Chestnut Shell Research Articles

ZIF-based boronic acid modified molecular imprinted polymers in combination with silver nanoparticles/glutathione coated graphene oxide adsorbent for the selective enrichment of ellagic acid

This study focuses on the extraction of ellagic acid (EA), a valued phenolic compound, from agricultural waste chestnut shell samples. A novel approach is introduced using a combination of boronic acid-modified molecularly imprinted polymer (ZIF@B@MIP) and a nanocomposite of graphene oxide-coated silver nanoparticles (GO@Ag@GSH) to enhance EA enrichment. ZIF@B@MIP precisely captured EA through boronate affinity-based molecular imprinting recognition. ZIF@B@MIP employs boronate affinity-based molecular imprinting recognition to precisely capture EA, while GO@Ag@GSH provides ample adsorption sites. The synergistic effect of ZIF@B@MIP and GO@Ag@GSH demonstrates excellent enrichment capability and selectivity for EA. High-performance liquid chromatography (HPLC) is employed for sensitive EA detection, achieving a maximum adsorption capacity of 46.25 mg g–1 and an imprinting factor of 3.01. The adsorption capacity to different structural analogue was investigated, and the selectivity coefficient was used to evaluate the selectivity, and its value was 1.16–3.01. The method successfully enriches EA in chestnut shell samples with a recovery rate of 95.6 %–110.1 %. This research presents an innovative approach for effective phenolic components enrichment from natural resources for pharmaceutical and biochemical applications.

Hydrothermal Synthesis of MnO2 Microspheres and Their Degradation of Toluene.

Various urchin-like MnO2 materials were obtained with a facile hydrothermal method through controlling the Mn precursor, reaction time, and reaction temperature. The property of MnO2 materials was characterized by scanning electron microscopy, X-ray diffraction, and H2 temperature-programmed reduction. The results showed that the Mn precursor could significantly impact the morphology of as-prepared MnO2. When the precursor was Mn(CH3COO)2·4H2O, the MnO2 morphology consisted of tennis-like microspheres assembled by nanorods. While the precursor was MnCl2·4H2O, the sample morphology was a chestnut shell, and the samples were sea urchin microspheres, as the precursor was MnSO4·H2O. At the same time, the morphology of MnO2 was affected by hydrothermal time and temperature. The nanoneedles on the microsphere surface gradually lengthened with increasing hydrothermal time and hydrothermal temperature, until nanowires were formed. MnO2 crystallinity was also influenced by hydrothermal temperature. It was γ-MnO2 as the temperature was 50 and 80 °C while evolved to be α-MnO2 and β-MnO2 when the temperature increased to 140 °C. As MnO2 (MnO2-1 h, MnO2-2 h, MnO2-4 h, and MnO2-6 h) was prepared to degrade toluene, all the samples could completely catalyze toluene at the temperature of 225 °C. However, the MnO2-4 h showed the best catalytic effect at a lower temperature.

Novel insights into enzymes inhibitory responses and metabolomic profile of supercritical fluid extract from chestnut shells upon intestinal permeability

The health benefits of chestnut (Castanea sativa) shells (CSs) have been ascribed to phytochemicals, mainly phenolic compounds. Nevertheless, an exhaustive assessment of their intestinal absorption is vital considering a possible nutraceutical application. This study evaluated the bioactivity of CSs extract prepared by Supercritical Fluid Extraction and untargeted metabolomic profile upon in-vitro intestinal permeation across a Caco-2/HT29-MTX co-culture model. The results demonstrated the neuroprotective, hypoglycemic, and hypolipidemic properties of CSs extract by inhibition of acetylcholinesterase, α-amylase, and lipase activities. The untargeted metabolic profiling by LC-ESI-LTQ-Orbitrap-MS unveiled almost 60 % of lipids and 30 % of phenolic compounds, with 29 metabolic pathways indicated by enrichment analysis. Among phenolics, mostly phenolic acids, flavonoids, and coumarins permeated the intestinal barrier with most metabolites arising from phase I reactions (reduction, hydrolysis, and hydrogenation) and a minor fraction from phase II reactions (methylation). The permeation rates enhanced in the following order: ellagic acid < o-coumaric acid < p-coumaric acid < ferulaldehyde ≤ hydroxyferulic acid ≤ dihydroferulic acid < ferulic acid < trans-caffeic acid < trans-cinnamic acid < dihydrocaffeic acid, with better outcomes for 1000 µg/mL of extract concentration and after 4 h of permeation. Taken together, these findings sustained a considerable in-vitro intestinal absorption of phenolic compounds from CSs extract, enabling them to reach target sites and exert their biological effects.

Experimental investigation of chestnut shells gasification

Fossil fuels substitution with renewable energy sources is necessary for an effective decarbonization. Biomass can represent a valid alternative to fossil fuels, reducing greenhouse gas emissions. Furthermore, bioenergy generation avoids costs and problems related to biomass disposal. This study presents the energetic valorisation of chestnut shells, a byproduct of the chestnut transformation processes. Through a thermo-conversion system based on gasification, this material was considered not as a waste, but as a resource to be exploited to produce bioenergy and biochar. The fuel gas produced through the gasification process can partially replace the LPG currently used to meet the energy required for the brulage and steam peeling processes. Experimental gasification tests were carried out to evaluate this biomass by means of a laboratory scale micro-gasifier (Imbert downdraft type). Chestnut shells were pelletized with a pelletizer machine to avoid the bridging effect inside the gasifier and increase its energy density. The fuel gas obtained was sampled and analyzed to measure its composition and HHV. In addition, the gasification efficiency was calculated obtaining a value of 70%, a result in line with the ones obtained with higher quality biomasses.

Organic substrates in the development of camu-camuzeiro (Myrciaria dubia (H. B. K.) McVaugh) in the amazon region

Amazon is the largest tropical forest on the planet, it has a variety of plant species with emphasis on manyfruit trees, such as the camu-camuzeiro (Myrciaria dubia (H. B. K.) McVaugh), which occurs naturally on thebanks of rivers, lakes, lowlands and flooded forest of the Amazon. The objective of this study is to evaluate thedevelopment of camu-camuzeiro seedlings in different organic substrates. The experiment was conductedin the seedling production nursery of the Federal Rural University of Amazon. The experimental design wasentirely randomized, with ten treatments and five repetitions, each portion was represented by ten plants,totaling 500 seedlings. The substrates evaluated were: T1 - Humus; T2 - Humus + Bird manure; T3 - Humus + Bovinemanure; T4 - Humus + Açaí kernel; T5 - Humus + Chestnut shell; T6 - Humus + Chestnut shell + Poultry manure;T7 - Humus + Bovine manure + Chestnut shell; T8 - Humus + Açaí kernel + Poultry manure; T9 - Humus + Açaíkernel + Bovine manure; T10 - Commercial. The different substrates used influenced the development of camucamuzeiroseedlings evaluated at 180 days. The treatments with a substrate based on Humus (T1), Humus + Açaíkernel (T4), Humus + Chestnut shell (T5), Humus + Chestnut shell + Poultry manure (T6), Humus + Bovine manure +Chestnut shell (T7), Humus + Açaí Kernel + Bovine manure (T9) and the commercial substrate (T10) are the bestfor a satisfactory development of this crop in the production field.

Physicochemical Characterization of Potassium Hydroxide Pretreated Chestnut Shell and Its Bioconversion to Lactic Acid by Lacticaseibacillus rhamnosus

Lactic acid (LA) is an important platform chemical with a wide range of applications, including bioplastic materials, and demand for it is growing rapidly. However, the high cost of feedstock for LA production is a major barrier to industrial production. This study designed a process to produce LA from chestnut shell (CS), a low-cost biomass. The entire process includes KOH pretreatment, enzymatic saccharification, and fermentation. This study investigated the chemical compositions and physicochemical properties of raw CS and KOH pretreated CS (KpCS) to evaluate the impact of the pretreatment process that enhances the conversion of cellulose into glucose. The results showed that KOH affected the lignin removal and surface morphological changes of CS, and FT-IR and TGA patterns correlated to increased cellulose fractions were found. In the fermentation process, Lacticaseibacillus rhamnosus was selected as a prominent LA producer, and the fermentation using KpCS hydrolysate was carried out. As a result, cell growth (27%), glucose consumption (23%), and LA production (21%) were all achieved higher than the control group. The LA production yield from our suggested process was estimated to be 187 g/kg CS, and we concluded that CS has a high potential as a feedstock for LA production.

ADSORPTION OF DEEP RED ON AC PREPARED FROM CHESTNUT SHELL

Adsorption of Deep Red (DR) on activated carbon (AC) produced from chestnut shell has been studied. Chemical activation process with ZnCl2 was applied to the ground chestnut shells at 3:1 (ZnCl2/Raw Material) impregnation ratio, and then at 500 °C, the carbonization process was used to produce AC. The surface area of the AC was defined as 2187 m2/g. Effects of AC dose, contact time, pH, temperature and initial concentration on deepred adsorption have been studied. In experimental studies, 97.4% dye removal was achieved using 0.1 g AC at pH 2.5, 45°C and at 100 mg/L. Dye removal has been seen to increase at all initial concentrations as the temperature increased. The kinetic data are corresponding to the pseudo 2nd order kinetic model. The finding was that the adsorption process corresponding to the Freundlich isotherm model. According to ΔS, ΔH, and ΔG thermodynamic data, DR adsorption on AC is an endothermic and chemical adsorption. The study’s findings revealed that AC prepared from chestnut shell is suitable for removing DR from aqueous solutions.

Study on removal of oxytetracycline by KOH-modified chestnut shell biochar: Based on two-dimensional spectroscopy and molecular density functional theory

The adsorption type and mode of biochar have been extensive research. However, as an indispensable link to reveal the adsorption mechanism, the study of the adsorption sequence is greatly lacking, especially for different pollutants, the way of adsorption is different. In this study, the observation of the adsorption sequence was amplified by KOH modification and optimization of experimental conditions. Persistent radicals (PFRs) combined with liquid mass spectrometry (LC-MS) eliminated interference from oxidation-reduction. Notability, two-dimensional correlation spectroscopy (2D-COS), Raman and Fourier-transform infrared (FTIR) spectroscopy reveals that the vibration amplitude and velocity of the hydroxyl group are better than those of the carboxyl group, methyl group, and methylene group under time interference. Electrostatic adsorption (EA), H-bood (HB), and π-π* contribute 63.5 %, 35.3 %, and 1.2 %, respectively, to the adsorption of oxytetracycline (OTC). The density functional calculation shows that the nucleophilic and electrophilic reactions of OTC are easy to occur near oxygen atoms and nitrogen atoms. The Fukui function proves that the free radical weight of the N atom is 0.096, which is further confirmed the theoretical predictions by liquid chromatography and four-stage electrostatic field orbital trap mass spectrometry. Finally, this study provides a deeper insight into the biochar adsorption OTC.

Crystal violet adsorption onto modified biosorbent prepared from agricultural waste: kinetics, isotherm and thermodynamic studies

The present study investigated crystal violet removal by modifying the chestnut shell with a chemical activation method. For this purpose, H2SO4 and NaOH pretreatments were applied to the chestnut shell and the pretreatment method that gave the best performance under the same conditions was determined. The best adsorption efficiency was achieved with the NaOH pretreatment (99.06%) and the crystal violet adsorption reached equilibrium within 60 min. After selecting the best chemical activation method, the modified chestnut shell was characterized before and after adsorption (FTIR and SEM). Furthermore, the effects of parameters such as pH, initial crystal violet concentration, adsorbent dosage, temperature, and contact time were observed. Moreover, isotherm, kinetics and thermodynamics of the adsorption process were researched in detail. The best results were obtained with the Langmuir isotherm model (R2=0.99) and the pseudo-second-order kinetic model (R2=0.99). Thermodynamic parameters showed that the adsorption process is spontaneous, endothermic and feasible.

Chestnut shells in the diet of lamb: Effects on growth performance, fatty acid metabolism, and meat quality

This study aimed to formulate a diet for finishing lambs that included chestnut shells, an underexploited by-product of chestnut industry, and evaluate its effects on in vivo performance and meat quality. Twenty-eight male lambs (race Romane; 27.9 ± 2.7 kg bodyweight) were divided into 4 groups and fed 4 different pelleted diets: one control, one containing chestnut shells (CNS), one containing sainfoin, and one containing both. After 21 days of feeding trial, at slaughter, rumen and abomasum digesta were sampled for the analysis of fatty acid (FA) profile, and meat was analysed for FA profile, vitamins content, and oxidative stability. All lambs showed similar growth performance and carcass characteristics. The CNS diet limited (P = 0.001) ruminal biohydrogenation, increasing (P < 0.050) the C18:1 trans11 proportion in both rumen and abomasum. Consequently, the C18:1 trans11 content of CNS meat was more than 50% higher (P = 0.006) than in the other groups. No differences in the discolouration and lipid oxidation of raw meat were observed over 9 days of refrigerated storage. The phenolic compounds of chestnut shells may have preserved the low native α-tocopherol level of the CNS diet. Chestnut shells can be fed to lambs without detrimental effect on performance, potentially improving meat FA profile.

Predicting the effects of in-vitro digestion in the bioactivity and bioaccessibility of antioxidant compounds extracted from chestnut shells by supercritical fluid extraction – A metabolomic approach

Chestnut (Castanea sativa) shells (CS) are an undervalued antioxidant-rich by-product. This study explores the impact of in-vitro digestion on the bioaccessibility, bioactivity, and metabolic profile of CS extract prepared by Supercritical Fluid Extraction, aiming its valorization for nutraceutical applications. The results demonstrated significantly (p < 0.05) lower phenolic concentrations retained after digestion (38.57 µg gallic acid equivalents/mg dry weight (DW)), reaching 30% of bioaccessibility. The CS extract showed antioxidant/antiradical, hypoglycemic, and neuroprotective properties after in-vitro digestion, along with upmodulating effects on antioxidant enzymes activities and protection against lipid peroxidation. The metabolic profile screened by LC-ESI-LTQ-Orbitrap-MS proved the biotransformation of complex phenolic acids, flavonoids, and tannins present in the undigested extract (45.78 µg/mg DW of total phenolic concentration) into hydroxybenzoic, phenylpropanoic, and phenylacetic acids upon digestion (35.54 µg/mg DW). These findings sustain the valorization of CS extract as a promising nutraceutical ingredient, delivering polyphenols with proven bioactivity even after in-vitro digestion.

Process optimization and characterization of nanocellulose from chestnut shell

Nanocellulose, a unique and promising natural substance extracted from cellulose-based materials, has gained tremendous attention for its use in various applications. Latest studies hypothesized that green extraction techniques reveal high-yield cellulose nanoparticles with lower environmental hazard and also highlighted that selectivity and characteristics of final products are highly dependent upon process parameters. This study aimed to produce nanocellulose powders from the chestnut shell –an agroindustrial waste without pertinent reuse– by acid hydrolysis (conventional), microwave-assisted acid hydrolysis, hydrotropic solvent, and deep eutectic solvent extraction techniques. The effectiveness of process parameters was investigated, and optimum conditions were determined by targeting the highest yields for each method. Additionally, the physico-chemical and microstructural properties of nanocellulose powders produced by each method were analyzed to investigate the product characteristics. The highest yield was obtained by deep eutectic solvent extraction (99.2%) followed by hydrotropic solvent (89.6%), conventional (64.5%), and microwave-assisted (34.1%) extractions. The methods bearing strong acid solvents resulted in a higher crystallinity index (up to 81%). The highest viscosity and absolute zeta potential values were obtained in deep eutectic solvent extraction as 843.6 cp and −23.7 mV, respectively. For all nanocellulose suspensions, the storage modulus (G′) was greater than the loss modulus (G″), indicating a more gel-like behavior. Nanocellulose powders produced by different methods had characteristic Fourier transform Infrared (FTIR) spectrum. The results of X-ray diffractometer (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) evidenced that nanofibrils could be produced via hydrotropic and deep eutectic solvent extraction systems while acid hydrolysis, i.e., conventional and microwave-assisted extraction generate nanocrystals. Obtained results indicated that green solvent systems could be utilized in the production of nanocellulose with many advantages, including efficiency, sustainability, reduced environmental harm, and low cost.

Chestnut Shell Polyphenols Inhibit the Growth of Three Food-Spoilage Bacteria by Regulating Key Enzymes of Metabolism.

The microbial contamination of food poses a threat to human health. Chestnut shells, which are byproducts of chestnut processing, contain polyphenols that exert various physiological effects, and thus have the potential to be used in food preservation. This study investigates the bacteriostatic effect and mechanism(s) of the action of chestnut shell polyphenols (CSPs) on three food-spoilage bacteria, namely Bacillus subtilis, Pseudomonas fragi, and Escherichia coli. To this end, the effect of CSPs on the ultrastructure of each bacterium was determined using scanning electron microscopy and transmission electron microscopy. Moreover, gene expression was analyzed using RT-qPCR. Subsequent molecular docking analysis was employed to elucidate the mechanism of action employed by CSPs via the inhibition of key enzymes. Ultrastructure analysis showed that CSPs damaged the bacterial cell wall and increased permeability. At 0.313 mg/mL, CSPs significantly increased the activity of alkaline phosphatase and lactate dehydrogenase, as well as protein leakage (p < 0.05), whereas the activity of the tricarboxylic acid (TCA) cycle enzymes, isocitrate dehydrogenase and α-ketoglutarate dehydrogenase, were inhibited (p < 0.05). The expression levels of the TCA-related genes gltA, icd, sucA, atpA, citA, odhA, IS178_RS16090, and IS178_RS16290 are also significantly downregulated by CSP treatment (p < 0.05). Moreover, CSPs inhibit respiration and energy metabolism, including ATPase activity and adenosine triphosphate (ATP) synthesis (p < 0.05). Molecular docking determined that proanthocyanidins B1 and C1, the main components of CSPs, are responsible for the antibacterial activity. Therefore, as natural antibacterial substances, CSPs have considerable potential for development and application as natural food preservatives.

Exploring the potential of conventional and flash pyrolysis methods for the valorisation of grape seed and chestnut shell biomass from agri-food industry waste

Residual biomass is a valuable and growing by-product, but often underutilized. This research aims to investigate the possible strategies for the energetic valorisation of agri-food industry wastes: grape seed and chestnut shell. Pyrolysis thermal process was the selected for this work. Applied to biomass, pyrolysis is a promising method for the simultaneous production of biochar, bio-oil, and gas. Two different pyrolysis processes were conducted: conventional pyrolysis at 750 °C and flash pyrolysis at 750 °C and 850 °C. Flash pyrolysis yielded superior product properties compared to conventional pyrolysis. The gas obtained through flash pyrolysis presented a four-fold higher high heating value due to increased CH4 and H2 content. Bio-oil contains over 90% of polycyclic aromatic hydrocarbons, and calorific value reached up to 32 MJ kg−1 for grape seed, which is 7% more than bioethanol HHV. Biochar can be used both as fuel or as activated carbon precursor due to its high carbon content (91%). Calorific value of chestnut shell biochar (32.7 MJ kg−1), comparable to mineral coals, increased by 72% with respect to the value of this untreated raw material. This work approved the potential of flash pyrolysis as a method to process biomass wastes in a renewable energy scenario.

Exploring the Impact of In Vitro Gastrointestinal Digestion in the Bioaccessibility of Phenolic-Rich Chestnut Shells: A Preliminary Study

Chestnut shells (CS), the principal by-product of the chestnut processing industry, contain high concentrations of flavonoids and other polyphenols with huge interest for the nutraceuticals field. Nonetheless, the bioaccessibility and bioactivity of phytochemicals can be influenced by their digestibility, making it imperative to evaluate these activities prior to application of CS as a nutraceutical ingredient. This work aims to appraise the effects of in vitro simulated gastrointestinal digestion on the bioaccessibility, bioactivity, and metabolic profiling of CS. An increase in the total phenolic and flavonoid contents, antioxidant/antiradical properties, radical scavenging capacity, and inhibition on acetylcholinesterase activity was evidenced during in vitro simulated digestion. Metabolomic profiling by LC-ESI-LTQ-Orbitrap-MS revealed changes during the simulated digestion, particularly in phenolic compounds (46% of total compounds annotated), lipids (22%), phenylpropanoids (9%), organic acids (7%), carbohydrates (5%), nucleosides (5%), amino acids (4%), and alcohols (1%). Phenolic acids (gallic acid, syringic acid, and hydroxyphenylacetic acid) and flavonoids (epicatechin) were the major polyphenolic classes identified. The heatmap-positive correlations highlighted that the bioactivity of CS is closely related to the phenolic compounds and their bioaccessibility. These findings suggest the reuse of CS as a potential nutraceutical ingredient with antioxidant and neuroprotective effects, encouraging the use of appropriate extraction and/or encapsulation techniques to enhance the bioaccessibility of phenolic compounds.

Ultraviolet blocking ability, antioxidant and antibacterial properties of newly prepared polyvinyl alcohol-nanocellulose‑silver nanoparticles-ChunJian peel extract composite film

In this work, nanocellulose (CNC) from waste water chestnut (WCT) shell was firstly used for preparing nanocomposite films, by using ChunJian peel extract (CJPE) as a green reducing agent to synthesize silver nanoparticles (AgNPs), and then loading them into polyvinyl alcohol-nanocellulose (PVA-CNC) matrix, a multifunctional nanocomposite material that could be used in food packaging was developed. The prepared films were tested for mechanical strength, barrier properties, thermal properties, antibacterial, antioxidant and biocompatibility through various characterizations. The PVA-CNC-AgNPs-CJPE film had good thermostability, mechanical strength, barrier properties, and biocompatibility. Compared with pure PVA film and PVA-CNC film, PVA-CNC-AgNPs-CJPE could shield over 95 % of the UVB (320–275 nm) spectrum and UVC (275–200 nm) spectrum and most of the UVA (400–320 nm). By disk diffusion analysis, the inhibition zones of PVA-CNC-AgNPs-CJPE film against E. coli, P. aeruginosa, S. aureus and E. faecalis were 22.3 mm, 25.0 mm, 22.0 mm and 19.3 mm, respectively. The milk antibacterial simulation test confirmed that PVA-CNC-AgNPs-CJPE film could effectively limit bacterial reproduction and prolong the shelf life of milk. PVA-CNC-AgNPs-CJPE film had excellent UV barrier properties, good antioxidant properties and high-efficiency antibacterial activity, which is expected to be widely used in sustainable nanocomposite food packaging.

Surface area and porosity development of catalyst using agricultural waste Chestnut shell biomass as a bio-source for ethyl oleate production

By calcination and sulfurating Chestnut shell biomass (CNS), a solid acid catalyst was synthesized. In the preparation of the catalyst, a range of calcination temperatures (150 °C–350 °C) and time 2 h, a range of sulfonation temperatures (80 °C–160 °C), and a range of times (1–6 h) were examined in order to determine the effect on catalytic activity. The CNS300–SO3H catalyst was characterized by Brunauer-Emmett–Teller (BET), Fourier transforms infrared (FT–IR) spectroscopy, N2–adorption and desorption, and thermogravimetric analysis (TGA). A higher acid density (8.626 mmol/g–1) was found with the CNS300–SO3H catalyst, as well as a higher surface area (1198.12 m2/g–1). As part of the catalytic activity test, prepared catalysts were tested for their ability to catalyze the esterification of oleic acid with ethanol. Results revealed that a sulfonated activated carbon–CNS-derived acid catalyst is capable of esterifying oleic acid to about (95.25%) conversion. Chestnut-prepared catalysts showed better performance due to their high specific surface areas. Furthermore, the hydrophobic nature of the CNS300–SO3H catalyst made it stable for up to nine cycles of recycling. Catalyst is recyclable, and cheap feedstock makes the overall process more cost-effective and environmentally friendly.

Alkaline-thermal and mild ultrasonic pretreatments for improving biomethane yields: Impact on structural properties of chestnut shells

The high fiber content of chestnut shells (CS) makes biomethane production inefficient when using the anaerobic digestion (AD) method. Therefore, this study has evaluated for the first time the combined effect of alkaline-thermal (AT) and mild ultrasonic (US) pretreatments prior to the AD of CS. The cumulative biomethane yields (CMY) of untreated and pretreated (4% NaOH + 100 °C thermal + US) CS were 79.10 ± 7.9 and 266.9 ± 9.3 mL CH4/g VS, respectively. The effects of the pretreatment of lignocellulosic biomass at different intensities were interpreted according to amounts of lignocellulosic solubilization, soluble chemical oxygen demand/total chemical oxygen demand, and scanning electron microscope images. Solubilization of the lignin from CS with pretreatments varied between 44.5 and 65.6% w/w. The use of AT pretreatments, together with US pretreatments, successfully increased the solubility of lignocellulosic compounds compared to the first case, whilst CMYs showed a positive correlation with lignocellulosic solubilization amounts. After pretreatments, total volatile fatty acid (VFA) concentrations were measured in the anaerobic process, from which the highest VFA was measured to be 1555 ± 108 mg HAc L-1, well below the appropriate value for AD (≤8000 mg HAc L-1). After pretreatments, the CMYs were successfully simulated by the modified Gompertz and Logistic model (R2 = 0.942–0.984). This study presents a promising strategy in the sense that the biomethane yield of CS containing large amounts of fiber can be significantly increased by combined AT and mild US pretreatment methods.

Simulated Gastrointestinal Digestion of Chestnut (Castanea sativa Mill.) Shell Extract Prepared by Subcritical Water Extraction: Bioaccessibility, Bioactivity, and Intestinal Permeability by In Vitro Assays.

Chestnut shells (CSs) are an appealing source of bioactive molecules, and constitute a popular research topic. This study explores the effects of in vitro gastrointestinal digestion and intestinal permeability on the bioaccessibility and bioactivity of polyphenols from CS extract prepared by subcritical water extraction (SWE). The results unveiled higher phenolic concentrations retained after gastric and intestinal digestion. The bioaccessibility and antioxidant/antiradical properties were enhanced in the following order: oral < gastric ≤ intestinal digests, attaining 40% of the maximum bioaccessibility. Ellagic acid was the main polyphenol in the digested and undigested extract, while pyrogallol-protocatechuic acid derivative was only quantified in the digests. The CS extract revealed potential mild hypoglycemic (<25%) and neuroprotective (<75%) properties before and after in vitro digestion, along with upmodulating the antioxidant enzymes' activities and downregulating the lipid peroxidation. The intestinal permeation of ellagic acid achieved 22.89% after 240 min. This study highlighted the efficacy of the CS extract on the delivery of polyphenols, sustaining its promising use as nutraceutical ingredient.

Eco-friend air electrode for flexible quasi-solid-state electrolyte zinc-air battery based on spherical glucose biochar derived from biorefinery process

Biorefinery using waste biomass is a key technology for sustainable development and is widely used in renewable energy production. However, biorefineries for energy storage applications have rarely been studied. In this study, a zinc-air battery (ZAB), which is one of the eco-friendlier energy storage devices, is proposed using the biorefinery process. The spherical glucose biochar (SGBC) was produced by a two-step process. The first step was the saccharification which included NaOH pretreatment and enzymatic hydrolysis. The second step was the carbonization including hydrothermal reactions and carbonization. The SGBC/MnO2/poly(3,4-ethylenedioxythiophene) (PEDOT) composite (SMP) was produced by in-situ polymerization with Fe(ClO4)3. The SMP exhibited excellent oxygen reduction reactions (ORR) and oxygen evolution reaction (OER) comparable to Pt/C due to the complementary effects of each component. Therefore, the fabricated flexible quasi-solid-state electrolyte SMP-based ZAB (SMP-ZAB) displayed high performance. The SMP-ZAB exhibited a peak power density of 101.2 mW/cm3. The discharge was maintained for 9.6 h at 5 mA/cm3 and the charge-discharge cycle was maintained for 16 h without remarkable potential change (5 min each for charge and discharge at 5 mA/cm3). In addition, the SMP-ZAB could theoretically produce 9540 cells from 1000 g of chestnut shell (CNS), demonstrating the potential of mass production for industrial-scale production (electrode area: 4 cm2). These results suggest that the SMP-ZAB could be applied as a future wearable energy device with an eco-friendly process.