Browsing by Author "Escobar-Avello, Danilo"

Now showing 1 - 7 of 7
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    Condensed tannins from Pinus radiata bark: Extraction and their nanoparticles preparation in water by green method
    (2024) Cabrera-Barjas, Gustavo; Butto-Miranda, Nicole; Nesic, Aleksandra; Moncada-Basualto, Mauricio; Segura, Rodrigo; Bravo-Arrepol, Gaston; Escobar-Avello, Danilo; Moeini, Arash; Riquelme, Sebastian; Neira-Carrillo, Andronico
    This work reports for the first time the production of condensed tannin nanoparticles stable in water via modification with glycine betaine. Pine bark, as a byproduct from the paper industry, was used as a source of condensed tannins of high molecular weight. Different glycine betaine concentrations were tested to produce condensed tannin nanoparticles, and the obtained nanoparticles were subjected to several characterization techniques (Dynamic Light Scattering, Field emission scanning electron microscopy, Zeta potential, Fourier transform infrared spectroscopy-Attenuated total reflectance, thermogravimetric analysis). The results showed that the highest stability possessed nanoparticles with 40 wt% glycine betaine. The average particle size distribution evaluated by scanning microscopy was 124 nm. Besides, the glycine betaine-modified condensed tannin nanoparticles demonstrated higher thermal stability with the starting degradation temperature at 238 degrees C. Finally, obtained nanoparticles showed an antioxidant capacity of 34,209 +/- 2194 mu mol ET/100 g and low cytotoxicity towards healthy human cells, representing the high potential to be used as a carrier of active compounds in agriculture, food, drug and medical sector.
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    Extracted Eucalyptus globulus Bark Fiber as a Potential Substrate for Pinus radiata and Quillaja saponaria Germination
    (2024) Ferrer-Villasmil, Victor; Fuentealba, Cecilia; Reyes-Contreras, Pablo; Rubilar, Rafael; Cabrera-Barjas, Gustavo; Bravo-Arrepol, Gaston; Escobar-Avello, Danilo
    This study aimed to explore alternative substrates for growing forest species using eucalyptus bark. It evaluated the potential of extracted Eucalyptus globulus fiber bark as a substitute for commercial growing media such as coconut fiber, moss, peat, and compost pine. We determined the physicochemical parameters of the growing media, the germination rate, and the mean fresh and dry weights of seedlings. We used the Munoo-Liisa Vitality Index (MLVI) test to evaluate the phytotoxicity of the bark alone and when mixed with commercial substrates. Generally, the best mixture for seed growth was 75% extracted eucalyptus bark fiber and 25% commercial substrates. In particular, the 75E-25P (peat) mixture is a promising substitute for seedling growth of Pinus radiata, achieving up to 3-times higher MLVI than the control peat alone. For Quillaja saponaria, the best growth substrate was the 50E-50C (coconut fiber) mixture, which had the most significant MLVI values (127%). We added chitosan and alginate-encapsulated fulvic acid phytostimulants to improve the performance of the substrate mixtures. The fulvic acid, encapsulated or not, significantly improved MLVI values in Q. saponaria species and P. radiata in concentrations between 0.05 and 0.1% w/v. This study suggests that mixtures with higher levels of extracted fiber are suitable for growing forest species, thus promoting the application of circular economy principles in forestry.
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    Forest by-Product Valorization: Pilot-Scale Pinus radiata and Eucalyptus globulus Bark Mixture Extraction
    (2023) Santos, Jorge; Escobar-Avello, Danilo; Fuentealba, Cecilia; Cabrera-Barjas, Gustavo; Gonzalez-Alvarez, Julia; Martins, Jorge M.; Carvalho, Luisa H.
    One of the most important by-products generated in the forestry industry is the bark obtained during the debarking process. Pine (Pinus radiata D. Don) and eucalyptus (Eucalyptus globulus L.) are the main important tree species exploited in the Chilean forestry industry. The bark of P. radiata D. Don is an interesting source of extracts, rich in condensed tannins, with potential uses in biopolymer and bioadhesive preparation. Conversely, the E. globulus bark extracts are rich in hydrolyzable tannins with few applications. Nevertheless, the forest industry generates a high volume of these by-products, simultaneously. Then, it is interesting to determine a suitable process for the joint valorization of both forest by-products at a large scale. In this work, alkaline extraction (NaOH and Na2SO3) was performed at a pilot scale of a mixture of E. globulus and P. radiata barks prepared at different ratios (0%-100%). The effect of bark mixture composition on the resulting extract's properties was evaluated. All extracts were characterized according to their chemical composition by FTIR-ATR, MALDI-TOF, and molecular weight distribution (GPC). In addition, the Stiasny number was tested to determine the potential use of extracts in bioadhesive formulation. The self-condensation reaction of resulting extracts was studied using Dynamic Mechanical Analysis (DMA) and Automated Bond Evaluation System (ABES) techniques. Results show a good interaction between condensed and hydrolyzable tannins from both species' barks. It also demonstrated the potential application of the obtained extracts, for a bark ratio of 50:50, in the formulation of bioadhesives for particleboard manufacture. The obtained product showed a similar performance to that of the bioadhesive formulated with the extract obtained using only P. radiata bark.
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    Grape Canes (Vitis vinifera L.) Applications on Packaging and Particleboard Industry: New Bioadhesive Based on Grape Extracts and Citric Acid
    (2022) Santos, Jorge; Pereira, Joao; Escobar-Avello, Danilo; Ferreira, Irene; Vieira, Carlos; Magalhaes, Fernao D.; Martins, Jorge Manuel; Carvalho, Luisa H.
    The main by-product generated in the wine industry are the grape canes, derived from the pruning process. In order to increase the valorisation possibilities of this highly polyphenolic lignocellulosic material, this work focuses on its applicability in the materials industry. As a first step, we demonstrate the viability of using grape cane particles as raw material for particleboard production, combined with a melamine formaldehyde urea (MFU) binder. In addition, looking for the application of these particleboards in the food packaging industry, particleboards based on grape canes were also produced using a new bioadhesive, obtained from the grape cane extract and citric acid. The self-condensation reaction of the grape cane extracts, and the curing reaction with citric acid, were studied by FTIR-ATR and ABES showing the feasibility of this new bioadhesive formulation. Looking for a zero-waste process, the effect of the type of raw material (fresh grape cane, solid by-product of the extraction) and of the extract used on the properties of particleboard were also studied. Citric acid was demonstrated to be a good crosslinking agent for grape cane extract. This work shows that it is possible to produce a new lignocellulosic product based only on grape cane particles using a binder based on grape cane extracts and citric acid. The implemented methodology allowed producing particleboards with applicability in the food-packaging industry, minimizing the waste generated in the process.
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    High-value compounds obtained from grape canes (Vitis vinifera L.) by steam pressure alkali extraction
    (2022) Santos, Jorge; Escobar-Avello, Danilo; Magalhaes, Pedro; Martins, Jorge Manuel; Gonzalez-alvarez, Julia; Carvalho, Luisa Hora de
    The main by-product generated by the wine industry is the grape canes derived from the pruning process. The aim of the current work was the valorisation of this highly poly phenolic lignocellulosic material, by alkali extraction methodology avoiding alcoholic solvents use. In lignocellulosic by-products valorisation, it is important to take into account the variability of the raw material. In the case of vine pruning this may be due to the different varieties used, the geographical area, the climate, or the processing. It is, however, important to develop a global strategy for valorisation, from a biorefinery and circular economy point of view. In this work, the grape canes were characterised, before and after the extraction process, by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) spectroscopy. Changes in cellulose crystallinity, hemicellulose content and structural conformation of proteins, due to the alkali thermal extraction process were identified and evaluated. For the first time, a steam pressure alkali extraction method was used on this material. The products were characterised by FTIR-ATR and Matrix Assisted Laser Desorption Ionisation-Time of Flight (MALDI-TOF) mass spectrometry. The presence of high-value compounds such as stilbene oligomers and condensed tannins was demonstrated in the extracts. The work shows the viability of the steam pressure alkali extraction, a simple and environmentally friendly method, for grape cane valorisation. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
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    Pretreated Eucalyptus globulus and Pinus radiata Barks: Potential Substrates to Improve Seed Germination for a Sustainable Horticulture
    (2023) Escobar-Avello, Danilo; Ferrer, Victor; Bravo-Arrepol, Gaston; Reyes-Contreras, Pablo; Elissetche, Juan P.; Santos, Jorge; Fuentealba, Cecilia; Cabrera-Barjas, Gustavo
    Commercial forest plantations in Chile are dominated by pine (Pinus radiata) and eucalyptus (Eucalyptus globulus). Tree bark is the main by-product of the forestry industry and has low value, but great potential for use as an agricultural substrate. However, the direct use of bark fibers may cause plant phytotoxicity due to the presence of polyphenolic and other compounds. This study aims to evaluate the physicochemical properties of E. globulus and P. radiata bark after water extraction treatments. The phytotoxicity of the resulting extracted bark alone and that mixed with commercial substrates (coconut fiber, moss, peat, and composted pine) at different ratios (25 to 75 wt%) were assessed using the Munoo-Liisa vitality index (MLVI) test. For all treatments, the seed germination and growth of radish (Raphanus sativus) and Chinese cabbage (Brassica rapa) species were evaluated and compared to a commercial growing medium (peat) as a control. The optimal mixture for seed growth was determined to be 75% extracted E. globulus bark fiber and 25% commercial substrates such as peat (P), coconut fiber (C), moss (M), and composted pine (CP), as indicated by the MLVI and germination results. Two phytostimulant products, chitosan and alginate-encapsulated fulvic acid, were added to the best substrate mixture, with the purpose of improving their performance. Encapsulated fulvic acid at 0.1% w/v was effective in promoting plant growth, while chitosan at all of the concentrations studied was effective only for mixture 75E-25CP. The mixture of E. globulus fiber and commercial substrates, containing a high proportion of water-extracted fiber (75%), shows the potential to be used in the growth of horticultural crops and in the plant nursery industry.
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    Prototypes of nutraceutical products from microparticles loaded with stilbenes extracted from grape cane
    (2022) Avendano-Godoy, Javier; Ortega, Elisa; Urrutia, Manuel; Escobar-Avello, Danilo; Luengo, Javiana; von Baer, Dietrich; Mardones, Claudia; Gomez-Gaete, Carolina
    Grape canes (Vitis vinifera L.) are an important source of bioactive stilbenes, but they are considered a pruning residue. Despite the potential advantages for human health, the low aqueous solubility and stability limits their usage in commercial goods.This research aimed to improve knowledge about the solubility and stability of the main stilbenes present in important residues of the wine industry, such as grape canes (V. vinifera L. cv. Pinot Noir), through the formation of inclusion complexes with cyclodextrins (CDs) and subsequent polymeric microencapsulation.The formation of inclusion complexes between stilbenes presents in grape cane extracts and 15 mM hydroxypropyl-fl-cyclodextrin (HP-fl-CD) increased the aqueous solubility of (E)-resveratrol, (E)-e-viniferin and (E)-piceatannol by 2.8, 5.4 and 1.9 times, respectively. The microencapsulation (by spray drying) of the inclusion complexes using maltodextrin (MD) (10% w/v) allowed us to improve the stability of the stilbenes, obtaining a retention percentage of 81.9 +/- 2.2% after 60 min of UV irradiation (254 nm). The lower size microparticles (MPs) formulation was 10.9 +/- 0.9 mu m and had a stilbene loading of 0.61 +/- 0.01 mg/100 mg of MPs. The prototype tablets and capsules made from the MPs presented suitable characteristics for their eventual use.The microencapsulation of inclusion complexes between stilbenes presents in grape cane extracts and HP-fl-CD, using MD as a matrix component, is useful to increase the solubility and stability of stilbenes. The prepared MPs can be used for the development of nutraceutical products.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.