Improving gelling properties of myofibrillar proteins incorporating with cellulose micro/nanofibres

The effects of cellulose microfibres (CMFs, Average size: 100 ± 5 μm) and cellulose nanofibres (CNFs, Average size: 60 ± 3 nm) on the properties of myofibrillar protein (MP) gels from duck breast meat were studied. The results demonstrated that CMFs and CNFs were mostly connected to MP by non-covalent bonds, the diffusion and cross-linking of MP molecules was promoted, and a denser and more complete gel network was formed. With the increases of CMFs and CNFs concentration (0–10%), the hardness was increased by 13.15% and 19.78% for CMFs10% and CNFs10% gels, respectively, and the elasticity was increased by 40% and 80%, respectively. At the same concentration (0–10%), the increase in gel hardness, viscoelasticity and immobilised water content was greater in the CNFs-MP group than in the CMFs-MP group. The CNFs-MP group had a tighter gel network, and CNFs had a better potential to improve the gelation performance of MP.     

Pulsed Electric Field Assisted Extraction of Cellulose From Mendong Fiber (Fimbristylis globulosa) and its Characterization

In the present work, the properties of cellulose extracted from mendong fiber have been investigated. The experiments were conducted by two different methods to extract the cellulose from mendong fiber, which is extracted by alkali and alkali assisted by PEF. The cellulose was analyzed using X-ray diffraction, Fourier Transform Infra Red, Thermogravimetric Analysis, and compared with cellulose of commercial product. The morphology of cellulose after extraction was observed using both optical and Scanning Electron Microscope. The crystalline structure properties of cellulose extracted from mendong fiber assisted by pulsed electric field (PEF) were similar to the commercial cellulose.     

Comparative study of the effect of TiO2 support composition and Pt loading on the performance of Pt/TiO2 photocatalysts for catalytic photoreforming of cellulose

Herein, catalytic aqueous phase photoreforming of cellulose was carried out over Pt/m-TiO₂ (i.e., mixed phase of anatase and rutile) and Pt/anatase catalysts to investigate the effect of the TiO₂ support structure and Pt loading on the production of H₂. The effect of the TiO₂ support on the properties of the resulting Pt/TiO₂ catalysts (such as actual Pt loading and BET surface area) was not significant. At low Pt loading of 0.16 wt.%, the TiO₂ supports affected the sub-nanometre Pt structures which was confirmed by the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) characterisation (using CO as the probe). Conversely, the effect of TiO₂ supports on larger Pt particles (on 1 wt.% catalysts) was insignificant possibly due to the reduced effect of restructuration of bigger Pt particles on the TiO₂ supports. With an increase in Pt loading from 0.16 wt% to 1.00 wt.%, the normalised H₂ production rate (with respect to the actual supported Pt amount and specific surface area of the catalysts) showed a decreasing trend over the two types of the catalysts, i.e., from 10.6 to 1.4 μmol h⁻¹ m⁻² mg_Pt⁻¹ for Pt/m-TiO₂, and from 8.5 to 1.2 μmol h⁻¹ m⁻² mg_Pt⁻¹ for Pt/anatase. Specifically, large Pt particle sizes reduced the CO₂/H₂ production from cellulose photoreforming over both Pt/m-TiO₂ and Pt/anatase catalysts, indicting an important role played by Pt particle size in photoreforming. Interestingly, in this study, the m-TiO₂ supported catalysts only showed the benefits of enhanced charge separation across the phase junction in producing H₂ with small Pt particles (at sub-nanometre), whilst, when large Pt particles (at around 1–2 nm) were supported, such a benefit was not significant in cellulose photoreforming. The promoting effect of small, sub-nm particles is attributed to the better capture of photoelectrons from bulk TiO₂ and better activity of H⁺ coupling on small Pt particle. Further fundamental study on such guest-host interactions is devised to optimise Pt/TiO₂ catalysts for improving H₂ production from photoreforming reactions.     

A viewpoint on the gastrointestinal fate of cellulose nanocrystals

BackgroundCellulose nanocrystalline (CNC) particles possess unique functional properties such as vastly modifiable surface, considerable mechanical strength and acid resistance, as well as, high aspect ratio. CNCs have received great attention for application in diverse fields of technology including (composite) hydrogels fabrication for the gastric protection and enteral delivery of drugs and nutraceuticals.Scope and approachThe orogastrointestinal digestibility and absorbability of the orally administered CNCs is overviewed in the current article. At first, some surface charge-related characteristics of acid-isolated CNCs are communicated. Then, the biocompatibility and biodegradability of CNCs and CNC-reinforced hydrogels are reviewed, followed by presenting credible digestion and absorption scenarios. Finally, the post-absorption metabolism of CNCs is briefly debated.Key findings and conclusionsBacterial cellulose shows good biocompatibility and hemocompatibility. CNC oxidation provides biologically beneficial impacts; for instance, the TEMPO- and periodate-oxidized CNCs have been shown to regulate some blood metabolic variables and improve the degradability in simulated human blood plasma, respectively. Spherical and carboxyl-bearing cellulose nanoparticles can be isolated through ammonium persulfate digestion. The sphericity of particles results in faster cellular uptake. Negatively-charged CNCs are non-mucoadhesive and thus upon ingestion can penetrate into the buccal and intestinal mucosa. One may augment the absorption of CNCs by targeted receptor-mediated endocytosis. It was postulated that sodium bicarbonate secretion into the duodenum can alter CNCs surface chemistry and influence CNC interaction with gut microbiota.     

Nickel supported on low-rank coal for steam reforming of ethyl acetate

Ethyl acetate is a volatile organic compound (VOC) that has emerged as a major environmental pollutant and also one of representative components of bio-oil. In this study, mostly metallic Ni particles (size: <10 nm) were finely dispersed on low-rank coal (LRC) by the ion-exchange process. Catalytic steam reforming of ethyl acetate (EA) was performed over Ni supported on Eco LRC (Ni/Eco) to reduce EA emissions and simultaneously produce H₂. EA reforming over 17.7 wt% Ni/Eco at 400 °C results in H₂ yield of 70%–80%; this is comparable to that achieved with reforming over commercial Ni/Al₂O₃. Advantageously, metallic Ni particles are dominant over Ni oxides on LRC, and therefore, the pre-reduction step routinely required for an alumina-supported catalyst can be skipped. Furthermore, deactivation by coking is slower with Ni/Eco than with Ni/Al₂O₃ during long-term operation, probably because of the smaller particle size and preferential adsorption on the coal support.     

β-glucosidase supplementation during biomass hydrolysis: How low can we go?

Corn stover was pretreated with dilute sulfuric acid to test the interaction effects of pH, cellulase loading and β-glucosidase loadings on biomass hydrolysis rates. A response surface model was developed showing that β-glucosidase supplementation had limited practical impact on hydrolysis between 0.5 and 2 CBU FPU⁻¹. The only significant interaction in the model was between pH and β-glucosidase loading but it also had little practical significance. Corn stover and corn cob were used to test the effects of further β-glucosidase reduction. Significant hydrolysis improvements were seen when 0.2 CBU FPU⁻¹ were added but very little improvement was seen for higher loadings. Residual cellobiose concentrations confirmed these findings but suggest that further reductions would have more noticeable negative effects on hydrolysis rates. Results show that β-glucosidase supplementation during biomass hydrolysis can be reduced to between 10% and 20% of typical loadings.     

Cross-linking of cellulose and poly(ethylene glycol) with citric acid

A novel approach to modifying native cellulosic fibres with poly(ethylene glycol) (PEG) impregnation and simultaneous cross-linking by citric acid (CA) was investigated. To understand the contributions of different components in the system, control references with just CA and cellulosic fibres (filter paper) were studied. The effect of sodium hypophosphite as a catalyst was also assessed. The results revealed that ester bonds are indeed formed in the cellulose–PEG–CA reaction system, as indicated by weight percentage gain (WPG) and FTIR analysis. The best results were achieved by using 5% CA and 10% PEG (calculated as weight-% from cellulose). In the reaction, the environmentally friendly CA prevents PEG from being leached out of cellulose during washing, resulting in promising future applications in dimensionally stabilized products based on cellulosic fibres.     

Combination of Reaction and Separation in Heterogeneous Catalytic Hydrogenation of Ethylformate

Continuous hydrogenation reaction of ethyl benzoylformate was studied over a (–)‐cinchonidine (CD)‐modified Pt/Al₂O₃ catalyst. The catalyst showed a good stability, and high enantioselectivity was achieved in the fixed‐bed reactor. Chromatographic separation of (R)‐ and (S)‐ethyl mandelate originating from a post‐continuous hydrogenation reaction of ethyl benzoylformate over the (–)‐CD‐modified Pt/Al₂O₃ catalyst was investigated in the same reaction mixture. A commercial column filled with a chiral selector resin was chosen as a perspective preparative‐scale adsorbent. Since adsorption equilibrium isotherms were linear within the entire investigated range of concentrations, they were determined by pulse experiments for the isomers present in a post‐reaction mixture. Breakthrough curves were measured and described successfully by the dispersive plug‐flow model with linear driving force approximation.     

Lignin solvated in zwitterionic Good's buffers displays antibacterial synergy against Staphylococcus aureus

The volume of industrial lignin is expected to increase with the deployment of biorefineries that convert lignocellulosic biomass to renewable chemicals and fuels. Interest in using lignin for value-added biomedical applications requires understanding of its effects on mammalian and microbial cells, which has been impaired by the toxicity of the solvents used to solubilize lignin. In this study, lignin is solvated in zwitterionic Good's buffers compatible with culture media. Up to 100 mg lignin can be solvated in 1 ml of 3-morpholinopropane-1-sulfonic acid (MOPS, pH 7.2) within 60 min at room temperature, whereby MOPS acts as a chaotropic agent. The addition of MOPS-solvated lignin to cultures of Staphylococcus aureus UAMS-1 containing a subinhibitory concentration of tunicamycin reduced growth more than 99% compared to tunicamycin alone, making lignin of interest as an antibiotic adjuvant. This effect of lignin is attributed to damage to the bacterial cell membrane.     

Properties of starch–cellulose fiber films produced by tape casting coupled with infrared radiation

Tape casting is a suitable process for large-scale production of biodegradable films. This study presents a comparison of three drying procedures of starch–cellulose films: i) conduction drying, ii) infrared drying (42.3?W?m^?2, higher infrared heating power damaged the films), and iii) conduction-infrared drying. All the drying procedures were performed at approximately 60°C. Drying times from the second and third methods were close to 1?h, half the time observed for conduction drying. Films from the second and third methods showed similar hygroscopicity (0.15?g.?g^?1, RH 43%), tensile strength (31.3?MPa, RH 58%), and glass transition temperature (?12.13°C, RH 43%).