Furan Compounds Research Articles

Stabilization of bio-oil from simulated pyrolysis oil using sulfided NiMo/Al2O3 catalyst

Pyrolysis oil comprises compounds with a broad range of functional groups making its thermal/catalytic upgrading challenging due to the formation of undesired char. In this context, the current contribution addresses the thermal and catalytic hydrotreatment of a simulated pyrolysis oil containing all the representative groups of compounds under bio-oil stabilization conditions (180–300 °C, 60 bar, 4 h) using sulfided NiMo/Al2O3. The effect of reaction conditions and different oxygenated organic compounds on the yields and properties of products was compared thoroughly. Interestingly, a correlation between the presence/absence of oxygenated furan and sugar compounds was found to significantly affect the yield of liquid product containing stabilized compounds. The presence of such compound groups significantly enhances the solid formation via oligomerization and polymerization reactions. To gain further insight, the solid products were analyzed/characterized in detail to elucidate their characteristics by extracting them into a dimethyl sulfoxide (DMSO) soluble and insoluble solid fraction. It was found that in the presence of NiMo/Al2O3, increasing temperature from 180 to 300 °C enhances the formation of liquid product due to transformation of some of the soluble solids, while for experiments without the catalyst, the formation of solids was significantly higher. Oppositely, during heating up to 180 °C, no solids were found in the case without the catalyst, however the presence of the catalyst during heating resulted in solid formation due to various catalytic reactions that promoted char formation. Analysis of solids revealed that the structure of soluble solids at lower temperatures (180 °C) using the catalyst was closely related to sugar derivatives, whereas the corresponding insoluble solids with higher molecular weight were not fully char-like developed. However, at higher temperatures, the soluble and insoluble solid compositions were found to contain aliphatic compounds and fully developed char, respectively. Therefore, the stabilization of furan particularly with attached carbonyl groups and sugars derivatives in pyrolysis oil is of great importance to improve upgrading efficiency.

Appraisals on the anticancer properties of Mentha species using bioassays and docking studies

The medicinal properties of Mentha species are highly regarded due to their pro-health biological properties. This study aimed to investigate the fractions and bioactive compounds that are responsible for anticancer properties of the Mentha species. Firstly, the cytotoxic effects of leaves and hairy roots extracts from two Mentha species including Mentha piperita L. and Mentha spicata L., were assessed by MTT assay. Then, a bioassay-guided fractionation of an extract with higher toxicity against cancer cells was conducted to yield the bioactive compound. Among all the four extracts tested, the leaf extract of M. piperita possessed the greatest cytotoxic activity against A549, MCF-7, and PC-3 cells. Bioassay-guided fractionation revealed that the purified fraction showed a cytotoxic effect (IC50 =54.8 μg/mL) against the PC-3 cancer cell line and exhibited potent anticancer activity by inducing apoptosis and wound healing properties, as well as upregulating the expression of tumor suppressor genes. Analytical investigations on the purified fraction utilizing LC-MS NMR, and FT-IR methodologies indicated that the identified anticancer metabolite was considered as a furanic compound called 2-ethylhexyl 5-hydroxyfuran-2 carboxylate, which is reported for the first time here. Molecular docking analyses indicated that the furan derivative has a great potential to differentially interact with cancer-related receptors. Therefore, this evidence suggests that the Mentha species has valuable anticancer bioactive compounds that could be considered in phytochemical-based cancer therapy programs.

Anthrone method combined with adsorption of interferents as a new approach towards reliable quantification of total carbohydrate content in pyrolysis bio-oils

Carbohydrates are a group of compounds abundantly present in pyrolysis bio-oils. Their quantitative analysis however presents many challenges such as possible co-elution with other oxygenates when liquid chromatographic methods are used. For a cheaper and faster analysis, spectrophotometric methods are a convenient alternative. Most of the absorption spectrometry-based methods stem from the reaction scheme, where the carbohydrates are converted into furfural or 5-hydroxymethylfurfural (HMF) derivatives and simultaneously react with colorizing agents such as phenol or anthrone. Alternatively, the produced compounds can be determined in the UV region without the addition of colorizing agent. An obvious problem arises when these furanic compounds are already present in the mixture, which is the case with most biomass-based pyrolysis bio-oils. In this study, we quantified the responses of 26 potential interferents that are expected to be present in the water-soluble fraction of bio-oils as well as 13 different carbohydrates. To mitigate the interferences, we used styrene-divinylbenzene polymeric resin adsorbents to separate the less polar interferents from the aqueous bio-oil extract and naturally formed bio-oil aqueous phases. A derivatization-GC-MS method was used as a reference for comparison of the results. We found that the adsorption step is crucial for acquiring more precise and accurate results. The anthrone method was the least susceptible to interferences and simultaneously produced results that were the closest to the reference GC-MS method. Statistical analysis showed no significant differences between the optimized anthrone method and the reference GC-MS method.

Selective Aqueous Extraction and Green Spectral Analysis of Furfural as an Aging Indicator in Power Transformer Insulating Fluid

Furfural is an intermediary and aldehyde compound degraded from paper insulation, which is used with liquid fluid in power transformers. It can be utilized as an important indicator to evaluate the degradation degree of the paper insulation and the condition of transformers to predict their lifetime. However, the conventional methods are inevitably inconvenient as they require additional derivatization with hazardous agents and time-consuming chromatographic separation and processes. In this work, a facile and green analysis method for the determination of furfural concentration in the insulating fluid of operating power transformers was developed. As furfural was selectively extracted from the insulting fluid by deionized water, the aqueous solution could be directly subjected to a UV spectral analysis without any derivatization using hazardous agents or hindrance of the fluid in the UV spectrum. The results showed that the spectral method could obtain a favorable linear relationship between the concentration of furfural and its characteristic absorbance at 280 nm (λ max). The limit of detection (LOD) was below 0.1 ppm, which is a sufficient detection level to evaluate the condition of the insulating fluid. Furthermore, the method was compared with the conventional HPLC and colorimetric analyses, revealing satisfactory accuracy and verification of the results. It is possible to measure the furfural concentration in situ using a portable UV-spectrometer at a single wavelength, 280 nm, after simple extraction in the field. This approach offers a novel and green analytical method to quantitatively determine the aromatic furan compounds in a power transformer’s insulating fluid in place without the use of an organic extraction solvent or hazardous reagents for derivatization and analysis.

Evaluation of Organofunctionalized Polydimethylsiloxane Films for the Extraction of Furanic Compounds.

Hybrid membranes with three different thicknesses, PMDS_C1, PMDS_C2, and PMDS_C3 (0.21 ± 0.03 mm, 0.31 ± 0.05 mm, and 0.48 ± 0.07 mm), were synthesized by the sol-gel method using polydimethylsiloxane, hydroxy-terminated, and cyanopropyltriethoxysilane. The presence of cyano, methyl, and silicon-methyl groups was confirmed by FTIR analysis. Contact angle analysis revealed the membranes' hydrophilic nature. Solvent resistance tests conducted under vortex and ultrasonic treatments (45 and 60 min) demonstrated a preference order of acetonitrile > methanol > water. Furthermore, the membranes exhibited stability over 48 h when exposed to different pH conditions (1, 3, 6, and 9), with negligible mass losses below 1%. The thermogravimetric analysis showed that the material was stable until 400 °C. Finally, the sorption analysis showed its capacity to detect furfural, 2-furylmethylketone, 5-methylfurfural, and 2-methyl 2-furoate. The thicker membrane was able to adsorb and slightly desorb a higher concentration of furanic compounds due to its high polarity provided by the addition of the cyano groups. The results indicated that the membranes may be suitable for sorbent materials in extracting and enriching organic compounds.

The sustainable production of succinic anhydride from renewable biomass

The selective production of C4 bulk chemicals from biomass is significant to replace the traditional method from petroleum resource. In this work, the succinic anhydride (SAN) is directly prepared from bio-based furanic platform compounds utilizing the visible light-induced oxygenation process, in which m-tetraphenyl porphyrin (H2TPP) and molecular oxygen was employed as the photocatalyst and terminal oxidant, respectively. Under optimal conditions, a 99.9% conversion with 97.8% selectivity of SAN was obtained from furoic acid (FAC) at room temperature. Moreover, the transformation of furfural and furfuryl alcohol with this system can also generate SAN, and the product selectivity is controllable by tuning light intensity and time. Furthermore, the EPR detection, isotope labeling, and control experiments exhibited that the generation of singlet oxygen plays a crucial role and 5-hydroxy-2(5H)-furanone is the main intermediate during the reaction. Finally, a possible reaction mechanism for the production of SAN from furanic compound is proposed.

Pyrolysis of Chilean Southern Lignocellulosic Biomasses: Isoconversional Kinetics Analysis and Pyrolytic Products Distribution.

Biomass provides potential benefits for obtaining value-added compounds instead of straight burning; as Chile has forestry potential that supports such benefits, it is crucial to understand the biomasses' properties and their thermochemical behaviour. This research presents a kinetic analysis of thermogravimetry, and pyrolysis of representative species in the biomass of southern Chile, heating biomasses at 5 to 40 °C·min-1 rates before being subjected to thermal volatilisation. The activation energy (Ea) was calculated from conversion using model-free methods (Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Friedman (FR)), as well as the Kissinger method based on the maximum reaction rate. The average Ea varied between KAS 117 and 171 kJ·mol-1, FWO 120-170 kJ·mol-1, and FR 115-194 kJ·mol-1 for the five biomasses used. Pinus radiata (PR) was identified as the most suited wood for producing value-added goods based on the Ea profile for the conversion (α), along with Eucalyptus nitens (EN) for its high value of reaction constant (k). Each biomass demonstrated accelerated decomposition (an increase in k relative to α). The highest concentration of bio-oil containing phenolic, ketonic, and furanic compounds was produced by the forestry exploitation biomasses PR and EN, demonstrating the viability of these materials for thermoconversion processes.

A Composite Whole-Biomass Tannin–Sucrose–Soy Protein Wood Adhesive with High Performance

Whole-biomass adhesives are the research hotspot of wood adhesives andcan improve the competitiveness of adhesives. The tannin–sucrose adhesive studied by our research group shows good bonding performance, but poor bonding stability induced by low viscosity. In this study, the tannin–sucrose adhesive was modified by isolated soybean protein (SPI), the effect of the SPI substitution ratio for tannin on the properties of the tannin–sucrose–SPI composite adhesive was investigated, and the bonding mechanism was explored using Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry (TG), X-ray diffraction (XRD), and gas chromatography–mass spectroscopy (GC–MS). The results showed that: (1) when the SPI substitution ratio was above 40%, the viscosity of the composite adhesive increased significantly, which effectively avoided adhesive leakage. (2) The tannin–sucrose–SPI composite adhesive displayed high bonding performance and water resistance. (3) The FTIR and GC–MS results revealed that the curing mechanism of the tannin–sucrose–SPI adhesive was very complicated, but it was certain that the conversion of sucrose into furan compounds, especially 5-hydroxymethylfurfural (5-HMF), was the core of the cross-linking reaction of the adhesive when elevating temperature. (4) The macromolecules and high reactivity of SPI compensated for the shortage of high temperature required for the conversion of sucrose into furanic cross-linkers so that the tannin–sucrose–SPI adhesive experienced an efficient curing reaction at a low temperature, and the reaction degree and thermal stability of the curing product increased.

Study of Brewer's Spent Grain Environmentally Friendly Processing Ways.

This article is devoted to the study of the effect of electrochemically activated water (catholyte with pH 9.3) on organic compounds of the plant matrix of brewer's spent grain in order to extract various compounds from it. Brewer's spent grain was obtained from barley malt at a pilot plant by mashing the malt followed by filtration and washing of the grain in water and storing it at (0 ± 2) °C in craft bags. For the organic compound quantitative determination, instrumental methods of analysis (HPLC) were used, and the results were subjected to mathematical analysis. The study results showed that at atmospheric pressure, the alkaline properties of the catholyte showed better results compared to aqueous extraction with respect to β-glucan, sugars, nitrogenous and phenolic compounds, and 120 min was the best period for extraction at 50 °C. The excess pressure conditions used (0.5 ÷ 1 atm) revealed an increase in the accumulation of non-starch polysaccharide and nitrogenous compounds, while the level of sugars, furan and phenolic compounds decreased with increasing treatment duration. The waste grain extract ultrasonic treatment used revealed the effectiveness of catholyte in relation to the extraction of β-glucan and nitrogenous fractions; however, sugars and phenolic compounds did not significantly accumulate. The correlation method made it possible to reveal the regularities in the formation of furan compounds under the conditions of extraction with the catholyte: Syringic acid had the greatest effect on the formation of 5-OH-methylfurfural at atmospheric pressure and 50 °C and vanillic acid under conditions of excess pressure. Regarding furfural and 5-methylfurfural, amino acids had a direct effect at excess pressure. It was shown that the content of all furan compounds depends on amino acids with thiol groups and gallic acid; the formation of 5-hydroxymethylfurfural and 5-methylfurfural is influenced by gallic and vanillic acids; the release of furfural and 5-methylfurfural is determined by amino acids and gallic acid; excess pressure conditions promote the formation of furan compounds under the action of gallic and lilac acids. This study showed that a catholyte allows for efficient extraction of carbohydrate, nitrogenous and monophenolic compounds under pressure conditions, while flavonoids require a reduction in extraction time under pressure conditions.

Cocoa volatile compounds affect aroma but not taste

Flavor is one of the most essential indicators for determining the quality of cocoa beans, especially fine flavor cocoa. The volatile compound in the beans affect the mechanism the flavor emergence. Therefore, this study aimed to identify the volatile compound in the aromatic and non-aromatic cocoa groups as one of FFCs indicator. It was conducted at the Indonesian Coffee and Cocoa Research Institute, Jember, East Java, Indonesia. Furthermore, the genetic material used consisted of six aromatic cocoa genotypes, such as DR 2, ICCRI 03, ICCRI 07, ICCRI 09, MCC 02, and TSH 858 as well as four non-aromatic genotypes such as Sulawesi1, Sulawesi 2, KW 516, and KEE 2. A completely randomized block design (RCBD) was used with three repetitions. The fermented bean samples of each genotype were analyzed of volatile compound at the Food and Science Laboratory, Jember Polytechnic, East Java and sensory test was conducted by three certified panelists from ICCRI. Data were analyzed by orthogonal contrast analysis with IRRI's STAR 2.0.1 software. While the Microsoft Excel 2019 and R Studio were used for correlation analysis and heatmaps. The results showed aldehydes, acids, esters, pyrroles, and pyrazines of aromatic cocoa bean group higher than the non-aromatic. The alanine and terpenoid compounds was only found in clones DR 2 and ICCRI 03, while the alcohol and phenol compounds dominated in the non-aromatic group. Genotypes were grouped into six groups, based on flavor and volatile compound. ICCRI 09 characterized by strong acidity with a fresh fruit, spicy and sweet aroma as well as containsed aldehydes. Furthermore, ICCRI 03, MCC 02, and TSH 858 bean had weaker acidity and aroma than ICCRI 09 and contain terpenoids. ICCRI 07 had a nutty and woody aroma and was dominated by furan and pyrazine compounds. While Sulawesi 1 had a putrid aroma and alkaloids. The genotype groups of KW 516, KEE2, and Sulawesi 2 had astringent taste, dirty/dusty and moldy aroma as well as contained alcohol and phenol. Keywords: Aromatic; Flavor; Non-aromatic; Theobroma cacao L; Volatile compounds

Therapeutic Potential of HMF and Its Derivatives: a Computational Study.

Over the past century, chemicals and energy have increasingly been derived from non-renewable resources. The growing demand for essential chemicals and shrinking inventory make reliable, sustainable sources essential. Carbohydrates offer by far the greatest carbon supply. Furan compounds, a particular family of dehydration products, are believed to offer high chemical potential. Here, we analyze 5-HMF (5, hydroxymethylfurfural) and some of its derivatives in particular, a furan-type platform chemical. To analyze the therapeutic potential of HMF and its derivatives, this study utilized cutting-edge technologies such as computer-aided drug design, virtual screening, molecular docking, and molecular dynamic simulation. We conducted 189 docking simulations and examined some of the most promising dock poses using the molecular dynamic simulator. As for the receptors for our compounds, the leading candidates are human acetylcholinesterase, beta-lactamases, P. aeruginosa LasR, and S. aureus tyrosyl-tRNA synthetases. Out of all derivatives considered in this study, 2,5-furandicarboxylic acid (FCA) performed best.

Tracing the Volatilomic Fingerprint of the Most Popular Italian Fortified Wines.

The aim of the current study was to provide a useful platform to identify characteristic molecular markers related to the authenticity of Italian fortified wines. For this purpose, the volatilomic fingerprint of the most popular Italian fortified wines was established using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Several volatile organic compounds (VOCs), belonging with distinct chemical groups, were identified, ten of which are common to all the analyzed fortified Italian wines. Terpenoids were the most abundant chemical group in Campari bitter wines due to limonene's high contribution to the total volatilomic fingerprint, whereas for Marsala wines, alcohols and esters were the most predominant chemical groups. The fortified Italian wines VOCs network demonstrated that the furanic compounds 2-furfural, ethyl furoate, and 5-methyl-2-furfural, constitute potential molecular markers of Marsala wines, while the terpenoids nerol, α-terpeniol, limonene, and menthone isomers, are characteristic of Vermouth wines. In addition, butanediol was detected only in Barolo wines, and β-phellandrene and β-myrcene only in Campari wines. The obtained data reveal an adequate tool to establish the authenticity and genuineness of Italian fortified wines, and at the same time constitute a valuable contribution to identify potential cases of fraud or adulteration to which they are subject, due to the high commercial value associated with these wines. In addition, they contribute to the deepening of scientific knowledge that supports its valorization and guarantee of quality and safety for consumers.

RESEARCH OF THE PETROLEUM COKE THERMAL PROPERTIES IN ACTIVATED CARBON PRODUCTION PROCESS

Petroleum cokes are the products of deep thermal processing of heavy oil residues – asphaltenes, resins, fuel oil, tar, etc. The high carbon content in petroleum cokes composition and the ability to thermal modification make them a promising raw material to product activated carbons. This paper presents the results of studies of petroleum coke obtained by the method of delayed coking, with an increased yield of volatile substances as raw materials to use in activated carbon technology. Based on the results of thermogravimetric analysis and analysis of technological parameters of obtaining petroleum coke, the modes of thermal modification of samples in the process of obtaining activated carbon were selected. The pyrolytic gas chromatography method was used to identify the products of thermal decomposition of petroleum coke samples at different stages of activated carbon production technology. It is shown that the main gaseous products of pyrolysis are polycyclic aromatic hydrocarbons that release in the temperature range from 200 to 600 °C. During pyrolysis of carbonized coke samples, gaseous products do not release, and during pyrolysis of activated coke, the release of furan compounds and benzene is observed. Samples of petroleum coke modified with a solution of nitric acid, during pyrolytic analysis, show a complete absence of volatile pyrolysis products. Based on samples of petroleum coke that have been pretreated by various methods, series of activated carbon samples were obtained and their porous structure was studied. The use of a nitric acid solution for pretreatment of a sample of petroleum coke led to an increase in specific surface area and volume of sorption pores over 30-47%. For citation: Farberova E.A., Pershin E.A., Maksimov A.S., Khodyashev N.B., Smirnov S.A., Kuz’minykh K.G. Research of the petroleum coke thermal properties in activated carbon production process. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 6. P. 102-110. DOI: 10.6060/ivkkt.20236606.6776.

Synthesis, crystal structure, and DFT study of 4-((furan-2-ylmethyl)amino)benzoic acid and N'-acryloyl-N'-phenylfuran-2-carbohydrazide compounds

4-((furan-2-ylmethyl)amino)benzoic acid and N'-acryloyl-N'-phenylfuran-2-carbohydrazide are important intermediates for the synthesis of furan compounds with furan ring. In this paper, the title compounds were obtained by two-step reaction respectively. The structures of the title compounds were confirmed by FTIR, 1H and 13C NMR spectroscopy, and mass spectrometry. At the same time, single crystals of the title compounds were measured by X-ray diffraction and subjected to crystallographic and conformational analyses. The molecular structures were further calculated using density functional theory (DFT), which were compared with the X-ray diffraction value. The results of the conformational analysis indicate that the molecular structures optimized by DFT were consistent with the crystal structures determined by single crystal X-ray diffraction. In addition, the molecular electrostatic potential and frontier molecular orbitals of the title compounds are further investigated by DFT, and some physicochemical properties of the compounds are revealed.

Differences in the Volatilomic Urinary Biosignature of Prostate Cancer Patients as a Feasibility Study for the Detection of Potential Biomarkers.

Prostate cancer (PCa) continues to be the second most common malignant tumour and the main cause of oncological death in men. Investigating endogenous volatile organic metabolites (VOMs) produced by various metabolic pathways is emerging as a novel, effective, and non-invasive source of information to establish the volatilomic biosignature of PCa. In this study, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to establish the urine volatilomic profile of PCa and identify VOMs that can discriminate between the two investigated groups. This non-invasive approach was applied to oncological patients (PCa group, n = 26) and cancer-free individuals (control group, n = 30), retrieving a total of 147 VOMs from various chemical families. This included terpenes, norisoprenoid, sesquiterpenes, phenolic, sulphur and furanic compounds, ketones, alcohols, esters, aldehydes, carboxylic acid, benzene and naphthalene derivatives, hydrocarbons, and heterocyclic hydrocarbons. The data matrix was subjected to multivariate analysis, namely partial least-squares discriminant analysis (PLS-DA). Accordingly, this analysis showed that the group under study presented different volatomic profiles and suggested potential PCa biomarkers. Nevertheless, a larger cohort of samples is required to boost the predictability and accuracy of the statistical models developed.

Oxidative fast pyrolysis of biomass in a quartz tube fluidized bed reactor: Effect of oxygen equivalence ratio

The effect of oxygen equivalence ratio (ER) on oxidative fast pyrolysis of pine sawdust was investigated in a quartz tube fluidized bed reactor. The results showed that the introduction of oxygen into fluidizing gas would mainly oxidize the biochar, thus provided the largest contribution to heat demand during biomass pyrolysis towards autothermal operation. The increase of ER from 0 to 11.15% decreased the biochar yield from 21.03 to 9.5 wt%. The enthalpy for fast pyrolysis of pine sawdust was about 1084.49 kJ/kg, and a theoretical ER to achieve autothermal pyrolysis was thus calculated as ∼3.92%. The addition of oxygen indeed changed the formation and distribution of bio-oil. With ER of 6.47%, although the bio-oil yield decreased slightly, the light compounds in bio-oil (e.g., linear alcohols/carbonyls/acids, furan compounds and cyclopentanones/cyclohexanones) were largely consumed, while the heavy compounds (e.g., phenols/aromatic hydrocarbons and anhydrosugars) were mostly retained with the formation of anhydrosugars being promoted.

Effect of post-milling process on the oxidation of the rice bran

The rancidity of rice bran is predominantly triggered by lipophilic enzyme activities. Bran stabilisation and defatting are the typical processes to inactivate the processes that cause rancidity. However, little is known about how this impacts the development of volatile compounds related to odour in the rice bran. The effects of the post-milling process on the development of secondary volatile oxidation compounds in the rice bran during storage were investigated. Based on the identified metabolites, there were three possible major pathways in the formation of off-odour and key aroma degradation of the stabilised rice bran during storage, including lipid oxidation, the Maillard reaction, and Strecker degradation. Butanal-2 methyl and furan compounds contributed to the cocoa, nutty, and malty aroma and were considered the important key aroma in the defatted stabilised bran. By contrast, butanal, hexanal, 2-hexenal, butanoic acid, hexanoic acid, pentanoic acid, and heptanoic acid were the discriminant volatile compounds in the non-defatted bran, and they were considered as the markers of rancidity of non-defatted stabilised rice. It can thus be suggested that the defatting process positively contributed to the low abundance of volatile oxidation products that are responsible for bran rancidity by slowing down the formation of lipid-derived oxidation products.

Ultrasonic pretreatment effect on the co-pyrolysis characteristics and products of bagasse and municipal sludge

Orthogonal experiments were conducted to determine for the effect of frequency, power, reaction time, and mixing ratio on the co-pyrolysis characteristics and products of bagasse and municipal sludge. After ultrasonic pretreatment, the carbon content in the sample increased and the nitrogen content decreased. The thermogravimetric analysis results revealed that the pyrolyzed ultrasonic samples only had one peak, and the maximum mass loss rate and comprehensive pyrolysis characteristic index (D) values increased. Range analysis revealed that experimental conditions of 45 kHz, 200 W, and 2 h assisted in decreasing the residue, whereas 45 kHz, 200 W, 1 h assisted in increasing D. The GC/MS results revealed that the main components of the co-pyrolyzed bagasse and sludge were hydrocarbon, ketone, phenol, ether, alcohol, aldehyde, acid, ester, furfural, furan, allose, and nitrogen-containing. The proportion of ketones, phenols and alcohols increased rather noticeably after pretreatment. The proportion of hydrocarbon, furan, allose, and nitrogen-containing compounds decreased noticeably. The acid proportion decreased when CaO was added. Lower frequencies and lower powers assisted in increasing the phenol and alcohol ratios and decreasing the acid ratio. The addition of CaO could promote the formation of phenol and alcohol, and might reduce the proportion of acid.

Risk/Benefit Evaluation of Chia Seeds as a New Ingredient in Cereal-Based Foods.

Chia seed (Salvia hispanica L.) is a food rich in protein, fiber, polyunsaturated fatty acids and antioxidants. Consequently, its incorporation in food formulations may be desirable from a nutritional and healthy point of view. However, there is concern regarding the formation of process contaminants when they are subjected to thermal processing. The objective of this study was to incorporate different amounts of ground chia seeds in a biscuit model to evaluate the effect on the antioxidant capacity and formation of acrylamide and furfurals. Seven standard "Maria-type" biscuit formulations were prepared, replacing wheat flour with different amounts of ground chia seeds (defatted and non-defatted), from 0% (control biscuit) to 15% (respect to total solids in the recipe). Samples were baked at 180 °C for 22 min. Compared with the control biscuit, chia formulations increased the content of nutrients, antioxidant capacity (ABTS) and phenolic compounds (Folin-Ciocalteau method) but also doubled acrylamide levels and even raised more than 10 times furanic compound concentrations. Results indicate that the use of chia seeds as ingredients in new cereal-based formulations would improve the nutritional profile but also increase the occurrence of chemical process contaminants. This paradox should be carefully considered in the context of risk/benefit analysis.

Recent Advances in the Efficient Synthesis of Useful Amines from Biomass-Based Furan Compounds and Their Derivatives over Heterogeneous Catalysts

Bio-based furanic oxygenates represent a well-known class of lignocellulosic biomass-derived platform molecules. In the presence of H2 and different nitrogen sources, these versatile building blocks can be transformed into valuable amine compounds via reductive amination or hydrogen-borrowing amination mechanisms, yet they still face many challenges due to the co-existence of many side-reactions, such as direct hydrogenation, polymerization and cyclization. Hence, catalysts with specific structures and functions are required to achieve satisfactory yields of target amines. In recent years, heterogeneous catalytic synthesis of amines from bio-based furanic oxygenates has received extensive attention. In this review, we summarize and discuss the recent significant progress in the generation of useful amines from bio-based furanic oxygenates with H2 and different nitrogen sources over heterogeneous catalysts, according to various raw materials and reaction pathways. The key factors affecting catalytic performances, such as active metals, supports, promoters, reaction solvents and conditions, as well as the possible reaction routes and catalytic reaction mechanisms are studied and discussed in depth. Special attention is paid to the structure–activity relationship, which would be helpful for the development of more efficient and stable heterogeneous catalysts. Moreover, the future research direction and development trend of the efficient synthesis for bio-based amines are prospected.