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For the last two decades, the aromatic aldehyde 5‐hydroxymethyl‐furfural (5‐HMF) has been the subject of several investigations for its pharmacologic potential. In 2004, the Safo group reported that 5‐HMF has potent antisickling activity by targeting and ameliorating the primary pathophysiology of hypoxia‐induced sickling of erythrocytes (red blood cells [RBC]). Following the encouraging outcome of the preclinical and phase I/II clinical studies of 5‐HMF for the treatment of sickle cell disease (SCD), there have been multiple studies suggesting 5‐HMF has several other biological or pharmacologic activities, including anti‐allergic, antioxidant, anti‐hypoxic, anti‐ischemic, cognitive improvement, anti‐tyrosinase, anti‐proliferation, cytoprotective, and anti‐inflammatory activities. The wide range of its effects makes 5‐HMF a potential candidate for treating a variety of diseases including cognitive disorders, gout, allergic disorders, anemia, hypoxia, cancers, ischemia, hemorrhagic shock, liver fibrosis, and oxidative injury. Several of these therapeutic claims are currently under investigation and, while promising, vary in terms of the strength of their evidence. This review presents the research regarding the therapeutic potential of 5‐HMF in addition to its sources, physicochemical properties, safety, absorption, distribution, metabolism, and excretion (ADME) profiles. [ABSTRACT FROM AUTHOR]

Two samples, simple-battered chicken (SBC) and normal-battered chicken (NBC), with different batters were deep-fat fried at various conditions and volatile compounds and 5-hydroxymethylfurfural (5-HMF) was analysed. The moisture content of the air-fried samples was significantly higher than that of the deep-fat fried samples in the same batter samples. A total of 72 volatile compounds (8 aldehydes, 15 monoterpenes, 12 sesquiterpenes, 2 terpene alcohols, 4 benzenes, 13 pyrazines, 2 pyridines, 6 furans, 5 alcohols, 2 pyrroles, and 3 others) were detected in fried chicken breast, and air-fried SBC possessed the highest total amount of volatile compounds. Furthermore, 5-HMF was exclusively detected in NBC samples; in particular, 1.27 ± 0.06 and 0.41 ± 0.02 μg/mL were detected in deep- and air-fried NBC, respectively. This study indicates the potential of air frying to reduce the formation of 5-HMF while maintaining quality characteristics, suggesting the need for further study on other hazardous compounds. [ABSTRACT FROM AUTHOR]

The purpose of this experiment was to study the acute toxic effect of 5-hydroxymethylfurfural (5-HMF) on Kunming mice and to evaluate the toxic response characteristics, target organs and doseresponse relationship of the product in Kunming mice. Eighty SPF male Kunming mice were randomly divided into 8 groups with 10 mice in each group. After a week of adaptive feeding, 8 different doses of 5-HMF solution were given by oral administration. The results showed that after intragastric administration, Kunming mice developed dyspnea, shortness of breath, huddling, squinting, hair erection and death, and the frequency decreased with the decrease of dose. In terms of body weight, compared with the control group, the drug had no significant effect on body weight. The acute toxicity LD50 of Kunming mice was 3 152.800 mg/kg calculated by modified Kirschner method. Histopathological examination of surviving animals showed that the toxic target organ of 5-HFM was kidney and inflammatory cell infiltration was found in the interstitium adjacent to the interlobular vein. According to the grading standard of WHO oral exogenous toxicants, 5-HMF is of low toxicity. [ABSTRACT FROM AUTHOR]

The renewable 5‐hydroxymethylfurfural (5‐HMF) has gained a wide interest from the chemistry community as a valuable biobased platform opening the way to many applications. Despite an impressive number of publications reporting either its preparation or its functionalization, its direct use in fine chemistry, and especially in multi‐component reaction (MCR), is less reported. Here, we report a complete study of the use of 5‐HMF in the Hantzsch dihydropyridines synthesis. The strategy was applied to a scope of β‐dicarbonyl molecules (including β‐ketoesters and 1,3‐diketones) in a 3‐component procedure leading to a series of symmetrical 1,4‐dihydropyridines derived from 5‐HMF in excellent yields. The study was extended to the 4‐component protocol using one equivalent of a β‐ketoester and one equivalent of 5,5‐dimethyl‐1,3‐cyclohexanedione (dimedone), which efficiently provided the corresponding unsymmetrical dihydropyridines. [ABSTRACT FROM AUTHOR]

Sulfonated carbon catalysts exhibit superior catalytic performance for production of biobased chemicals, but the catalyst preparation approaches are still suffered from high corrosion and possible pollution risks. In this paper, lignin extracted from corn stover was used to prepare lignin-based activated carbon, which was then subjected to grafting modification by sulfur dioxide nonthermal plasma method to construct a novel lignin-derived solid acid catalyst (LP-LDSA). The catalytic performances of LP-LDSA were further determined by dehydration of fructose to produce 5-HMF in a biphasic solvent system composed by dimethyl sulfoxide (DMSO) and water. Under the optimal conditions, the 5-HMF yield and reaction selectivity were 88.9% and 89.4%, respectively. This LP-LDSA catalyst also exhibited excellent stability and reusability in five sequential reaction batches. This method has advantages of shorter solid acid preparation duration, lower energy consumption, and higher catalytic stability, presenting an innovative and green method for sulfonation production of solid acid catalyst. [ABSTRACT FROM AUTHOR]

The current work demonstrates the fabrication of cerium-aluminum oxide (CAO) catalysts for the dehydration of fructose to the platform chemical 5-hydroxymethylfurfural (5-HMF). CAO materials with varying chemical compositions and textural properties were obtained through calcination at different temperatures. The fructose conversion and yield of 5-HMF of the catalysts were determined in a dimethyl sulfoxide system. The CAO catalysts were thoroughly characterized, and their catalytic performances evaluated to uncover the origins of their fructose conversion efficiency and product selectivity. The CAO catalyst obtained by calcination at 500 °C (CAO-500) registered remarkably high fructose conversions (~ 95%) and 5-HMF yields (~ 91%) with no side product generation which means that under the optimal process conditions (120 °C, 120 min) determined in the study, the catalyst produces 5-HMF almost exclusively. The exceptional catalytic performance of CAO-500 was intimately linked to the physical and chemical synergies emerging from the co-existence of crystalline (CeO2) and amorphous (Al(OH)3) components in its matrix resulting from the calcination process. This unique composition makes CAO-500 structurally robust and with the necessary abundance of Lewis and Bronsted acid sites that facilitate highly selective fructose conversion to 5-HMF. [ABSTRACT FROM AUTHOR]

Reductive amination of biomass aldehydes is a vital process to synthesize chemical intermediates primary amine, but the selectivity is severely compromised by the self‐condensation of highly reactive imine intermediates. Herein, we proposed a solution by manipulating the adsorption configuration of secondary imine via defect engineering. Specifically, a gradient reduction strategy was used to adjust the driving force of NiCo alloy crystallization, thus motivating the formation of metal vacancy clusters. The primary amine selectivity was raised from 70.9% to 95.1% with defect concentration increased from 36.1% to 42.5% on catalysts. In situ fourier transform infrared spectroscopy (FTIR) and density functional theory demonstrated metal vacancy clusters induced remarkable NiCo electron transfer, which strengthened electronic coupling between secondary imine with catalyst, resulting in a flat configuration that was conducive to CN bond breakage to guarantee smooth conversion into primary amines. This catalyst exhibited potential real‐life application prospects for its low cost, universality in reductive amination of various aldehydes, and long‐life reusability. [ABSTRACT FROM AUTHOR]

In this era of industrial revolution and diminishing petroleum reserves, alternative options (woody biomass) for building next-generation fuels need to be critically explored. Here, process engineering aspects of 5-hydroxymethylfurfural (5-HMF) from Bambusa bamboo in ionic liquid ([Bmim]Cl) in the presence of a catalyst, CrCl3, in batch reactor have been explored in great detail. 5-HMF upon hydrogenation liberates 2,5-dimethylfuran (DMF), which is a liquid fuel. To maximize the production of platform chemical-5-HMF, effects of different mixing speeds (150–1200 rpm) and temperatures (120–160 °C) were captured on the yield of 5-HMF and glucose. A highest 5-HMF yield (25%) was obtained at 120 °C and 1200 rpm within a reaction time of 6 h. Moreover, a kinetic analysis of transformation of biomass into 5-HMF was carried out using curve fitting to estimate kinetic constants k1, k2, and k3. Mixing at asymptotic limits, i.e., no mixing (0 rpm) and very high mixing (1200 rpm), enables us to devise mixing regimes: 0–400 rpm, mass transfer–limited regime; 400–1100 rpm, intermediate regime; and > 1100 rpm, reaction-limited regime. Thus, tremendous improvement in reaction rate constants (k1, k2, k3) was observed when operated at higher mixing conditions (reaction-limited regime). Mixing limitation for this IL-based system can be eliminated by operating the reactor above 800 rpm, whereas lower temperature restricts conversion of 5-HMF to LA and FA. Hence, higher mixing speeds, i.e., > 1100 rpm, and lower temperature, i.e., ≈ 120 °C, can be suggested as the optimum operating conditions for maximization of platform chemical-5-HMF in the catalytic conversion of Bambusa bamboo in batch reactor. [ABSTRACT FROM AUTHOR]

5‐hydroxymethylfurfural (5‐HMF) has been considered as an important biomass‐based platform chemical for its wide applications. Currently, the production of 5‐HMF from the catalytic dehydration of glucose is preferred, in which the Brønsted and Lewis acids in catalysts play an important role. Here, it was found that MIL‐53(Al) modified with tin was an active, selective, and reusable catalyst for the transformation of glucose to 5‐HMF in dimethyl sulfoxide (DMSO) solvent. Around 42.3% yield of 5‐HMF with 93% glucose conversion was achieved, when the prepared metal‐organic frameworks (MOFs) was used as the catalyst, showing superior catalytic performance compared with most of other MOFs. Moreover, the catalyst possessed inert catalytic properties in water with almost no any influence on the conversion of glucose, suggesting a compelling opportunity to act as a support material. [ABSTRACT FROM AUTHOR]

2,5‐Bis(propoxymethyl)furan (BPMF) is a potential biofuel candidate but it is difficult to synthesize it selectively. The Lewis acid sites and Brønsted acid sites of the catalyst play a key role BPMF's selectivity. In the present work, the effect of tunable acidic properties such as the Lewis and Brønsted acidity of Sn‐Hβ and Sn‐dAlβ (Sn in dealuminated Hβ) catalysts on the selectivity of BPMF was studied by carrying out one‐pot reductive etherification of 5‐hydroxymethylfurfural (5‐HMF) using 2‐propanol as a hydrogen donor. The catalysts that were prepared underwent analysis using techniques such as temperature‐programmed desorption of ammonia (NH3‐TPD), powder X‐ray diffraction, transmission electron microscopy, pyridine‐IR spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurement, and Fourier transform infrared spectroscopy. Under the optimized reaction conditions, which included a temperature of 150 °C, a catalyst loading of 0.25 g, a reaction time of 4 h, and a concentration of 1 g of 5‐HMF, impressive results were obtained: 93.57% conversion of 5‐HMF and 98.54% selectivity towards BPMF. It was observed that the catalysts remained active for up to five cycles and slight/moderate change was observed in the conversion of 5‐HMF, while the selectivity of BPMF remained intact. [ABSTRACT FROM AUTHOR]

5-Hydroxymethylfurfural (HMF), a leading platform combination for altering biomass to diverse biomass-derived chemicals and biofuels, has been engrossed in spacious consideration. In this perusal, a new catalyst modified with sulfonic acid and -Cl functional group UiO-66-SO3H-Cl was first used as an efficiently heterogeneous catalyst with the overlapping effect of three functional groups of Lewis acid, Brønsted acid and -Cl group binding site was synthesized to convert glucose to HMF. The Lewis acid site is responsible for the isomerization of glucose to fructose, and the dehydration of fructose to HMF is the responsibility of the Brønsted acid site. The -Cl group facilitates the hydrolysis of glucose by forming a hydrogen bond with glucose and reducing the activation energy, thus increasing the production rate of HMF. The synthesized catalysts were analyzed using XRD, FT-IR, FE-SEM, EDS, and XPS. The amount of Zr, Cl, and S elements reported in the newly synthesized catalyst in this research by EDS is 37.44%, 1.01%, and 6.8%, respectively. The existence of C 1s (284.8 eV), O 1s (531.9 eV), Cl 2p (200.4 eV), Zr 3d (185.2 eV), and S 2p (168.4 eV) of UiO-66-SO3H-Cl was confirmed by conducting XPS analysis. The reaction range of 5-HMF produced from glucose by each of UiO-66, UiO-66-SO3H, and UiO-66-SO3H-Cl catalysts, was 10%, 23% and 74%, respectively, as determined by UV-Vis analysis was decided the results show that the UiO-66-SO3H-Cl catalyst with three functional groups synergistically increases the production of HMF from glucose. Conversion of glucose to HMF by UiO-66-SO3H-Cl multifunctional solid catalyst: Lewis acid (Zr cation) and Brønsted acid (SO3H group) are active sites for isomerizing glucose to fructose and dehydration of fructose to HMF, respectively. The -Cl group forms a hydrogen bond with glucose, increasing the production rate of HMF. [ABSTRACT FROM AUTHOR]

5-Hydroxymethfurural (5-HMF) is naturally found in a variety of foods and beverages and represents a main inhibitor in the lignocellulosic hydrolysates used for fermentation. This study investigated the impact of 5-HMF on the genomic stability and phenotypic plasticity of the yeast Saccharomyces cerevisiae. Using next-generation sequencing technology, we examined the genomic alterations of diploid S. cerevisiae isolates that were subcultured on a medium containing 1.2 g/L 5-HMF. We found that in 5-HMF-treated cells, the rates of chromosome aneuploidy, large deletions/duplications, and loss of heterozygosity were elevated compared with that in untreated cells. 5-HMF exposure had a mild impact on the rate of point mutations but altered the mutation spectrum. Contrary to what was observed in untreated cells, more monosomy than trisomy occurred in 5-HMF-treated cells. The aneuploidy mutant with monosomic chromosome IX was more resistant to 5-HMF than the diploid parent strain because of the enhanced activity of alcohol dehydrogenase. Finally, we found that overexpression of ADH6 and ZWF1 effectively stabilized the yeast genome under 5-HMF stress. Our findings not only elucidated the global effect of 5-HMF on the genomic integrity of yeast but also provided novel insights into how chromosomal instability drives the environmental adaptability of eukaryotic cells. [ABSTRACT FROM AUTHOR]

In this study, which incorporates many principles of green chemistry (use of renewable feedstocks, catalysis, improvement of energy efficiency, and harmless solvents and auxiliaries), the single-phase catalytic conversion of cellulose to 5-HMF in over silica-alumina catalysts was investigated. A series of dual-template silica-alumina catalysts with CTAB as the main template and F127 or triethylamine (TEA) as the co-template were synthesized at a low temperature of 60 °C and characterized by XRD, N2 adsorption-desorption technique, FT-IR and pyridine adsorption FT-IR. The surface area is increased by using the second template in silica-alumina catalyst. In addition, the acidity of the surface was changed by using the second template. The cellulose conversion and yield of 5-HMF increased from 36% to 52% and from 3.13% to 4.24%, respectively, due to the properties gained by using the second template. 52% cellulose conversion and 8.13% selectivity of 5-HMF were obtained in aqueous medium, 220 °C and 6 h reaction time with the catalyst using TEA as co-template. Eco-friendly silica catalysts synthesized at low temperatures with a dual template can be considered as a potential alternative for the conversion of cellulose into value-added biobased products. [ABSTRACT FROM AUTHOR]

Most adhesives used in the wood-based panel (WBP) industry are petroleum-based and are associated with environmental impact and price fluctuations. Furthermore, most have potential adverse health impacts, such as formaldehyde emissions. This has led to interest from the WBP industry in developing adhesives with bio-based and/or non-hazardous components. This research focuses on the replacement of phenol-formaldehyde resins by Kraft lignin for phenol substitution and 5-hydroxymethylfurfural (5-HMF) for formaldehyde substitution. Resin development and optimization was carried out regarding varying parameters such as molar ratio, temperature or pH. The adhesive properties were analyzed using a rheometer, gel timer and a differential scanning calorimeter (DSC). The bonding performances were evaluated using an Automated Bonding Evaluation System (ABES). Particleboards were produced using a hot press, and their internal bond strength (IB) was evaluated according to SN EN 319. Hardening of the adhesive could be achieved at low temperatures by increasing or decreasing the pH. The most promising results were obtained at pH 13.7. The adhesive performances were improved by adding filler and extender (up to 28.6% based on dry resin) and several boards were produced reaching P1 requirements. A particleboard achieved a mean IB of 0.29 N/mm2, almost reaching almost P2 requirements. However, adhesive reactivity and strength must be improved for industrial use. [ABSTRACT FROM AUTHOR]

In this work, the microwave-assisted reaction of 5-hydroxymethylfurfural (5-HMF) into valuable ether and acylated production formation was investigated with the help of molybdophosphoric acid encapsulated dendritic fibrous silica (KCC-1) as a catalyst. XRD, N2 adsorption-desorption, SEM, FT-IR, NH3-TPD, and TEM were used to analyze the physicochemical and structural properties of the synthesized catalysts. The microwave etherification of 5-HMF with ethanol was tested using synthesized catalysts. The effects of the reaction temperature, reaction time, catalytic amount, and microwave power were investigated. The resulting MPA-KCC-1 and IMPA-KCC-1 catalysts demonstrated excellent activity for the etherification of 5-HMF with ethanol, producing 5-(hydroxymethyl) furfural diethyl acetal (HMFDEA) and 5-(ethoxymethyl)furfural diethyl acetal (EMFDEA) products selectively. The significant advantages of the work are the selective production of EMFDEA at 82%, the catalyst can be easily removed via filtration, and the catalyst activity remains nearly intact even after five reaction cycles. [ABSTRACT FROM AUTHOR]

Research background. The processing method generally affects the toxicity and biological activity of aged sorghum vinegar. This study investigates the changes in the intermediate Maillard reaction products of sorghum vinegar during ageing and the in vivo hepatoprotective effects of pure melanoidin obtained from it. Experimental approach. High-performance liquid chromatography (HPLC) and fluorescence spectrophotometry were utilized to quantify intermediate Maillard reaction products. The CCl4-induced liver damage in rats was used to evaluate the protective role of pure melanoidin in rat liver. Results and conclusions. Compared with the initial concentration, the 18-month ageing process caused a 1.2- to 3.3-fold increase in the concentrations of intermediate Maillard reaction products, i.e. 5-hydroxymethylfurfural (HMF), 5-methylfurfural (MF), methyglyoxal (MGO), glyoxal (GO) and advanced glycation end products (AGEs). The concentrations of HMF in the aged sorghum vinegar were 6.1-fold higher than the 450 μM limit standard for honey, implying the need for shortening the ageing of the vinegar in practice for safety concerns. Pure melanoidin (Mr>3.5 kDa) demonstrated significant protective effects against CCl4-induced rat liver damage, as evidenced by normalized serum biochemical parameters (transaminases and total bilirubin), suppressing hepatic lipid peroxidation and reactive oxygen species, as well as increasing glutathione amount and restoring antioxidant enzyme activities. Histopathological analysis revealed that melanoidin in vinegar reduced cell infiltration and vacuolar hepatocyte necrosis in rat liver. The findings demonstrated that a shortened ageing process should be considered in practice to ensure the safety of aged sorghum vinegar. Vinegar melanoidin is a potential alternative for the prevention of hepatic oxidative damage. Novelty and scientific contribution. This study demonstrates that the manufacturing process had a profound influence on the generation of vinegar intermediate Maillard reaction products. In particular, it revealed the in vivo hepatoprotective effect of pure melanoidin from aged sorghum vinegar, and provides insight into the in vivo biological activity of melanoidin.

The use of the renewable platform molecule 5‐hydroxymethylfurfural (5‐HMF) in multi‐component reaction with a diamine and an alkynone to generate seven‐membered 1,5‐benzodiazepines is described. Due to the sensitivity of 5‐HMF to strong acidic and basic conditions, the investigation required an in‐depth revisit of reaction parameters as compared to benchmark aldehydes. Among catalysts/solvents couples, ammonium acetate in ethanol proved to be a clean and efficient system. These optimized conditions were subsequently used to investigate the scope of the reaction providing a library of 1,5‐benzodiazepines in moderate to good yields from a wide range of diversely substituted diamines and alkynones or alkyl alkynoates. [ABSTRACT FROM AUTHOR]

Kinetic model is an important approach for quantitative expression of the mechanism of polysaccharide degradation to value-added products. This study conducted a mechanistic kinetic comparison for acidic degradation of terrestrial biomass-derived cellulose and marine algae-derived agarose to monosaccharides and 5-hydroxymethylfurfural (5-HMF). A pseudo-homogeneous first-order reaction kinetic model with Arrhenius-type temperature dependence was applied to interpret acidic degradation process of cellulose and agarose. The subsequent sensitivity analysis of the impact of rate constants on the production of monosaccharides and 5-HMF predicted in the kinetic model was performed. Results showed that rate constant of polysaccharide hydrolysis (k1) exceeded rate constants of monosaccharide dehydration (k2) and 5-HMF degradation (k3) during agarose decomposition process, but was opposite in cellulose depolymerization process. The corresponding activation energy of agarose hydrolysis (64.5 kJ mol−1) was much lower than that of cellulose hydrolysis (121.4 kJ mol−1). Agarose was demonstrated to be superior to cellulose for producing monosaccharides and 5-HMF. The desired yields of monosaccharides and 5-HMF from agarose were obtained 58.5% and 27.5%, respectively. Subsequent sensitivity analysis revealed that rate constants k1 and k3 were the key factors controlling production of monosaccharides and 5-HMF from agarose, respectively. [ABSTRACT FROM AUTHOR]

The potential benefits of microwave irradiation for fructose dehydration into 5 hydroxymethylfurfural (5-HMF) have been quantified over a sulfonated metal–organic framework (MOF), MIL 101(Cr)-SO3H. The effects of temperature (140–170 °C), batch time (5–300 min), and catalyst-to-substrate ratio (0.1–0.01 g/g) were systematically mapped. After 10 min of microwave (MW) irradiation at 140 °C in a DMSO–acetone reaction medium, practically complete fructose conversion was obtained with a 70% yield of 5-HMF. Without MW, i.e., using conventional heating (CH) at the same conditions, the fructose conversion was limited to 13% without any 5-HMF yield. Rather, 90 min of CH was required to reach a similarly high conversion and yield. The profound impact of moving from CH towards MW conditions on the reaction kinetics, also denoted as the microwave effect, has been quantified through kinetic modeling via a change in the Gibbs free energy of the transition state. The modeling results revealed an eight-fold rate coefficient enhancement for fructose dehydration owing to MW irradiation, while the temperature dependence of the various reaction steps almost completely disappeared in the investigated range of operating conditions. [ABSTRACT FROM AUTHOR]

Acclimatization to hypoxia or high altitude involves physiological adaptation processes, to influence oxygen (O2) transport and utilization. Several natural products, including aromatic aldehydes and isothiocyanates stabilize the R-state of hemoglobin (Hb), increasing Hb-O2 affinity and Hb-O2 saturation. These products are a counter intuitive therapeutic strategy to increase O2 delivery during hypoxia. 5-Hydroxymethylfurfural (5-HMF) is well known Amadori compound formed during the Maillard reaction (the non-enzymatic browning and caramelization of carbohydrate-containing foods after thermal treatment), with well documented effects in Hb-O2 affinity. This study explores the therapeutic potential of 5-HMF on left ventricular (LV) cardiac function (LVCF) during hypoxia. Anesthetized Golden Syrian hamsters received 5-HMF i.v., at 100 mg/kg and were subjected to stepwise increased hypoxia (15, 10, and 5%) every 30 min. LVCF was assessed using a closed chest method with a miniaturized conductance catheter via continuous LV pressure-volume (PV) measurements. Heart hypoxic areas were studied using pimonidazole staining. 5-HMF improved cardiac indices, including stroke volume (SV), cardiac output (CO), ejection fraction (EF), and stroke work (SW) compared to the vehicle group. At 5% O2, SV, CO, EF, and SW were increased by 53, 42, 33, and 51% with 5-HMF relative to vehicle. Heart chronotropic activity was not statistically changed, suggesting that differences in LV-CF during hypoxia by 5-HMF were driven by volume dependent effects. Analysis of coronary blood flow and cardiac muscle metabolism suggest no direct pharmacological effects from 5-HMF, therefore these results can be attributed to 5-HMF-dependent increase in Hb-O2 affinity. These studies establish that naturally occurring aromatic aldehydes, such as 5-HMF, produce modification of hemoglobin oxygen affinity with promising therapeutic potential to increase O2 delivery during hypoxic hypoxia.

Ziziphus jujuba cv. Goutouzao (GTZ) was pretreated by macerating with phenolic additives (green tea powder, tea polyphenols, EGCG and pomegranate peel ellagic acid) before the blackening process to improve the functional quality. The antioxidant capacity and physicochemical properties during the process of different treatment groups were evaluated by high-performance liquid chromatography (HPLC) and spectrophotometric assays. The results showed that the total phenolic content and antioxidant capacity were higher with each tested additive than the blank control group. Among them, the EGCG group had the highest total phenolic content and the strongest antioxidant capacity, whereby the total phenolic content of the blackened jujube was 24.59 times higher than the control group at the end of blackening (84 h). The scavenging of DPPH radicals, scavenging of ABTS radicals and total reducing capacity were 26.36, 5.51 and 4.58 times higher than those of the control group, respectively. The 5-hydroxymethylfurfural (5-HMF) content of blackened jujube in the EGCG and tea polyphenol groups was significantly reduced, and was 72.36 and 36.47% lower than the control group at the end of blackening, respectively. The green tea powder, EGCG and ellagic acid groups had the highest cyclic adenosine monophosphate (cAMP) content at the end of blackening, which was 50, 70 and 87% higher than in the control group, respectively. Correlation analysis showed a highly significant negative correlation between total phenolic content and 5-HMF content (p < 0.01). The heatmap showed that the EGCG-macerated blackened jujube had the best comprehensive medicinal profile, with low 5-HMF, high residual cAMP, and increases total phenolic content, resulting in high antioxidant activity. [ABSTRACT FROM AUTHOR]

Catalysts are very important in the use of cellulose, the main component of biomass, as a raw material for the large-scale production of liquid fuels and chemicals. 5-Hydroxymethylfurfural (HMF) is an extremely important intermediate in the fine chemical industry. HMF can be synthesized by acid-catalyzed dehydration of fructose, glucose, cellulose, or sucrose. The conversion of cellulose to HMF is challenging due to its chemical structure. The objective of the present study was to devise a more facile synthesis method using transition metal-doped montmorillonite catalysts (10Cr-Mnt, 10Cu-Mnt, 10Fe-Mnt, and 10Zn-Mnt) by wet impregnation. Samples were characterized by X-ray powder diffraction, specific surface area, and NH3-TPD analyses. The synthesized catalysts were used for the conversion of cellulose to 5-HMF in an aqueous medium. Among the metals studied, Cr showed the greatest catalytic activity. With the use of this catalyst, efficient conversion of cellulose to 5-HMF was achieved, affording a conversion yield of 93.47% and 5-HMF yield of 9.07% within 6 h at 200°C. The study described here could be useful for the efficient conversion of cellulose into 5-HMF, as well as into other biomass-derived chemicals. [ABSTRACT FROM AUTHOR]

Hydrogenation of aldehydes with heterogeneous manganese catalysts is an appealing approach for producing alcohols. In this paper, we report a novel and robust MnO/PN-800 catalyst for the hydrogenation of versatile biomass-derived platform molecules in the presence of molecular hydrogen as a reductant. The effect of catalyst concentration, the operating hydrogen pressure, and the reaction temperature on the catalyst activity was investigated in detail. Under the mild reaction conditions, the full conversion of furfuraldehyde, 5-Methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde (5-HMF) to their corresponding alcohols was achieved without any by-product formation. Additionally, other aromatic aldehydes bearing fluoro, chloro, and nitro moieties were also tolerated. The fresh and spent MnO/PN-800 catalyst was thoroughly characterized using XPS, powder-XRD, HR-TEM, N 2 adsorption-desorption, and Raman spectroscopy. Noteworthy, the MnO/PN-800 catalyst can be recovered by centrifugation and then reused directly in the subsequent hydrogenation reactions. Importantly the synthetic utility of this protocol up to ∼5 g-scale is realized. Finally, our novel MnO/PN-800 nanocatalyst was successfully employed for the direct synthesis of furfuryl alcohol in high yields from raw sugarcane bagasse. We believe that these findings will help to advance the manganese-catalyzed hydrogenation reactions. [Display omitted] • Waste biomass as a carbon support. • MnO/PN-800 as an efficient catalyst for hydrogenation of bio-based aldehydes. • Hydrogenation of FA, 5-MFA, and 5-HMF to their corresponding alcohols. • Synthesis of furfuryl alcohol from raw sugarcane biomass. [ABSTRACT FROM AUTHOR]

This work demonstrated the promise of using industrial-grade sugar syrups derived from corn and wood, i.e., high fructose corn syrup (HFCS), glucose corn syrup (GCS) and wood-based sugar (TMP-Bio Sugar), as cheaper and competitive feedstocks for 5-HMF production using niobium phosphate as a heterogeneous solid acid catalyst in a biphasic continuous-flow tubular reactor. 5-HMF yield as high as 53.1% with 100% sugar (glucose and fructose) conversion was obtained from catalytic dehydration of HFCS-90 (containing 90 wt% fructose) at 150 °C, with feed concentration of 200 mg/ml (glucose and fructose) and aqueous to organic phase ratio of 1:5 (v/v). Catalyst stability with time was tested over 20 h of continuous-time on stream, and the reusability of the catalyst was studied after in-situ regeneration of the used catalyst by calcination in the air for removing the deposited humins and coke on the surface of the catalyst particles. The regenerated catalyst showed good activity with almost constant selectivity, although at lower glucose conversion and reduced 5-HMF yield compared to the fresh catalyst, indicating that the in-situ regeneration process could recover a part of the acid sites on the catalyst surface. The produced humins during the reaction were characterized by Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA) and elemental analysis (CHNS). The results showed high aromaticity and the presence of a high degree of unsaturated compounds in the structure of humins. [Display omitted] • Continuous flow catalytic conversion of industrial-grade sugars to 5-hydroxymethylfurfural. • NbP catalyst is effective for selective conversion of HFCS-90, HFCS-55, glucose corn syrup (GCS) and wood-based TMP-bio sugar. • 21–53% yield of 5-HMF was obtained from different biomass-derived sugar syrups. • NbP catalyst is regenerated and reused. • Humins byproduct is identified and characterized. [ABSTRACT FROM AUTHOR]

A selective and sensitive method using a high-performance liquid chromatography-UV detector (HPLC-UV) for the simultaneous determination of Patulin (PAT) and 5-(hydroxymethyl)furfural (5-HMF) in honey and apple juice was developed. The sample preparation technique QuEChERS was applied to increase the sensitivity and selectivity. The linear ranges for PAT and 5-HMF detected by the method were 2.0 ppb ÷ 200.0 ppb and 2.0 ppm ÷ 20 ppm. The results of method validation show that the recovery efficiency for PAT ranged from 92.8% ÷ 98.2% with % RSDr from 0.56% ÷ 0.63% and from 97.9% ÷ 101.2% with %RSD 0.39% ÷ 0.67% for 5-HMF and LOD and LOQ values of the method for PAT and 5-HMF detection were respectively: 0.6 and 2.0 ppb; 0.6 and 2.0 ppm. The influence of the matrix effect on the accuracy, repeatability, and recovery of the method was insignificant. The proposed method was applied to quantify the content of PAT, and 5-HMF in actual samples, collected in Ho Chi Minh City, Vietnam. The result showed that PAT was not found in honey samples but was detected in 5 of 10 apple juice samples. In addition, 5-HMF was detected in 3 of 10 honey samples and 10 of 10 apple juice samples. [ABSTRACT FROM AUTHOR]

Research background. The processing method generally affects the toxicity and biological activity of aged sorghum vinegar. This study investigates the changes in the intermediate Maillard reaction products of sorghum vinegar during ageing and the in vivo hepatoprotective effects of pure melanoidin obtained from it. Experimental approach. High-performance liquid chromatography (HPLC) and fluorescence spectrophotometry were utilized to quantify intermediate Maillard reaction products. The CCl4-induced liver damage in rats was used to evaluate the protective role of pure melanoidin in rat liver. Results and conclusions. Compared with the initial concentration, the 18-month ageing process caused a 1.2-to 3.3-fold increase in the concentrations of intermediate Maillard reaction products, i.e. 5-hydroxymethylfurfural (HMF), 5-methylfurfural (MF), methylglyoxal (MGO), glyoxal (GO) and advanced glycation end products (AGEs). The concentrations of HMF in the aged sorghum vinegar were 6.1-fold higher than the 450 µM limit standard for honey, implying the need for shortening the ageing of the vinegar in practice for safety concerns. Pure melanoidin (Mr>3.5 kDa) demonstrated significant protective effects against CCl4-induced rat liver damage, as evidenced by normalized serum biochemical parameters (transaminases and total bilirubin), suppressing hepatic lipid peroxidation and reactive oxygen species, as well as increasing glutathione amount and restoring antioxidant enzyme activities. Histopathological analysis revealed that melanoidin in vinegar reduced cell infiltration and vacuolar hepatocyte necrosis in rat liver. The findings demonstrated that a shortened ageing process should be considered in practice to ensure the safety of aged sorghum vinegar. Vinegar melanoidin is a potential alternative for the prevention of hepatic oxidative damage. Novelty and scientific contribution. This study demonstrates that the manufacturing process had a profound influence on the generation of vinegar intermediate Maillard reaction products. In particular, it revealed the in vivo hepatoprotective effect of pure melanoidin from aged sorghum vinegar, and provides insight into the in vivo biological activity of melanoidin. [ABSTRACT FROM AUTHOR]

Currently, the production of furan aldehydes from raw biomass suffers from low furfural yield and high energy consumption. In this study, a recyclable and practical method was explored for the preparation of furfural from corn stover by the one-pot reaction by acidic lithium bromide solution (ALBS) without pretreatment and enzymolysis. In the ALBS reaction, the furan aldehydes were generated by the degradation of lignocellulose; however, the products were unstable and were further dehydrated to form humins. So, dehydration reaction was inhibited in this study, and the high yield of furan aldehydes was obtained, in which 2.94 g/L of furfural and 2.78 g/L of 5-hydroxymethyl furfural (5-HMF) were generated with high solid loading (10 wt%), the presence of commercial catalyst ZSM-5 and co-solvent tetrahydrofuran (THF) at 140 °C for 200 min. Via this method, almost 100% of hemicellulose was transformed to furfural, and 40.71% of cellulose was transformed to 5-HMF, which was based on the theoretical yield of HMF (8.35 g) from glucose (29.30 g) produced from cellulose. After the reaction, the catalyst ZSM-5 was the main component in the solid residue and kept a suitable performance. THF azeotrope was easily separated from the slurry by evaporation. During the removal of THF, lignin was precipitated from the liquid phase and showed lower molecular weight and abundant active groups, which was a potential feedstock for producing valuable aromatics and polymers. Thus, in a one-pot reaction, the ideal yield of furan aldehydes from raw biomass was obtained on a lab scale, and the catalyst, THF, and LiBr were easily recycled, which provided an option to realize the economical production of sustainable furan aldehydes from raw biomass. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acetone presence as solvent enhances the selectivity to furans. • Furans from sugars can be obtained with a continuous flow reactor with a solid catalyst. • The TON of the catalysts depends on the hydrophobicity of the surface. • Acetone recycling allows the use of high sugar concentrations in water. The dehydration of sugars (fructose, glucose, and xylose) was studied using different resins and silicas functionalized with sulfonic as catalysts and a mixture of acetone/water 80:20 as the solvent in a flow system. The reaction conditions (temperature, sugar concentration, and residence time) were studied. The high concentrations of acetone in the solvent favor selectivity for furan compounds but difficult the solubility of the sugars The activity tests revealed different behaviors between acid catalysts employed, catalysts based on resins are more active, but the intrinsic activity (TOF) of silica-based catalysts are higher, these behavior are related with the amount of sulfonic groups and surface nature of the catalysts respectively. A life study (more than 100 h) of selected catalysts was carried out showing that the resin-based catalysts are pretty stable, but the silica counterpart deactivates by leaching of the organic groups that contain the sulfonic groups. The studied flow process that combines a heterogenous catalyst and acetone/water solvent is a very promising candidate to be scaled up to an industrial scale. [ABSTRACT FROM AUTHOR]

A highly active and selective mesoporous TiO 2 was developed by the sol-gel hydrolysis technique for the selective transformation of glucose to 5-hydroxymethylfurfural (5-HMF). The catalytic performance was tested in a glass tube reactor, and the reaction parameters were optimized using response surface methodology (RSM). The best-optimized reaction conditions were obtained using four-factors, four-responses, and the 5-level central composite design (CCD) integrated with the desirability approach. At the optimum reaction condition, RSM predicted complete conversion of glucose and a very high 5-HMF yield of ~56% in the dimethylsulfoxide (DMSO) solvent. The predicted yield of other major products, including formic acid (FA) and levulinic acid (LA), was ~18% and ~2%, respectively. The empirical process model developed by RSM was validated by the experimental data generated. Experimental results demonstrated that the TiO 2 catalyst developed can easily be recycled with a constant glucose conversion and 5-HMF yield. Further, a new liquid-liquid extraction method (LLE) is proposed to extract 5-HMF from the product. The results depicted that 5-HMF can easily be extracted from the product mixture with very high purity (~96%). Additionally, the Power-Law kinetic study suggested that the conversion of glucose over TiO 2 followed the first-order kinetics, and the calculated activation energy was 67.5 kJ mol−1. [Display omitted] • Highly selective and stable TiO 2 catalyst was developed for glucose dehydration. • Response surface methodology was used to optimize the reaction condition. • A maximum 5-hydroxymethylfurfural yield of 56% was achieved at ~100% conversion. • Glucose dehydration reaction followed the first-order Power-Law. • A new liquid-liquid extraction process is proposed for the separation of 5-HMF. [ABSTRACT FROM AUTHOR]

Dehydration of glucose for the production and separation of 5-hydroxymethylfurfural (5-HMF) with high purity has been performed. For selective production of 5-HMF from glucose, a new sulfated-ZnO catalyst with a combined hexagonal-monoclinic phase was developed and characterized by several techniques. The catalyst characterization results demonstrated a significant variation of physicochemical properties of hexagonal ZnO after sulfate impregnation. The glucose dehydration was performed in a glass reactor in a dimethyl sulfoxide (DMSO) medium. The effect of several important reaction parameters including temperature (120–160 °C), time (1–8 h), catalyst loading (25–100 wt%), and sulfate loading on ZnO with respect to glucose (1.5–4.5M) was evaluated. Results demonstrated that the sulfated-ZnO catalyst containing both the Brønsted (B) and Lewis (L) acid sites was very active and selective to 5-HMF compared to pure hexagonal ZnO containing only Lewis acidic sites (LAS). It was also observed that the higher (B + L) acidity of catalysts propagated the rehydration process, which led to the formation of various unwanted side products. The maximum glucose conversion of 96.2% with ~35% yield of 5-HMF was obtained at 160 °C after 6 h of reaction, with 2.5M-SO 4 2−/ZnO catalyst. Among all others, the 2.5M-SO 4 2−/ZnO catalyst was the best due to the presence of an optimum acidity with an appropriate B/L ratio. Further, the catalyst separation and recycling studies were performed. The results revealed that the 2.5M-SO 4 2−/ZnO catalyst could be recycled multiple times without substantial loss of catalytic activity and 5-HMF yield. Furthermore, a liquid-liquid extraction process was developed, demonstrating that almost 100% of 5-HMF could be extracted from the product solution with ~97% purity. [Display omitted] • The SO 4 2− impregnated on ZnO generated additional Lewis and Brønsted acid sites. • 2.5M-SO 4 2−/ZnO demonstrated ~35% 5-HMF yield with ~96.2% conversion at 160 °C. • Catalyst developed can be recycled with constant activity and 5-HMF yield. • 5-HMF was separated from the product mixture with very high purity. [ABSTRACT FROM AUTHOR]

This paper presents all-atom molecular dynamics to understand the separation behavior of 5-hydroxymethylfurfural (5-HMF) from 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM] + [BF 4 ] - using alkylated phenols as extractants. We have utilized four solvents such as 4-methyl phenol (4-MP), 4-ethyl phenol (4-EP), 4-propyl phenol (4-PP), and 4-butyl phenol (4-BP). We perform structural, dynamic, and rigorous thermodynamic analyses of 5-HMF in the mixture of ILs and solvents. The [BMIM] + [BF 4 ] - show a strong interaction with phenols. The self-diffusion coefficient of 5-HMF shows a 3-fold increase with a decrease in the methyl group on the phenol. The solvation-free energy (ΔG solvation ) of 5-HMF shows favorably in phenols. On the other hand, the transfer free energy (ΔG transfer ) of 5-HMF presents favorable from ILs to phenols. The partition coefficient (log P) values show favorability for separation of 5-HMF using phenols. Overall, the molecular level analysis provides the role of the alkyl group effect on the phenols for extracting 5-HMF from the ILs., (© 2024 Wiley-VCH GmbH.)

The transformation from fossil resources, crude oil and natural gas to biomass-derived feedstocks is an urgent and major challenge for the chemical industry. The valorization of lignocellulose as renewable resource is a promising pathway offering access to a wide range of platform chemicals, such as vanillin, furfural and 5-HMF. The subsequent conversion of such platform chemicals is one crucial step in the value-added chain. The electrochemical hydrodimerization (EHD) is a sustainable tool for C-C coupling of these chemicals to their corresponding hydrodimers hydrovanilloin, hydrofuroin and 5,5´-bis(hydroxymethyl)hydrofuroin (BHH). This review covers the current state of art concerning the mechanism of the electrochemical reduction of biobased aldehydes and studies targeting the electrochemical production of these hydrodimers in aqueous media. Moreover, the subsequent conversion of these hydrodimers to valuable additives, polymers and long carbon chain synfuels will be summarized offering a broad scope for their application in the chemical industry., (© 2024 Wiley‐VCH GmbH.)

In this work, the microwave-assisted reaction of 5-hydroxymethylfurfural (5-HMF) into valuable ether and acylated production formation was investigated with the help of molybdophosphoric acid encapsulated dendritic fibrous silica (KCC-1) as a catalyst. XRD, N2 adsorption-desorption, SEM, FT-IR, NH3-TPD, and TEM were used to analyze the physicochemical and structural properties of the synthesized catalysts. The microwave etherification of 5-HMF with ethanol was tested using synthesized catalysts. The effects of the reaction temperature, reaction time, catalytic amount, and microwave power were investigated. The resulting MPA-KCC-1 and IMPA-KCC-1 catalysts demonstrated excellent activity for the etherification of 5-HMF with ethanol, producing 5-(hydroxymethyl) furfural diethyl acetal (HMFDEA) and 5-(ethoxymethyl)furfural diethyl acetal (EMFDEA) products selectively. The significant advantages of the work are the selective production of EMFDEA at 82%, the catalyst can be easily removed via filtration, and the catalyst activity remains nearly intact even after five reaction cycles.

Most adhesives used in the wood-based panel (WBP) industry are petroleum-based and are associated with environmental impact and price fluctuations. Furthermore, most have potential adverse health impacts, such as formaldehyde emissions. This has led to interest from the WBP industry in developing adhesives with bio-based and/or non-hazardous components. This research focuses on the replacement of phenol-formaldehyde resins by Kraft lignin for phenol substitution and 5-hydroxymethylfurfural (5-HMF) for formaldehyde substitution. Resin development and optimization was carried out regarding varying parameters such as molar ratio, temperature or pH. The adhesive properties were analyzed using a rheometer, gel timer and a differential scanning calorimeter (DSC). The bonding performances were evaluated using an Automated Bonding Evaluation System (ABES). Particleboards were produced using a hot press, and their internal bond strength (IB) was evaluated according to SN EN 319. Hardening of the adhesive could be achieved at low temperatures by increasing or decreasing the pH. The most promising results were obtained at pH 13.7. The adhesive performances were improved by adding filler and extender (up to 28.6% based on dry resin) and several boards were produced reaching P1 requirements. A particleboard achieved a mean IB of 0.29 N/mm2, almost reaching almost P2 requirements. However, adhesive reactivity and strength must be improved for industrial use.

To enhance the selective fructose dehydration to 5-hydroxymethylfurfural (HMF), an efficient dehydration of fructose to 5-HMF in H2O-MIBK- pressured CO2 in 20 min at 200 °C with a better product yield of 85.6% and 89.1% product selectivity was achieved. The high activity attributed to the combination of the weak acidity by CO2 dissolved in the water and the efficient separation of fructose with 5-HMF in this H2O-MIBK two-phase system. The possible reaction mechanism is discussed. It was found that the solvents ratio was the one of key factors determining the yield of target products. Compared to the related reported results in the reaction, this process characterized of more favorable product yield and higher selectivity, it can be considered as a potential technique for the scale-up production of 5-HMF from fructose. [ABSTRACT FROM AUTHOR]

The colour quality and functional activity of dried fruits are important quality indexes. The purpose of this study was to evaluate the effects of heat pump drying with different air velocity on browning‐related reactions and antioxidant activities of products and their storage counterparts. The results showed that apple cubes possessed different Maillard reaction levels, polyphenol and pectin variation, and antioxidant capacity, which could be controlled by different drying air velocity when the temperature is constant. In present work, high air velocity (2.0–2.5 m/s) drying (HHD) apple cubes possessed 22.58% more browning comparing to low air velocity (0.02–0.50 m/s) drying (LHD), which correlated with its 8.13 μg/g, 132.35 μg/g and 6.21% more of 5‐HMF, chlorogenic acid and DE level of pectin, respectively. Interestingly, the b value of HHD and LHD samples decreased after storage, which was related to the DE, GalA, structural properties (Ratio1, Ratio2 and Ratio3) and conformational properties (PDI, RG and RC) of pectin in samples. Besides, HHD treatment promoted higher DPPH and FRAP capacity than LHD, which significantly involved Mw of pectin. The research would provide a new insight from the perspective of pectin for regulating the browning and antioxidant activity in apple thermal process. [ABSTRACT FROM AUTHOR]

Catalytic synergism was observed for a bimetallic Pd−Ir catalyst supported on activated carbon for chemoselective hydrogenation of 5‐hydroxymetahyl furfural (5‐HMF) to 2, 5‐(bishydroxymethyl) furan (BHMF) with complete conversion and 97 % selectivity under very mild reaction conditions. The structural characterization like XRD, N2 sorption, FE‐SEM and TEM suggested formation of fine nanoparticles (1.95–3.08 nm) having very higher surface area, uniform distribution and mesoporous nature of the material. XPS spectra and Pyridine‐IR spectroscopy revealed formation of Pd‐PdO and Ir/IrO2/IrO3 interface on the catalytic surface along with strong Brönsted acidic sites which were responsible for high efficiency of catalyst at 80 °C, 100 psig H2 pressure at 5‐HMF/Catalyst=20 and within 2.5 h of reaction time. A plausible reaction mechanism is also elucidated based on structure activity correlation. [ABSTRACT FROM AUTHOR]

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Abstract Hydrogen bond donor solvents such as aromatic solvents inhibit the secondary degradation of cellulose‐derived primary pyrolysis products. In a previous study, we found that the formation of solid carbonized products was completely inhibited during cellulose pyrolysis in aromatic solvents, with 5‐hydroxymethylfurfural (5‐HMF) recovered in certain yields instead. This indicated that 5‐HMF is an intermediate in cellulose carbonization. To confirm this hypothesis, the thermal reactivity of 5‐HMF was investigated. At 280 °C, pure 5‐HMF polymerized into a hard glassy substance through OH group elimination, but further conversion was slow. When pyrolyzed in the presence of glycerol, a model of coexisting primary pyrolysis products from cellulose, a coupling reaction proceeded. Reactions characteristic of cellulose carbonization then occurred, including the formation of acidic groups and benzene‐type structures in the solid products. These results confirmed the above hypothesis. The molecular mechanism of cellulose carbonization is discussed, focusing on the crystalline nature.

Dehydration of glucose into 5-hydroxymethylfurfural (5-HMF) is an effective approach for generating bio-based chemicals. Metal-organic frameworks (MOFs) are notable catalysts for this process due to their unsaturated metal centers. Functionalized MOFs further enhance these catalytic properties. This study investigates the catalytic abilities of MIL-101(Cr) and MIL-101(Cr)-NH 2 for glucose dehydration into 5-HMF using an H 2 O + DMSO solvent system. Using Response Surface Methodology (RSM), the reaction parameters (temperature, time, and catalyst amount) were optimized to maximize 5-HMF yield. Results showed that at 180 °C, MIL-101(Cr) achieved a 5-HMF yield of 21 % with a selectivity of 22 %, while MIL-101(Cr)-NH 2 achieved a 5-HMF yield of 55 % with a selectivity of 56 %. MIL-101(Cr) demonstrated a glucose conversion rate of 92 %, and MIL-101(Cr)-NH 2 achieved a conversion rate of 99 % after 3 h at 180 °C. The optimized 5-HMF yield predicted by RSM for MIL-101(Cr) was 53.8 %, whereas the experimentally obtained value was 24.23 %. For MIL-101(Cr)-NH 2 , the predicted 5-HMF yield was 35.46 %, with an experimental value of 47.51 %. The Lewis acidic nature of MIL-101(Cr) arises from the Cr sites, while MIL-101(Cr)-NH 2 exhibits both Lewis acidic characteristics from the Cr sites and Brønsted basic characteristics from the non-coordinated primary amine groups. The experimental results highlight the potential of MIL-101(Cr)-NH 2 , which produced a higher 5-HMF yield compared to MIL-101(Cr). The dual nature of MIL-101(Cr)-NH 2 enhances glucose dehydration to 5-HMF, resulting in significantly higher yields. This study underscores the effectiveness of MIL-101(Cr)-NH 2 in converting glucose to 5-HMF, advancing biomass utilization efficiency. A Comparative Study on Optimizing Reaction Parameters for the Dehydration of Glucose into 5-Hydroxymethylfurfural with MIL-101(Cr) and MIL-101(Cr)-NH 2 : A Response Surface Methodology Approach. [Display omitted] • First reported use of MIL-101(Cr)-NH 2 for 5-HMF synthesis. • Dual catalytic nature of MIL-101(Cr)-NH 2 enhances glucose conversion to 5-HMF. • RSM optimized conditions for maximum 5-HMF yield from MIL-101(Cr)-NH 2. • MIL-101(Cr)-NH 2 achieved a remarkable 55 % yield of 5-HMF. [ABSTRACT FROM AUTHOR]

Southern Chile native potatoes are an interesting raw material to produce novel snacks like colored potato chips. These novel products should be comprehensively evaluated for the presence of undesirable compounds such as acrylamide, 5-hydroxymethylfurfural and furan, the main neoformed contaminants in starchy rich fried foods. This study evaluated the neoformed contaminant levels and oil content on chips made from eleven Chilean potato accessions and compared them with commercial samples. The neoformed contaminant contents were related to Maillard reaction precursor levels (reducing sugars and asparagine) and secondary metabolites (phenolic compounds and carotenoids). Neoformed contaminants correlated well among them and were weakly correlated with reducing sugars and asparagine. Acrylamide level in native potato chips ranged from 738.2 to 1998.6 μg kg−1 while from 592.6 to 2390.5 μg kg−1 in commercial samples. Thus, there is need to implement neoformed contaminant mitigation strategies at different steps of the production chain of colored potato chips. [Display omitted] • Neo-formed contaminants in chips made from Chilean potato genotypes is reported. • High cultivar dependance was observed in neoformed contaminants and Maillard precursors. • Colored chips presented on average higher acrylamide levels than conventional ones. • Furan and 5-HMF levels correlated positively with acrylamide. [ABSTRACT FROM AUTHOR]

The state of Pernambuco, in the northeast Brazil, is one the biggest bee honey producers in the country, especially in semiarid microregions called "Sertão", or hinterlands. Its unique biome characterized by xerophyte Caatinga vegetation presents a unique flora with many medicinal properties. One of these microregions, Sertão do Pajeú, has stood out for its growing honey production. The present work reported for the first time a characterization of this honey and evaluated its potential for the production of alternative nutraceutical products. Samples from Sertão do Pajeú and two other regions of the State were collected and subjected to analyses as recommended by the Brazilian legislation. As the most striking characteristics, honeys from this microregion showed darker colour, higher content of phenolic compounds and elevated antioxidant activity than that from other locations. The high content of 5-HMF, together with high diastase activity, indicated that it is an intrinsic property of this honey. And finally, fermented worts containing the probiotic yeast Saccharomyces boulardii were supplemented with honey and sucrose as reference. The results showed that samples stocked in the presence of honey presented high level of cell longevity over 60 days of storage under refrigeration. In addition, those cells became very tolerant to the simulation of the gastrointestinal tract. Therefore, this honey greatly increased the probiotic potential of the yeast. This shows the nutraceutical potential of honey from Sertão do Pajeú. [ABSTRACT FROM AUTHOR]

The conversion of waste lignocellulosic biomass into biomass platform chemicals is very promising. In this work, a novel resin-based solid acid catalyst was obtained by condensation of furfuryl alcohol with furfural, and mild calcination and sulfonation process. Then it was used to convert sugars and biomass to obtain furan compounds. Results showed that the solid acid with a furfural to furfuryl alcohol molar ratio of 3:1 is an irregular mesoporous material, with a specific surface area of 134.18 m2/g and an acid content of 2.723 mmol/g, which is extremely stable below 200 °C. 82.2 % (from fructose), 15.8 % (from glucose), 10.0 % (from cellobiose) yields of 5-HMF and 35.5 % (from xylose) yield of furfural could be obtained at 160 °C for 2 h. It can be reused more than 5 times and can restore the best catalytic effect after re-sulfonation. Notably, in the catalytic conversion of rice husk, rice straw, camphor tree branch and leaves under typical reaction conditions, 5-HMF and furfural was in yields of 9.4–24.5 % and 20.3–47.9 %, respectively. Moreover, a 10 % water dropwise to solvent can effectively promote the catalytic conversion of biomass, while there is a significant inhibitory effect after it exceeds 20 %. [Display omitted] • Alcohol formaldehyde resin-based solid acids were prepared. • The resin is mesoporous structure with high acid content and good stability. • 82.2 % 5-HMF (fructose) and 35.5 % furfural (xylose) were obtained via resin catalysis. • 9.4–24.5 % 5-HMF and 20.3–47.9 % furfural were produced from four natural biomass. • 10 % water dropwise to solvent can promote the catalytic conversion of biomass. [ABSTRACT FROM AUTHOR]

• One-pot LA synthesis from macroalgae by ionic resin-catalyzed hydrothermal conversion. • 30.3 % LA yielded at 200 °C and 90 min with 12.5 % biomass and 50 % catalyst/biomass. • The use of Purolite CT269DR presents significant potential for the synthesis of LA. • The relationship between CS and LA synthesis was matched to the sigmoidal equation. Gracilaria verrucosa is red algae (Rhodophyta) that is particularly significant because of its potential for bioenergy production as a sustainable and environmentally friendly marine bioresource. This study focuses on the production of levulinic acid from G. verrucosa using hydrothermal conversion with an ionic resin Purolite CT269DR as the catalyst. By optimization of the conversion condition, a 30.3 % (22.58 g/L) yield of levulinic acid (LA) (based on carbohydrate content) was obtained at 200 °C for 90 min with 12.5 % biomass and 50 % catalyst loading of biomass quantity. Simultaneously, formic acid yielded 14.0 % (10.42 g/L). The LA yield increased with increasing combined severity (CS) levels under tested ranges. Furthermore, the relationship between CS and LA synthesis was effectively fitted to the nonlinear sigmoidal equation. However, as the yield of sugar decreased, LA yield was linearly increased. Thus, the use of ionic resin as a heterogeneous catalyst presents significant potential for the manufacture of platform chemicals, specifically LA, through the conversion of renewable marine macroalgae. [ABSTRACT FROM AUTHOR]

The potential benefits of microwave irradiation for fructose dehydration into 5 hydroxymethylfurfural (5-HMF) have been quantified over a sulfonated metal–organic framework (MOF), MIL 101(Cr)-SO3H. The effects of temperature (140–170 °C), batch time (5–300 min), and catalyst-to-substrate ratio (0.1–0.01 g/g) were systematically mapped. After 10 min of microwave (MW) irradiation at 140 °C in a DMSO–acetone reaction medium, practically complete fructose conversion was obtained with a 70% yield of 5-HMF. Without MW, i.e., using conventional heating (CH) at the same conditions, the fructose conversion was limited to 13% without any 5-HMF yield. Rather, 90 min of CH was required to reach a similarly high conversion and yield. The profound impact of moving from CH towards MW conditions on the reaction kinetics, also denoted as the microwave effect, has been quantified through kinetic modeling via a change in the Gibbs free energy of the transition state. The modeling results revealed an eight-fold rate coefficient enhancement for fructose dehydration owing to MW irradiation, while the temperature dependence of the various reaction steps almost completely disappeared in the investigated range of operating conditions.