Partially O-acetylated xylo-oligosaccharides (DXO) isolated from almond shells by autohydrolysis ... more Partially O-acetylated xylo-oligosaccharides (DXO) isolated from almond shells by autohydrolysis as well as their de-acetylated form (DeXO) were subjected to chemical, molecular, and structural analyses. They represent a mixture of neutral and acidic oligomers and low-molecular weight polymers related to (4-O-methyl-D-glucurono)-D-xylan. DXO and DeXO showed direct mitogenic activity and enhancement of the T-mitogen-induced proliferation of rat thymocytes, indicating the immunostimulatory potential of the almond shell xylo-oligosaccharides.
ABSTRACT Xylose-based oligosaccharides produced from xylan-rich hemicelluloses (xylo-oligomers) a... more ABSTRACT Xylose-based oligosaccharides produced from xylan-rich hemicelluloses (xylo-oligomers) are carbohydrates with potential food and pharmaceutical uses. Autohydrolysis of lignocellulosic biomass is an efficient way to produce xylo-oligomers in a reasonable yield and a wide variety of compositions (anhydroarabinose/anhydroxylose and acetyl/anhydroxylose mass ratios). In this work, we develop a kinetic model for the autohydrolysis of xylan in lignocellulosic biomass that describes the yields of the different reaction products and explains the changes in the chemical composition of the xylo-oligomers due to reaction temperature and time. This model assumes that xylan is made up of three monomers (xylose, arabinose, and acetic acid) and that there are two xylan fractions with different compositions and reactivities toward hydrolysis. Both fractions are hydrolyzed to xylo-oligomers, which are hydrolyzed to xylose, arabinose, and acetic acid. Finally, monosaccharides dehydrate to furfural and degradation products. The model is validated with experimental data obtained for the autohydrolysis of corncobs in a batch reactor system at temperatures from 150 to 190 °C. The amount and composition of each xylan fraction, as well as the activation energies and frequency factors for all the reactions, are calculated from the experimental data. This model provides a satisfactory interpretation of the experimental data.
... Ethers and esters prepared from xylan and xylo-oligosaccharides have been synthesized and use... more ... Ethers and esters prepared from xylan and xylo-oligosaccharides have been synthesized and used as thermoplastic compounds for biodegradable plastics, water soluble films, coatings, capsules, and tablets (Glasser, Jain, & Sjöstedt, 1995), also for the preparation of xylan ...
Process intensification is one of the most promising areas in chemical engineering. Related to me... more Process intensification is one of the most promising areas in chemical engineering. Related to membranes, it means that the reac-tion and separation/purification steps are combined in a new single unit. This can be carried out in enzymatic membrane reactors (EMRs), which ...
Process intensification is one of the most promising areas in chemical engineering. Related to me... more Process intensification is one of the most promising areas in chemical engineering. Related to membranes, it means that the reac-tion and separation/purification steps are combined in a new single unit. This can be carried out in enzymatic membrane reactors (EMRs), which ...
... Daniel Montané,* Débora Nabarlatz, Anna Martorell, Vanessa Torné-Fernández, and Vanessa Fierr... more ... Daniel Montané,* Débora Nabarlatz, Anna Martorell, Vanessa Torné-Fernández, and Vanessa Fierro. Departament d'Enginyeria Química, ETSEQ Rovira i Virgili University, Av. Països Catalans 26, 43007 Tarragona (Catalunya), Spain. Ind. Eng. Chem. Res. ...
Partially O-acetylated xylo-oligosaccharides (DXO) isolated from almond shells by autohydrolysis ... more Partially O-acetylated xylo-oligosaccharides (DXO) isolated from almond shells by autohydrolysis as well as their de-acetylated form (DeXO) were subjected to chemical, molecular, and structural analyses. They represent a mixture of neutral and acidic oligomers and low-molecular weight polymers related to (4-O-methyl-D-glucurono)-D-xylan. DXO and DeXO showed direct mitogenic activity and enhancement of the T-mitogen-induced proliferation of rat thymocytes, indicating the immunostimulatory potential of the almond shell xylo-oligosaccharides.
ABSTRACT Xylose-based oligosaccharides produced from xylan-rich hemicelluloses (xylo-oligomers) a... more ABSTRACT Xylose-based oligosaccharides produced from xylan-rich hemicelluloses (xylo-oligomers) are carbohydrates with potential food and pharmaceutical uses. Autohydrolysis of lignocellulosic biomass is an efficient way to produce xylo-oligomers in a reasonable yield and a wide variety of compositions (anhydroarabinose/anhydroxylose and acetyl/anhydroxylose mass ratios). In this work, we develop a kinetic model for the autohydrolysis of xylan in lignocellulosic biomass that describes the yields of the different reaction products and explains the changes in the chemical composition of the xylo-oligomers due to reaction temperature and time. This model assumes that xylan is made up of three monomers (xylose, arabinose, and acetic acid) and that there are two xylan fractions with different compositions and reactivities toward hydrolysis. Both fractions are hydrolyzed to xylo-oligomers, which are hydrolyzed to xylose, arabinose, and acetic acid. Finally, monosaccharides dehydrate to furfural and degradation products. The model is validated with experimental data obtained for the autohydrolysis of corncobs in a batch reactor system at temperatures from 150 to 190 °C. The amount and composition of each xylan fraction, as well as the activation energies and frequency factors for all the reactions, are calculated from the experimental data. This model provides a satisfactory interpretation of the experimental data.
... Ethers and esters prepared from xylan and xylo-oligosaccharides have been synthesized and use... more ... Ethers and esters prepared from xylan and xylo-oligosaccharides have been synthesized and used as thermoplastic compounds for biodegradable plastics, water soluble films, coatings, capsules, and tablets (Glasser, Jain, & Sjöstedt, 1995), also for the preparation of xylan ...
Process intensification is one of the most promising areas in chemical engineering. Related to me... more Process intensification is one of the most promising areas in chemical engineering. Related to membranes, it means that the reac-tion and separation/purification steps are combined in a new single unit. This can be carried out in enzymatic membrane reactors (EMRs), which ...
Process intensification is one of the most promising areas in chemical engineering. Related to me... more Process intensification is one of the most promising areas in chemical engineering. Related to membranes, it means that the reac-tion and separation/purification steps are combined in a new single unit. This can be carried out in enzymatic membrane reactors (EMRs), which ...
... Daniel Montané,* Débora Nabarlatz, Anna Martorell, Vanessa Torné-Fernández, and Vanessa Fierr... more ... Daniel Montané,* Débora Nabarlatz, Anna Martorell, Vanessa Torné-Fernández, and Vanessa Fierro. Departament d'Enginyeria Química, ETSEQ Rovira i Virgili University, Av. Països Catalans 26, 43007 Tarragona (Catalunya), Spain. Ind. Eng. Chem. Res. ...
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Papers by Debora Nabarlatz