Furfuryl Alcohol Content Research Articles

Solvent-promoted selective chemocatalytic hydroxymethylation of biomass furanic compounds

Functionalizing biomass-derived furanic chemicals is of great importance towards biorefinery processes but challenging, especially working at elevated substrate concentrations. We herein report the intervention of 1,4-dioxane co-solvent availably to catalyze hydroxymethylation of furfuryl alcohol (FA) in formalin over Hβ zeolite, giving high yield to 2,5-dihydroxymethylfuran (DHMF), a versatile building block. Impressively, the facilitating effect of 1,4-dioxane on DHMF production became more pronounced with increasing FA feeding concentration, and the yield raised from 19.5 % to 67.8 % from a high FA concentration of 10 wt%. The 1,4-dioxane served not only as a catcher of formaldehyde hydrate to access substrate FA, but also as a shield to restrain undesirable condensation side-reactions. The developed protocol demonstrated an excellent universality in boosting the hydroxymethylation of electrondrawing-group-free furanic molecules (e.g., furan, 2-methylfuran). The understanding of these solvation effects can be employed to effectively manipulate and improve the hydroxymethylation of furanic compounds.

Using isopropanol as the hydrogen donor to achieve by-product-free biological hydrogenation in water with carbonyl reductase

In this study, the reaction equilibrium was broken using isopropanol as a co-substrate, which was different from previous glucose as a co-substrate for furfural reduction, solving the problems of many by-products, low selectivity, and the addition of sodium phosphate buffers. The volatility of isopropanol and acetone prevented the production of by-products to the reaction system, improving the conversion and selectivity. 10 g/L furfural could be converted into furfuryl alcohol in pure water, and the furfural conversion was 90%, furfuryl alcohol selectivity was 100%, and the concentration of furfuryl alcohol could reach more than 20 g/L through accumulation reaction. No by-products were produced in this reaction system, and a single furfuryl alcohol product was obtained in the water catalytic system, which was convenient for downstream separation and purification. At the same time, based on the theory of the NADH coenzyme cycle system, this catalytic method could complete the conversion of various aldehydes into the corresponding alcohols, and it could be expanded to various biological hydrogenation projects, which has important industrial development and production prospects.

Acrylamide increases and furanoic compounds decrease in plant-based meat alternatives during pan-frying

Plant-based meat alternatives are gaining popularity as protein sources. However, pan-frying may lead to the formation of potentially harmful food contaminants. We investigated the formation of acrylamide and furanoic compounds in four different plant-based meat alternatives and two meat burger patties during pan-frying at 160 and 200 °C. The highest acrylamide contents (72. ± 7.7 and 69.2 ± 9.5 µg/kg, respectively) were found in soy flour- and sunflower-protein based patties fried at 200 °C. Unprepared pea and soy protein-based burger patties contained the highest furfural amounts (2832.8 ± 576.2 and 2683.0 ± 868.5 µg/kg, respectively). Furfuryl alcohol content was highest in soy flour-based patties and increased temperature-dependently up to 1120.9 ± 383.4 µg/kg. Based on the tolerable intake calculated by the EFSA Scientific Panel on Contaminants in the Food Chain, these amounts do not pose a health risk. Nevertheless, since plant-based novel food are being increasingly consumed, further investigations into the formation of food contaminants in novel processed foods are warranted.

Leachability of Fast-Growing Wood Impregnated with Low Concentrations of Furfuryl Alcohol

Furfurylation can effectively improve the quality of fast-growing wood, but its leachability is unclear. In this study, fast-growing poplar (Populus sp.) and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) were impregnated with low concentrations of 5%–20% furfuryl alcohol (FA), and the chemical and microscopic changes during leaching tests were analyzed by UV spectra and confocal laser scanning microscopy (CLSM). The results show that FA impregnation can regulate the weight percentage gain, but its effectiveness in regulating the cell wall bulking coefficient decreased as the impregnation concentration was increased. Impregnation with 15% and 20% FA showed no significant difference in the effect on volume swelling efficiency. The inverse relationship between the concentration of FA and the leaching rate was demonstrated by leaching tests, UV spectra, and CLSM. Notably, the leaching rate of poplar and Chinese fir wood was more than 30% when impregnated with 5% FA. Although the entirety of the furfuryl alcohol was deposited in the cell wall when impregnated with low concentrations of FA, the binding was not stable. The weight percentage gain of furfurylated Chinese fir was greater than that of poplar, but its leaching rate was lower, indicating that the cured furfuryl alcohol resin in poplar was not as stable as that in Chinese fir. Therefore, differences in tree species should be considered in low-concentration FA impregnation, as the improvement effect of concentrations below 10% on the properties of fast-growing wood is weak and the leaching rate of FA is significant.

The Influence of Impregnation Methods and Curing Conditions on the Physical and Multiscale Mechanical Properties of Furfurylated Bamboo

Furfurylation is an effective and green method for wood or bamboo modification that can significantly improve its physical and mechanical properties and the resistance against biological deterioration and the attack of subterranean termites. To elucidate the effect of furfurylation on the physical and multiscale mechanical properties of bamboo, the conditions of the furfurylation process were modified to cause an independent variation of the physical and multiscale mechanical properties in differently-treated bamboo samples. This was achieved by impregnating bamboo samples with solutions containing 15%, 30%, 50%, or 70% furfuryl alcohol (FA) by either of the two impregnation processes, vacuum pressure (V-P) and soaking (S) impregnation, while applying different curing conditions (wet- or dry-curing). The physical properties we measured included the absorption rate, weight percent gain (WPG), swelling efficiency (SE), and anti-swelling efficiency (ASE); the macro-mechanical properties involved the modulus of rupture (MOR), the modulus of elasticity (MOE), parallel-to-grain compressive strength (CS), and tensile strength (TS); the micro-mechanical properties included the tensile strength of bamboo’s vascular bundle and hardness and the indentation modulus of bamboo’s fiber cell walls. Finally, the correlation between the different physical and mechanical properties of the modified bamboo samples was analyzed. The results indicate that V-P impregnation made bamboo more permissible for the penetration of FA, while wet-curing was more conducive to ensuring a high curing rate. The dimensional stability of the bamboo samples treated with a high FA concentration through V-P impregnation and of those furfurylated by the S-Wet process using either medium or high FA concentrations was significantly increased. However, the dimensional stability of the bamboo samples modified with either low or medium FA concentrations decreased in both dry and wet curing. In terms of mechanical strength, furfurylation had little effect on the macro- and micro-mechanical properties of bamboo and was slightly improved in comparison to untreated samples. The results also showed a positive correlation between the macro- and micro-mechanical strength of the modified bamboo samples and a significant negative correlation between the mechanical strength and ASE. In soaking impregnation, the WPG and ASE were positively correlated, while the WPG and CS were negatively correlated. Interestingly, the correlation between the mechanical properties and ASE was not significant. Finally, both V-P-Wet and S-Wet approaches can be recommended for bamboo furfurylation, the former being time-saving and having a high curing rate in FA resin while significantly improving the moisture absorption and mechanical strength of bamboo. The advantage of the latter process is simplicity, a high utilization rate of FA, and a significant improvement in the dimensional stability of bamboo.

Effect of Furfurylation on Bamboo-Scrimber Composites

Bamboo is a material with excellent development prospects. It is increasingly used in furniture, decoration, building, and bridge construction. In this study, Furfurylated bamboo bundles and phenol-formaldehyde resin were used to make bamboo-scrimber composites (BSCs) via molding-recombination and hot-pressing processes. The effects of the impregnation mode, furfuryl-alcohol concentration, and curing temperature on the various physical-mechanical properties and durability of the composites were evaluated. Scanning-electron microscopy (SEM) was used to observe the microstructural differences. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were employed to investigate changes in the chemical constituents. The heat resistance was also investigated using thermogravimetric analysis. The results showed that the density of the furfurylated BSC increased by up to 22% compared with that of the BSC-C with the same paving mode. The furfurylated BSCs had lower moisture contents: the average moisture content of the furfurylated BSCs was 25~50% lower than that of the BSC-C. In addition, the furfurylated BSCs showed better dimensional stability and durability, since the decay-resistance grade of the BSCs was raised from decay resistance (class II) to strong decay resistance (class I). In terms of the mechanical properties, the furfurylation had a slight negative effect on the mechanical strength of the BSCs, and the modulus of rupture (MOR) and horizontal shear strength (HSS) of the BSCs were increased to a certain extent under most of the treatment conditions. In particular, the highest HSS for indoor use and MOR of the furfurylated BSCs increased by 21% and 9% compared with those of the untreated BSCs, respectively. The SEM results indicated that the FA resin effectively filled in the bamboo-cell cavities and vessels, and the modified bamboo-parenchyma cells were compressed more tightly and evenly. The FTIR and XPS spectroscopy showed that the hydroxyl group of carboxylic acid of the bamboo-cell-wall component reacted with that of the furan ring, and the cellulose and hemicellulose underwent acid hydrolysis to a certain extent after the furfurylation. Overall, the present study highlights the potential of furfurylation as a modification method to enhance BSC products. Further research should focus on improving the ability of furfurylated BSCs to prevent the growth of Botryodiplodia theobromae. Additionally, the influence of furfuryl-alcohol resin on the bonding strengths of PF adhesives should be further clarified.

Production of Molecular Iodine via a Redox Reaction between Iodate and Organic Compounds in Ice.

The abiotic mechanism of molecular iodine (I2) production from iodate (IO3-) remains largely unknown. Here, we demonstrate the production of I2 in the presence of IO3- and organic compounds in ice. When the solution containing IO3- (100 μM) and furfuryl alcohol (100 μM) at pH 3.0 was frozen at -20 °C, 13.1 μM of I2 was produced with complete degradation of furfuryl alcohol after 20 min. However, there was little change in the IO3- and furfuryl alcohol concentrations in water at 25 °C. The production of I2 in ice is due to the freeze concentration effect, which induces the accumulation of IO3-, furfuryl alcohol, and protons in the ice grain boundaries. This behavior facilitated the production of I2 via a redox reaction between IO3- and organic compounds. The production of I2 increased with increasing furfuryl alcohol concentration and decreasing pH. However, freezing temperature had a minor effect on the maximum production of I2. The production of I2 is highly dependent on the type of organic compounds. It was higher for organic compounds with higher electron-donating properties. This study suggests a new mechanism for I2 production, which is helpful for predicting precisely the atmospheric I2 budget in cold regions.

Production and characterisation of self-blowing lignin-based foams

Self-blowing lignin-furanic foams were produced using formulations comprising Kraft lignin and furfuryl alcohol as the major components. Diethyl ether, Tween 85 and sulphuric acid were used as blowing agent, surfactant and catalyst. The influence of the components and the ratio of furfuryl alcohol to lignin was investigated with regard to the foam density, mechanical properties, water absorption, thermal properties, and fire behaviour. Depending on the formulation, the density of lignin-furanic foams ranged between 60 and 320 kg m−3. Increasing the furfuryl alcohol content increased the density of the foams. Low-density foams were obtained with a higher proportion of diethyl ether. The compression strength and modulus of elasticity (MoE) of lignin-furanic foams also increased with foam density. All lignin-furanic foams showed good thermal stability and residual masses by thermogravimetric analysis. Cone calorimetric analysis showed that lignin-furanic foams have poor flammability and self-extinguish within few seconds.

Microstructural and Thermo-Mechanical Characterization of Furfurylated Douglas Fir.

Fast-growing wood has become a major source of materials for the wood industry in recent years, but defects have limited its use. Therefore, modification is urgently needed for the more efficient application of wood products. In this study, a 30 to 50% solution of furfuryl alcohol (FA) was impregnated into Douglas fir sapwood. The microstructure and thermal properties of the specimens before and after furfurylation were evaluated by different techniques. The weight percentage gain (WPG) of modified wood increased up to 22.97%, with the polymerized FA distributed in cell lumens and cell walls, as well as chemically bound to wood components. The polyfurfuryl alcohol (PFA) was mainly located in the tracheids, ray parenchyma cells, and resin canals. In addition, the furfurylated cell walls were greatly thickened. Raman spectra showed that modified wood had significant background fluorescence that covered other peaks. Differential Scanning Calorimetry analysis revealed that the cross-linking reaction between FA and wood changed the shape of curves, with no endothermic or exothermic peaks within the programmed temperature. Moreover, Thermogravimetry and Dynamic Mechanical Analysis results both confirmed that the furfurylation increased the thermal stability of Douglas fir. The percentage of the final mass loss of untreated specimen was 80.11%, while the highest one of furfurylated specimen was 78.15%, and it gradually decreased with increasing FA concentration. The storage modulus (E') and loss modulus (E″) of the furfurylated wood were both lower, and the damping factor (tan δ) was higher than the untreated one. When the temperature reaches about 75 °C, the untreated specimen began to soften and deform. At 90 °C, it fractured completely while the furfurylatedone remained stable. This study demonstrated that furfurylation can improve wood properties and elongate its service life.

Sound Insulation Performance of Furfuryl Alcohol-Modified Poplar Veneer Used in Functional Plywood.

Plywood has poor sound insulation due to its insufficient areal density, which cannot satisfy the demands of an indoor acoustic environment. This report proposed to use furfuryl alcohol to impregnate poplar veneer as a raw material for plywood and explored the sound insulation potential of furfuryl alcohol-modified poplar veneer. The effect of different formulations on the sound insulation performance of modified veneers was discussed, such as furfuryl alcohol concentrations, catalyst categories, and solvent categories. The weight percent gain (WPG) and areal density (AD) were used to evaluate the impregnation effectiveness of furfuryl alcohol modification. The sound insulation was measured by the impedance tube method. The results showed that the WPG of the furfuryl alcohol-modified veneers was evident, and the AD was effectively improved. Furthermore, the average sound insulation of furfuryl alcohol-modified poplar veneer was 25.68~40.10 dB, which increased by 10.8~19.1% compared with that of unmodified veneer. The modified veneer with 50% furfuryl alcohol concentration, taking isopropanol as a solvent, and maleic anhydride as a catalyst, had the optimal sound insulation performance. At the same time, the cell microstructure and chemical components were characterized by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) theory to explain the sound insulation mechanism further. The results showed that the distortion of cell walls was improved, suggesting a change in the mechanical properties of the cell wall. At the same time, more micropores formed since the filling of furfuryl alcohol resin, yielding a tortuous propagation pathway, so the sound insulation performance improved. Finally, it demonstrated the potential of furfuryl alcohol-modified poplar veneer as raw material to prepare plywood with excellent sound insulation.

Effect of Impregnation with a Low-Concentration Furfuryl Alcohol Aqueous Solution on Hygroscopic Properties of Chinese Fir and Poplar Wood

Furfurylation with a low concentration of furfuryl alcohol (FA) promotes the improvement of the properties and the effectiveness of FA on cell–wall action without darkening the furfurylated wood to the point that it affects its applications. In this paper, the effects of furfurylation on the hygroscopicity and water uptake dimensional stability of poplar (Populus sp.) and Chinese fir (Cunninghamia lanceolata) were analyzed. Meanwhile, the distribution of FA resin, the relationship between wood and water, the change in pore size distribution, and the weight percentage gain and cell wall bulking coefficient of wood were also investigated. The results were as follows: (1) A low concentration of FA could better enter the cell walls of the Chinese fir than the poplar, as FA resin was almost cured in the secondary walls, cell corners, and compound middle lamellae when a 10% concentration of FA was applied to the Chinese fir and poplar. When the FA concentration was increased to 30%, there were no significant increases in the amount of FA entering the cell walls and the amounts of FA cured in the cell lumen of the poplar were greater than those of the Chinese fir. Meanwhile, the modification of cell walls was more suitable in poplar than in Chinese fir. (2) The pointed ends of the pit chambers and the pit apertures (800–1000 nm) in the poplar and the small pores of the pit membranes and the pit apertures (1–6 μm) in the Chinese fir were partially deposited by the FA resin, which formed new pores in the size ranges of 80–600 nm and 15–100 nm, respectively. The porosity of the poplar was greater than that of the Chinese fir, and the bulk density of the poplar was less than that of the Chinese fir before and after modification. (3) Furfurylation with a low concentration of FA was able to better reduce the equilibrium moisture content, improve the anti-swelling efficiency, and enhance the dimensional stability of the poplar wood compared to the Chinese fir. Furfurylation effectively reduced water uptake due to the hydrophobic property of the FA resin. The water uptake of the Chinese fir increased by 17%–19% in second cyclic water soaking when treated with FA with various concentrations, which indicated the loss and leaching of FA resin during the test. Low-field NMR was used to demonstrate that the furfurylation not only reduced the amount of water but also affected the combination state of bound and free water with wood. Thus, furfurylation at a low concentration is a feasible method by which to extend applications of furfurylated wood.

Replacing liquid chromatography with tailored ion chromatography: A green method for detecting furfuryl alcohol and understanding its properties

Furfuryl alcohol (FFA) is a furan derivative potentially hazardous to human health, and it is now ubiquitously found in foods and used for identifying singlet oxygen (1O2) in environmental studies. However, current analytical methods for FFA in water are mostly based on gas chromatography and liquid chromatography (LC), which inevitably employ organic solvents as extractants or eluents that can result in harmful wastes production and extra treatment costs. To solve this issue, we herein developed a green analytical method to measure FFA without using organic solvents by a tailored ion chromatography (IC) equipped with ultraviolet (UV) detector. The method demonstrated a calibration curve fitting well (R2 > 0.99) for a wide FFA concentration range (i.e., 0.1 ∼ 10.0 mg/L) and a method detection limit (0.031 mg/L) comparable to LC method. The recoveries of FFA dosed into real samples exceeded 86.4% with the relative standard deviations below 2.5%. Next, we examined the property and reactivity of FFA through the method. It was found that FFA's acid-dissociation coefficient (i.e., pKa) was not 9.55, which disagrees with an earlier report. FFA was resistant to 254 nm UV or hydrogen peroxide (H2O2) but vulnerable to H2O2-assisted 254 nm UV or 185 nm vacuum UV, confirming that FFA was sensitive to hydroxyl radicals. Interestingly, FFA was degraded to less extent in water dosed with both sodium hypochlorite (NaOCl) and H2O2 than that dosed with NaOCl only, suggesting that the reaction between NaOCl and H2O2 does not produce 1O2. Given that this IC method can analyze FFA, NaOCl, and H2O2 simultaneously in one run, the evidences presented here may have helped clear a controversy about the 1O2 formation possibility by NaOCl and H2O2.

Nano-H-ZSM-5 with Short b-Axis Channels as a Highly Efficient Catalyst for the Synthesis of Ethyl Levulinate from Furfuryl Alcohol

For the ethanolysis of biomass-derived furfuryl alcohol (FA) to value-added ethyl levulinate (EL), the development of an efficient solid acid catalyst is very important for industrial application with high FA concentration. Herein, a H-ZSM-5 catalyst with nano b-axis channels (NB-H-ZSM-5) was synthesized and used for the conversion of FA. Detailed catalyst characterization proved that the NB-H-ZSM-5 catalysts (Si/Al = 25∼125) with ∼70 nm b-axis channels were successfully prepared. The NB-H-ZSM-5 catalyst with Si/Al = 75 showed the highest activity. Its structural characteristics allowed for fast diffusion of reactants and products and full utilization of active sites, which endowed it with higher activity compared to commercial H-ZSM-5 (C-H-ZSM-5). Its moderate acidity effectively inhibited the polymerization of FA even at a high FA concentration of 20 wt %. The spent catalyst was easily regenerated by coke burn-off to give a good recyclability. Furthermore, based on the proposed reaction network, a method of physically mixing the NB-H-ZSM-5 (75) catalyst with a small amount of Amberlyst-15 was proposed to further increase the EL yield from 64.7 to 82.1% at an FA concentration of 6 wt %.

The Distribution and Polymerization Mechanism of Polyfurfuryl Alcohol (PFA) with Lignin in Furfurylated Wood

There is increasing interest in furfurylated wood, but the polymerization mechanism between its internal polyfurfuryl alcohol (PFA) and lignin is still uncertain. This paper investigated the distribution of PFA and the feasibility of the polymerization of PFA with lignin in furfurylated balsa wood. The wood first immersed in the furfuryl alcohol (FA) solution followed by in situ polymerization and the distribution of PFA was characterized by Raman, fluorescence microscopy, SEM, and CLSM. Then, the mill wood lignin (MWL) of balsa wood and lignin model molecules were catalytically polymerized with PFA, respectively, studying the mechanism of interaction between PFA and lignin. It was concluded that PFA was mainly deposited in cell corner with high lignin concentration, and additionally partly deposited in wood cell cavity due to high concentration of FA and partial delignification. TGA, FTIR, and NMR analysis showed that the cross-linked network structure generated by the substitution of MWL aromatic ring free position by PFA hydroxymethyl enhanced the thermal stability. New chemical shifts were established between PFA and C5/C6 of lignin model A and C2/C6 of model B, respectively. The above results illustrated that lignin-CH2-PFA linkage was created between PFA and lignin in the wood cell wall.

Uncovering Insights to the Reaction Mechanism of the Electrochemical Hydrogenation and Hydrogenolysis of Furanic Species

Biomass derived compounds may be used as platform molecules for valorization to value-added products and biofuels. Two such molecules are furfural (FF) and 5-(hydroxymethyl)furfural (HMF). Using electricity as the energy source, FF and HMF can be upgraded by electrochemical hydrogenation and hydrogenolysis (ECH) reactions. The products of interest when FF is used as the starting molecule are the hydrogenation product, furfuryl alcohol (FA), a chemical intermediate, and the hydrogenolysis product, 2-methylfuran (MF), a biofuel. Similarly, HMF undergoes ECH to form 2,5-dihydroxymethylfuran (DHMF), a chemical intermediate, and 2,5-dimethylfuran (DMF), a biofuel. Existing studies probe the effect of electrode, electrolyte, applied potential, and temperature on reaction efficiency and selectivity, however fundamental questions remain about the reaction pathway and kinetics. This study elucidates the reaction pathway of FF and HMF to products through bulk electrolysis ECH.The ECH reactions were carried out via potentiostatic bulk electrolysis in an H-type cell with Cu flag working electrode in acidic electrolyte (0.5M H2SO4). By sampling the electrolyte at various times throughout the reaction, the product distribution with time for the ECH reactions was developed. The concentration of HMF and its products was determined by HPLC and the concentration of FF and its products was determined by GCMS. For 90 minutes of FF ECH, the concentration of both FA and MF increased steadily with reaction time; neither showed signs of further consumption. This observation indicates that FF ECH occurs over two separate, parallel paths to FA and MF. This is further evidenced by the lack of reaction to MF when FA is used as the starting molecule for ECH.

Dimensionally stable and highly durable bamboo material prepared through a simple surface furfurylation

Furfurylation has long been adopted for wood modification, and found to be effective for bamboo as well. However, traditional full impregnation furfurylation would reduce the dimensional stability of bamboo although its biological durability was improved. Here, we found surface modification with furfuryl alcohol (surface furfurylation) was particularly suitable for bamboo, which is extremely hard to be treated due to its low transverse mass transportation. To optimize the surface furfurylation process for bamboo, an orthogonal experiment was designed with several key physical and mechanical properties tested, including weight percent gain (WPG), equilibrium moisture content (EMC), anti-swelling efficiency (ASE), modulus of rupture (MOR), modulus of elasticity (MOE). Using this process, dimensionally stable (ASE could reach as high as 50% by volume) and highly biological durable (strong resistance against mould, decay and termite) bamboo material with low consumption of furfuryl alcohol (FA) (average WPG lower than 15%) were prepared avoiding significant reduction in mechanical properties. Furthermore, a parameter combination of 70% FA concentration, 105 ℃ curing temperature, and 5 h curing time was proposed as an optimized process for pilot-scale production based on orthogonal experiments and range analysis.

Preparing highly durable bamboo materials via bulk furfurylation

Bamboo is an important sustainable material for construction industry due to its combined advantages of easy availability, fast renewability, and excellent mechanical performance. However, its low biological durability and poor treatability limit its use for structural and outdoor building material. In this study, highly durable bamboo materials were prepared through a facile modification process called bulk furfurylation for the first time. The modified bamboo was found to be highly mold resistant and exhibited strong resistance to decay fungi and termites with a furfuryl alcohol (FA) weight percentage gain (WPG) as low as 10%. A strong positive correlation was detected between WPG and termite resistance, but not for mold or decay resistance. The mechanical properties of the furfurylated bamboo were moderately enhanced at low FA concentrations and were much less affected by curing temperature and time. Based on these results, it is concluded the furfurylated bamboo would have wide application in construction.

One-pot biosynthesis of furfuryl alcohol and lactic acid via a glucose coupled biphasic system using single Bacillus coagulans NL01

Furfuryl alcohol is an important reduction product from biomass derived furfural. This study developed one-pot biosynthesis of furfuryl alcohol and lactic acid by a glucose coupled biphasic system using single Bacillus coagulans NL01. Water/dioctyl phthalate is chosen as biphasic system to alleviate the toxicity of furfural and furfuryl alcohol. Under the optimal conditions, the high-concentration conversion (208 mM) of furfural was successfully converted in 6 h reaction with 98% furfural conversion and 88% furfuryl alcohol selectivity. Notably, glucose as co-substrate could be effectively converted to lactic acid in this biphasic system. About 264 mM furfuryl alcohol and 64.2 g/L lactic acid were simultaneously produced from 310 mM furfural and 71.3 g/L glucose within 8.5 h by a fed-batch strategy. The developed approach can not only increase the produced furfuryl alcohol concentration but also reduce the cost of overall approach by lactic acid co-production, indicating its potential for industrial applications.

Fully Automated Identification of Coffee Species and Simultaneous Quantification of Furfuryl Alcohol Using NMR Spectroscopy.

Coffee is a popular beverage with two species, Coffea canephora and C. arabica, being commercially exploited. The quality and commercial value of coffee is dependent on species and processing. C. arabica typically obtains a higher price on the market compared to C. canephora. Coffee beans undergo roasting during processing, resulting in the formation of flavor compounds including furfuryl alcohol which has been classified by the International Agency for Research on Cancer as possibly carcinogenic to humans (Group 2B). The aim of this study was to identify coffee species and other properties using nuclear magnetic resonance (NMR) spectroscopy, specifically to conduct quantification of the roasting process contaminant furfuryl alcohol. The quantification of furfuryl alcohol was performed from the NMR spectra using the pulse length-based concentration (PULCON) methodology. Prior to NMR analysis, samples were extracted using deuterated chloroform. Roasting experiments identified the maximum roasting temperature to be the most significant factor in the formation of furfuryl alcohol. Among the coffee species, C. canephora was found to contain a relatively lower amount of furfuryl alcohol compared to C. arabica. The roasting of wet processed coffee resulted in higher contents of furfuryl alcohol. Geographical origin and variety within species had no influence on the furfuryl alcohol content. Validation results show that NMR spectroscopy is fit-for-purpose to obtain targeted information of coffee samples. The PULCON NMR methodology allows a simple, rapid and accurate determination of constituents of coffee.

Freezing-enhanced non-radical oxidation of organic pollutants by peroxymonosulfate

This study presents a freezing method for accelerating the peroxymonosulfate (PMS)-mediated degradation process. The degradation of furfuryl alcohol (FFA) in the presence of PMS was markedly accelerated by freezing. The degradation efficiency of FFA was only 10.4% in aqueous solution at 25 °C, but 100% degradation was achieved in frozen solution at −20 °C after 3 h of reaction at [FFA] = 20 µM and [PMS] = 100 µM. This accelerated PMS-mediated degradation of FFA in the frozen solution is due to the concentration of both PMS and FFA in ice grain boundaries, which increases the collision frequency between PMS and FFA thereby facilitating redox transformation. The mapping images of PMS and FFA in the frozen sample obtained using confocal Raman microscopy provide clear evidence of the accumulation of PMS and FFA in the ice grain boundaries after freezing. The experimental results with sulfate radical (SO4−) scavengers, no production of hydroxyl radicals (OH) and SO4−, and the highly pollutant-dependent degradation efficiency suggest that the PMS-mediated degradation in frozen solution primarily proceeds through the direct electron transfer from organic pollutants to PMS (non-radical mechanism) rather than the reaction of SO4− or OH with organic pollutants (radical mechanism). The degradation efficiency of the PMS/freezing system was similar across the pH range of 3–10. In addition, the PMS/freezing system worked efficiently in the temperature range of −10 to −35 °C. This result implies that the PMS/freezing system can be operated without external energy in cold regions.