Biomolecules extraction from forest biomass

295 p

Biomolecules extraction from forest biomass

295 p

Energy and environmental analysis of flavonoids extraction from bark using alternative solvents

[EN] Tree barks are rich in extractive compounds, among which the flavonoids are considered as products of interest. Due to the increase in the demand for these natural products, the development of efficient and sustainable extraction processes is needed. This work aimed to study the selective extraction of flavonoids from Larix decidua bark using an environmentally friendly process. For this purpose, different extraction techniques as well as different solvents were used in order to achieve the highest flavonoid content. The characterisation results revealed improvements in extraction yield not only with the use of intensification processes, but also with the use of ionic liquids as solvents with a proven selectivity for flavonoids. [C4C1im]Br and [C4C1im][BF4] considerably improved the total flavonoid content in comparison with the other extraction methods. The antioxidant capacities of all the extracts obtained were very high, confirming their potential for different applications. The [C4C1im]Br (25 wt%) was selected as the best solvent not only because of its good flavonoid extraction ability, but also because of the good antioxidant properties of the extract, and simultaneous microwave-ultrasound assisted extraction was the most energy saving process.This research was financially supported by the Basque Government (scholarship of young researchers training of Leyre Sillero and project IT1008-16). Leyre Sillero would like to acknowledge the support received from the Imperial College London during her stay

Bioactive molecules in wood extractives: Methods of extraction and separation, a review

Bioactive molecules are those capable of interacting with living organisms, causing changes in them. Wood extractives contain important amounts of these molecules, and some of them have good antioxidant and antimicrobial activity, which favors their use as preservatives. Several different extraction methods are employed to obtain the extractives, some of which have been used for a long time. However, these conventional methods have significant disadvantages, being the most important ones high solvent, energy, and time consumption. To overcome these drawbacks, new extraction techniques are being developed whose aim is also the optimization of the process. Separation techniques such as chromatography and molecular distillation allow extractives purification and the acquisition of the desired molecules. This review aims to provide an overview of the extraction and purification methods used for wood bioactive molecules. To this end, issues such as raw material, solvent type, solid/liquid ratio (SLR), temperature, pressure, and extraction time are discussed. The application of extractives as preservatives for low durability woods is also analyzed. The study concludes that the quality and quantity of bioactive molecules, besides depending on the raw material, are determined by the employed methods and solvents to obtain these molecules. Therefore, the choice of method and solvent is of fundamental importance to achieve the desired results.Mateus Berwaldt Santos would like to thank to the Federal Institute of Education, Science and Technology Sul-rio-grandense for granting him paid permission to complete his doctorate. Leyre Sillero would also like to thank to the Spanish Ministry of Universities for the Margarita Salas fellowship for the re-qualification of the Spanish university system financed by the European Union-Next Generation EU

Pistacia vera L. leaves as a renewable source of bioactive compounds via microwave assisted extraction

The production of pistachio in Tunisia generates a large amount of potentially valuable waste, such as leaves, that could be used as source of bioactive compounds. In this work, the extraction of phytochemicals from Pistacia vera L. leaves (male and female) by microwave-assisted extraction (MAE) has been investigated. A response surface methodology (RSM) was used for the optimization of bioactive compounds extraction, where the independent variables were temperature and extraction time, and the dependent variable was extraction yield. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS, and FRAP) and antimicrobial activity of the extracts obtained at optimal conditions for both leaves were evaluated and compared not only between them, but also with the extracts obtained by maceration. The optimum extraction conditions were 70 ? and 61 ?, and 5.6 and 12 min for male and female leaves respectivily. The best results were achieved for female leaves by MAE with 36% of extraction yield, TPC of 196.35 mg gallic acid equivalents (GAE)/g dry weight (DW), TFC of 83.34 mg catechin equivalents (CE)/g dry weight (DW), and high antioxidant and antimicrobial activities. The evaluation of biological activity of the extracts showed that MAE provides extracts with better antioxidant and antimicrobial capacities then those obtained by maceration. More-over, UPLC-DAD-ESI-MS was performed to confirm the presence of some phenolic compounds in MAE extracts, such as quercetin, apigenin and myricetin derivatives. The results revealed that MAE is an efficient technique for the extraction of active components from Pistacia vera L. leaves.The authors greatly acknowledge the financial support of the Ministry of Higher Education and Scientific Research of Tunisia. L.S. would like to thank to the Spanish Ministry of Universities for the Margarita Salas fellowship for the requalification of the Spanish university system financed by the European Union -Next GenerationEU

Life Cycle Assessment of various biorefinery approaches for the valorisation of almond shells

In the near future, sustainable and efficient biorefineries would be essential for the production of commodity chemicals and high-added value compounds. Therefore, in this work, six scenarios differing on the delignification steps and cellulose conversion routes were assessed via Life Cycle Assessment methodology in order to study the environmental impacts derived from the conversion of an abundant agricultural residue (almond shells) into high added-value products and select the most suitable one for large-scale valorisation. The assessments were conducted employing experimental results and processing them by SimaPro software. The main conclusion achieved suggested that the enzymatic hydrolysis of the solid from any delignification step entailed the highest environmental impacts and had the highest relative contribution in all the studied impact categories with a maximum of 74%, which was ascribed to Scenario 5. It was also concluded that the organosolv delignification process affected overall more negatively than the alkaline treatment having bigger impacts especially in abiotic depletion (ADP) and photochemical oxidation (POP) categories. Finally, it can be stated that the best route for valorising the almond shell in a biorefinery facility is composed of autohydrolysis (common for every scenario), alkaline delignification, bleaching and acid hydrolysis steps for the obtaining of oligosaccharides, lignin and nanocrystals as products.Authors want to acknowledge the University of the Basque Country UPV/EHU, as well as the Spanish Ministry of Science and Innovation (CTQ2016-78689-R) for supporting financially this research. L.S. and R.F. would like to acknowledge the Departmentof Economic Development and Infrastructures of the Basque Government (scholarship of young researchers training) . A.M. and I.D, would like to thank the University of the Basque Country (Training of Researcher Staff, PIF17/207 and grant reference DOCREC19/47, respectively)

Extraction of flavonoid compounds from bark using sustainable deep eutectic solvents

[EN] The use of green solvents in extraction processes, especially for applications of lignocellulosic biomass, has been extensively studied over the last years. Among the range of different green solvents, deep eutectic solvents (DES) show promising results for extraction processes. Therefore, the aim of this work was the use of DES as additives in aqueous mixtures for the selective extraction of flavonoid compounds from the bark of Larix decidua. For this purpose, bark has been treated using different solvent ratios consisting of a DES/H2O mixture (0, 25, 50 and 75 wt%). Two DES were studied, choline chloride:urea and choline chloride:1,4-butanediol. In order to study the success of the extractions, the extracts and the remaining solid fraction were characterised. From the results, it was concluded that the choline chloride:1,4-butanediol (75 wt%) gave the best results, obtaining the richest extracts in flavonoids (383 mg CE/g dried bark extract), as well as those with the highest antioxidant capacity. These good results confirm the capacity of this DES to obtain active biomolecules for further application.Authors would like to thank the Department of Economic Development and Infrastructures of the Basque Government for the financial support (scholarship of young researchers training). Leyre Sillero would also like to thank Imperial College London for their support during her stay

Characterisation of bark of six species from mixed Atlantic forest

[EN] Bark is one of the most available by-product derived from the wood-base industry because of the total volume of the tree that comprised. This study aimed at evaluating the chemical composition of barks of six typical species of the mixed Atlantic forest of the Basque Country and the potential of their extractives. The used species were Northern red oak (Quercus rubra), Common oak (Quercus robur), Common ash (Fraxinus excelsior), Iberian White birch (Betula celtiberica), Sweet chestnut (Castanea sativa) and Black locust (Robinia pseudoacacia). Differences between chemical compositions of all the barks were noted. Extractive content was very high for all the barks remarking Sweet chestnut and Common ash with the highest content with 31.89 and 29.44% respectively. The suberin content was higher than 3% with a maximum value for Black locust of 16.37%. Variation of EtOH/H2O was high depending on studied species with a range of extraction yield of 3.08to15.77%. Total phenolic content of the bark extracts ranged from 178.11 to 635.08 mg GAE/g of dry bark extract and total flavonoid content from 439.19 to 1021.78 mg CE/g of dry bark extract. The antioxidant capacity of the bark extracts was measured by DPPH, ABTS and FRAP and the obtained values were ranged from 167.23 and 1912.38 mg TE/g dried bark extract, 561.92 to 1556.57 mg TE/g dried bark extract 146.11 to 640.30 mg TE/g dried bark extract, respectively. The structural differences were confirmed by GPC and FT-IR, where it was observed an average molecular weight differences and different spectra. The obtained results confirm the high interest in barks source as biomolecules for specific uses such as cosmetics or pharmaceuticals among others.The authors would like to thank the Department of Economic Development and Infrastructure of the Basque Government (scholarship of young researchers training and project 30.2017-00095) for supporting financially this research

Fractionation of non-timber wood from Atlantic mixed forest into high-value lignocellulosic materials

[EN] The forestry industry in the Basque Country has experienced an abandonment of small-sized forests in which native and introduced species tend to regrow if unattended; thus, requiring an intervention under which proper forest management is implemented. This paper evaluates the potential fractionation of lignin and cellulose from six tree species coming from such mixed forests as a value-added use of wood discarded by logging within the frame of sustainable forest management. The species used were Northern red oak, common oak, common ash, Iberian white birch, sweet chestnut, and black locust. The different wood samples were treated with an Organosolv treatment and elemental chlorine-free bleaching to fractionate them to their main components, recovering the cellulose and the lignin. Cellulose was defibrillated via high-pressure homogenization to obtain cellulose nanofibers. The resulting lignin and cellulose nanofibers were analyzed. The results support the idea that this process offers the opportunity to treat different raw materials in the same process, with corresponding possible economic benefits.Authors want to acknowledge the University of the Basque Country UPV/EHU, as well as the European Agricultural Fund for Rural Development and the Department of Economic Development and Infrastructure of the Basque Government (project 30.2017-00095) for supporting financially this research. L.S. would like to acknowledge the Department of Economic Development and Infrastructures of the Basque Government (scholarship of young researchers training)

Multiproduct biorefinery based on almond shells: impact of the delignification stage on the manufacture of valuable products

In this work, an integral valorisation of almond shells through a biorefinery approach was studied. The three main components of almond shells were extracted, isolated and characterised. The autohydrolysis process permitted the extraction of the hemicellulosic fraction obtaining a liquor rich in xylooligosaccharides (22.12 g/L). Then, two different delignification processes, alkaline and organosolv treatments, were proposed to obtain a very high purity lignin (≈90%) which could be further valorised for a wide variety of applications. The valorisation of the high cellulosic content of the delignified solids was carried out using two different methods. On the one hand, producing cellulose nanocrystals and on the other hand obtaining glucose by an enzymatic hydrolysis as well as a spent solid mainly composed by lignin (≈78 wt.%). Thus, the proposed biorefinery approach could contribute to a circular economy as all the main components of the almond shells could be revalorised by environmentally friendly procedures.The authors would like to acknowledge the financial support of the Spanish Ministry of Science, Innovation and Universities (CTQ2016-78689-R). A.M. would like to thank the University of the Basque Country (Training of Researcher Staff, PIF17/207). L.S. and R.F. would like to acknowledge the Department of Economic Development and Infrastructures of the Basque Government (scholarship of young researchers training