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Abdessalem Mrabet - One of the best experts on this subject based on the ideXlab platform.
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antioxidant phenolic extracts obtained from secondary tunisian date varieties phoenix dactylifera l by hydrothermal Treatments
Food Chemistry, 2016Co-Authors: Abdessalem Mrabet, Ana Jimenezaraujo, Juan Fernandezbolanos, Fatima Rubiosenent, Antonio Lamamunoz, Marianne Sindic, Guillermo RodriguezgutierrezAbstract:Abstract Three common non-commercial Tunisian date varieties were treated by two thermal systems, obtaining a liquid fraction which was characterized and its antioxidant capacity determined. The concentration of total phenols in the three varieties (Smeti, Garen Gazel, and Eguwa) was increased by Steam Explosion Treatment up to 5311, 4680, and 3832 mg/kg of fresh dates, and their antioxidant activity up to 62.5, 46.5 and 43.1 mmol Trolox®/kg of fresh date, respectively. Both thermal Treatments increased the content of phenolic acids. Additionally, a long scale study was carried out in a pilot plant, with Steam Treatment at 140 °C and 160 °C for 30 min. The liquid phase was extracted and fractionated chromatographically using adsorbent or ionic resins. The phenolic profiles were determined for each fraction, yielding fractions with interesting antioxidant activities with EC 50 values of up to 0.08 mg/L or values of TEAC of 0.67 mmol Trolox®/g of extract.
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Antioxidant phenolic extracts obtained from secondary Tunisian date varieties (Phoenix dactylifera L.) by hydrothermal Treatments
Food chemistry, 2015Co-Authors: Abdessalem Mrabet, Juan Fernández-bolaños, Marianne Sindic, Ana Jiménez-araujo, Fátima Rubio-senent, Antonio Lama-muñoz, Guillermo Rodríguez-gutiérrezAbstract:Abstract Three common non-commercial Tunisian date varieties were treated by two thermal systems, obtaining a liquid fraction which was characterized and its antioxidant capacity determined. The concentration of total phenols in the three varieties (Smeti, Garen Gazel, and Eguwa) was increased by Steam Explosion Treatment up to 5311, 4680, and 3832 mg/kg of fresh dates, and their antioxidant activity up to 62.5, 46.5 and 43.1 mmol Trolox®/kg of fresh date, respectively. Both thermal Treatments increased the content of phenolic acids. Additionally, a long scale study was carried out in a pilot plant, with Steam Treatment at 140 °C and 160 °C for 30 min. The liquid phase was extracted and fractionated chromatographically using adsorbent or ionic resins. The phenolic profiles were determined for each fraction, yielding fractions with interesting antioxidant activities with EC 50 values of up to 0.08 mg/L or values of TEAC of 0.67 mmol Trolox®/g of extract.
Yoshitoshi Nakamura - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Cellulose Nanofiber from Steam-exploded Japanese Cedar
Bioresources, 2017Co-Authors: Akihiro Suzuki, Chizuru Sasaki, Chikako Asada, Yoshitoshi NakamuraAbstract:Cellulose nanofiber (CNF) was produced from Japanese cedar using a new environmentally friendly pulping process, i.e. a Steam Explosion Treatment followed by water and acetone extractions. The effect of the Steam Explosion Treatment on the morphological, chemical, and mechanical properties of Steam-exploded CNF were clarified. The increase of Steam Explosion severity markedly decreased the molecular weight of α-cellulose in the Steam-exploded cedar pulp. The maximum tensile strength value of 88.9 MPa and Young’s modulus value of 12.9 GPa were obtained for the films made from Steam-exploded CNF at a Steam pressure of 35 atm for a Steaming time of 5 min. The results obtained in this work were useful for developing a new production method of CNF from various Steam-exploded woody biomass.
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Steam Explosion Treatment for ethanol production from branches pruned from pear trees by simultaneous saccharification and fermentation.
Bioscience biotechnology and biochemistry, 2014Co-Authors: Chizuru Sasaki, Chikako Asada, Ryosuke Okumura, Yoshitoshi NakamuraAbstract:This study investigated the production of ethanol from unutilized branches pruned from pear trees by Steam Explosion preTreatment. Steam pressures of 25, 35, and 45 atm were applied for 5 min, followed by enzymatic saccharification of the extracted residues with cellulase (Cellic CTec2). High glucose recoveries, of 93.3, 99.7, and 87.1%, of the total sugar derived from the cellulose were obtained from water- and methanol-extracted residues after Steam Explosion at 25, 35, and 45 tm, respectively. These values corresponded to 34.9, 34.3, and 27.1 g of glucose per 100 g of dry Steam-exploded branches. Simultaneous saccharification and fermentation experiments were done on water-extracted residues and water- and methanol-extracted residues by Kluyveromyces marxianus NBRC 1777. An overall highest theoretical ethanol yield of 76% of the total sugar derived from cellulose was achieved when 100 g/L of water- and methanol-washed residues from 35 atm-exploded pear branches was used as substrate.
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Direct hydrolysis of cellulose to glucose using ultra-high temperature and pressure Steam Explosion
Carbohydrate polymers, 2012Co-Authors: Chizuru Sasaki, Chikako Asada, Sumimoto Keisuke, Yoshitoshi NakamuraAbstract:Abstract Hydrolysis of two cellulosic materials, i.e. microcrystalline cellulose powder (MC) and cuprammonium rayon fiber (BEMCOT), to glucose was carried out by Steam Explosion Treatment with ultra-high temperature and pressure Steam aiming at an effective usage of unutilized cellulosic materials. 50 g of cellulosic materials were charged in a sealed reactor (2 L) of the Steam Explosion apparatus kept at Steam pressures of 50, 55, 60, and 62 atm for a Steaming time of 1 min. The maximum yield of water soluble sugars, 52.8%, was obtained at a Steam pressure of 62 atm and a Steaming time of 1 min for MC. Furthermore, the maximum yield of water soluble sugars, 67.7%, was obtained at a Steam pressure of 60 atm and a Steaming time of 1 min for BEMCOT. This water soluble sugars contained 63.1% and 61.0% of glucose, respectively; they are corresponding to 33.3 g and 41.0 g of glucose contained in 100 g of dry Steam-exploded cellulosic material.
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Novel extraction method of antioxidant compounds from Sasa palmata (Bean) Nakai using Steam Explosion
Process Biochemistry, 2007Co-Authors: Akihiro Kurosumi, Chizuru Sasaki, Fumihisa Kobayashi, Kentaro Kumada, Godliving Mtui, Yoshitoshi NakamuraAbstract:Abstract Antioxidant compounds were extracted from various parts of Sasa palmata (Bean) Nakai, a bamboo plant whose leaves are commonly used to wrap foodstuffs such as Sushi in Japan. Highest concentrations of antioxidant compounds existed in the leaf part of S. palmata. Steam Explosion Treatment followed by hot water and methanol extractions was used for separating the antioxidant compounds from S. palmata leaf. The Steam Explosion Treatment is the physical–chemical Treatment which crushes a sample by sudden reduction of the pressure in reactor to atmospheric pressure after Steaming the sample at high temperature and pressures. Sasa palmata leaf was hydrolyzed by Steaming and crushed by the rapid decompression. The optimal condition of Steam Explosion for the effective extraction of antioxidant compounds from S. palmata was determined as a Steam of temperature of 250 °C and a Steaming time of 1 min. In these conditions 217.41 mg/(g-Sasa leaf) of phenolic compounds and 142.81 mg/(g-Sasa leaf) of radical scavenging activity, that was expressed as butylated hydroxyanisole (BHA), were obtained.
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production of methane gas from japanese cedar chips pretreated by various delignification methods
Biochemical Engineering Journal, 2006Co-Authors: Harumi Take, Yoshitoshi Nakamura, Yoshifumi Andou, Fumihisa Kobayashi, Yasuji Kurimoto, Masaaki KuwaharaAbstract:Methane fermentation of woody waste was carried out using various preTreatment methods for delignification in order to evaluate the efficient preTreatment method for producing methane gas from woody waste. Japanese cedar (Cryptomeria japonica) chips were used as sample of woody waste. As preTreatment methods, refiner Treatment, Steaming Treatment, Steaming Treatment followed by refiner Treatment, basidiomycete fungi Treatment, and Steam Explosion Treatment were attempted and the methane gas evolved from treated wood chips were compared. The Steam Explosion Treatment resulted in the most effective preTreatment method for methane fermentation from woody waste among the preTreatment methods. The Steam Explosion at a Steam pressure of 4.51 MPa and a Steaming time of 5 min was the optimal preTreatment method for obtaining a large amount of methane gas in energy saving manner. The strong correlation between the amount of methane gas evolved and the ratio of amount of Klason lignin was observed. The study confirmed the necessity of preTreatment for delignification of cedar wood waste.
Guillermo Rodríguez-gutiérrez - One of the best experts on this subject based on the ideXlab platform.
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Phenols recovery after Steam Explosion of Olive Mill Solid Waste and its influence on a subsequent biomethanization process.
Bioresource technology, 2017Co-Authors: Antonio Serrano, Fernando G. Fermoso, Bernabé Alonso-fariñas, Guillermo Rodríguez-gutiérrez, Juan Fernández-bolaños, Rafael BorjaAbstract:Abstract A promising source of high added value compounds is the Olive Mill Solid Waste (OMSW). The aim of this research was to evaluate the viability of a biorefinery approach to valorize OMSW through the combination of Steam Explosion, phenols extraction, and anaerobic digestion. Steam Explosion Treatment increased the total phenol content in the Steam exploited OMSW, which was twice than that the total phenol content in raw OMSW, although some undesirable compounds were also formed. Phenol extraction allowed the recovery of 2098 mg hydroxytyrosol per kg of OMSW. Anaerobic digestion allowed the partial stabilization of the different substrates, although it was not improved by the Steam Explosion Treatment. The economic suitability of the proposed biorefinery approach is favorable up to a phenol extract price 90.7% lower than the referenced actual price of 520 €/kg.
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Antioxidant phenolic extracts obtained from secondary Tunisian date varieties (Phoenix dactylifera L.) by hydrothermal Treatments
Food chemistry, 2015Co-Authors: Abdessalem Mrabet, Juan Fernández-bolaños, Marianne Sindic, Ana Jiménez-araujo, Fátima Rubio-senent, Antonio Lama-muñoz, Guillermo Rodríguez-gutiérrezAbstract:Abstract Three common non-commercial Tunisian date varieties were treated by two thermal systems, obtaining a liquid fraction which was characterized and its antioxidant capacity determined. The concentration of total phenols in the three varieties (Smeti, Garen Gazel, and Eguwa) was increased by Steam Explosion Treatment up to 5311, 4680, and 3832 mg/kg of fresh dates, and their antioxidant activity up to 62.5, 46.5 and 43.1 mmol Trolox®/kg of fresh date, respectively. Both thermal Treatments increased the content of phenolic acids. Additionally, a long scale study was carried out in a pilot plant, with Steam Treatment at 140 °C and 160 °C for 30 min. The liquid phase was extracted and fractionated chromatographically using adsorbent or ionic resins. The phenolic profiles were determined for each fraction, yielding fractions with interesting antioxidant activities with EC 50 values of up to 0.08 mg/L or values of TEAC of 0.67 mmol Trolox®/g of extract.
Francesco Alfani - One of the best experts on this subject based on the ideXlab platform.
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effect of inhibitors released during Steam Explosion Treatment of poplar wood on subsequent enzymatic hydrolysis and ssf
Biotechnology Progress, 2008Co-Authors: Maria Cantarella, Laura Cantarella, Alberto Gallifuoco, Agata Spera, Francesco AlfaniAbstract:Steam-exploded (SE) poplar wood biomass was hydrolyzed by means of a blend of Celluclast and Novozym cellulase complexes in the presence of the inhibiting compounds produced during the preceding Steam-Explosion preTreatment process. The SE temperature and time conditions were 214 degrees C and 6 min, resulting in a log R(0) of 4.13. In enzymatic hydrolysis tests at 45 degrees C, the biomass loading in the bioreactor was 100 g(DW)/L (dry weight) and the enzyme-to-biomass ratio 0.06 g/g(DW). The enzyme activities for endo-glucanase, exo-glucanase, and beta-glucosidase were 5.76, 0.55, and 5.98 U/mg, respectively. The inhibiting effects of components released during SE (formic, acetic, and levulinic acids, furfural, 5-hydroxymethyl furfural (5-HMF), syringaldehyde, 4-hydroxy benzaldehyde, and vanillin) were studied at different concentrations in hydrolysis runs performed with rinsed SE biomass as model substrate. Acetic acid (2 g/L), furfural, 5-HMF, syringaldehyde, 4-hydroxybenzaldehyde, and vanillin (0.5 g/L) did not significantly effect the enzyme activity, whereas formic acid (11.5 g/L) inactivated the enzymes and levulinic acid (29.0 g/L) partially affected the cellulase. Synergism and cumulative concentration effects of these compounds were not detected. SSF experiments show that untreated SE biomass during the enzymatic attack gives rise to a nonfermentable hydrolysate, which becomes fermentable when rinsed SE biomass is used. The presence of acetic acid, vanillin, and 5-HMF (0.5 g/L) in SSF of 100 g(DW) /L biomass gave rise to ethanol yields of 84.0%, 73.5%, and 91.0% respectively, with respective lag phases of 42, 39, and 58 h.
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Effect of Inhibitors Released during Steam‐Explosion Treatment of Poplar Wood on Subsequent Enzymatic Hydrolysis and SSF
Biotechnology progress, 2008Co-Authors: Maria Cantarella, Laura Cantarella, Alberto Gallifuoco, Agata Spera, Francesco AlfaniAbstract:Steam-exploded (SE) poplar wood biomass was hydrolyzed by means of a blend of Celluclast and Novozym cellulase complexes in the presence of the inhibiting compounds produced during the preceding Steam-Explosion preTreatment process. The SE temperature and time conditions were 214 degrees C and 6 min, resulting in a log R(0) of 4.13. In enzymatic hydrolysis tests at 45 degrees C, the biomass loading in the bioreactor was 100 g(DW)/L (dry weight) and the enzyme-to-biomass ratio 0.06 g/g(DW). The enzyme activities for endo-glucanase, exo-glucanase, and beta-glucosidase were 5.76, 0.55, and 5.98 U/mg, respectively. The inhibiting effects of components released during SE (formic, acetic, and levulinic acids, furfural, 5-hydroxymethyl furfural (5-HMF), syringaldehyde, 4-hydroxy benzaldehyde, and vanillin) were studied at different concentrations in hydrolysis runs performed with rinsed SE biomass as model substrate. Acetic acid (2 g/L), furfural, 5-HMF, syringaldehyde, 4-hydroxybenzaldehyde, and vanillin (0.5 g/L) did not significantly effect the enzyme activity, whereas formic acid (11.5 g/L) inactivated the enzymes and levulinic acid (29.0 g/L) partially affected the cellulase. Synergism and cumulative concentration effects of these compounds were not detected. SSF experiments show that untreated SE biomass during the enzymatic attack gives rise to a nonfermentable hydrolysate, which becomes fermentable when rinsed SE biomass is used. The presence of acetic acid, vanillin, and 5-HMF (0.5 g/L) in SSF of 100 g(DW) /L biomass gave rise to ethanol yields of 84.0%, 73.5%, and 91.0% respectively, with respective lag phases of 42, 39, and 58 h.
Guillermo Rodriguezgutierrez - One of the best experts on this subject based on the ideXlab platform.
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antioxidant phenolic extracts obtained from secondary tunisian date varieties phoenix dactylifera l by hydrothermal Treatments
Food Chemistry, 2016Co-Authors: Abdessalem Mrabet, Ana Jimenezaraujo, Juan Fernandezbolanos, Fatima Rubiosenent, Antonio Lamamunoz, Marianne Sindic, Guillermo RodriguezgutierrezAbstract:Abstract Three common non-commercial Tunisian date varieties were treated by two thermal systems, obtaining a liquid fraction which was characterized and its antioxidant capacity determined. The concentration of total phenols in the three varieties (Smeti, Garen Gazel, and Eguwa) was increased by Steam Explosion Treatment up to 5311, 4680, and 3832 mg/kg of fresh dates, and their antioxidant activity up to 62.5, 46.5 and 43.1 mmol Trolox®/kg of fresh date, respectively. Both thermal Treatments increased the content of phenolic acids. Additionally, a long scale study was carried out in a pilot plant, with Steam Treatment at 140 °C and 160 °C for 30 min. The liquid phase was extracted and fractionated chromatographically using adsorbent or ionic resins. The phenolic profiles were determined for each fraction, yielding fractions with interesting antioxidant activities with EC 50 values of up to 0.08 mg/L or values of TEAC of 0.67 mmol Trolox®/g of extract.