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Bagasse and straw are the two feedstocks used to produce cellulosic ethanol from sugarcane. Although this technology is advancing commercially, the differentiation between bagasse and straw remains elusive. This work investigates bagasse and straw supply, conditioning, and pretreatment in a pilot-scale steam-explosion continuous reactor (~ 10 kg/h feed) to illuminate the critical feedstock differences for process scale-up. Evaluating biomass across four sequential harvest seasons (2018–2021) shows that straw supplied in bales requires extra conditioning to reduce mineral matter and particle size before feeding into the reactor. Moreover, straw composition is more variable and consistently has lower contents of glucan (35.6–38.8%) and carbohydrate potential (glucose + xylose, 649–704 kg/dry tonne) compared to bagasse (40.8–42.9%; 735–760 kg/dry tonne). Biomass pretreatments without (190 °C, 5–15 min) and with sulfuric acid catalyst (149–170 °C; 5–15 min; 0.5–5.12%, m/m) show that straw differs from bagasse by presenting a higher acid neutralization capacity and about 5% of labile glucans. These results suggest that straw crushing and aqueous pre-extraction are promising strategies to reduce the dissimilarities with bagasse, thus facilitating the development of feedstock-agnostic biorefining. [ABSTRACT FROM AUTHOR]

Bitter melon vine (an agricultural waste product with high fiber content) is difficult to treat and has caused problems in the environment. This research aims to produce biochar through low-temperature pyrolysis assisted by non-polluting steam explosion. The physical and chemical properties of the biochar were characterized using scanning electron microscopy (SEM) images, specific surface area measurements (BET), X-ray diffraction patters (XRD), elemental analysis (EA), and Fourier transform infrared spectroscopy (FTIR). Next, the adsorption mechanism of methylene blue (MB) on the steam-exploded bitter melon vine biochar pyrolyzed at 200 °C (qBC200) and the effects of adsorption time, pH, initial concentration, adsorption temperature, and adsorbent dosage on the adsorption effect were investigated. Steam explosion destroyed the dense structure of the plant, increased the number of oxygen-containing surface functional groups, and improved the adsorption performance of the material. Therefore, qBC200 more effectively adsorbed MB than untreated biochar, reaching a saturated adsorption capacity of 267.72 mg/g. The MB adsorption kinetics and isothermal adsorption process of qBC200 align with the pseudo-second-order kinetic model and Langmuir isothermal equation (monolayer adsorption), respectively. The thermodynamic results show that MB adsorbs via a spontaneous, entropy-increasing exothermic reaction. The adsorption mechanism involves electrostatic attraction, hydrogen bonding, and π–π interactions. The prepared biomass with high fiber content is a promising new material for wastewater treatment. [ABSTRACT FROM AUTHOR]

The effect of different treatments on the depollution properties of rice husk to improve its biosorption efficiency has been investigated. The dye and heavy metal removal of treated rice husk samples were studied using methylene blue and Cu2+ as pollutant indicators. Moreover, olive oil has been used for oil removal performance tests. Although the adsorption investigation revealed that dye and Cu2+ removal is the highest using raw rice husk and steam-explosion acid-treated rice husk, respectively, steam-explosion rice husk presents more sustainability considering its cost and performance in both pollutant environments, while its oil removal capacity is outstanding compared to the raw rice husk too. Then, steam-explosion rice husks can be considered low-cost biosorbent materials for wastewater treatment that do not require high initial investments. The samples were characterized by FTIR, SEM, and EDX to compare the effect of composition and morphology on their depollution properties. The variety of functional groups present in treated rice husk based on the FTIR results improves the adsorption of MB and Cu2+. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The active ingredients extracted from plant materials play an important role in human life and health, and the extraction is a critical step in the preparation of them. It is necessary to develop a sustainable and green extraction. Steam explosion pretreatment enhanced extraction is a higher efficiency, lower equipment investment, less hazardous chemicals and environment-friendly technique, which has been widely used to extract active ingredients from various plant materials. In this paper, current progress and future prospects of steam explosion pretreatment enhanced extraction are overviewed. The equipment, operating steps, strengthening mechanism, critical process factors are comprehensively introduced. Furthermore, recent applications and comparisons with other techniques are discussed in depth. Finally, the future development trends are prospected. The current results show that steam explosion pretreatment enhanced extraction has the advantage of high efficiency. Moreover, steam explosion is simple in equipment, and easy to operate. In conclusion, steam explosion pretreatment can be effectively used to enhance the extraction of active ingredients from plant materials. [ABSTRACT FROM AUTHOR]

Using lignocellulosic materials as a feedstock to produce ethanol is an alternative to cleaner energy production. The pretreatment and enzymatic hydrolysis steps play a role in breaking down the lignocellulosic structure and making the sugars available for fermentation. Non-ionic surfactants have been included in the cellulosic ethanol production process to increase ethanol titers. Non-ionic surfactants commonly contribute to the enzymatic digestion of lignocelluloses, but there are doubts about whether they are beneficial or harmful in the pretreatment and ethanol fermentation steps. This study evaluated Tween 80 (polysorbate 80) in pretreatment, enzymatic hydrolysis, and fermentation with Saccharomyces cerevisiae PE2 to obtain ethanol from green coconut fiber (GCF). To reduce the GCF's recalcitrance and to increase enzyme accessibility, the material was pretreated using steam explosion (severity factor of 3.71 and 4.24), alkaline (sodium hydroxide), and sequential steam explosion/alkaline pretreatment in the presence of the surfactant. The surfactant did not increase delignification in steam explosion pretreatment, but it increased the sugar release when compared to the pretreatments without Tween 80. The addition of the surfactant during enzymatic hydrolysis increased glucose production in all experiments. Adsorption experiments showed that Tween 80 increased enzymatic activity. The highest glucose production was 20.31 ± 0.48 g/L and cellulosic conversion of 65.12% after adding 1.0% (w/v) Tween 80 in sequential steam explosion/alkaline pretreatment and enzymatic hydrolysis. Simultaneous saccharification and fermentation (SSF) and semi-simultaneous saccharification and fermentation (SSSF) strategies were investigated with the surfactant addition. When 2.0% (w/v) Tween 80 was added in all fermentations, it hindered ethanol production. A fed-batch SSSF and nonisothermal-fed-batch-SSSF were also performed, along with an enzyme fed-batch strategy. The highest ethanol concentration achieved was 48.21 ± 1.13 g/L by adding 1.0% (w/v) Tween 80 to the nonisothermal-fed-SSSF with 30% (w/v) solid loading. [ABSTRACT FROM AUTHOR]

Due to the neglect of reactor features which can substantially influence results, there are divergences on whether the decompression step of steam explosion pretreatment affects biomass saccharification and subsequent bioethanol production. An original innovative reactor is presented, which adopts new-designed pilot-operated pneumatic (POP) mode to maximize the effect of decompression, to settle divergences. Based on the reactor, three series of experiments set at 0.5, 1.0, and 1.5 MPa pressure with 0- and 10-min residence times were conducted with wheat straw as feedstock, compositional/structural adaptation, and enzymatic digestibility as targets. Results show that decompression alone improved the porosity of feedstock and led to a maximum increase of 17% in specific surface area (SSA). However, no decompression effects could be confirmed on chemical depolymerization and cellulose crystalline destruction, which were mainly attributed to the hydrothermal autohydrolysis and highly correlated with the severity factor (logR0). According to the enzymatic hydrolysis test, decompression promoted the reducing sugar yield of wheat straw by 6–11% due to the modification of porosity, but autohydrolysis still played the definitive role and an appropriate severity (logR0 = 3.36) is necessary to sufficiently exploit the function of decompression. This paper provides more integral information for further optimization of the method. [ABSTRACT FROM AUTHOR]

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Background: 2-Naphthol, a carbocation scavenger, is known to mitigate lignin condensation during the acidic processing of lignocellulosic biomass, which may benefit downstream processing of the resulting materials. Consequently, various raw materials have demonstrated improved enzymatic saccharification yields for substrates pretreated through autohydrolysis and dilute acid hydrolysis in the presence of 2-naphthol. However, 2-naphthol is toxic to ethanol-producing organisms, which may hinder its potential application. Little is known about the implications of 2-naphthol in combination with the pretreatment of softwood bark during continuous steam explosion in an industrially scalable system. Results: The 2-naphthol-pretreated softwood bark was examined through spectroscopic techniques and subjected to separate hydrolysis and fermentation along with a reference excluding the scavenger and a detoxified sample washed with ethanol. The extractions of the pretreated materials with water resulted in a lower aromatic content in the extracts and stronger FTIR signals, possibly related to guaiacyl lignin, in the nonextractable residue when 2-naphthol was used during pretreatment. In addition, cyclohexane/acetone (9:1) extraction revealed the presence of pristine 2-naphthol in the extracts and increased aromatic content of the nonextractable residue detectable by NMR for the scavenger-pretreated materials. Whole-slurry enzymatic saccharification at 12% solids loading revealed that elevated saccharification recoveries after 48 h could not be achieved with the help of the scavenger. Glucose concentrations of 16.9 (reference) and 15.8 g/l (2-naphthol) could be obtained after 48 h of hydrolysis. However, increased inhibition during fermentation of the scavenger-pretreated hydrolysate, indicated by yeast cell growth, was slight and could be entirely overcome by the detoxification stage. The ethanol yields from fermentable sugars after 24 h were 0.45 (reference), 0.45 (2-naphthol), and 0.49 g/g (2-naphthol, detoxified). Conclusion: The carbocation scavenger 2-naphthol did not increase the saccharification yield of softwood bark pretreated in an industrially scalable system for continuous steam explosion. On the other hand, it was shown that the scavenger's inhibitory effects on fermenting microorganisms can be overcome by controlling the pretreatment conditions to avoid cross-inhibition or detoxifying the substrates through ethanol washing. This study underlines the need to jointly optimize all the main processing steps. [ABSTRACT FROM AUTHOR]

Using renewable steam-exploded poplar (SEP) as carbon source, nickel metal doped carbon hybrid materials were designed to synthesize catalysts (Ni/SEP) with certain oxygen evolution reaction (OER) properties and were compared with nickel catalysts supported on metal organic framework structure (ZIF67-Ni). The roles of SEP support in Ni-based catalyst were considered. Scanning electron microscope (SEM) images confirmed that the fiber could better hinder the aggregation of metal particles. Fourier transform infrared spectroscopy (FT-IR) indicated the presence of surface OH groups after the reduction process. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses confirmed the major form of metallic Ni in the resulting Ni catalysts. Carbon materials as carriers, the synergetic effect of Ni-doped, and carbon carrier played an important role in facilitating the kinetics of OER, which was similar to the carrier of metal-organic frame material. Notably, the Ni/SEP (11.3 mF/cm-2) and ZIF67-Ni (37.2 mF/cm-2) with better OER performance exhibited a smaller double layer capacitances (Cdl), suggesting the intrinsic OER catalytic activity of the Ni/SEP and ZIF67-Ni were much higher in comparison to the ZIF67-Ni/SEP. Moreover, the inferior performance of Ni/SEP further indicated that the synergistic effect between carbon and Ni/NiO contributes to the enhanced OER activity. [ABSTRACT FROM AUTHOR]

Pine wilt disease is one of the most serious forest diseases that kills pine trees. Most of the nematode-infected pines are fumigated or locally incinerated and are thus not appropriately utilized. This study explored methods to utilize abandoned nematode-infected pines. The chemical compositions of healthy and nematode-infected pines were analyzed, and the neuroprotective effects of phenolic compounds extracted after steam explosion treatment were investigated. In terms of chemical composition, the nematode-infected pine chips suffered more damage from the steam explosion treatment than the healthy pine chips. In addition, the total phenolic compound content showed a clear difference depending on the presence of infection and steam explosion conditions. The maximum total phenolic compound content of extracted ethanol was found when the nematode-infected pine chip was subjected to steam explosion with a severity factor (Ro) of 3.82. The steam exploded pine extract of 10 µg/mL inhibited glutamate-induced early apoptotic cell death compared to cells treated with 10 mM glutamate alone. These results suggested that steamexploded pine can be used as an effective natural material for neuronal cell protection. [ABSTRACT FROM AUTHOR]

The oil tree peony (Paeonia ostii) is widely cultivated for their high value seed oil, and its roots also have high medicinal value, but they are often discarded and wasted as by-products. In this study, a set of steam explosion (SE) and ultrasound (US)-assisted extraction/purification methods of insoluble bound phenols (IPs) from oil peony roots (PR) were explored and developed. The IPs were obtained through SE pre-treatment (120 °C, 15 min) and US-assisted alkaline extraction (0.25 W/cm2, 4 h and 4 M NaOH). Their total phenolic content (TPC) significantly increased from 112.26 mg gallic acid/g dry weight (mg GAE/g dw) with traditional method to 185.59 mg GAE/g dw. Subsequently, the IPs were purified into PIPs using LX-83 resin. The optimized purification conditions were pH = 4, 3.0 mg GAE/mL of IPs, 0.25 W/cm2 adsorption for 120 min, as well as 60 % ethanol desorption solution, and 0.25 W/cm2 desorption for 30 min. The TPC of the PIPs increased to 254.74 mg GAE/g dw. Notably, typical compounds in IPs and PIPs were identified and quantified by HPLC-MS and their antioxidant and anti-tyrosinase activities were also evaluated by chronometry. The results showed that paeoniflorin and benzoyl-paeoniflorin increased by about 10-fold in the PIPs. Additionally, they demonstrated superior antioxidant and tyrosinase inhibitory activities compared to IPs. Therefore, the innovative extraction and purification process greatly improved the yield of bound phenols and recovered paeoniflorin from non-medicinal PR. The process may also provide a reference for the in-depth development of medicinal PR, ultimately achieving more efficient PR development and utilization. [Display omitted] • The integrated process improves the yield of insoluble phenols from peony (IP). • IP are raised by steam explosion and ultrasound-assisted alkaline extraction. • US enhances adsorption/desorption of IPs using LX-83 resins. • The sum of 5 typical compounds increases from 0.47 (IPs) to 3.24 mg/g (PIPs). • PIPs showed higher antioxidant and anti-tyrosinase activities. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Laminaria japonica polysaccharide, which is an important bioactive substance of Laminaria japonica with anti‐inflammatory and antioxidant effects. In this study, the molecular weight, functional groups and surface morphology were investigated to evaluate the digestive properties of Laminaria japonica polysaccharide before and after steam explosion.The results indicated that the Laminaria japonica polysaccharide entered the large intestine to be utilized by the gut microbiota after passing through the oral, gastric and small intestinal. Meanwhile, Laminaria japonica polysaccharide of steam explosion promoted the growth of beneficial bacteria Phascolarctobacterium and Intestinimonas, and increased the content of acetic, propionic and butyric acids, which was 2.29‐folds, 2.60‐folds and 1.63‐folds higher than the control group after 48 h of fermentation.This study reveals that the effect of steam explosion pretreatment on the digestion in vitro and gut microbiota of Laminaria japonica polysaccharide will provide a basic theoretical basis for the potential application of Laminaria japonica polysaccharide as a prebiotic in the food industry. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Ethyl levulinate (EL) production from steam‐exploded corn straw (SCS) in a cascade of reaction using a Brønsted (B) acid and a Lewis (L) acid in ethanol was studied. The entangled structure of corn straw could be obviously damaged through steam explosion when the pressure was 1.5 MPa holding 10 min. The content of cellulose can be increased from 35.9% to 46.8%, and the contents of hemicellulose and lignin were changed from 16.7% to 8.8% and 22.6% to 27.5%, respectively. EL yield was significantly increased from 10.7 to 24.6 wt% under optimal reaction conditions (L/B = 1/20 [mol/mol], 205°C, 90 min, 1.8 g of SCS, 60 mL of ethanol). According to kinetic models, the activation energies for the main and side reactions were 56.8 and 110.5 kJ mol−1, respectively. It suggested that SCS was more easily to be converted to EL rather than other by‐products. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gaps (HOMO‐LUMO gaps) of cellobiose over the mixed acids in ethanol were significantly reduced with frontier molecular orbital (FMO) theory. This work provides an effective strategy for EL production from agricultural waste straws. [ABSTRACT FROM AUTHOR]

The biochemical pathway for propionic acid (PA) production is an interesting alternative that can include the utilization of biomass as feedstock. This study evaluated the utilization of Agave bagasse (AB), a lignocellulosic residue, to produce PA by Propionibacterium acidipropinici in batch systems (125 mL‐hermetic bottles and 1000 mL‐bioreactor). The process included a steam explosion pretreatment at 142°C for 15 min and enzymatic hydrolysis, where solid loading (2.75% and 5% in pretreatment and 2.5%, 3.75%, and 5% in enzymatic hydrolysis) was evaluated. Furthermore, the enzymatic concentrations of 18.3 filter paper unit (FPU)/gAB (1×) of Cellic® CTec2 and 1.5× and 3× were tested. The yields of total carbohydrates (TC) obtained at the two solid loadings tested in the pretreatment were statistically similar, but the 3x enzymatic concentration enhanced the yields of TC, glucose, and xylose (0.23 ± 0.01, 0.15 ± 0.01 and 0.03 ± 0.01 g/gAB, respectively). The hydrolysates obtained under these conditions were evaluated as carbon sources for PA production, obtaining a productivity of 0.069 ± 0.006 g/L h and a yield product/substrate of 0.44 gPA/gTC. The control of pH in the culture reduced the fermentation time in the bioreactor by 52% compared with the hermetic bottles without pH control. The potential of hydrolysates as carbon sources for PA production was evidenced, as approximately 50% of the initial carbon was converted to this product. The observed yield product/substrate was similar to those reported from hydrolysates of diverse biomass types, pretreatments, or enzymatic cocktails and the same or related microorganisms. However, the system studied has advantages, such as not requiring the addition of chemical or detoxification stage, and lower temperature and time compared to other pretreatments. [ABSTRACT FROM AUTHOR]

Protein has become an increasingly valuable food component with high global demand. Consequently, unconventional sources, such as industrial and agroindustrial wastes and by-products, emerge as interesting alternatives to meet this demand, considering the UN Sustainable Development Goals and the transition to a circular economy. In this context, this work presents a review of the use of Steam Explosion (SE), a green technique that can be employed as a pretreatment for various waste materials, including bones, hide/leather, feathers, and wool, aimming the extraction of protein compounds, such as low molecular weight biopeptides, gelatin, and keratin, as well as to enhance the protein functionality of grains and meals. The SE technique and the main factors affecting the process's efficiency were detailed. Promising experimental studies are discussed, along with the mechanisms responsible for protein extraction and functionality improvement, as well as the main reported and suggested applications. In general, steam explosion favored yields in subsequent extraction processes, ranging from 27 to 95%, in addition to enhancing solubility and functional protein properties. Nonetheless, it is crucial to maintain the continuity of research on this topic to drive advancements in ensuring the safety of the extracted compounds for use in consumable products and oral ingestion. [ABSTRACT FROM AUTHOR]

Background: Xylitol, a five-carbon polyalcohol, is used in the food and pharmaceutical industries and as a building block in the synthesis of high-value chemicals. It can be sustainably produced from renewable sources through xylose assimilating microbe fermentation. Results: We screened microbial strains for xylitol production and identified Wickerhamomyces anomalus Z1 as a key xylitol producer. Utilizing lignocellulosic biomass hydrolysates for xylitol production poses challenges due to microbial sensitivity to inhibitors from biomass pre-treatment. In this study, an adaptive laboratory evolution (ALE) of W. anomalus Z1 was performed by culturing the yeast in a mineral medium supplemented with gradual increases of sugarcane bagasse hemicellulosic hydrolysate (SCHH) obtained by intensified steam explosion pretreatment. The performance of the adapted yeast, named Wickerhamomyces anomalus ALE, was assessed in comparison to the wild-type strain regarding its capacity to produce xylitol using SCHH. The evolved yeast reached a xylitol yield of 0.11 g xylitol/g xylose whereas the wild-type strain could not produce xylitol. Removing acetic acid from SCHH enhanced W. anomalus ALE performance, with optimal results at 75% hydrolyzed hemicellulose, yielding 0.44 g xylitol/g xylose and 13.41 g/L xylitol. Conclusions: This study demonstrates the potential of W. anomalus ALE in successfully valorizing the hemicellulosic fraction of sugarcane bagasse for sustainable xylitol production.How to cite: Bonfiglio F, Cagno M, Nuñez L, et al. Xylitol production by a Wickerhamomyces anomalus strain adapted for enhanced tolerance to sugarcane bagasse hemicellulosic hydrolysate with high content of fermentation inhibitors. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.05.004.

Abstract Background 2-Naphthol, a carbocation scavenger, is known to mitigate lignin condensation during the acidic processing of lignocellulosic biomass, which may benefit downstream processing of the resulting materials. Consequently, various raw materials have demonstrated improved enzymatic saccharification yields for substrates pretreated through autohydrolysis and dilute acid hydrolysis in the presence of 2-naphthol. However, 2-naphthol is toxic to ethanol-producing organisms, which may hinder its potential application. Little is known about the implications of 2-naphthol in combination with the pretreatment of softwood bark during continuous steam explosion in an industrially scalable system. Results The 2-naphthol-pretreated softwood bark was examined through spectroscopic techniques and subjected to separate hydrolysis and fermentation along with a reference excluding the scavenger and a detoxified sample washed with ethanol. The extractions of the pretreated materials with water resulted in a lower aromatic content in the extracts and stronger FTIR signals, possibly related to guaiacyl lignin, in the nonextractable residue when 2-naphthol was used during pretreatment. In addition, cyclohexane/acetone (9:1) extraction revealed the presence of pristine 2-naphthol in the extracts and increased aromatic content of the nonextractable residue detectable by NMR for the scavenger-pretreated materials. Whole-slurry enzymatic saccharification at 12% solids loading revealed that elevated saccharification recoveries after 48 h could not be achieved with the help of the scavenger. Glucose concentrations of 16.9 (reference) and 15.8 g/l (2-naphthol) could be obtained after 48 h of hydrolysis. However, increased inhibition during fermentation of the scavenger-pretreated hydrolysate, indicated by yeast cell growth, was slight and could be entirely overcome by the detoxification stage. The ethanol yields from fermentable sugars after 24 h were 0.45 (reference), 0.45 (2-naphthol), and 0.49 g/g (2-naphthol, detoxified). Conclusion The carbocation scavenger 2-naphthol did not increase the saccharification yield of softwood bark pretreated in an industrially scalable system for continuous steam explosion. On the other hand, it was shown that the scavenger's inhibitory effects on fermenting microorganisms can be overcome by controlling the pretreatment conditions to avoid cross-inhibition or detoxifying the substrates through ethanol washing. This study underlines the need to jointly optimize all the main processing steps.

Rice bran from 3 rice varieties, namely Daohuaxiang, Changlixiang and Ganwanxian No.40 were used as raw materials to investigate the effect of steam explosion on structural and properties of soluble dietary fiber in rice bran of different varieties. The structure alteration of SDF in rice bran treated by steam explosion was observed by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The impact of steam explosion on SDF functional properties of rice bran was studied by a series of evaluation indicators, such as water holding, oil holding, cholesterol adsorption, glucose adsorption, α-amylase inhibition and antioxidant capacity. The results showed that steam explosion could increase some absorption peaks intensity in the infrared spectrum of SDF, decrease crystallinity and form loose and porous structure of rice bran SDF from 3 rice varieties. The SDF contents in Daohuaxiang, Changlixiang and Ganwanxian No.40 rice bran by steam explosion were increased by 87.22%, 94.72% and 70.31%, respectively. Notably, the functional properties of steam-exploded rice bran from 3 rice varieties, such as water retention, oil retention, cholesterol adsorption capacity under human gastric fluid environment, glucose adsorption capacity, ABTS+ and OH free radical scavenging rate and total antioxidant capacity were significantly increased compared with control group (P

In this work, steam explosion (SE) was applied to prompt the rapid extraction of ergosterol and polysaccharides from Flammulina velutipes root (FVR) waste. Ultrasound-assisted saponification extraction (UASE) followed by water extraction was used to prepare ergosterol and polysaccharides. The results indicated that SE destroyed the complicated structure of FVR and increased its internal porosity and surface roughness. SE caused the thermal degradation of FVR's structural components and increased the polysaccharide content 0.97-fold. As a result, the extraction yield and efficiency of ergosterol and polysaccharides were improved. The theoretical maximum extraction concentration (C∞) and diffusion coefficient (D) were increased by 34.10% and 78.04% (ergosterol) and 27.69% and 48.67% (polysaccharides), respectively. The extraction yields obtained within 20–30 min of extraction time exceeded those of untreated samples extracted after several hours. For polysaccharides, SE led to a significant reduction in the average molecular weight, increased the percentage of uronic acids and decreased the neutral sugar percentage. The monosaccharide composition was changed by SE, with an increase in the molar ratio of glucose of 64.06% and some reductions in those of other monosaccharides. This work provides an effective method for the processing of fungi waste and adds to its economic value, supporting its high-value utilization in healthcare products. [ABSTRACT FROM AUTHOR]

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BACKGROUND RESULTS CONCLUSION Java tea is widely consumed and has multiple health effects. This study established a steam explosion (SE) pretreatment method to prepare Java tea‐leaf powders. The physicochemical, functional properties, phenolic extraction, and antioxidant activity of Java tea‐leaf powders produced by simple and SE‐assisted milling methods were investigated.In comparison with simple milling, SE pretreatment broke the cell wall effectively and reduced the particle size of Java tea‐leaf powders. Steam explosion‐treated powders showed higher values for sensory signals, bulk and tap density, and for the water solubility index. After SE treatment, the adsorption capacities to glucose, soybean oil, and cholesterol of leaf powders were increased by up to 55, 95, and 80% respectively. The extracts from SE‐treated powders also showed higher total polyphenol content and antioxidant activity.Steam explosion treatment is helpful for the improvement of functional properties and antioxidant activity, which can benefit the development and application of Java tea‐leaf powders. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This research aims to explore a sustainable way of utilizing pineapple leaf fibres (PALF) to develop flushable wipes with a higher disintegration percentage. The suitable fibre extraction method has been determined, and the extracted PALF is subjected to steam-explosion using a sodium hydroxide (NaOH) solution with varying NaOH concentration, pressure, and time. Flushable wipes are manufactured using the wet-laid nonwoven technique from steam-exploded pineapple leaf microfibres. From SEM analysis, it is observed that the fibre bundles are separated into individual micro-sized fibres (3–4 μm) after steam explosion. The effect of process parameters in steam explosion treatment on disintegration percentage with respect to shaking speed and time has been explored and then compared with commercial products. The result indicates that the micro-fibres obtained by steam explosion of PALF with 1.5% NaOH at 25 psi for 60 min demonstrate excellent flushability properties (~96.67% disintegration), which exceeds the commercial product by 27.62%. This suggests a potential to meet the EDANA/INDA flushability standards, making it a viable good flushable wipe that won't cause drainage clog. This research concludes that the steam-exploded PALF is found to be beneficial in the hygiene and health care segments for the production of emerging and essential flushable wipes, taking advantage of its unique property of fibrillation on steam explosion. [ABSTRACT FROM AUTHOR]

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A plantain pseudostem was harvested and processed on the same day. The process began with manually separating the sheaths (80.85%) and the core (19.14%). The sheaths were subjected to a mechanical shredding process using paddles, extracting 2.20% of lignocellulosic fibers and 2.12% of sap, compared to the fresh weight of the sheaths. The fibers were washed, dried, combed, and spun in their native state and subjected to a steam explosion treatment, while the sap was subjected to filtration and evaporation. In the case of the core, it was subjected to manual cutting, drying, grinding, and sieving to separate 12.81% of the starch and 6.39% of the short lignocellulosic fibers, compared to the fresh weight of the core. The surface modification method using steam explosion succeeded in removing a low proportion of hemicellulose and lignin in the fibers coming from the shims, according to what was shown by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC), achieving increased σmax and ε from the tensile test and greater thermal stability compared to its native state. The sap presented hygroscopic behavior by FT-IR and the highest thermal stability from TGA, while the starch from the core presented the lowest hygroscopic character and thermal stability. Although the pseudostem supplied two types of fibers, lower lignin content was identified in those from the core. Finally, the yarns were elaborated by using the fibers of the sheaths in their native and steam-exploded states, identifying differences in the processing and their respective physical and mechanical properties. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cereal straw stands out as one of the most abundant and globally distributed agricultural residues. Traditional applications cope with a limited amount of production, leaving the remainder in the field for natural decomposition. Managing cereal straw through controlled biological transformation under anaerobic conditions holds the potential to generate added value in the form of bioenergy. However, the lignocellulosic composition of these substrates poses challenges for organic degradation, often requiring energy-intensive pretreatments. A detailed study with a comprehensive calculation of the overall energy balance of the integrated process is proposed, aiming to provide real added value and replicability. Three scenarios for wheat straw transformation were investigated, incorporating two preliminary pre-treatment stages—mechanical milling and physicochemical steam explosion. Three conditions of pretreatment were essayed, varying the time exposure of the steam explosion. The subsequent energy integration analysis revealed that the process was optimized by up to 15% in the final energy balance when the steam explosion was set to 10 min. The macromolecular composition determination revealed that the thermal pretreatment reduced the lag phase of the hydrolysis step through hemicellulose breakdown. [ABSTRACT FROM AUTHOR]

Lignocellulose biomass is a renewable resource with a large quantity, wide coverage, and low cost. It has gradually been developed and applied from biomass to biofuels, feedstuffs, and other value-added products. Such high-value transformation and comprehensive utilization have become important parts of “taking the path of green development and building a green production system”. However, the natural anti-degradation barrier and unique physicochemical properties of lignocellulose, as well as the rigid network of the three major components of cellulose, hemicellulose, and lignin, have been the long-term bottleneck of efficient conversion. The reasonable and effective pretreatment techniques are the key steps in the resource recovery process. This paper focuses on the analysis of basic composition and structural characteristics of lignocellulose biomass. On the basis of summarizing the advantages and disadvantages of traditional pretreatment methods such as physical, chemical, and biological methods, it emphasizes the development history, processing types, scope of application, working principle, reaction stages, technical characteristics, main parameters, and possible by-product effects of steam explosion. In addition, it involves research progress in the fiber modification, structural changes, dissolution characteristics, oligosaccharide preparation, active ingredient extraction, and ruminant feed utilization of biomass. It is also pointed out that the new trend in the post-treatment process after steam explosion assisted by microbial fermentation dominated by fungi and bacteria, as well as the exogenous addition of carbohydrase. Finally, the difficulties and challenges faced by steam explosion in future commercialization, industrialization, and large-scale production promotion are summarized. The corresponding breakthrough points and solution strategies are analyzed and proposed. The degradation effects of steam explosion technology on common by-product types of feed raw materials, as well as its reasonable application in the diet of monogastric animals, are discussed. It is aimed to provide new ideas and technical guidance for the potential development, value-added, and feed application of biomass resources using this means. [ABSTRACT FROM AUTHOR]

In this work, coffee silverskin (CSS) fibers were subjected to alkali pretreatment (ALK‐CSS) and alkali pretreatment, followed by a 4‐bar steam explosion process (SEW4). Both treated fibers presented a higher degree of crystallinity, enhanced thermal resistance and also cleaner, rough, and defibrillated surface due to the removal of noncellulosic components, as was shown in scanning electron microscopy, thermogravimetric analysis, Fourier‐transform infrared spectra, and x‐ray diffraction (XRD) results. The SEW4 fibers were incorporated into the poly(butylene adipate‐co‐terephthalate) (PBAT) matrix in contents up to 5% wt. through melt processing. PBAT/SEW4 composites were evaluated by their microstructure, thermal properties, degree of crystallinity, and hydrophilic behavior. XRD results showed PBAT/SEW4 composites with higher degrees of crystallinity and contact angle tests revealed increased composite hydrophobicity with the increase of SEW4 content in the PBAT matrix. This work describes the importance of recovering coffee lignocellulosic waste and producing value‐added by‐products, especially in packaging manufacturing. [ABSTRACT FROM AUTHOR]

Pleurotus eryngii (PE) has been sought after for its various health benefits and high content of phenolic compounds. This study explored the feasibility of steam explosion (SE)-assisted extraction of polysaccharides with high antioxidant capacities from PE. An orthogonal experimental design (OED) was used to optimize the SE-assisted extraction of PE. The influence of the optimized SE-assisted extraction on the physicochemical properties of PE polysaccharides was determined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), monosaccharide compositional analysis and antioxidant capacity assays. Under optimal SE conditions, SE-assisted extraction increased the polysaccharide yield by 138% compared to extraction without SE-assistance. In addition, SEM demonstrated that SE-assisted extraction markedly altered the spatial structure of Pleurotus eryngii polysaccharides (PEP), and monosaccharide compositional analysis revealed that this pretreatment significantly increased the proportions of some monosaccharides, such as glucose, rhamnose and arabinose, in the isolated PEP. FTIR spectra indicated no change in the major chemical functional groups of PEP. PEP extracted by SE-assisted extraction had significantly increased free radical scavenging and antioxidant capacities. In conclusion, SE-assisted extraction appears to be a novel polysaccharide extraction technology, which markedly increases extraction yields and efficiency and can increase the biological activity of polysaccharide extracts. [ABSTRACT FROM AUTHOR]

The pretreatment step has a major role in ethanol production as it breaks the lignocellulosic material structure, which improves the digestibility in the enzymatic hydrolysis and increases the ethanol yield during fermentation. The purpose in this study was to pretreat green coconut fiber (GCF) with steam explosion (SE) to produce ethanol. Different severity factors (ranging between 2.18 and 4.24) were performed and the humidification process of the raw material before pretreatment was also evaluated. Considering that SE did not provide lignin removal nor significant improvement in enzymatic digestibility, a subsequent alkaline pretreatment was carried out to overcome these challenges. The alkaline pretreatment using NaOH increased delignification, either as a stand-alone or in the sequential pretreatment. The sequential SE/alkaline pretreatment provided higher values of hydrolysis yield (54.74%), total reducing sugars (29.17 ± 1.21 g/L), and glucose production (16.65 ± 0.82 g/L) when compared to the separated pretreatments. Thereafter, simultaneous saccharification and fermentation (SSF) and semi-simultaneous saccharification and fermentation (SSSF) strategies were evaluated using Saccharomyces cerevisiae PE2, Saccharomyces cerevisiae CAT-1, and Kluyveromyces marxianus ATCC 36,907 yeasts with different solid loadings (5, 10, and 15% w/v). The pre-saccharification step increased ethanol yield and ethanol concentration in all experiments. The highest ethanol concentration (24.88 ± 1.04 g/L) was achieved using SSSF with 15% (w/w) solid loading, while the ethanol obtained in SSF experiments was equal to 21.62 ± 0.87 g/L using the same solid loading. The sequential SE/alkaline pretreatment was a successful combination, improving sugars' production and leading to a high ethanol concentration. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The biochemical pathway for propionic acid (PA) production is an interesting alternative that can include the utilization of biomass as feedstock. This study evaluated the utilization of Agave bagasse (AB), a lignocellulosic residue, to produce PA by Propionibacterium acidipropinici in batch systems (125 mL‐hermetic bottles and 1000 mL‐bioreactor). The process included a steam explosion pretreatment at 142°C for 15 min and enzymatic hydrolysis, where solid loading (2.75% and 5% in pretreatment and 2.5%, 3.75%, and 5% in enzymatic hydrolysis) was evaluated. Furthermore, the enzymatic concentrations of 18.3 filter paper unit (FPU)/gAB (1×) of Cellic® CTec2 and 1.5× and 3× were tested. The yields of total carbohydrates (TC) obtained at the two solid loadings tested in the pretreatment were statistically similar, but the 3x enzymatic concentration enhanced the yields of TC, glucose, and xylose (0.23 ± 0.01, 0.15 ± 0.01 and 0.03 ± 0.01 g/gAB, respectively). The hydrolysates obtained under these conditions were evaluated as carbon sources for PA production, obtaining a productivity of 0.069 ± 0.006 g/L h and a yield product/substrate of 0.44 gPA/gTC. The control of pH in the culture reduced the fermentation time in the bioreactor by 52% compared with the hermetic bottles without pH control. The potential of hydrolysates as carbon sources for PA production was evidenced, as approximately 50% of the initial carbon was converted to this product. The observed yield product/substrate was similar to those reported from hydrolysates of diverse biomass types, pretreatments, or enzymatic cocktails and the same or related microorganisms. However, the system studied has advantages, such as not requiring the addition of chemical or detoxification stage, and lower temperature and time compared to other pretreatments.

A surface response design was employed to develop a sodium hydroxide (NaOH) pretreatment method for Quercus variabilis Blume using low NaOH concentration at low temperature. Nevertheless, the persistent issues associated with alkaline pretreatment of lignocellulose, namely high-water consumption and wastewater generation, remain prevalent in this pretreatment process. To address these challenges, this study aimed to conduct enzymatic hydrolysis of NaOH-treated Q. variabilis Blume without the intermediary washing steps. The results revealed that, following pretreatment and solid-liquid separation, NaOH-treated Q. variabilis Blume could be directly subjected to cellulase-mediated hydrolysis with pH adjustment, eliminating the need for washing steps. The maximum enzymatic hydrolysis efficiency reached 95.9% under specific conditions (1.2% NaOH, 8.9 °C, 32.1 h). This approach offers a promising avenue to enhance the enzyme hydrolysis rate of NaOH-treated lignocellulose. Notably, the low-temperature and low-concentration NaOH treatment effectively removed a substantial portion of lignin and hemicelluloses, resulting in a higher crystallinity index of the cellulose-rich residue compared to substrates treated solely with steam explosion. The integration of direct pretreatment and alkaline treatment emerges as an environmentally friendly and economically viable method for producing glucose and high-purity lignin. The obtained lignin can be further transformed into high-value products within the biorefinery framework.

Abstract Glycerol-assisted instant catapult steam explosion (ICSE) of lignocellulose is an effective pretreatment method for enhancing sugar production compared to glycerol-free ICSE. In this study, glycerol-assisted ICSE of corn stover was studied in order to understand the reaction mechanisms and further optimize the process. Results showed that water extraction of corn stover prior to ICSE reduced pseudo-lignin formation. The combination of water extraction and glycerol-assisted ICSE led to the formation of lignin with a lower molecular weight (Mw) of 2851 g/mol than 3521 g/mole of that from the combination of water extraction and glycerol-free ICSE. 1H-13C NMR analysis revealed that glycerol likely reacted with lignin carboxylic OHs through esterification while etherification of aliphatic OHs was not observed in ICSE. These lignin analyses indicated that glycerol protected lignin from condensation/repolymerization during glycerol-assisted ICSE. Enzymatic hydrolysis results showed that without water extraction increasing glycerol usage from 0.2 kg/kg stover to 0.4 kg/kg stover improved glucan digestibility to 78% but further increase to 0.5 kg/kg stover reduced glucan digestibility. In addition, at the glycerol usage of 0.2–0.4 kg/kg stover, washing of pretreated stover for removal of glycerol and other biomass-derived compounds did not improve glucan digestibility compared to unwashed ones. Combination of water extraction and glycerol-assisted ICSE led to a high glucan digestibility of 89.7% and a total glucose yield of 25.5 g glucose/100 g stover, which were 30.1% and 7.5 g/100 g stover higher than those derived from glycerol-free ICSE of stover, respectively. Since glycerol is a low-cost carbon source, the resulting enzymatic hydrolysate that contained both glucose and glycerol may be directly used to produce bioproducts by microbial fermentation. Graphical Abstract

The industrial processing of coconut to produce valuable foods, such as water and milk, generates large volumes of waste, especially the fruit shell. Despite this, material can be used in bioprocess applications, e.g., the production of enzymes, its recalcitrance hinders the cultivation of microorganisms, and low productivity is usually achieved. In this study, the production of cellulolytic enzymes through solid-state fermentation (SSF) and their extraction was investigated using the green coconut fiber pretreated by steam explosion, followed by alkali. The fungus Trichoderma reesei CCT-2768 was cultivated, using an experimental design, to study the effect of the water activity and the amount of biomass in the reactor. The combination of the pretreatment strategies yielded more porous biomass, with less hemicellulose (5.38%, compared to 10.15% of the raw biomass) and more cellulose (47.77% and 33.96% in the pretreated and raw biomasses, respectively). The water activity significantly affected the production of cellulases, with maximum activity yielded at the highest investigated value (0.995). Lastly, the extraction of the enzymes from the cultivation medium was studied, and a 9 g/L NaCl solution recovered the highest CMCase and FPase activities (5.19 and 1.19 U/g, respectively). This study provides an important contribution to the valorization of the coconut residue through (i) the application of the steam explosion technology to optimize the production of cellulases using the SSF technology and (ii) their extraction using different solvents.

Bamboo fibers (BFs) at different ages (1, 3, and 5 years old) were prepared by pretreatment and steam explosion. The results demonstrated that the separation degrees of BFs increased with the age of the bamboo. The combined effects of pretreatment and steam explosion partially removed the hemicellulose and lignin from BFs, while the crystalline structure of cellulose remained unaltered. The water vapor adsorption isotherms of BFs at different ages all showed a typical S-shape and could be classified as type II, and the hysteresis of BFs increased with the age of the bamboo. After pretreatment and steam explosion, the tissues in the vascular bundle were effectively crushed, and the parenchyma tissues were dislodged and separated from the fiber sheath. During the steam explosion process, hot steam penetrated the bamboo’s pores, including the pores induced by pretreatment. This caused fractures and delamination in the interface between the vascular bundle and the parenchyma tissues. These cracks progressed layer by layer along the vascular bundle interface, leading to the fracture of the bamboo.

Abstract Background Steam explosion pretreatment has been proven to be an effective treatment for breaking down the recalcitrant character of lignin–carbohydrate complexes (LCC) in lignocellulosic biomass. This study investigated the production of lignin-derived products from steam-exploded palm oil mill lignocellulosic biomass waste (POMLBW), that is, empty fruit bunches (EFB), kernel shells (KS), and kernel fibers (KF), also known as mesocarp fibers. Steam explosions cause lignin depolymerization, which forms various polyphenols. The low average molecular weight of the steam-exploded lignin-derived products and their antioxidant activities could potentially enhance their antimicrobial activities. Methods POMLBW was steam-exploded with various degrees of severity factors (R 0 : 4.03, 4.91, 5.12, 5.35, and 5.65). Steam-exploded POMLBW produces lignin-derived products such as low-molecular-weight lignin (LML) and water-soluble lignin (WSL). Antioxidant activity was evaluated using 0.5 mM 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Polyphenol content was evaluated using the Folin–Ciocalteu method. The antimicrobial activity was evaluated using an agar diffusion assay with Gram-positive and Gram-negative bacteria, and the thermal characteristics were evaluated using differential scanning calorimetry and thermogravimetric analysis. Results WSL and LML resulted in high radical scavenging activity (RSA) of approximately 95% and 80%, with 0.25 g/L and 0.5 g/L of EC50, where the polyphenol amount was 242–448 mg/g (catechin eq.) and 20–117 mg/g (catechin eq.) under all LML and WSL conditions, respectively. The steam-exploded POMLBW had an average molecular weight of 1589–2832 Da, and this condition, including high RSA and polyphenol amounts, was responsible for the high antimicrobial activities of LML against both Gram-positive (Salmonella enterica, Pseudomonas aeruginosa, and Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Additionally, the thermal properties investigations revealed that the glass transition temperature was 80–90 °C (Tg), the melting temperature (T m) was 338–362 °C, and the start temperature was 101–128 °C at the beginning of mass loss. Conclusions These results show that the lignin-derived product from steam-exploded POMLBW has the potential for antioxidant (LML and WSL) and antimicrobial (LML) applications with good thermal resistance. Graphical Abstract

In order to investigate the differences in volatile components and major aroma characteristics between tea made from tender and mature leaves of Eucommia ulmoides pre-treated by steam explosion (SE), an electronic nose (E-nose) and headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) were applied to analyze the effect of SE on the volatile components in tea made from tender and mature leaves of the Eucommia ulmoides cultivar ‘Huazhong 8’. The results showed that the principal component analysis (PCA) and linear discriminant analysis (LDA) models fitted well the E-nose data, which suggested that the aroma characteristics of both tender and mature leaf tea were significantly different between with and without SE pretreatment. Altogether, 177 volatile components were identified by HS-SPME-GC-MS, among which 24 were selected as aroma active substances by orthogonal partial least squares discriminant analysis (variable importance in the projection (VIP) value ≥ 1) and Kruskal-Wallis H test (P < 0.05). The key aroma substance of tender leaf tea without SE was dihydroactinidiolide. The key aroma substances of tender leaf tea with SE were dihydroactinidiolide, nonanal, benzaldehyde and phenylacetaldehyde, contributing to citrus-like, flowery, caramelic, bitter almond-like, nutty, rose-like and chocolate-like aromas. No key aroma substances were found in mature leaf tea without SE, while dihydroactinidiolide and nonanal were identified the key aroma substances in mature leaf tea with SE, contributing to sweet peach-like, woody, citrus-like, flowery and caramelic aromas. The results of this study can provide a reference for the development of beverage products based on Eucommia ulmoides leaves.

ABSTRACTBamboo fiber (BF) has emerged as a promising natural, environmentally friendly material for use in composite materials. The steam explosion process plays a crucial role in preparing BFs suitable for composites. In this study, the effects of solid–liquid ratio, explosion pressure, and explosion holding time on BF preparation were investigated by orthogonal experiments, and the structural and chemical changes occurring during the separation of BF were also investigated. The results showed that the combined method of alkali treatment and steam explosion successfully produced BFs with good morphology. The highest yield of fine fibers (39.07%) was obtained at a solid–liquid ratio of 2:1, explosion pressure of 2.2 MPa, and explosion holding time of 4 min. BFs obtained using the optimal values exhibited dispersed fiber bundles, partial removal of hemicellulose and lignin, and improved crystallinity. Furthermore, the hygroscopicity of BFs decreased, reaching a minimum of 15% under the optimal process conditions. The optimization of steam explosion parameters can help to improve the extraction efficiency of fine fibers for composites and promote the industrialization of BFs prepared by steam explosion.

Semi-solid wastes from the beverage industry, like agave bagasse or brewery spent grains, were partly turned to the liquid phase by employing hydrothermal carbonization (HTC) or steam explosion (SE). The methane release in anaerobic batch assays of those extracts reached 316–362 mL g−1 of chemical oxygen demand for the SE pretreatment and 162–173 mL g−1 COD for HTC employed as a pretreatment. However, the yield of chemical oxygen demand in the extracts depends on both the pretreatment as well as the substrate. HTC applied to agave bagasse yielded 0.281 g of COD per gram of biomass, which is more than twice the amount from SE. In contrast, SE is more than 3 times effective than HTC using brewery spent grains as substrate with a yield of 0.582 g COD g−1. The combination of both process conversion efficiencies led to an available energy recovery of up to 0.4 for SE of spent grains and up to 0.1 for HTC of agave bagasse in relation to the energy content of substrate. For the latter, the slow and incomplete bioconversion of substrates obtained by HTC must be overcome. This holistic approach to sustainable management of large quantities of agro-industrial wastes turns an on-site environmental challenge into the availability of in-house renewable energy. [ABSTRACT FROM AUTHOR]

Glycerol-assisted instant catapult steam explosion (ICSE) of lignocellulose is an effective pretreatment method for enhancing sugar production compared to glycerol-free ICSE. In this study, glycerol-assisted ICSE of corn stover was studied in order to understand the reaction mechanisms and further optimize the process. Results showed that water extraction of corn stover prior to ICSE reduced pseudo-lignin formation. The combination of water extraction and glycerol-assisted ICSE led to the formation of lignin with a lower molecular weight (Mw) of 2851 g/mol than 3521 g/mole of that from the combination of water extraction and glycerol-free ICSE. 1H-13C NMR analysis revealed that glycerol likely reacted with lignin carboxylic OHs through esterification while etherification of aliphatic OHs was not observed in ICSE. These lignin analyses indicated that glycerol protected lignin from condensation/repolymerization during glycerol-assisted ICSE. Enzymatic hydrolysis results showed that without water extraction increasing glycerol usage from 0.2 kg/kg stover to 0.4 kg/kg stover improved glucan digestibility to 78% but further increase to 0.5 kg/kg stover reduced glucan digestibility. In addition, at the glycerol usage of 0.2–0.4 kg/kg stover, washing of pretreated stover for removal of glycerol and other biomass-derived compounds did not improve glucan digestibility compared to unwashed ones. Combination of water extraction and glycerol-assisted ICSE led to a high glucan digestibility of 89.7% and a total glucose yield of 25.5 g glucose/100 g stover, which were 30.1% and 7.5 g/100 g stover higher than those derived from glycerol-free ICSE of stover, respectively. Since glycerol is a low-cost carbon source, the resulting enzymatic hydrolysate that contained both glucose and glycerol may be directly used to produce bioproducts by microbial fermentation. Highlights: Glycerol-assisted ICSE of corn stover improved enzymatic glucose production. Water extraction prior to ICSE further enhanced sugar production. Enzymatic hydrolysis was not affected by glycerol from glycerol-assisted ICSE. Sequential water extraction and ICSE led to a high glucan digestibility of 89.7%. Glycerol likely had a multiple role in ICSE and enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

Summary: This study aimed to recover protein hydrolysate from chicken bone by steam explosion and investigate its calcium‐binding capacity and potential pro‐osteogenic activity. The results showed that the recovery rate was significantly affected by pressure, time, and filling ratio. The molecular weight distribution and amino acid composition of the protein hydrolysate were also analysed. Furthermore, the protein hydrolysate extracted at 12 min, 1.8 MPa and 40% filling ratio showed well calcium‐binding capacity, and the peptides‐calcium chelate showed good stability at different temperatures. The cell experiment showed that the peptides‐calcium chelate can significantly improve the osteogenic activity of MC3T3‐E1 cells, including the proliferation, differentiation, and mineralisation. In conclusion, the steam explosion was an effective strategy to recover protein hydrolysate with well calcium‐binding capacity and potential pro‐osteogenic activity from chicken bone. This study provided new insights and theoretical bases for the application of steam explosion in extracting protein hydrolysate to improve bone health. [ABSTRACT FROM AUTHOR]

The industrial processing of coconut to produce valuable foods, such as water and milk, generates large volumes of waste, especially the fruit shell. Despite this, material can be used in bioprocess applications, e.g., the production of enzymes, its recalcitrance hinders the cultivation of microorganisms, and low productivity is usually achieved. In this study, the production of cellulolytic enzymes through solid-state fermentation (SSF) and their extraction was investigated using the green coconut fiber pretreated by steam explosion, followed by alkali. The fungus Trichoderma reesei CCT-2768 was cultivated, using an experimental design, to study the effect of the water activity and the amount of biomass in the reactor. The combination of the pretreatment strategies yielded more porous biomass, with less hemicellulose (5.38%, compared to 10.15% of the raw biomass) and more cellulose (47.77% and 33.96% in the pretreated and raw biomasses, respectively). The water activity significantly affected the production of cellulases, with maximum activity yielded at the highest investigated value (0.995). Lastly, the extraction of the enzymes from the cultivation medium was studied, and a 9 g/L NaCl solution recovered the highest CMCase and FPase activities (5.19 and 1.19 U/g, respectively). This study provides an important contribution to the valorization of the coconut residue through (i) the application of the steam explosion technology to optimize the production of cellulases using the SSF technology and (ii) their extraction using different solvents. [ABSTRACT FROM AUTHOR]

To reduce the adverse physical effects on the oral mucosa caused by excessive hardness of betel nut fibers, steam explosion was used to soften betel nuts. The effect of three operating parameters (pressure holding time, explosion pressure, and initial moisture content) on the morphology, texture, and chemical composition of the betel nuts was investigated. The fiber hardness and Shore hardness decreased by 56.17%–89.28% and 7.03%–34.29%, respectively, and the transverse tensile strength and fiber tensile strength also decreased by up to 60.72% and 24.62%, respectively. Moreover, the coefficient of static friction and moisture content increased. After steam explosion, the betel nut increased in transverse diameter, became darker and more yellow–red in color, and showed a damaged microstructure. The contents of free phenol and alkaloids decreased after steam explosion treatment, with free phenols and total alkaloids decreasing from 34.32 mg(GAE)/g and 7.84 mg/g to 21.58 mg(GAE)/g and 6.50 mg/g, respectively, after the A‐50 s treatment condition. The steam explosion increased the quantity of phenols, alkaloids, and soluble solids released from the betel nut under the same simulated release conditions of the texture analyzer. The research also showed that increased pressure holding time and explosion pressure enhanced the explosion efficiency, while the initial moisture content was reduced the explosion efficiency. Therefore, steam explosion is an effective pretreatment approach to soften betel nut and facilitate healthy development of the betel nut industry. [ABSTRACT FROM AUTHOR]

Rice bran (RB) is a major by-product of the rice industry, and the high proportion (~90%) of insoluble fibre (IF) is the main reason limiting its applications in foods. Thus, the objective of this research is to enhance the solubility of rice bran fibre and decrease the molecular weight (MW) of the soluble fibre (SF) fraction through ultrasound (US) and steam explosion (SE) treatments. The main sugars in the RB fibre were xylose and arabinose, with glucose, galactose, and mannose present in the side chains. The ratio of Ara/Xyl was 0.92 for the un-purified and 1.02 for the purified RB, reflecting the high degree of substitution of the xylan backbone. The highest amount of SF was obtained from RB treated at 60% US amplitude, 20 min treatment, where 7.8% (un-purified) and 35.2% (purified), respectively. For SE treatments, the amount of SF in un-purified RB increased as the pressure increased from 0.3 and 0.6 MPa, which were 6.10±0.34 and 8.83±0.56%, respectively. Meanwhile, the highest SF fraction (35.2%) of purified RB was obtained from the SE treatment at 0.6 MPa. The SF produced from both treatments mainly contained oligosaccharides with MW <1 kDa, with those produced by the SE treatment generally smaller than those by the US treatment. Purification of RB significantly enhanced the efficiency of the US and SE treatments in breaking down the IF into the SF. [ABSTRACT FROM AUTHOR]

Co-briquetting of coal fines and lignocellulosic biomass is a possible path for incorporating biomass energy into the current coal-based infrastructure, although the cost and performance of conventional binders remain problematic. The use of steam-exploded sugarcane bagasse (SE SCB) as a binder for coal fines briquetting was therefore investigated. SE SCB (produced at 140–220°C for 15 min) was mixed with high-ash bituminous coal-fines at various concentrations (0–18%), and briquetted at a pressure value of 24 MPa and at various temperatures (25–180°C). Following multivariate optimization, an optimal steam explosion temperature range of 185–195°C was found. At these pretreatment temperatures, sufficient disruption of the lignocellulosic structure occurred, resulting in increased binding between coal fines and SCB, while higher temperatures resulted in detrimental destruction of fiber structure and reduction in binding performance. A synergistic interaction between briquetting temperatures and SE SCB content above 100°C and 13%, respectively, substantially improved briquette properties. At these optimum conditions, the briquettes had a compressive strength of 1205 kPa, an abrasion resistance of 97%, water absorption index of 82%, and a wet compressive strength of 501 kPa. Briquettes maintained structural integrity when pyrolyzed at 700°C and had a post-pyrolysis compressive strength of 134 kPa, indicating that SE SCB could potentially be a suitable binder for coal fines briquetting. [ABSTRACT FROM AUTHOR]

Steam explosion breaks down the polymeric matrix and enables the recovery of valuable compounds from lignocellulosic feedstock. In the steam explosion process, biomass is treated with high-pressure steam which subsequently generates large quantities of a condensed aqueous liquid (process effluent) and a filtered aqueous liquid (filtrate) that contain furfural, 5-hydroxymethylfurfural, 5-methylfurfural, methanol, and acetic acid as major constituents. This study addresses the identification and quantification of value-added chemicals in the aqueous product streams using quantitative analytical nuclear magnetic resonance spectroscopy with water suppression. This work reports a screening study for two different types of sawdust (Norway spruce and birch) at two different scales (4 L and 10 L reactors) using different reaction temperatures (190–223 °C) and corresponding pressures (13–24 bar), with and without the addition of SO2 gas. The duration of all experiments was 8 min. The process effluents contained acetic acid, methanol, formic acid, 5-methylfurfural, and furfural. Acetic acid (0.5 g/kg dry input biomass) and furfural (1.0 g/kg dry input biomass) were more abundant than methanol, formic acid, and 5-methylfurfural for both feedstocks. The addition of SO2 increased the furfural yields, indicating more efficient hydrolysis of hemicelluloses under acidic conditions. Filtrate samples also contained 5-hydroxymethylfurfural, with the highest concentrations (5.7–6.0 g/kg dry input biomass) in the filtrates from spruce. The different feedstocks and steam explosion temperatures strongly influenced the overall yields of the target compounds, in some cases tripling the concentrations. The results can be used to improve the profit margins in a pellets and chemicals biorefinery, as demonstrated in the ArbaOne pellets plant. [ABSTRACT FROM AUTHOR]

Effects of steam explosion (SE) treatment (0.3-1.0 MPa, 30-90s) on the physicochemical and functional properties of dietary fiber (DF) extracted from tea residue were investigated. Results showed that SE led to the formation of porous and less compact microstructures of tea residues. Compared with the control sample (12.41 g/100g), the content of soluble dietary fiber (SDF) was markedly increased by SE, reaching the maximum of 23.03g/100g when steam explored at 0.5 MPa for 90s, due to the degradation of insoluble dietary fiber (IDF). The physicochemical and functional properties were significantly influenced by SE treatments. IDF exhibited decreased water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) after SE, whereas the physicochemical properties of SDF from SE-treated tea residues (0.3 MPa, 90s) were greatly improved. The glucose absorption capacity (GAC), cholesterol adsorption capacity (CAC), and nitrite ion adsorption capacity (NIAC) of both IDF and SDF showed trends of first increasing and then decreasing, indicating that excessive SE treatment resulted in poor properties of DF. These findings are of great value for the high-value utilization of agricultural by-product and development of functional foods. [ABSTRACT FROM AUTHOR]