Search Results (87)

Bioethanol manifests an extraordinary potential to overcome the severe energy crises and reliance on fossil fuels, yet it supports the sustainable and cost-effective production of fuels for automobile engines and contributes to the reduction of greenhouse gas (GHG) emissions and other global climate-related challenges. The present study examines the potential of Mixed Lignocellulosic Biomass (MLB) as a sustainable feedstock for the consistent year-round production of bioethanol. The primary MLB sources considered in this research to underscore the significance of this heterogeneous strategy include sweet sorghum bagasse (SSB), sugarcane bagasse (SCB), and date palm trunk (DPT). Each of the three feedstocks, i.e., SSB, SCB, and DPT, were individually subjected to alkaline pretreatment, a step aimed at breaking down structural barriers and facilitating greater release of fermentable sugars during fermentation. Likewise, the alkaline-pretreated biomasses were subjected to simultaneous saccharification and fermentation (SSF) for 96 h, both individually as well as in various combined proportions. Individually, pretreated sweet sorghum bagasse (SSB) fibers produced the highest ethanol concentration, of 30.79 ± 0.44 g/L; an ethanol yield of 0.40 ± 0.62 g/g; an ethanol productivity of 0.42 ± 0.87 g/L/h; and a theoretical ethanol yield of 79.81% at 72 h. In contrast, the combination of MLB (50% of pretreated SSB and 50% of DPT fibers) produced a significantly higher ethanol concentration of 31.47 ± 0.57 g/L and an ethanol productivity of 0.653 ± 0.24 g/L/h in much less time, i.e., 48 h of SSF fermentation. The empirical data confirms that MLB offers a sustainable paradigm for ethanol biosynthesis by curtailing fermentation time and optimizing economic and operational efficacy. Full article

This study investigated the physicochemical properties of Camellia oleifera husks collected from three regions of Jiangxi Province (Ganzhou—GZ, Yichun—YC, and Jiujiang—JJ) and extracted tea saponins via microwave-assisted solvent extraction (MASE), aiming to provide a theoretical basis for the high-value utilization of this agricultural by-product. The husks from YC were rich in bioactive compounds such as tea saponins (16.29 ± 0.02%), with lower cellulose (21.05 ± 1.05%) and lignin (12.48 ± 1.14%) contents and higher hemicellulose (27.40 ± 0.80%) content. The husks from JJ exhibited abundant porosity and a larger specific surface area (40–60 mesh, 4.15 ± 0.04 m²/g). Single-factor extraction experiments indicated that the microstructure and chemical composition of Camellia oleifera husks significantly affected the extraction efficiency of saponins, tannins, and flavonoids. The optimal extraction conditions for tea saponins were established using Box–Behnken response surface methodology, with the liquid-to-solid ratio identified as the most critical factor. Optimal conditions for GZ husks were a liquid-to-solid ratio of 46.75 mL/g, ethanol concentration of 35.5%, extraction time of 6 min, and microwave power of 350 W, with the extraction yield of 7.49 ± 0.01%. Optimal conditions for YC husks were a liquid-to-solid ratio of 50.55 mL/g, ethanol concentration of 40.13%, extraction time of 6 min, and microwave power of 350 W, with the extraction yield of 16.29 ± 0.02%. Optimal conditions for JJ husks were a liquid-to-solid ratio of 47.44 mL/g, ethanol concentration of 37.28%, extraction time of 6 min, and microwave power of 350 W, with the extraction yield of 9.39 ± 0.02%. The study provides important scientific evidence for understanding the structure–function relationship of Camellia oleifera husks and offers practical guidance for developing sustainable industrial processes to convert agricultural by-products into high-value bioactive compounds, thereby promoting resource recycling and economic benefits in the Camellia oleifera industry. Full article

The growing demand for renewable energy has spurred an interest in non-edible feedstocks for biofuel production. Ricinus communis (castor) seeds are a promising resource due to their high oil and starch content, as well as their adaptability to marginal lands. This study evaluated the integrated use of R. communis seeds for the production of biodiesel and bioethanol using eco-efficient technologies. Ultrasound-assisted extraction enhanced oil recovery reached a maximum yield of 34%, surpassing the conventional Soxhlet method. Transesterification was optimized through factorial design, achieving a predicted biodiesel yield of 97% (Qualitek 4.0, 90% confidence interval), with an experimental maximum yield of 90.8% under optimal conditions (24:1 methanol-to-oil ratio, 0.4% catalyst, 90% sonication amplitude, 60 min). The biodiesel met international standards for engine applications. Starch from the residual seed cake was hydrolyzed with enzymatic complexes, yielding 6.8 g/L of reducing sugars, equivalent to 91.4% hydrolysis yield. Fermentation of the hydrolysates with Zymomonas mobilis produced 3.1 g/L ethanol, corresponding to 90.8% of the theoretical yield. This integrated approach exemplifies a circular bioeconomy model by combining biodiesel and bioethanol production, maximizing resource utilization, and minimizing waste. The results highlight the potential of R. communis as a sustainable, scalable feedstock for renewable energy, contributing to energy security and environmental sustainability. Full article

This study investigated how different extraction parts of raw materials and different flocculation methods affect the extraction yield, structure, and properties of sodium alginate. The aim was to improve the quality of sodium alginate and provide theoretical guidance for upstream enterprises. In this study, Lessonia nigrescens (LN) was used as a raw material. The alkali treatment conditions were optimized. The optimal extraction conditions were determined to be a 2% sodium carbonate concentration, a duration of 4 h, a material-to-liquid ratio of 1:40, and a temperature of 60 °C, achieving an extraction yield of 43.03%. LN was categorized into blades, stipes, holdfasts, and whole seaweed for comparative analysis, and sodium alginate was flocculated using the acid, calcium, and ethanol methods. Structural and physicochemical analyses showed that the mannuronic acid/guluronic acid (M/G) ratios of the twelve sodium alginate samples ranged from 5.73 to 8.76. The LN part had a greater influence on the M/G ratio than the flocculation method. The relative molecular weight (2343–3074 kDa) and viscosity (170–331 mPa·s) exhibited consistent trends. For the same part, the effect of the flocculation method on the molecular weight followed the order ethanol > acid > calcium. The physicochemical properties of the extracted sodium alginate met the requirements specified in the physicochemical index standard GB 1886.243-2016 of China. Full article

The growing demand for organic products is having a transformative effect on the alcoholic beverage industry. This work investigates the possibility of producing organic ethanol only from sugarcane final molasses as a nutrient vector and Saccharomyces cerevisiae in the absence of inorganic nitrogen or phosphorus compounds. The Plackett–Bürman design included the pseudo-factors (X4–X6) due to the experimental design requirements. These factors represent the possible influence of uncontrolled variables, such as pH or nutrient interactions. Subsequently, a predictive quadratic model using Box–Behnken design with the real variables (sugar concentration, yeast dose, and incubation time) was developed and validated $(R^2=0.977)$ with internal validation; given the lack of replications and the sample size, this value should be interpreted with caution and not as generalizable predictive evidence. Further experiments with replications and cross-validation will be required to confirm its predictive capacity. Through statistical optimization, the maximum cell proliferation of $432\times {10}^6$ cells/mL was achieved under optimal conditions of 8°Brix sugar concentration, 20 g/L dry yeast, and 3 h incubation time. The optimized fermentation process produced 7.8% v/v ethanol with a theoretical fermentation efficiency of 78.52%, an alcohol-to-substrate yield of 62.15%, and a productivity of 1.86 g/L·h, representing significant improvements of 21.9%, 24.6%, 31.0%, and 10.1%, respectively, compared with non-optimized conditions. The fermentation time was reduced from 48 to 42 h while maintaining superior performance. These results demonstrate the technical feasibility of producing organic ethanol using certified organic molasses and no chemical additives. Overall, these findings should be regarded as proof of concept. All experiments were single-run without biological or technical replicates; consequently, the optimization and models are preliminary and require confirmation with replicated experiments and external validation. Full article

The utilisation of agrifood waste ashes has the potential to enhance the nutrient content of cereal crops, thereby optimising both yield and grain quality. This study investigated rye grain composition, the fermentation efficiency, and volatile compounds in mashes made from crops fertilised with agrifood waste ashes derived from the combustion of corn cob, wood chips, and biomass with defecation lime. The ashes were applied at 2, 4, and 8 t/ha, separately and as mixtures of corn cob (25%) with wood chips (75%) and corn cob (50%) with biomass and defecation lime (50%). Rye mashes were prepared using the pressureless starch liberation method. The starch content in the majority of the rye grains was comparable to the control sample (57.12 g/100 g). The range of ethanol concentrations observed in the fermented mashes was from 55.55 to 68.12 g/L, which corresponded to fermentation yields of 67.25–76.59% of theoretical. The lowest fermentation yield was exhibited by the mash derived from rye cultivated on soil fertilised with a 50:50 mixture of ashes from corn cob and biomass with defecation lime at 8 t/ha. This mash contained more than double the acetaldehyde concentration and total aldehyde content compared to the other samples. These findings demonstrate the potential of using waste biomass ash as a source of macro- and microelements for rye cultivation, enabling the production of agricultural distillates. To ensure high fermentation efficiency and low aldehyde levels, ash dosage and composition need to be established based on experimental optimisation. Full article

The electrochemical reduction of carbon monoxide (COER) offers a promising route for generating value-added multi-carbon (C₂₊) products, such as ethanol, but achieving high catalytic performance remains a significant challenge. Herein, we performed comprehensive density functional theory (DFT) computations to evaluate CO-to-ethanol conversion on single metal atoms anchored on graphitic carbon nitride (TM/g–CN). We showed that these metal atoms stably coordinate with edge N sites of g–CN to form active catalytic centers. Screening 20 TM/g–CN candidates, we identified V/g–CN and Zn/g–CN as optimal catalysts: both exhibit low free-energy barriers (<0.50 eV) for the key ^*CO hydrogenation steps and facilitate C–C coupling via an Eley–Rideal mechanism with a negligible kinetic barrier (~0.10 eV) to yield ethanol at low limiting potentials, which explains their superior COER performance. An analysis of d-band centers, charge transfer, and bonding–antibonding orbital distributions revealed the origin of their activity. This work provides theoretical insights and useful guidelines for designing high-performance single-atom COER catalysts. Full article

Cowpea (Vigna unguiculata L.) pods are an underexploited by-product of legume production with significant antioxidant potential. Their recovery and characterization support sustainable waste valorization in agri-food systems. This study aimed to optimize the extraction of phenolic compounds (PCs) with antioxidant capacity (AOC) from cowpea pods and identify key bioactives through experimental and theoretical approaches. First, high-intensity ultrasound extraction was optimized using response surface methodology with ethanol–water mixtures. Under optimal conditions (20% amplitude, 15 min, 50% ethanol), the ethanolic extract (Eo) showed higher total phenolic content (TPC) and AOC than the aqueous extract (Wo). Subsequently, fractionation by Sephadex LH-20 chromatography yielded fractions E2 and W2 with enhanced TPC and AOC. Phytochemical profiling showed that E2 was enriched in caftaric acid, p-coumaric acid, and morin, while W2 had higher levels of caftaric, p-coumaric, and caffeic acids. Finally, density functional theory was used to assess thermodynamic parameters linked to antioxidant mechanisms (HAT, SET-PT, SPLET), revealing morin as the most effective radical scavenger, followed by caffeic and caftaric acids. These findings show that AOC depends not only on phenolic concentration but also on molecular structure and solvent interactions. Thus, cowpea pod extracts and fractions hold promise for antioxidant-rich formulations in food, nutraceutical, or cosmetic applications. Full article

The presence of various inhibitory compounds in lignocellulosic hydrolysates poses a significant challenge for bioethanol production, requiring yeasts with exceptional multistress tolerance. This study introduces the novel application and demonstrates the robust performance of the nonconventional yeast Saccharomycodes ludwigii APRE2 for efficient bioethanol production directly from undetoxified sugarcane bagasse hydrolysate (SBH) at 37 °C. This approach critically eliminates the need for the costly detoxification pretreatments often required in industrial processes. Initial experiments confirmed S. ludwigii APRE2’s capability to ferment undetoxified SBH. To optimize fermentation efficiency, a central composite design (CCD) approach was implemented. This statistical method identified the following precise optimal parameters: sugar concentration (143.95 g/L), diammonium phosphate (4.99 g/L), pH (4.98), yeast extract (8.94 g/L), and magnesium sulfate (2.22 g/L). Under these optimized conditions, impressive results were achieved: a maximum ethanol concentration of 38.11 g/L, productivity of 1.59 g/L·h, and yield of 0.45 g/g. Notably, the ethanol productivity and theoretical yield achieved by S. ludwigii APRE2 using this inhibitor-rich, undetoxified SBH (containing acetic acid, formic acid, furfural, and 5-(hydroxymethyl)furfural) were superior to those previously reported for other ethanologenic yeasts under similar challenging conditions. This research establishes S. ludwigii APRE2 as a highly promising and industrially viable candidate for sustainable bioethanol production from lignocellulosic biomass, with its key novelty being its superior performance on undetoxified feedstocks, potentially reducing overall production costs. Full article

The endocarp of Exocarpium Citri Grandis (ECG) is abundant in various bioactive components, such as polysaccharides; however, there are few studies on them. Thus, it is highly necessary to carry out further research on the structural characterization and biological activities of ECG polysaccharides (EPs), which are important bioactive substances. In this study, water-extracted EPs were precipitated by ethanol with final concentrations of 50%, 70%, and 90% (v/v), respectively. Three crude polysaccharides (EP50, EP70, and EP90) were fractioned successively. The three polysaccharide fractions were structurally elucidated and were investigated in vitro for their biological activities related to glucose metabolism containing inhibitory effects on α-glucosidase and non-enzymatic glycosylation and their antioxidant capacities. The main results are summarized as follows: (1) Gradient ethanol precipitation and physicochemical properties of EPs: The yields of EP50, EP70, and EP90 were 11.18%, 0.57%, and 0.18%, respectively. The total sugar contents were 40.01%, 52.61%, and 53.46%, and the uronic acid contents were 30.25%, 18.11%, and 8.17%, respectively. In addition, the three fractions had the same composition of monosaccharides, including rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid, with differences in the content of neutral and acidic monosaccharides. They all may be branched polymers and spherical conformation, and they were acidic polysaccharides containing esterified and non-esterified uronic acids, pyranose-form sugars, and glycosidic linkages of α-configuration and β-configuration, with esterification degrees of 32.25%, 28.82%, and 15.58%, respectively. Meanwhile, EP50, EP70, and EP90 were mainly amorphous, and the molecular conformation in solution was a spherical branching polymer without a triple helix structure. The EPs exhibited excellent thermal stability, with their structures remaining stable below 170 °C. (2) In terms of activity research, the results showed that EPs had a good α-glucosidase inhibitory effect with IC₅₀ values of 1.17 mg/mL, 1.40 mg/mL, and 2.72 mg/mL, respectively, among which EP50 was the best. EP50, EP70, and EP90 displayed antioxidant activity by scavenging DPPH and ABTS radicals as well as oxygen radical absorbance capacity. Among them, EP90 had the strongest antioxidant activity. Furthermore, the EPs showed prominent effects on the inhibitory activity of non-enzymatic glycosylation. In summary, the research on the extraction of polysaccharide from ECG provides a technical reference for the further utilization of ECG resources. This study on antioxidant activity provides theoretical support for their use as a natural antioxidant. As oxidation and glycation are relevant to diabetic complications, the result of this work suggests that EPs may be effective in preventing and treating diabetic complications. Full article

The high viscosity and oxygen content of pyrolysis crude oil hinder the advancement of pyrolysis technology. To address the issue, this study conducted hydrodeoxygenation upgrading experiments on pyrolysis crude oil using hydrothermal directional conversion. A variable analysis was performed to assess the differences in upgrading effects based on the active metal (Ru, Pt) and the supports (activated carbon, Nb₂O₅, MgO) of the supported catalyst, and further investigations were conducted on the catalyst with bimetallic doping modification. Optimal reaction conditions were determined by adjusting the reaction temperature. Additionally, directional conversion studies of model compounds were carried out to elucidate the reaction pathway. The results indicated that the Pt/MgO catalyst achieved the highest yield of stable and combustible compounds (hydrocarbons, alcohols, ethers, esters, and ketones), with a yield of 17.8 wt%. Upon modification with Ni doping, the yield increased by 49.5%. The upgrading effect improved with an increase in reaction temperature, and the yield of target compounds was 26.7 wt% at 290 °C, with an energy conversion rate of 72.6% and a selectivity of 75.8%. Moreover, the physicochemical properties of the upgraded oil were similar to those of ethanol. All three model compounds underwent 100% conversion. This study provides both experimental support and a theoretical foundation for the further development of biomass conversion technology. Full article

The aim of the present study was to optimize the process parameters for the extraction and purification of total flavonoids from Polygonum perfoliatum L., in addition to analyzing their chemical composition and evaluating their activity against varicella-zoster virus (VZV) and antioxidant activity. The optimum extraction process was determined using one-way and response surface methods with the following conditions: ethanol concentration of 82.00%, temperature of 90.29 °C, solid-to-liquid ratio of 1:32.78 g/mL, extraction time of 1.5 h, and two extractions with a yield of 14.98 ± 0.11 mg/g. Purification was then carried out using D101 macroporous resin to obtain a flavonoid purity of 43.00 ± 2.55%, which was 3.38 times higher than that of the crude extract (12.74 ± 1.04%). Further purification was carried out using a 1:9 hybrid column of macroporous resin and polyamide, and the purity of flavonoids was enhanced to 59.02 ± 2.23%, which is 1.37 times higher than that of the macroporous resin purifier (43.00 ± 2.55%) and 4.63 times higher than that of the crude extract (12.74 ± 1.04%). Seventy-nine flavonoids were identified using ultra-performance liquid chromatography-tandem high-resolution mass spectrometry (UPLC-HRMS). In addition, the purified flavonoids showed good anti-VZV and antioxidant activities. Therefore, this study can provide technical support and theoretical basis for the further development and utilization of Polygonum perfoliatum L. resources. Full article

The study aimed to evaluate the genetic diversity of 41 sweet sorghum genotypes from seven countries for key biofuel-related traits over two sorghum growing seasons (2020 and 2021) in a semi-arid Mediterranean environment. Genotypes were assessed for key bioethanol production traits such as fresh stalk yield (FSY), juice yield (JY), Brix, dry biomass yield (DBY), theoretical juice ethanol yield (JEY), theoretical lignocellulosic ethanol yield (LEY), theoretical total ethanol yield (TEY), as well as their potential for solid biofuel production, measured through bagasse ash, nitrogen, and moisture content. Significant variations were observed among genotypes across most traits, analyzed using analysis of variance, principal component analysis, and hierarchical cluster analysis, identifying DBY, LEY, and TEY as the primary contributors to overall genetic variation. Cluster analysis grouped the genotypes into five distinct clusters, highlighting the diversity in biofuel-related traits. The correlation analysis revealed significant positive relationships between traits such as FSY, DBY, and TEY, indicating that higher biomass production directly enhances ethanol output. Strong positive correlations between FSY and TEY underscore the importance of biomass yield in maximizing ethanol production. However, traits like bagasse ash and nitrogen contents, which were negatively correlated with JEY, LEY, and TEY, present challenges in improving biomass combustion quality. The study concludes that certain genotypes, particularly ‘Yellow Bonnet’ and ‘IS 3556’, exhibited strong potential for biofuel production in semi-arid Mediterranean climates where water scarcity and high temperature favor genotypes with high biomass and sugar yields. These genotypes demonstrated high JEYs, LEYs, and TEYs, suggesting their adaptability to the unique environmental stresses of this region, making them good candidates for sustainable biofuel production in similar climates. Full article

The orthogonal array design method was used to optimize ultrasonic-assisted extraction of resveratrol from peanut sprouts. The results showed that the highest extraction yield of resveratrol using ultrasonic-assisted extraction could be up to 1.1%. The optimal extraction conditions were liquid to solid ratio of 30:1 (mL/g) and ethanol concentration of 80% (v/v) as solvent for 40 min at the temperature of 70 °C. AB-8 macroporous adsorption resin was used to purify the crude extract and the resveratrol content increased to 47.5% after one treatment run. The optimal adsorption parameters were initial concentrations in the sample solution of 2 mg/mL, a pH of 5.0, a flow rate of 2 mL/min, and a temperature of 25 °C. The optimal desorption parameters were 60% ethanol and a flow rate of 1 mL/min. The chemical composition of the peanut sprout’s resveratrol sample was investigated via HPLC, and the predominant constituents were found to be protocatechuic acid, catechins, caffeic acid, epicatechuic acid, resveratrol, and rutin. The antioxidant activities of the resveratrol were measured via the following different analytical methods: reducing power, 2,2-diphenyl-1-picrylhdrazyl (DPPH), hydroxyl radical-scavenger activity, superoxide radical-scavenger activity, the β-carotene bleaching test, and the scavenging nitrite test. The results indicated that the resveratrol in peanut sprouts have significant antioxidant activities and can be used as a source of potential antioxidant. And peanut sprout’s resveratrol has the potential and valuable application to be used as a new type of resveratrol resource. The finding of this study can provide some theoretical reference for the comprehensive utilization of peanut resources in the development of antioxidant health foods. Full article

To obtain carbon dots (CDs) with narrow full width at half maximum (FWHM) and long-wavelength emission, carbon sources with high conjugate sizes and abundant functional groups can be employed to synthesize CDs. In this study, orange-emissive carbon dots (OCDs) were synthesized with phloroglucinol and rhodamine B as precursors. When the molar ratio of them was 30:1, and ethanol was served as the solvent, OCDs with optimized emission wavelength at approximately 580 nm, an FWHM of 30 nm, and a quantum yield (QY) of 27.31% were obtained. Subsequently, the OCDs were incorporated into polyvinyl alcohol (PVA) to fabricate solid-state OCD/PVA fluorescent films, which exhibited an FWHM of 47 nm. The PVA matrix facilitated the dispersion of OCDs, thereby suppressing non-radiative energy transfer among the OCDs and enhancing luminescence efficiency. Consequently, compared with OCDs, the OCD/PVA film exhibited significant luminescent enhancement, and the QY of the composite film was increased to 84.74%. Moreover, OCD/PVA film showed good transmittance and thermal stability. This research offers a solid theoretical and experimental foundation for the potential applications of CDs in the field of solid-state lighting. Full article