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- Development of a sustainable, simple, and robust method for efficient l-DOPA extractionPublication . Polanowska, Katarzyna; Lukasik, Rafal M.; Kuligowski, Maciej; Nowak, JacekABSTRACT: l-3,4-dihydroxyphenylalanine (l-DOPA) is a medically relevant compound in Parkinson's disease therapy. Several extraction methods of l-DOPA from beans, including velvet and faba beans, have been described in the literature. However, these methods require the use of strong acids, long extraction times, or complex downstream processing, which makes the extraction of l-DOPA expensive and energy-demanding, limiting its industrial application. In addition, the stability of l-DOPA during the extraction process is critical, further complicating the extraction of adequate amounts of this amino acid. This work is the first report on a simple, rapid, greener, and robust extraction method of l-DOPA. The developed method consists of a quick homogenization step followed by a double extraction with 0.2% v/v acetic acid for 20 min and was applied to faba bean at a ratio of 1:25 with respect to the extracting solvent. This study also investigated the stability of l-DOPA during extraction and thermal treatment. The proposed method demonstrated to be robust and extraordinarily efficient for numerous cultivars of faba bean, velvet bean, and food products containing faba beans.
- Current pretreatment technologies for the development of cellulosic ethanol and biorefineriesPublication . Silveira, Marcos H. Luciano; Morais, Ana Rita C.; Lopes, André; Olekszyszen, Drielly Nayara; Lukasik, Rafal M.; Andreaus, Jurgen; Ramos, Luiz PereiraLignocellulosic materials, such as forest, agriculture, and agroindustrial residues, are among the most important resources for biorefineries to provide fuels, chemicals, and materials in such a way to substitute for, at least in part, the role of petrochemistry in modern society. Most of these sustainable biorefinery products can be produced from plant polysaccharides (glucans, hemicelluloses, starch, and pectic materials) and lignin. In this scenario, cellulosic ethanol has been considered for decades as one of the most promising alternatives to mitigate fossil fuel dependence and carbon dioxide accumulation in the atmosphere. However, a pretreatment method is required to overcome the physical and chemical barriers that exist in the lignin–carbohydrate composite and to render most, if not all, of the plant cell wall components easily available for conversion into valuable products, including the fuel ethanol. Hence, pretreatment is a key step for an economically viable biorefinery. Successful pretreatment method must lead to partial or total separation of the lignocellulosic components, increasing the accessibility of holocellulose to enzymatic hydrolysis with the least inhibitory compounds being released for subsequent steps of enzymatic hydrolysis and fermentation. Each pretreatment technology has a different specificity against both carbohydrates and lignin and may or may not be efficient for different types of biomasses. Furthermore, it is also desirable to develop pretreatment methods with chemicals that are greener and effluent streams that have a lower impact on the environment. This paper provides an overview of the most important pretreatment methods available, including those that are based on the use of green solvents (supercritical fluids and ionic liquids).
- Optimizing deep eutectic solvent pretreatment for enhanced glucan recovery from miscanthusPublication . Piedade, Patrícia J.; Nowotarski, Michal M.; Dudek, Gabriela; Lukasik, Rafal M.ABSTRACT: This work focuses on the use of the deep eutectic solvent composed of choline chloride and acetic acid (1 : 2) in the pretreatment of the perennial energy crop Miscanthus, commonly called silvergrass. The pretreatment time and temperature were optimized to achieve a maximum of the glucan and minimum of the lignin contents in the pretreated biomass. In the optimization approach, the maximal glucan recovery in the pretreated solid was also considered. The performed optimization resulted in conditions (2 h 52 min and 150 degrees C), at which a pretreated biomass contained 74.1 wt% and 9.5 wt% of glucan and lignin respectively, and a glucan recovery was as high as 87.0 wt%. Furthermore, the biocompatibility of deep eutectic solvent was evaluated by using enzymatic hydrolysis washed and unwashed pretreated biomass produced at optimal conditions. The enzymatic hydrolysis of washed biomass resulted in higher glucan and xylan conversion than those achieved from unwashed biomass, deeming the step of biomass washing necessary. This was confirmed by the fractal kinetics modelling that confirmed higher accessibility of glucan for washed biomass than for unwashed Miscanthus sample.
- Métodos de fraccionamento de biomassa para as biorrefinariasPublication . Carvalheiro, Florbela; Duarte, Luís C.; Lukasik, Rafal M.; Moniz, PatriciaO desenvolvimento de processos que permitam o fraccionamento eficiente da biomassa (tradicionalmente designados por pré-tratamentos) constitui uma parte muito significativa do esforço científico que tem sido feito para a transformação das biorrefinarias numa realidade industrial. Este artigo apresenta uma breve revisão dos processos de fraccionamento, sendo dada particular atenção a processos emergentes, discutindo também as suas possíveis vantagens e limitações.
- Biorefinery concept with green solvents towards the phenolic valorizationPublication . Lukasik, Rafal M.The efficient separation, hydrolysis and conversion of principal components of lignocellulosic biomass allows to produce chemicals and value added compounds. Ionic liquids (ILs) have been used for the pre-treatment and fractionation of biomass.1-3 The pre-treatment reveals that phenolic compounds were found in the IL phase. This work was devoted for the extraction of phenolic compounds from the recovered IL liquid using several adsorption resins in small scale batch processes. Phenolic compounds, such as vanillin, catechol and flavonoids were identified in extraction samples and also quantified. Temperature, residence time and water amount were evaluated in order to find optimal extraction conditions of phenolic compounds from IL.
- Deconstruction of the hemicellulose fraction from lignocellulosic materials into simple sugarsPublication . Gírio, Francisco; Carvalheiro, Florbela; Duarte, Luís C.; Lukasik, Rafal M.Hemicelluloses hold a great promise for the production of added-value compounds in the biorefinery framework. Specifically, the xylan-rich hemicelluloses from hardwoods and agro-industrial residues present themselves as effective feedstock choices for the biotechnological production of xylitol. This paper reviews the various hemicellulose structures present in such materials and critically evaluates the available processing options to produce xylose-rich fermentable hydrolysates. Currently, acid-based processes still present the best trade-off between operation easiness and xylose yield and recovery. Nevertheless, concerns regarding the impact of the fractionation processes on the overall upgradability of all biomass fractions (namely, cellulose and specially lignin) may turn the route to other strategies. Specifically, the combined/sequential use of processes targeting hemicellulose dissolution and hydrolysis might hold great promise for the economical production of pentoses.
- Efficient extraction of vicine from faba beans using reactive system of high-pressure CO2/waterPublication . Polanowska, Katarzyna; Nowak, Jacek; Lukasik, Rafal M.ABSTRACT: Vicine from faba bean is a causative agent of favism, a genetic disease, which manifests as hemolytic anemia. Despite that low vicine varieties of faba bean exist, they are not widely cultivated. Several extraction methods of vicine from faba beans have been presented in the literature, however, their low efficiency associated to time-consuming and costly process limit the practical use. This work for the first time addresses the employment of high-pressure CO2-assisted extraction of the pyrimidine glycosides from the faba bean. For this purpose, the effect of temperature, CO2 pressure and time on vicine extraction was scrutinized using Box-Behnken design of experiments. Response surface methodology was used to determine the optimal extraction conditions. At 40.7 °C, 8.1 bar of CO2 pressure and 5.1 min of extraction, 81% of total vicine should be extracted from faba bean.
- Manufacture of furfural in biphasic media made up of an ionic liquid and a co-solventPublication . Peleteiro, Susana; Lopes, André; Garrote, Gil; Lukasik, Rafal M.; Parajó, J. C.Xylose was converted into furfural operating in a medium containing the acidic ionic liquid (AIL) 1-butyl-3-methylimidazolium hydrogen sulfate, in the presence of toluene as a co-solvent. No catalytic species different from the AIL were needed for furfural production from xylose. Operating at 100.140 .C for 15.480 min in media containing 10 g xylose/100 g AIL and 2.4 g toluene/g (AIL + xylose), most furfural generated in the AIL phase was transferred to the co-solvent, limiting the losses caused by undesired side reactions. Operating under optimal conditions (140 .C for 240 min using 4.4 g toluene/g initial AIL phase), xylose was almost completely consumed, and furfural was obtained at 73.8% of the stoichiometric yield.
- CO2+Methanol+Glycerol : multiphase behaviourPublication . Carrera, Gonçalo V. S. M.; Visak, Zoran P.; Lukasik, Rafal M.; Ponte, Manuel NunesABSTRACT: The phase behaviour of the system CO2+methanol+glycerol has been studied at low concentrations of this trialcohol. The synthetic method was implemented in a visual sapphire cell. New phase diagrams were obtained at temperatures of 313.15 and 333.15 K. Different methanol/glycerol molar ratios of 113, 50 and 30 were considered and its influence on phase behaviour accounted for. Pressures were varied from 6.03 to 11.44 MPa. A specific experiment is reported, starting from an initial volume of 4 mL of liquid mixture methanol+glycerol (methanol/glycerol molar ratio 30), where, with a stepwise addition of CO2, diverse fluid phase phenomena were detected, such as VLE, Critical Point, VLLE, VLLLE, LLE and LE.
- Heterogeneously catalytic hydrogenation of animal fatty acids in supercritical CO2Publication . Muto, Stefania; Zaccheria, F.; Ravasio, N.; Lukasik, Rafal M.