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Ensuring environmental and social-economic sustainability in the use of materials from lignocellulosic biomass requires their fractionation and valorization of their main components. In this work, we used Eucalyptus urograndis wood to obtain chemicals and energy. The raw material was characterized in chemical terms and then subjected to autohydrolysis under variable operating conditions to optimize the extraction of hemicellulose derivatives relative to cellulose. The kinetics of the pyrolysis process was modeled in terms of activation energy and hydrogen production. Using temperatures in the range of 180–190 °C and treatment times in the range of 15–30 min allowed more than 74.5% of all hemicellulosic components in the raw material to be selectively extracted into the liquid post-hydrolysis phase, more than 90%of all glucan to remain in the solid phase and up to 27.8%of lignin to be removed. The thermal behavior of solid fraction was examined by thermogravimetric analysis, using variable heating rates under a nitrogen atmosphere, and the activation energy can be estimated by using the Flynn-Wall-Ozawa method. Based on the results, the pyrolysis of E. urograndis can be modeled as a first-order reaction. The activation energy (Ea) at a fractional conversion α between 0.3 and 0.7 was 183 to 199 KJ mol−1 for the raw material, whereas that for the solid residue from autohydrolysis ranged from 179 to 186 kJ mol−1 at same fractional conversion when operational temperature in autohydrolysis was upper 185 °C. Based on the results, using temperatures above 180 °C and times of 15 min or longer [i.e., operating at the (0,0) experimental point for the autohydrolysis process] in combination with degrees of conversion from 0.3 to 0.8 reduced the activation energy of the pyrolysis process in relation to the raw material by up to 12% and removed hemicellulose by more 74.5% from it. In parallel, the comparative analysis of the Ea values and the composition of the pyrolysis gas obtained showed a negative relationship between Ea and the amount of hydrogen produced. This work was funded by the Andalusian Regional Government (Project FEDER Andalucía, UHU-1255540 and postdoctor al fellowship) and the Spanish Government (National Program for Research Aimed at Social Challenges, Grant No. TQ2017-85251-C2- 1-R)

This work deals with the study of tea stalks from pruning debris using environmental friendly extraction technology to offer new healthy properties. In the manufacturing tea industry, tea trees require to be pruned every year and most of their remains are discarded as a waste with no economic value. Microwave aqueous extraction and pressurized hot water extraction process (autohydrolysis) were used to recover bioactive compounds from the tea branches. Operating at a fixed solid: liquid ratio (1:15), the effect of the maximum heating temperatures from 140 to 220 °C was studied. Liquid extracts were analysed for total phenolic, oligosaccharides, protein, mineral and heavy metals content, as well as for antioxidant capacity. The antitumoral possibilities were also determined for selected samples. The obtained results indicated that both processes could be used as an alternative to recover bioactive compounds from tea wastes, although microwave-assisted extraction allowed saving time when compared with autohydrolysis processing. The temperature exhibited a relevant effect on the total phenolic content and antioxidant capacity, decreasing with the microwave treatment and increasing with the autohydrolysis temperature. The obtained extracts could be adequate for incorporation in food and non-food fields., Graphical abstract Image 1, Highlights • Tea pruning remains were valorised using green extractions by microwave (MW) and autohydolysis (AH). • MW and AH were efficient technologies to recover bioactive compounds. • Values above 40 mg gallic acid equivalents/g extract and 0.10 g Trolox/g extract were identified. • Future applications in cosmetics, pharmacy or food industries should be explored.

The present paradigm of a new concept of biomass conversion system has been focused on the development of a multi-supply biorefinery concept towards a circular and sustainable bioeconomy. This work was focused on evaluating a mixture of six lignocellulosic biomass types, from forest ecosystems and biological resources from marginal land, in order to produce lactic acid (L-LA) by Lactobacillus rhamnosus within a multi-supply biorefinery scheme. The mixture of lignocellulosic biomass was submitted to autohydrolysis pretreatment under non-isothermal regime at 226 °C (corresponding to a severity of 4.15) yielding a glucan recovery of 93 % in the solid phase. Two different strategies were assayed for L-LA production, namely separated hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). The glucose to LA yield obtained for both assays was 1 g/g, although the volumetric productivity of SSF (2.5 g/Lh) was higher than SHF (0.8 g/Lh). Therefore, the SSF process was optimized through a factorial design to evaluate the effect of the independent variables, solids load (SL) and enzyme-substrate ratio (ESR), on LA production. The maximum concentration of LA was obtained using the highest solids load (16 %) and with the highest ESR (54 FPU/g). Finally, L-LA was produced using in a bioreactor under the optimized conditions from experimental design, obtaining 61.74 g/L of LA at 44 h, with an optical purity of 98 % and a LA yield of 0.97 g/g. This study showed the potential of multi-supply unexploited lignocellulosic biomass as a raw material to LA fermentation., Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of SFRH/BDE/109316/2015 unit, UIDB/04469/2020 unit, BLC3 Evolution Lda., COMPETE 2020 [3iBioeconomia: POCI-01-0246-FEDER-026758], COMPETE 2020 [POCI-01-0145-FEDER-006684], BioTecNorte operation [NORTE-01-0145-FEDER-000004] funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte and FEDER through COMPETE and of National Funds through FCT grants FCOMP-01-0124-FEDER-028359 [PTDC/BIA-MIC/2779/2012] and UID/NEU/04539/2013, info:eu-repo/semantics/publishedVersion

Hydrothermal treatments (HTT) are used in the biorefineries to effectively valorize carbohydrate fractions and their products. However, lignin is often marginalized as a secondary component. Herein, we propose a new biorefinery approach focused on lignin valorization. We demonstrate that high-value lignins can be extracted using a simple, green, and affordable process consisting of an optimized HTT followed by lignin extraction with aqueous acetone under ambient conditions. Significantly, the chemical structure and molecular mass of the lignin can be tailored by the selection of the process variables while maintaining a high yield, in the range of ∼60-90%. For example, the average molecular mass (Mw) of the isolated lignins is in the range between 2.5 and 5 kDa, while the amount of β-O-4 linkages is 4-28 per 100 Ar. The extracted lignins are further used to generate micro- and nanoparticles by using an aerosol flow system. The introduced lignin profiling affords control of particle properties, including average size and distribution, surface energy, and wettability. Overall, the suggested approach allows customization of lignin products while achieving a 58% reduction in the lignin particles production costs compared to the lowest prime figures reported so far.

This work targets the valorization of brewers spent grain (BSG) waste by ethanol production, providing strategies for increasing titers in the multiple process steps involved. High solid loadings and use of whole slurry from the pretreatment were evaluated, aiming to achieve high ethanol concentration and yield. As variability in BSG chemical composition presents a challenge for their valorization, six different BSGs were chemically characterized, which allowed the selection of two with high polysaccharide content. High solid loadings (up to 25%) were employed for the pretreatment of selected BSGs by autohydrolysis, an environmentally friendly process, to improve enzymatic saccharification and extract fermentable sugars as oligosaccharides and monosaccharides. As a result, high glucose concentrations (43.7 and 57.7?g L-1) and glucose yield (85.9 and 70.6 %) were obtained from the saccharification of the pretreated BSG whole slurry at 20 and 25% solid loading, respectively. Whole slurries from autohydrolysis were used as substrate for ethanol production by hybrid saccharification and fermentation. Two different Saccharomyces cerevisiae strains were evaluated and high ethanol concentration (42.27?g L-1) at a high yield (94.0 %) was achieved. The results attained by the combined intensification approaches qualify BSG waste as a valuable renewable resource for cost-effective ethanol production., This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and COMPETE 2020 (POCI-01-0145-FEDER006684), BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte and MultiBiorefinery project (POCI-01-0145-FEDER-016403). Furthermore, authors acknowledge Fermentum-Engenharia das Fermentações Lda., for providing raw material for this work., info:eu-repo/semantics/publishedVersion

One of the major challenges in biofuels production from lignocellulosic biomass is the generation of high glucose titers from cellulose in the enzymatic hydrolysis stage of pretreated biomass to guarantee a cost-effective process. Therefore, the enzymatic saccharification on cellulose at high solid loading is an alternative. In this work, the agave bagasse was hydrothermally pretreated and optimized at 194°C/30min, obtaining a pretreated solid rich in cellulose content (>46.46%), and subjected to enzymatic hydrolysis at high solid levels. A horizontal bioreactor was designed for enzyme saccharification at high solid loadings [25% (w/v)]. The bioreactor improved mixing efficiency, with cellulose conversions up to 98% (195.6g/L at 72h). Moreover, mathematical modeling of cellulase deactivation demonstrated that cellulases lose most of their initial activity in the first hours of the reaction. Also, cellulose was characterized by X-ray diffraction, and the pretreated solids were visualized using scanning electron microscopy., This project was funded by the Secretary of Public Education of Mexico - Mexican Science and Technology Council (SEP-CONACYT) with the Basic Science Project-2015-01 (Ref. 254808). Marcela Sofía Pino also thanks the National Council for Science and Technology (CONACYT, Mexico) for her Master Fellowship support (grant number: 611312/452636), and Dr. Michele Michelin thanks the Portuguese Foundation for Science and Technology (FCT) for her postdoctoral fellowship (SFRH/BPD/100786/2014)., info:eu-repo/semantics/publishedVersion

The aim of this study was to clarify the role of the relative amounts of hemicelluloses and lignin on the enzymatic hydrolysis of pretreated sugarcane bagasse, by using the glucans/lignin ratio and the glucans/xylans ratio as a quick estimation of the enzymes accessibility to cellulose. The samples were selected to contain about 3–20% lignin, 52–90% glucans, and 6–26% xylans (by extraction of hemicelluloses and delignification). The enzyme loads used for saccharification were 10 FPU of cellulases and 20 IU of β-glucosidases per gram of samples. Conversions of glucans to glucose were highly influenced by the chemical composition, varying between 18.1% and 83.4%. The concentration of lignin and xylans in the pretreated bagasse affects the conversion to glucose. High conversions are achieved when the substrates are highly delignified. Less delignified samples can also lead to high conversion when the percentage of xylans are also decreased. Thus, the removal of both lignin and xylans contributes to an increase in the accessibility of cellulases to cellulose. Fil: Vallejos, María Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentina Fil: Zambon, Marcia D.. Universidade de Sao Paulo; Brasil Fil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentina Fil: Curvelo, Antonio A. S.. Universidade de Sao Paulo; Brasil

The integral valorization of artichoke bracts generated during industrial canning of artichoke was assessed. The extraction of bioactive compounds was addressed with pressurized hot water under subcritical conditions. The performance of this stage on the extraction of phenolics with antioxidant properties and the saccharidic fraction using conventional and microwave heating was compared. The microwave assisted process was more efficient than the conventional one regarding extraction yields of total solubles, and glucose and fructose oligomers and phenolics, because lower operational temperatures and shorter times were needed. Degradation of fructose oligomers was observed at temperatures higher than 160 °C, whereas the maximal phenolic content occurred at 220 °C. Both the extracts and the residual solids, obtained at conditions leading to maximum phenolics yields, were evaluated for the production of starch-based hydrogels, supplemented with Paulownia leaves’ aqueous extracts. Xunta de Galicia | Ref. ED431G/02 Xunta de Galicia | Ref. ED431C-2016/041 Xunta de Galicia | Ref. EDC431C 2018/47 Ministerio de Economía, Industria y Competitividad (España) | Ref. BES-2016-076840 Agencia Estatal de Investigación | Ref. RYC2018-024454-I

Made available in DSpace on 2021-06-25T10:31:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Xylooligosaccharides (XOS) acts as a prebiotic, a food component that is not digested but stimulates the growth of beneficial microorganisms present in the intestine, such as bifidobacteria and lactobacilli, improving the health of the host. This study obtained XOS by comparing optimized conditions for acid hydrolysis and autohydrolysis of sugarcane bagasse, showing that is possible to produce XOS with minimum degradation of sugras. The acid hydrolysis process varied the parameters applying a 23 factorial design using 1–3% (m/v) sulfuric or acetic acid; a temperature of 100–160 °C and a reaction time of 15–55 min. The autohydrolysis was performed by 22 factorial design using the same range of temperature and time. The acetic acid hydrolysis of the sugarcane bagasse resulted in the conversion of xylan into XOS of 18.41% (m/m) with 1% (m/v) acid at 100 °C for 15 min, with xylopentaose/xylohexaose predominance. The hydrolysis of sugarcane bagasse with sulfuric acid resulted in 90.13% (m/m) of XOS with 2% (m/v) of acid at 79.55 °C for 35 min, with xylobiose prevalence. Autohydrolysis of bagasse resulted in 13.67% (m/m) xylan conversion into XOS at 172.4 °C for 35 min, with xylotetraose prevalence. The degradation sugar products were low for the conditions studied, with 0.31%, 0.16%, and 0.01% (m/m) of furfural using sulfuric, acetic, and autohydrolysis, successively. The results demonstrated that XOS with different degrees of polymerization can be produced applying specific pretreatment conditions of autohydrolysis, sulfuric, and acetic acid, with the minimum content of sugar degradation. Institute for Research in Bioenergy (IPBEN) São Paulo State University (UNESP) School of Pharmaceutical Sciences (FCF) Department of Bioprocesses and Biotechnology São Paulo State University (UNESP) Institute for Research in Bioenergy (IPBEN) São Paulo State University (UNESP) School of Pharmaceutical Sciences (FCF) Department of Bioprocesses and Biotechnology São Paulo State University (UNESP) FAPESP: 2017/22401–8 FAPESP: 2019/12997–6

Autohydrolysis is used for producing xylan-derived oligosaccharides from lignocellulosic biomass. Although numerous studies report optimized autohydrolysis conditions for various plants, few of these studies correlate process parameters with the resulting structural properties to their impact on intestinal bacterial communities. Thus, to further clarify these relationships, beechwood xylan (BWX)-derived substrates, processed under five conditions, were fermented in vitro by human gut microbiota. Autohydrolysis reduced the mean molecular size and substitutions of BWX. Distinct fermentation kinetics were observed with differing processing of BWX substrates, which correlated with impacts on community species evenness. The relative abundances of Bacteroides, Fusicatenibacter, Bifidobacterium, and Megasphaera within the fermentations varied with processing conditions. While the total short-chain fatty acid concentrations were the same among the treatments, processing conditions varied the extent of propionate and butyrate generation. Autolysis parameters may be an important tool for optimizing beneficial effects of xylan-derived fibers on human gut microbiota structure and function. Nanyang Technological University This work was supported by the institutional fund provided by Nanyang Technological University.

Banana's pseudostem pulp (BPP) is a potential by-product obtained in the mechanical fiber extraction of banana's pseudostem. Its chemical characterization revealed to have an interesting composition, with a high polysaccharides content and low content in lignin, which makes it particularly relevant for the biorefinery's biochemical platform. Autohydrolysis pretreatment, studied under isothermal (140 degrees C) and non-isothermal conditions (140-220 degrees C), yielded oligosaccharides, mainly gluco-oligosaccharides, as the main soluble products. The highest oligosaccharides production (24 g/100 g raw material) was obtained at a severity factor of 2.3. Autohydrolysis pretreatment effectively disrupted the structure of the material, inducing an improvement of the enzymatic digestibility from 73% for the raw material up to 90% for the most severe conditions. Two stage autohydrolysis, with increasing severity, was also studied, allowing to obtain a higher amount of oligosaccharides (32 g/100 g raw material) and higher digestibility of the remaining solid (up to 97%). info:eu-repo/semantics/publishedVersion

Corn stover is the most produced byproduct from maize worldwide. Since it is generated as a residue from maize harvesting, it is an inexpensive and interesting crop residue to be used as a feedstock. An ecologically friendly pretreatment such as autohydrolysis was selected for the manufacture of second-generation bioethanol from corn stover via whole-slurry fermentation at high-solid loadings. Temperatures from 200 to 240 &deg, C were set for the autohydrolysis process, and the solid and liquid phases were analyzed. Additionally, the enzymatic susceptibility of the solid phases was assessed to test the suitability of the pretreatment. Afterward, the production of bioethanol from autohydrolyzed corn stover was carried out, mixing the solid with different percentages of the autohydrolysis liquor (25%, 50%, 75%, and 100%) and water (0% of liquor), from a total whole slurry fermentation (saving energy and water in the liquid&ndash, solid separation and subsequent washing of the solid phase) to employing water as only liquid medium. In spite of the challenging scenario of using the liquor fraction as liquid phase in the fermentation, values between 32.2 and 41.9 g ethanol/L and ethanol conversions up to 80% were achieved. This work exhibits the feasibility of corn stover for the production of bioethanol via a whole-slurry fermentation process.

Made available in DSpace on 2020-12-12T02:45:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-15 Eucalyptus wood is the main source of fiber for the production of paper and cellulose in South America. One of the by-products of the pulp industry is sawdust generated during wood chip production; sawdust from Eucalyptus is denominated as Eucalyptus by-product (EB). Xylooligosaccharides (XOS) are oligomers mainly comprising xylose units, which have beneficial effects on health. In this study, was report the optimization of XOS production through the hydrothermal pretreatment (HP) of EB. A central composite experimental design comprising a 23-factorial design with six axial points and four replicates at the central point was employed to optimize the HP conditions for maximum XOS production using response surface method; these conditions were as follows: temperature of 161 °C, reaction time of 65 min, and consistency of 10 %. The hemicellulosic hydrolysate showed potential for the production of XOS, containing 60 milligrams of XOS per gram of EB. São Paulo State University (UNESP) School of Pharmaceutical Sciences (FCF) Department of Bioprocess Engineering and Biotechnology University of Antioquia (UdeA) School of Nutrition and Dietetic São Paulo State University (UNESP) School of Pharmaceutical Sciences (FCF) Department of Bioprocess Engineering and Biotechnology

Background Soil-derived exogenous ash (EA) poses a challenge toward lignocellulosic autohydrolysis due to its buffering capacity. Previous works focusing on this phenomenon have failed to also investigate the role that soluble salts, and organic matter plays in this system. Herein, sodium phosphate and sodium humate were employed as model buffering compounds representing soluble salts and organic matter and dosed into a de-ashed wheat straw (DWS) autohydrolysis process to show the potential impacts of WS attached soil conditioners on the WS autohydrolysis efficiency which would further affect the enzymatic digestibility of autohydrolyzed WS. Results Results showed that with the increasing loadings of sodium phosphate and sodium humate resulted in elevated pH values (from 4.0 to 5.1 and from 4.1 to 4.7, respectively). Meanwhile, the reductions of xylan removal yields from ~ 84.3–61.4% to 72.3–53.0% by loading (1–30 g/L) sodium phosphate and sodium humate during WS autohydrolysis lead to a significant decrease of cellulose accessibilities which finally lead to a reduction of the enzymatic digestibility of autohydrolyzed WS from ~ 75.4–77.2% to 47.3–57.7%. Conclusion The existence of different types soil conditioner model compounds results in various component fractions from autohydrolyzed WS in the process of autohydrolysis. A lack of sufficient xylan removal was found to drive the significant decrease in enzymatic accessibility. The results demonstrated the various effects of two typical tested soil conditioners on WS autohydrolysis and enzymatic hydrolysis.

This work was focused on evaluating two mixtures of lignocellulosic feedstock, forest and marginal land resources, in order to co-produce solid biofuel, oligosaccharides, and glucose under a biorefinery concept. The selection of renewable bio-mixtures was based on different criteria, namely, territorial distribution, fire risk during summer months and total sugar content. The two mixtures were submitted to autohydrolysis pretreatment under non-isothermal conditions (in the range of 190°C - 240°C corresponding to severity of 3.714.82). Both mixtures were compared in terms of fractionation (cellulose and lignin recoveries and hemicellulose solubilization), analyzed for thermal properties (high heating values) and for enzymatic susceptibility of cellulose. The highest xylan recoveries (62 and 69%), as xylose and xylooligosaccharides, were achieved for both mixtures in the liquid phase at 206°C. Autohydrolysis pretreatment increased the high heating values of the two mixtures presenting an alternative use of solid fraction as solid biofuel. Moreover, enzymatic susceptibility of these pretreated mixtures was also improved from 45 to 90% of glucose yield by increasing pretreatment severity. This comparative study of autohydrolysis showed a suitable process for the valorization of both mixtures within a biorefinery concept., This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE2020 (POCI-01-0145-FEDER-006684/ POCI-01-0145-FEDER-007440), the BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte and the MultiBiorefinery project (POCI-01–0145-FEDER-016403). Rita Pontes (SFRH/BDE/109316/2015) and Michele Michelin (SFRH/BPD/100786/2014) thank FCT for their doctoral and postdoctoral fellowships, respectively., info:eu-repo/semantics/publishedVersion

The production of tequila in Mexico generates a large amount of agave bagasse per year. However, this biomass can be considered as a potential source for biofuel production. In this study, it is described how the hydrothermal pretreatment was scaled in a bench scale, considering the severity index as a strategy. The best condition was at 180°C in isothermal regime for 20min with 65.87% of cellulose content and high concentration of xylooligosaccharides (15.31g/L). This condition was scaled up (using severity factor: [logR0]=4.11), in order to obtain a rich pretreated solid in cellulose to perform the enzymatic hydrolysis, obtaining saccharification yields of 98.5 and 99.5% at high-solids loading (10 and 15%, respectively). The pre-saccharification and fermentation strategy was used in the bioethanol production at 10 and 15% of total pretreated solids, obtaining 38.39 and 55.02g/L of ethanol concentration, corresponding to 90.84% and 87.56% of ethanol yield, respectively., Financial support is gratefully acknowledged from the Energy Sustainability Fund 2014-05 (CONACYT-SENER), Mexican Centre for Innovation in Bioenergy (Cemie-Bio), Cluster of Bioalcohols (Ref. 249564). We gratefully acknowledge support for this research by the Mexican Science and Technology Council (CONACYT, Mexico) for the Infrastructure Project – INFR201601 (Ref. 269461) and Basic Science Project – 2015-01 (Ref. 254808). Author Daniela L. Aguilar would like to thank the Mexican Science and Technology Council (CONACY, Mexico) for their master fellowship support (grant number: 582801/ 414478) andauthor ElisaZanuso thanksthe EnergySustainability Fund 2014-05 (CONACYT-SENER, Ref. 249564) for the undergraduate fellowship granted. Also, the authors thank Prof. Lucília Domingues and José Teixeira (University of Minho, Portugal) for kindly providing the yeast strain., info:eu-repo/semantics/publishedVersion

WOS: 000425561900040 Wheat straw was pretreated at 150 degrees C for 100 min at a liquor-to-straw ratio of 6 L/kg (oven dry basis) straw using aqueous formic acid (FA) concentrations ranging from 0 to 15 g/L. The results showed excellent sugar and lignin mass balances for pretreatment, and precipitated lignin in the hydrolysate obtained at 15 g/L of FA decreased to 0.31 g/100 g straw compared to autohydrolysis (no FA) of 0.94 g/100 g straw. The average molecular weight of precipitated lignin decreased from 1970 g/mole for autohydrolysis to 710 g/mole at 15 g/L of FA. The monomeric sugar yield during pretreatment improved from 3.83 g/100 g for autohydrolysis to 23.5 g/100 g at 15 g/L FA. TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) The authors would like to thank TUBITAK (The Scientific and Technological Research Council of Turkey) for supporting doctoral research grant for Omer OZYUREK and Umaine Ober Chair.

Bioethanol production from lignocellulose biomass offers a solution to current environmental challenges caused by fossil fuel energy resources, while satisfying the biorefinery concept. In this study, two-stage fractionation (autohydrolysis (AH) followed by glycerol organosolv delignification (GOD)) of sugarcane bagasse (SCB) was studied as a function of temperature, time, glycerol content and liquid-to-solid (LSR) ratio using experimental designs. The effect of three different AH pretreatment severities on delignification extents (DE) of the solid fractions were also evaluated. Scanning electron microscopy was used to examine the changes in the surface of SCB pretreated by AH. Energy balances of four fractionation conditions were estimated, and the use of pure and crude glycerol in GOD was evaluated based on DE and lignin contents. A DE of ∼64% was obtained at 210.3 °C, 40 min, LSR of 6.5 (v/w) and 80% (v/v) pure glycerol for GOD of SCB pretreated by AH at 175.8 °C, 49 min and LSR of 5.3 (v/w), which resulted in an energetic profitability (EP) of 141.48 MJ/kgSCB. The use of crude glycerol at 80% (v/v) under the same process conditions optimized for pure glycerol also proved to be feasible (DE of ∼64% and EP of 142.67 MJ/kgSCB), widening the possibilities for its direct use in GOD of SCB pretreated by AH in a 2G bioethanol integrated plant.

Non-isothermal autohydrolysis, an environmentally friendly pretreatment, was employed for the production of second generation bioethanol from fast-growing Paulownia wood, comparing two biorefinery strategies: (i) one-stage autohydrolysis pretreatment, and (ii) sequential two-stage autohydrolysis pretreatment. The first strategy allowed to either recover high amounts of hemicellulosic-derived compounds in the liquid phase (at lower severities) or to achieve high enzymatic susceptibility of the cellulose in the solid phase (at higher severities). Solid phase from lower severities pretreatments (optimal for the recovery of hemicellulosic compounds) achieved glucan to glucose conversions of 38.672.2% in the enzymatic hydrolysis assays. In this context, conditions for the obtainment of a liquor enriched in hemicelluloses and a highly enzymatically susceptible solid are not compatible. Therefore, the employment of the second strategy (sequential pretreatments in two stages) allowed to recover up to 85% of initial xylan as xylooligosaccharides and xylose in autohydrolysis liquor from first stage of autohydrolysis (at severity, S01 = 4.08) and enhance the enzymatic susceptibility of the solid phase to a glucan to glucose conversion close to 100% with the second stage of autohydrolysis (S01 = 4.08, S02 = 3.76, with a global severity of S0G = 4.25). Fermentation experiments confirmed the advantages of the sequential two-stage autohydrolysis (with a glucan to ethanol conversion close to 100% and high volumetric productivity). Finally, an overall mass balance and energy analysis were carried out, reflecting a suitable fractionation of Paulownia wood that would accomplish an energy recovery of 97.5%., Authors are grateful to MINECO (Spain) for the financial support of this work in the framework of the projects “Development of processes for the integral use of fast-growing biomass by means of the production of bioethanol and chemical products” with reference CTQ2012-30855, and “Multistage processes for the integral benefit of macroalgal and vegetal biomass” with reference CTM2015-68503-R, to Consellería de Cultura, Educacion ´ e Ordenacion ´ Universitaria (Xunta de Galicia) through the contract ED431C 2017/62-GRC to Competitive Reference Group BV1, and to the CITACA Strategic Partnership ED431E 2018/07, programs partially funded by European Regional Development Fund (FEDER). Pablo G. del Río would like to express gratitude to the Ministry of Science, Innovation and Universities of Spain for his FPU research grant (FPU16/04077)., info:eu-repo/semantics/publishedVersion

The potato processing industry produces peels, a good source of fibres, minerals and antioxidants, which could be recovered and used in the production of added-value products, such as gluten-free (GF) foods especially designed for the celiac population. This work is focused on the application of the bioactive fraction extracted from potato peels into GF pasta. Subcritical water extraction (autohydrolysis, AH) was performed on potato peel, and the obtained AH liquid extract was characterized in terms of total phenolic content and antioxidant activity. The selected AH temperature (220 °C at 2.2 MPa) was applied to peels from Kennebec, Neiker and Agria potato varieties, and the Agria extract was selected for application in GF pasta, as this was the one with higher antioxidant activity. The impact of Agria potato peel autohydrolysis extract on the nutritional composition and cooking quality of pasta was assessed. Results confirmed that the GF pasta enriched with potato peel extract presented suitable technological properties, coupled with attractive colour and with increased total phenolic content and antioxidant activity, which can contribute to improve the offer of GF products in the market info:eu-repo/semantics/publishedVersion

The autohydrolysis of Lentinus edodes was proposed for the extraction of components with antioxidant properties. Operation under non-isothermal conditions was evaluated and compared with isothermal heating. The influence of process severity was assessed in the range of 0.18 to 4.89 (temperature between 50 and 250 &deg, C), up to 80% (d.b.) The influence of process severity during the autohydrolysis of Lentinus edodes was assessed in the range &minus, 0.3 to 4.89 (temperature between 50 and 250 &deg, C). Up to 80% (d.b.) of the initial raw material could be solubilized at 210 &deg, C. The different behavior of the saccharide and phenolic fractions was observed with the treatment temperature. Whereas the highest concentration of the saccharide components (mainly glucooligosaccharides) was found at 210 &deg, C, the maximum phenolic yield was identified at 250 &deg, C. The phenolic content and the antiradical properties of the extract showed a continuous increase with the temperature range studied, and at 250 &deg, C, showed antiradical properties comparable to synthetic antioxidants. Autohydrolysis liquid fractions were used as solvents in the formulation of bioactive starch-based hydrogels, identifying a positive correlation between the gel softening and the extracts&rsquo, bioactivity features.

Sargassum muticum, an invasive macroalgae in Europe, was employed as material for third generation bioethanol production. As a first step, autohydrolysis was chosen as an eco-friendly pretreatment, seeking for a high enzymatic susceptibility of the solid phase and high content of hexoses as glucose, galactose and mannose, in both liquid and solid phases, which can be subsequently transformed in ethanol via fermentation. Besides, the search of a minimum consumption of energy in the pretreatment is also a key challenge in bioethanol production. At optimum conditions of autohydrolysis pretreatment, more than 90% of the glucan was recovered in the solid phase (while the other 10% appeared as glucooligosaccharides and glucose in the liquid phase). In the enzymatic hydrolysis carried out with the solid phases, glucan to glucose conversions of 94 and 89% were obtained, with the solid mixed with water and the whole slurry, respectively. Moreover, the whole slurry experiments, where all hexoses present in the raw material (glucose, galactose and mannose) from the solid and the liquid phases are fermented, allows to reach maximum ethanol yields of 80% (14.10?g of ethanol/L) referred to the theoretical yield, in a short time., Authors are grateful to spanish Ministry of Economy andCompetitiveness (research project “Multistage projects for the in-tegral benefit of macroalgae and vegetable biomass”with referenceCTM2015-68503) and to Xunta de Galicia (Galician CompetitiveResearch Group GRC 2017/62 and to the CITACA Strategic Partner-ship), these three programs partially funded by FEDER of EuropeanUnion; to the Portuguese Foundation for Science and Technology(reference UID/BIO/04469/2019 unit), and to European RegionalDevelopment Fund under the scope of Norte2020 - ProgramaOperacional Regional do Norte (reference NORTE-01-0145-FEDER-000004).Pablo G. del Río is grateful to the Ministry of Education,Culture and Sports of Spain for his FPU research grant., info:eu-repo/semantics/publishedVersion

Background The acid buffering capacity of high free ash in waste wheat straw (WWS) has been revealed to be a significant hindrance on the efficiency of autohydrolysis pretreatment. Previous researches have mainly relied on washing to eliminate the influence of ash, and the underlying mechanism of the ash influencing was not extensively investigated. Presently, studies have found that cations can destroy the acid buffering capacity of ash through cation exchange. Herein, different cations were applied to presoak WWS with the aim to overcome the negative effects of ash on autohydrolysis efficiency, further improving its enzymatic digestibility. Results Results showed that cations can be adsorbed on the surface of the material by electrostatic adsorption to change the acid buffering capacity of WWS. The acid buffering capacity of 120 mM Fe2+ presoaked WWS is reduced from 226.3 mmol/pH-kg of original WWS to 79.3 mmol/pH-kg. This reduced the autohydrolysis pretreatment medium pH from 5.7 to 3.8 and promoted the removal of xylan from 61.7 to 83.7%. In addition, the enzymatic digestibility of WWS was enhanced from 49.7 to 86.3% by presoaking with 120 mM Fe2+ solution. The relationship between enzymatic accessibility and hydrophobicity with enzymatic digestibility of the autohydrolyzed WWS was analyzed. Conclusions The results showed that the acid buffering capacity of the high free ash was detrimental for the autohydrolysis efficiency of WWS. After WWS was presoaked with different cations, the acid buffering capacity of ash was weakened by cation exchange and electrostatic adsorption, which improved the autohydrolysis efficiency. The results expound that the enzymatic digestibility of WWS can be enhanced through presoaking to reduce the ash-influencing effect on autohydrolysis.

Enzymatic hydrolysis accounts for 20% of the total cost in the conversion process of lignocellulosic biomass into bioethanol. Therefore, production of biomass-degrading enzymes by using lignocellulosic residue as a fermentation substrate may be an alternative to decrease the production costs. In this study, corncob (CC) has been pretreated by liquid hot water (LHW) at 200 °C for 30 min and used as inducer source for production of biomass-degrading enzymes by Trichoderma reesei MUM 97.53. The pretreatment was used to increase the cellulose content and the accessibility to lignocellulosic material. Although the filamentous fungus secreted a broad range of cellulolytic and hemicellulolytic enzymes when grown on untreated CC, higher enzyme productions were obtained when cultured on LHW-pretreated CC in a 2-L stirred tank bioreactor (STB). Besides, the effects of aeration (2 and 4 vvm) and agitation (150 and 250 rpm) rates on enzyme production were studied by submerged fermentation in a batch STB and correlated with the volumetric oxygen transfer coefficient (kLa). Maximal cellulase, xylanase, and -xylosidase productions were found at 150 rpm and 4 vvm, while the highest -glucosidase levels were obtained at 150 rpm and 2 vvm, that corresponded to kLa values of 32.50 h1 and 16.41 h1, respectively. At higher agitation, a lower enzymatic production was observed probably due to the high shear stress in the fungal hyphae., Michele Michelin is a recipient of a FCT fellowship (SFRH/BPD/100786/2014). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte., info:eu-repo/semantics/publishedVersion

Solid acids have been proposed as a hydrolytic agent for wood biomass dissolution. In this work, we presented an environmentally friendly physicochemical treatment to leave behind cellulose, dissolve hemicellulose, and remove lignin from poplar wood. Several pretreatments, such as autohydrolysis and disk refining, were compared to optimize and modify the process. The p-toluenesulfonic acid could extract lignin from wood with a small amount of cellulose degradation. Disk refining with subsequent acid hydrolysis (so-called physicochemical treatment) doubled the delignification efficiency. A comprehensive morphology and overall chemical composition were provided. The crystallinity index (CrI) of treated poplar was increased and the chemical structure was changed after physicochemical treatment. Optical microscopy and scanning electron microscopy analysis demonstrated physicochemical treatment affected the morphology of poplar wood by removing lignin and generating fiberization. In general, this work demonstrated this physicochemical method could be a promising fractionation technology for lignocellulosic biomass due to its advantages, such as good selectivity, in removing lignin while preserving cellulose.

Liquid hot water pretreatment is considered to be a promising method for increasing biomass digestibility due to the moderate operational conditions without chemical additions. A necessary step towards the scalability of this pretreatment process is performing pilot plant trials. Upscaling was evaluated with a scaling factor of 500, by using 50 mL in the laboratory and 25 L in a pilot plant batch reactor. Pretreatment times were varied from 30 to 240 min, and temperatures used were 180–188 °C, while applying similar heating profiles at both scales. The initial mass fraction of poplar wood chips ranged from 10% to 16%. Liquid hot water pretreatment at laboratory and pilot scale led to analogous results. The acetic acid analysis of the liquid and solid fractions obtained after pretreatment indicated that complete deacetylation of poplar biomass can be achieved.

Subcritical water extraction of Himanthalia elongata and the subsequent acetone fractionation to precipitate crude fucoidans generated a liquid phase which was used to recover alginates with a wide range of viscoelastic features and other soluble extracts with potential biological activities. The precipitated alginate was converted to sodium alginate using an environmentally friendly treatment before being characterized by Fourier transform infrared attenuated total reflectance, nuclear magnetic resonance, high performance size exclusion chromatography and rheological measurements. The cell viability of three human cell lines (A549, HCT-116, T98G) in the presence of the extracts obtained before and after acetone fractionation was assessed. Fractionation with different acetone volumes showed a slight effect in the behavior of the different tested cell lines. Results also indicated a notable effect of the processing conditions on the block structure and molar mass of the extracted biopolymer, with the subsequent impact on the rheological properties of the corresponding gelled matrices. Xunta de Galicia | Ref. ED481B 2018/071 Xunta de Galicia | Ref. ED431F 2020/01 Agencia Estatal de Investigación | Ref. RYC2018-024454-I Ministerio de Economía y Competitividad (España) | Ref. CTM2015-68503-R

In this study, a versatile process for the production of xylooligosaccharides (XOS) with a low degree of polymerization (DP 2-6) from hazelnut shells was designed. This process included autohydrolysis integrated with sequential enzymatic hydrolysis by crude xylanase produced with Aureobasidium pullulans NRRL Y-2311-1 from wheat bran. Autohydrolysis of hazelnut shells was carried out at a solid:liquid ratio of 1:6 (w/w) and 190 degrees C nonisothermally. The effects of several parameters on enzymatic hydrolysis of the autohydrolysis liquor were determined. The maximum XOS (DP 2-6) production was 22.5 g/L which was obtained at pH 5.0 and 40 degrees C using enzyme concentration of 240 U/g XOS and substrate concentration of 72 g/L. Under these conditions, 31.29 % of the substrate (total XOS) was converted to low-DP-XOS; xylobiose and xylotriose are being the major oligomers. This is the first study on the application of A. pullulans xylanase in production of xylooligomers from hazelnut shells., Scientific and Technological Research Council of Turkey-TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TOVAG 213O126, TOVAG 112O521], This work was financially supported by The Scientific and Technological Research Council of Turkey-TUBITAK (Project Numbers: TOVAG 213O126 and TOVAG 112O521).

The aim of this study was to evaluate strategies of detoxification and fermentation of the hemicellulosic liquors obtained from sugarcane bagasse autohydrolysis, for the biotechnological production of xylitol. Different sequences of detoxification treatments were performed, and their effects on sugars loss and inhibitors removal were evaluated. Fermentation assays were accomplished with commercial xylose to selectthe best yeast(C. guilliermondii, C.tropicalis) and the fermentation conditions ofthe detoxified spent liquors. Detoxification through a sequence oftreatments, including Ca(OH)2, IR-120 resin, activated charcoal, and IRA-67 resin, practically removed all inhibitors from the hemicellulosic spent liquors. Maximal concentration of xylitol obtained was 32.0 g L−1 (C. tropicalis, xylose: 104.1 g L−1, yield: 0.46 g g−1, productivity: 0.27 g L−1 h−1). The technological parameters to obtain a detoxified spent liquor rich in xylose and its bioconversion to xylitol were determined Fil: Vallejos, María Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentina Fil: Chade, Miriam Estela. Universidad Nacional de Misiones. Facultad de Cs.exactas Químicas y Naturales. Departamento de Medio Ambiente; Argentina Fil: Mereless, Elizabeth Beda. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina Fil: Bengoechea, Dora Inés. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina Fil: Brizuela, Johanna Gisela. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina Fil: Felissia, Fernando Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentina Fil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentina

Made available in DSpace on 2018-12-11T17:02:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-08-01 Samples of Eucalyptus urograndis and Eucalyptus grandis sawdust were autohydrolyzed in aqueous conditions to reach temperatures in the range 110-190 °C and reaction times of 0-150 min in a minireactor. In each minireactor were used a liquor:wood ratio (10:1 L:kg dry wood), in order to assess the effects of the autohydrolysis severity and the crystalline properties of cellulose. The content of extractives, lignin, holocellulose, cellulose, hemicelluloses and crystallinity index obtained from the solid fraction after autohydrolysis of sawdust were determined. This study demonstrated that the hemicelluloses were extensively removed at 170 and 190 °C, whereas cellulose was partly degraded to Eucalyptus urograndis and Eucalyptus grandis sawdust. The lignin content decreased, while the extractives content increased. It was defined that during autohydrolysis, had a slight decreased on crystalline structure of cellulose of Eucalyptus urogandis and Eucalyptus grandis. Laboratório de Celulose e Papel Departamento de Ciência Florestal Faculdade de Ciências Agronômicas/UNESP, Faz Experimental Lageado, Jose Barbosa de Barros, 1780 Departamento de Física e Biofísica Instituto de Biociências UNESP, Distrito de Rubião Júnior, S/N Laboratório de Celulose e Papel Departamento de Ciência Florestal Faculdade de Ciências Agronômicas/UNESP, Faz Experimental Lageado, Jose Barbosa de Barros, 1780 Departamento de Física e Biofísica Instituto de Biociências UNESP, Distrito de Rubião Júnior, S/N

Aspen wood was subjected to autohydrolysis as a pre-treatment to characterize the structural changes occurring in lignin fractions during the pre-treatment process. Milled wood lignin (MWL) was isolated from both the native aspen wood and hydrolyzed wood chips, and its structural features were characterized by Fourier transform infrared (FT-IR), quantitative 13C, two-dimensional heteronuclear single quantum coherence (2D HSQC), and 31P nuclear magnetic resonance (NMR) spectroscopies, gel permeation chromatography/multi-angle laser light scattering (GPC-MALLS), and thermal analysis. The lignin remaining in the hydrolyzed wood chips revealed more phenolic OH groups, fewer aliphatic OH groups, higher syringyl/guaiacyl ratios (S/G), higher molecular weights, and narrower polydispersities than the native lignin of aspen wood. The inter-unit linkages of β-O-4 were noticeable cleaved, but the condensed structures in the lignin formed when undergoing autohydrolysis of high severity, resulting in elevated amounts of C-C linkages. Moreover, it was found that autohydrolysis promoted the removal of -OCH3 groups and increased the thermal stability of lignin fractions.

Olive table industry, olive mills and olive pomace oil extraction industries annually generate huge amounts of olive stones. One of their potential applications is the production of bioethanol by fractionation of their lignocellulose constituents and subsequent fermentation of the released sugars using yeasts. In this work, we studied the influence of temperature (175–225 ◦C) and residence time (0–5 min) in the liquid hot-water pre-treatment of olive stones as well as the initial enzyme loading (different mixtures of cellulases, hemicellulases and β–glucosidases) in the later enzymatic hydrolysis on the release of fermentable sugars. The Chrastil’s model was applied to the D-glucose data to relate the severity of pre-treatment to enzyme diffusion through the pre-treated cellulose. Finally, the hydrolysate obtained under the most suitable conditions (225 ◦C and 0 min for pre-treatment; 24 CE initial enzyme concentration) was fermented into ethanol using the yeast Pachysolen tannophilus ATCC 32691. Considering the overall process, 6.4 dm3 ethanol per 100 kg olive stones were produced., Andalusia Regional Government (Spain) 01272/2005 AGR/6509

In this work, a sustainable and environmental friendly strategy for the biotechnological production of xylitol was proposed and optimized. For this purpose, corn cob was hydrothermally pretreated at high solid loadings (25%) for an efficient solubilization of xylan in hemicellulose derived compounds, xylooligosaccharides and xylose. Xylose enriched streams were obtained from the enzymatic saccharification of the whole slurry (solid and liquid fraction) resulting from the autohydrolysis pretreatment. The xylitol production in a simultaneous saccharification and fermentation (SSF) process, by the recombinant Saccharomyces cerevisiae PE-2-GRE3 strain, was optimized using different enzyme and substrate (pretreated corn cob solid) loadings by an experimental design. This study demonstrated a significant effect of substrate loading on the production process achieving a maximal concentration of 47g/L with 6.7 % of pretreated corn cob and 24 FPU/g of enzyme loading, with partial detoxification of the hydrolysate. Furthermore, the 1.42-fold increase in xylitol titer and 1.56-fold increase in productivity achieved in a SSF using an acetic acid free-hydrolysate evidenced the negative effect of acetic acid on the yeast-based xylitol production process. The combination of these green technologies and the optimization of the proposed strategy enhanced the overall xylitol production through the valorization of corn cob., This study was carried out at the Biomass and Bioenergy ResearchInfrastructure (BBRI)- LISBOA-01-0145-FEDER-022059, supported byOperational Programme for Competitiveness and Internationalization (PORTUGAL2020), by Lisbon Portugal Regional Operational Programme (Lisboa 2020) and by North Portugal Regional Operational Programme (Norte 2020) under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF).This was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, BioTecNorte operation (NORTE-01-0145 FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 and BIOVINO project (0688_BIOVINO_6_E)funded by INTERREG España - Portugal and European Regional Development Fund (ERDF). Sara L. Baptista (SFRH/BD/132717) thanksFCT for the doctoral fellowship., info:eu-repo/semantics/publishedVersion

In this work, valorization of Paulownia wood (PW) was proposed following several process configurations for biofuels and value-added compounds production. Firstly, autohydrolysis and ethanol-organosolv strategies were assessed separately for the fractionation of PW to enhance the enzymatic digestibility of cellulose. A third strategy focused on a sequential process (autohydrolysis and organosolv) was explored. Two temperatures were selected for the first stage of the combined process. High concentration of oligosaccharides (26.29 g/L) and high concentration of degradation products (17.21 g/L) were obtained at 210 and 230 °C, respectively. The solids obtained from both pretreatments were subjected to organosolv delignification (200 °C, 3 h and 50% ethanol) achieving delignification of 58 and 30% for the autohydrolyzed biomass at 210 °C and 230 °C, respectively. The combined process resulted in susceptible biomass able to produce 64 g/L of ethanol. Therefore, the strategies explored in this work open the possibility to build a refinery around Paulownia wood., Authors are grateful to MINECO (Spain) for thefinancial support ofthis work in the framework of the projects “Multistage processes for theintegral benefit of macroalgal and vegetal biomass” with referenceCTM2015-68503-R, and “Cutting-edge strategies for a sustainablebiorefinery based on valorization of invasive species” with reference PID2019-110031RB-I00, to Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia) through the contract ED431C 2017/62-GRC to Competitive Reference Group BV1, and to the CITACA Strategic Partnership ED431E 2018/07, programs partiallyfunded by European Regional Development Fund (FEDER). Pablo G. delRío and Beatriz Gullón would like to express their gratitude to theMinistry of Science, Innovation and Universities of Spain for his FPUresearch grant (FPU16/04077) and her RYC grant (RYC2018-026177-I), respectively., info:eu-repo/semantics/publishedVersion

8 páginas.-- 6 figuras.-- 3 tablas.-- 34 referencias., Following an integrated approach, Eucalyptus nitens wood samples were subjected to consecutive stages of aqueous fractionation and organosolv delignification, in order to separate hemicelluloses (mainly converted into soluble products from the aqueous stage) from lignin (largely converted into soluble fragments in the organosolv stage) and from cellulose (accumulated in the solid phase from pulping). The compositions of selected reaction media were studied by selected spectrophotometric, spectrometric, chromatographic, and nuclear magnetic resonance methods; and the solid phases from treatments were studied by diffractometry and scanning electron microscopy. The experimental information from the above tasks provides a deep insight on the yields, properties and potential applications of the target fractions in the scope of biorefineries., The authors are grateful to the Spanish Ministry of Economy and Competitivity for supporting this study in the framework of the research project ‘‘Modified aqueous media for wood Biorefineries’’ (reference CTQ2017-82962-R), partially funded by the FEDER program of the European Union.

Seaweeds are a novel source of important nutritional compounds with interesting biological activities that could be processed into added-value products. In this study, two previously developed products obtained by Laminaria ochroleuca processing (liquid extract and a pur&eacute, e-like mixture) were processed with Psyllium gel to develop functional hydrogels. The optimization of the formulation and the characterization of the Laminaria-Psyllium gels in terms of their mechanical features have allowed the proposal of potential food applications. A beneficial interaction was found between Laminaria and Psyllium in terms of the reinforcement of texture and rheological properties. The obtained outcomes could provide new healthy gelling formulations with attractive properties to alleviate the growing market demand of eco-novel food matrices.

Autohydrolysis (AH) prior to the kraft process is one way to valorize hemicelluloses. The presented results show that AH also has a beneficial effect insofar as kraft cooking can be substituted by soda cooking, and higher brightness levels can be achieved under the same bleaching conditions. The lignin has more free phenolic groups after AH, which is attributable to depolymerization, and which could partly explain the better pulping and bleaching results. Another explanation could be the lower amount of lignin involved in lignin carbohydrate complexes after an AH step.

Corncob was successively pretreated by liquid hot water (LHW) and ethanol organosolv (EO) in an integrated process. LHW was performed at 200°C for 30min, and EO was performed using uncatalyzed ethanolwater solutions, according to a design of experiments. The effects of the most influential operational variables (ethanol concentration, temperature and time) on yield and chemical composition of the fractions were assessed. Results showed the factor with the greatest effect was ethanol concentration (p, Michele Michelin is a recipient of a FCT fellowship (SFRH/BPD/100786/2014). This studywas supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. The authors thank André Mota and CVR – “Centro para a Valorização de Resíduos”, (Guimarães, Portugal) for supporting the gridding of the material; Paula Pereira and Maura Guimarães for the technical support., info:eu-repo/semantics/publishedVersion

The operating conditions for the autohydrolysis of eucalyptus wood were optimized with a view to maximizing hemicellulose extraction while preserving the integrity of glucan. The influence of the operating conditions used in the soda–anthraquinone pulping of the solid phase resulting from the autohydrolysis process was examined. Autohydrolysis of the raw material at a liquid/solid ratio of 8 kg water/kg material at 180°C for 30 min was found to provide a commercially useful liquid phase containing most of the starting hemicellulose. The autohydrolysis treatment allowed the subsequent production of soda–anthraquinone cellulose pulp and paper with properties as good as or even better than those obtained without the pretreatment.

The use of coconut fiber mature, green coconut shell, mature coconut shell and cactus is an important alternative as substrates for bioethanol production, since these lignocellulosic materials (LCMs) are abundant in Brazil, mainly in the Northeast Region. The first objective of this work was to evaluate the autohydrolysis pretreatment (AP) on these LCMs and the susceptibility of the treated materials to enzymatic hydrolysis (EH). The second part of the work deals with the application of semi-simultaneous saccharification and fermentation (SSSF) and simultaneous saccharification and fermentation (SSF) using Zymomonas mobilis, Pichia stipitis, Saccharomyces cerevisiae and as substrate the green coconut shell (selected according to the results obtained in the first part of the work). The LCMs after AP using the highest severity factor (4.64) showed changes in the chemical composition in comparison to the untreated LCMs: between the LCMs the cellulose increase was 48.55%, the hemicellulose decrease was 76.77% and an increase of 62.26% was observed for lignin. The green coconut shell was characterized by SEM, X-ray and FTIR after AP and its EH conversion into glucose was 92.52%. The best results on ethanol yield (90.09%) and ethanol productivity (0.21 g/(L h)) from green coconut shell were obtained by S. cerevisiae using SSSF. Overall, an efficient process for the bioethanol production from green coconut shell was developed., Brazilian research funding agencies CNPq (Proc:470356/2011-1) and CAPES (Proc:BEX5951/11-9).

The chemical industry is being forced to evaluate new strategies for more effective utilization of renewable feedstocks to diminish the use of fossil resources. In this literature review, the integration of both acidic and alkaline pretreatment phases of hardwood and softwood chips with chemical pulping is discussed. Depending on the pretreatment conditions, high-volume sulfur-free fractions with varying chemical compositions can be produced. In case of acidic pretreatments, the major products include carbohydrates (mono-, oligo-, and polysaccharides), whereas under alkaline (i.e., aqueous NaOH) pretreatment conditions, the sulfur-free fractions of aliphatic carboxylic acids, lignin, and extractives are primarily obtained. All these fractions are potentially interesting groups of compounds and can be used in a number of applications. Finally, the effects of pretreatments on pulping are also considered. Although it is believed that there are important advantages to be gained by integrating this type of renewable raw material-based production, in particular, with kraft pulping, sulfur-free pulping methods such as soda-AQ and oxygen/alkali delignification processes are also briefly discussed. peerReviewed

The biorefinery concept integrates processes and technologies for an efficient biomass conversion using all components of a feedstock. Sargassum muticum is an invasive brown algae which could be regarded as a renewable resource susceptible of individual valorization of the constituent fractions into high added-value compounds. Microwave drying technology can be proposed before conventional ethanol extraction of algal biomass, and supercritical fluid extraction with CO2 was useful to extract fucoxanthin and for the fractionation of crude ethanol extracts. Hydrothermal processing is proposed to fractionate the algal biomass and to solubilize the fucoidan and phlorotannin fractions. Membrane technology was proposed to concentrate these fractions and obtain salt- and arsenic-free saccharidic fractions. Based on these technologies, this study presents a multipurpose process to obtain six different products with potential applications for nutraceutical, cosmetic and pharmaceutical industries.

International audience; The purpose of this study is to target well-defined xylooligosaccharides by controlled sulfuric acidic hydrolysis of beechwood xylans. Parameters such as sulfuric acid and xylan concentrations, hydrolysis duration and temperature have been investigated, allowing optimum conditions to be determined (0.7 M H2SO4, 90 degrees C, 45 min). The obtained xylooligosaccharides show a well-defined structure and have been characterized using several techniques such as 1D and 2D nuclear magnetic resonance spectrometry and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. This work demonstrated that mild acidic hydrolysis conditions enable the reproducible production of xylooligosaccharides containing, on average, six xylose units and only one 4-O-methyl-D-glucuronic acid unit likely positioned at the non-reductive chain-end.