy-driven, exothermic behavior, primarily through physical adsorption involving hydrogen bonds and van der Waals forces. This work offered a new approach for advancing sorption dehumidification technology. Full article

This review aims to give evidence of the current developments and potential applications of emerging technological methods to improve the technological performance and the sensorial acceptability of wholegrain products. The review explores the technologies based on physical, i.e., micronization, steam explosion, high hydrostatic pressure, extrusion cooking, ohmic heating, and 3D printing, and biotechnological methods, such as fermentation and enzymatic treatments in the pre-milling, milling, and transformation steps of wholegrain products. The literature from the past decade for this review article was collected from electronic databases such as ScienceDirect, PubMed, Google Scholar, and Web of Science. Full article

Zirconium alloys are essential materials for nuclear fuel cladding. During a loss-of-coolant accident (LOCA), zirconium alloy cladding can oxidize in high-temperature steam (>1000 °C), generating hydrogen and releasing significant heat. Without timely emergency actions, this can result in hydrogen explosions or nuclear leakage. In this study, titanium nitride (TiN), chromium (Cr), and TiN–Cr composite coatings were deposited on the surface of Zr-4 alloy using the magnetron sputtering method. The coatings’ surface and cross-sectional morphologies were examined using scanning electron microscopy (SEM), and their phase structures were analyzed with X-ray diffraction (XRD). The mechanical properties were evaluated using scratch tests, and their resistance to high-temperature steam oxidation was tested in a tube furnace connected to a steam generator. The results showed that the TiN, Cr, and TiN–Cr coatings exhibited strong adhesion to the Zr-4 substrates, with distinct interfaces and pure phase structures. After high-temperature steam oxidation, cracks appeared on the surfaces of the TiN, Cr, and TiN–Cr coatings, likely due to differences in the thermal expansion coefficients of TiO₂, Cr₂O₃, and residual Cr layers. These cracks created pathways for the oxidizing medium, potentially leading to the oxidation of the substrate or inner layers of the composite coatings. For the Cr and TiN–Cr coatings, despite cracking of the Cr layer and melting of the TiN layer at high temperatures, the residual Cr layer effectively restricted oxygen diffusion into the Zr-4 substrate. This study suggests that layers with low melting points, such as TiN, are unsuitable for composite coatings in high-temperature applications. However, adding a Cr layer on top of the TiN layer to form a TiN–Cr composite coating improves adhesion between the coating and the substrate. The TiN–Cr composite coating functions as an effective diffusion barrier at temperatures up to 1200 °C, comparable to a pure Cr coating. Full article