Patricia Gullón Estévez

University of Vigo | UVIGO · Department of Chemical Engineering

Walnut kernels represent no more than 50–60% of the total weight of the fruit, so the sum of walnut shells generated every year is immense. Nonetheless, these shells could be further valorised for the extraction of their main constituents following a biorefinery scheme. Hence, the objective of this work was an integral valorisation of walnut shells...

The processing and valorization of hemicellulose fraction biomass from lignocellulosic material, it is an important alternative in these days for the production of high added value compounds and bioenergy in terms of biorefinery philosophy and impacting the development of the circular bioeconomy. For this reason, the development of processes at pil...

Multiple natural polymers have been investigated for the synthesis of hydrogels to the present date, but lignin has demonstrated to be a promising one for this purpose for the multiple advantages it offers. Lignin can be isolated from lignocellulosic material such as nut shells, which are usually undervalued wastes, and would be a great step forwar...

DOI: https://doi.org/10.1016/B978-0-12-821233-2.00004-6

Mixtures of xylooligosaccharides (XOS) were manufactured from Eucalyptus nitens samples by hydrothermal processing. In order to obtain a product suitable to be used as a prebiotic, the liquors obtained were subjected to a refining sequence consisting of a two-step membrane filtration followed by anion exchange and freeze-drying. The process propose...

In recent years, considerable importance is given to the use of agri-food wastes as they contain several groups of substances that are useful for the development of functional foods. As muscle foods are prone to lipid and protein oxidation and perishable in nature, the industry is in constant search of synthetic-free additives that help in retardin...

Traditional plants have been used in the treatment of disease and pain due to the beneficial properties from the antioxidant, anti-inflammation, analgesic and antibiotic activities. Asteraceae family is one of the most common groups of plants used in folk medicine. The species Achillea millefolium, Arnica montana, Bellis perennis, Calendula officin...

Food by-products contain a remarkable source of bioactive molecules with many benefits for humans; therefore, their exploitation can be an excellent opportunity for the food sector. Moreover, the revalorization of these by-products to produce value-added compounds is considered pivotal for sustainable growth based on a circular economy. Traditional...

This work deals with the revalorization of an important winery residue such as the vine shoots by the obtaining of oligosaccharides with potential prebiotic activity. The manufacture of these added-value products was performed by an autohydrolysis treatment assisted with microwaves to make the process less time consuming and more environmentally fr...

Polymeric materials such as hydrogels have become necessary in our daily lives. Hydrogels are three-dimensionally cross-linked polymeric networks that can absorb large amounts of water. Thanks to their properties, hydrogels are very useful in multiple application fields. However, they have usually been obtained from petroleum-derived polymers, cont...

In this work, a delignification process, using lime (Ca(OH)2) as an alternative alkali, was evaluated to improve enzymatic saccharification of corn stover cellulose, with the final goal of obtaining second-generation bioethanol. For that, an experimental design was conducted in order to assay the effect of temperature, lime loading, and time on the...

Phenolic compounds have received significant attention both by the consumers and scientific community in the last decades because of their wide range of beneficial health effects. The efficient extraction of these biocompounds from natural sources remains an important challenge because of the intrinsic limitations of the traditional extraction meth...

Pulsed electric field (PEF) is a promising technology to obtain high-quality, long-lasting milk and dairy products with fresh-like characters. This technology can inactivate most microorganisms, but also certain dairy enzymes affecting product safety. There are no systematic reports on the different quality and safety features of PEF-processed dair...

Anthocyanins are polyphenolic compounds belonging to the group of flavonoids in charge of providing red, purple, and blue colourations to different parts of trees and plants, such as leaves, flowers, fruits, roots, and stems. These substances have potential health benefits due to characteristics such as antioxidant and anti-inflammatory properties,...

Corn stover is the most produced byproduct from maize worldwide. Since it is generated as a residue from maize harvesting, it is an inexpensive and interesting crop residue to be used as a feedstock. An ecologically friendly pretreatment such as autohydrolysis was selected for the manufacture of second-generation bioethanol from corn stover via who...

Algae are not only of high ecological, but also of great economic importance. The industrial exploitation of algae has suffered a boom in the last two decades because they are a suitable source of interesting compounds for a number of sectors (agriculture, energy, food science, cosmeceutical, and pharmacology, among others) [1]. Among these compoun...

The search for food resources is a constant in human history. Nowadays, the search for natural and safe food supplies is of foremost importance. Accordingly, there is a renewed interest in eco-friendly and natural products for substitution of synthetic additives. In addition, microbial contamination of food products during their obtaining and distr...

Walnuts are nowadays widely consumed. Since the edible part of walnuts does not account more than 50–60% of their total weight, the total amount of shells produced annually is huge. However, as walnut shells are part of lignocellulosic biomass, they could be valorised via a biorefinery approach in order to extract their diverse constituents. For th...

In the last few decades, attention on new natural antimicrobial compounds has arisen due to a change in consumer preferences and the increase in the number of resistant microorganisms. Macroalgae play a special role in the pursuit of new active molecules as they have been traditionally consumed and are known for their chemical and nutritional compo...

Wild edible plants (WEPs) have been consumed since ancient times. They are considered as non-domesticated plants that grow spontaneously in nature, particularly on forests and bushlands, where they can be found and collected to be incorporated into the human nutrition. Increasingly, WEPs are gaining importance as they are potential sources of food...

Background In the last years, the consumption of olive oil has experienced a sharp rise due to its organoleptic and healthy properties and with this the wastes and by-products derived from the olive production and the olive oil industry have also increased causing important environmental and economic issues. However, the high content in bioactive c...

From ancient times, the medicinal properties of the different Eucalyptus species are well known. In fact, plants from this family have been used in folk medicine as antiseptics, and to treat different ailments of the upper respiratory tract such as sinus congestion, common cold, or influenza. Moreover, other biological activities were described for...

Paulownia is a rapid-growth tree with a high biomass production rate per year and low demand of water, which make it very suitable for intercropping systems, as it protects the crops from adverse climatic conditions, benefiting the harvest yields. Moreover, these characteristics make Paulownia a suitable raw material able to be fractionated in an i...

Hops (Humulus lupulus L.) are used traditionally in the brewing industry to confer bitterness, aroma, and flavor to beer. However, in recent years, it has been reported that female inflorescences contain a huge variety of bioactive compounds. Due to the growing interest of the consumers by natural ingredients, intense research has been carried out...

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...

In the last few years, the consumer’s concern with the relationship between health and diet has led to the search of foods with functional properties beyond the nutritional. In this framework, the consumption of pomegranate has increased due to their sensorial attributes and remarkable amounts of bioactive compounds, which generate, at the same tim...

In the last years, the consumption of meat products is associated with a higher incidence of hypertension and cardiovascular diseases. The outstanding profile of seaweeds in nutritive and bioactive compounds turns them into promising candidates to formulate healthy products. Accordingly, due to the increasing interest of consumers by new functional...

In this work, valorization of Paulownia wood (PW) was proposed following several process configurations for biofuels and value-added compounds production. Firstly, autohydrolysis and ethanol-organosolv strategies were assessed separately for the fractionation of PW to enhance the enzymatic digestibility of cellulose. A third strategy focused on a s...

Background Worldwide, huge amounts of by-products and wastes are generated in agri-food sector annually. This biomass is usually discarded provoking serious environmental problems. However, these residues represent an excellent source of bioactive compounds so that their exploitation can be considered as a promising possibility from an economic and...

A biorefinery scheme for the valorization of horse chestnut biowastes (a municipal solid waste) into added value bioactive compounds is proposed in this work. The bur fraction of horse chestnut was evaluated as a novel and cheap renewable feedstock to obtain valuable compounds suitable for their use in industrial applications. The integrated valori...

Background Meat and meat products have been recently perceived by consumers as unhealthy foods. To avoid this drawback, the reformulation is a feasible approach that allows obtaining custom meat-based products that incorporate compounds with certain beneficial properties for health and remove other attributes considered negative. In this framework,...

Hydrogels have become very popular in the last decades and they are widely employed in many application fields. Physically crosslinked hydrogels lack of toxic and expensive reagents and, thus, they enable a greener and a more economical synthesis process. Till date, many biopolymers have been explored for hydrogel synthesis, but lignin has promised...

Purple corn (Zea mays L.) is used for the preparation of traditional drinks and desserts, generating great quantities of residues. The scarce information about purple corn cob (PCC) is encouraging an interest in exploring its potential as a valuable source of bioactive compounds with benefits for human health. In this study, a green method based on...

Lignin is an excellent candidate to be used as a starting material for hydrogel synthesis due to its highly functional character. The exhaustible character of the fossil resources linked to the increase of plastic residues in the environment encourages an intensive research on biorenewable and biodegradable polymers to synthesize new materials. Tak...

The society and industrial sectors are facing important challenges regarding the production of bioproducts influenced by social responsibility and environmental consequences. Biorefinery development reports two important goals in the transition towards a bio-based economy: (i) the displacement of fossil-based products by biomass-based ones and (ii)...

This work deals with the optimization of the second stage of a biorefinery scheme to separate simultaneously cellulose and lignin from hydrothermally pre-treated vine shoots. For this, the suitability of the microwave-assisted alkaline delignification was assessed and optimized through a Box-Wilson experimental design. The optimum conditions (150 °...

The search of alternative plastics to replace the fossil-based ones has become an urgent matter in the last years. To contribute to this, the assessment of the incorporation of bio-oil into biodegradable PVA films was proposed in this work in order to obtain coating films with UV shielding properties. For this aim, organosolv-lignin-based bio-oil a...

Vine shoots were hydrothermally processed and the effect of the different assayed severities on the subsequent enzymatic saccharification of the remaining solids was evaluated. The solid obtained at a severity of 4.47 showed the highest yield on glucose (74.01%)and therefore, it was used as the substrate for the obtaining of bio-ethanol through a S...

Among lignocellulosic materials, chestnut shells (CNS) are a rejected feedstock from agro-food industry with promising possibilities as a suitable raw material to be used in a biorefinery scheme. The aim of this work was to optimize the alkaline delignification of CNS for the co-production of lignin and bio-ethanol. Under the optimal conditions (7....

Vine shoots were subjected to a hydrothermal treatment to cause the selective solubilisation of the hemicelluloses. The hemicelluloses solubilisation products were refined by a sequential processing with nanofiltration and ion exchange obtaining a refined product with a purity of 99%. A depth chemical and structural characterization of the purified...

A large amount of olive-derived biomass is generated yearly in Spain, which could be used as a potential source of bioactive compounds. The present work evaluates the recovery of natural antioxidants from olive tree pruning (OTP) and olive mill leaves (OML). For this purpose, the effect of different solvents on the total phenolic content (TPC), tot...

The infusion of yerba mate (Ilex paraguariensis St. Hil.) is the most popular tea-like beverage of southern Latin American countries, and its health benefits such as stimulating effect and antioxidant activity are well known. The exhausted mate leaves are managed as waste and are not currently exploited or valorized as a bio-resource. In this work,...

Hydrothermal treatment is an environmentally friendly technology that allows the solubilisation of hemicellulosic oligosaccharides with potential for their use as prebiotics. The purpose of this study was to solubilize oligosaccharides and antioxidant compounds from chestnut shells by a hydrothermal processing. The highest content of oligosaccharid...

The limitation of the fossil-resources has led the research to focus on the production of biomass-based fuels from lignocellulosic agricultural residues, as it is the case of the bio-ethanol. Due to the complex and heterogeneous structure of these residues, a delignification stage is usually necessary prior to a simultaneous saccharification and fe...

The winemaking industry generates high amounts of underutilized by-products worldwide, which represent a significant economic potential and a great challenge. The main by-product of winemaking is grape marc, consisting of the stalks, skin, pulp (pomace), and seeds that remain after pressing the grapes. Other grape processing by-products include vin...

The use of vine shoots as feedstock in biorefining activities to obtain bioproducts under efficient and optimized conditions could be crucial to make future high added value compounds and processes more sustainable. In this study, five different potential valorization scenarios from vine shoots differing on diverse extraction and delignification st...

The extraction of antioxidants from plant biomass is of high interest and it requires processing conditions that preserve the bioactivity of these compounds. The optimization of the solvent extraction of antioxidants from the leaves of Eucalyptus globulus is a key point for its exploitation at industrial scale. In this work, the Box-Behnken experim...

Non-isothermal autohydrolysis treatments of vine shoots were used as a method for hemicellulose solubilization and xylooligosaccharides (XOS) production. The proposed kinetic model allowed the selection of the operational conditions that maximize the oligosaccharides content and minimize the generation of undesired compounds such as monosaccharides...

Vine shoots, considered a residue from winery operations, possess valuable antioxidant and antimicrobial activities that can be potentially obtained under the scheme of biorefinery. In this framework, we evaluated the autohydrolysis of vine shoots combined with a further stage of extraction with ethyl acetate as viable valorization process. The ext...

The objective of this work was to study the suitability of the pretreated vine shoots as a source of lignin and to determine its structural features. The best conditions to achieve the aim of this work were 12% NaOH, 124°C and 105 min, as they permitted a removal of 67.7% of the lignin present in the pretreated vine shoots and the obtaining of a so...

Hemicelluloses are the second most abundant heterogeneous polysaccharides in nature. Among the several treatments that can be used for the solubilization of hemicelluloses to produce oligosaccharides from lignocellulosic biomass, the autohydrolysis reaction is the most widely used. Under suitable conditions, autohydrolysis enables high ligosacchari...

This work aimed the assessment of the use of artificial neural networks (ANNs) as alternative tool for modelling and predicting the suitability of sugar beet pulp (SBP) to produce oligosaccharides in comparison with the response surface methodology (RSM). The variables polygalacturonase to solid ratio (PGaseSR), cellulase activity to polygalacturon...

Aims: When skin dysbiosis occurs as a result of skin disorders, probiotics can act as modulators, restoring microbial balance. Several properties of selected probiotics were evaluated so that their topical application could be considered. Methods and results: Adhesion, antimicrobial, quorum sensing and antibiofilm assays were carried out with se...

This book is a compiled contribution from experts in the field of natural polymers, and it is organized into two volumes. The purpose of this book is to provide an entire catalogue of natural polymers, beginning with their introduction, mass production, qualitative and quantitative characterization and leading to their advanced applications in ever...

Quinoa and amaranth belong to the group of the so called "superfoods" and have a nutritional composition that confers multiple benefits. In this work, we explored the possibility of these foods exhibiting a prebiotic effect. These pseudocereals were subjected to an in vitro digestion and used as carbon sources in batch cultures with faecal human in...

A prebiotic is a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health. The most widely accepted prebiotics are lactulose, inulin, fructooligosaccharides (FOS), galactooligosaccharides (GOS), and the human milk oligosacchar...

Bioactive food packaging is an innovative approach for the prevention of the growth of food-spoilage microorganisms. Four active extracts from agroindustrial subproducts (Eucalyptus wood, almond shells, corn cobs and grape pomace) with demonstrated antioxidant activity have been investigated for bestowing antimicrobial activity to bioactive packagi...

Vine shoots were subjected to non-isothermal aqueous processing. A range of severities (S0) from 3.20 to 4.65 was assayed and their effects in terms of solubilization, composition, molar mass distribution, structural characterization and thermal stability of the liquors were studied using HPLC, HPSEC, TGA and FTIR. The spent solids were characteriz...

Natural polymer-based hydrogels have attracted special attention in the last few years owing to their unique characteristics such as biodegradability, biocompability, stimuli-responsive properties and biological functions finding applications in several fields such as biomedicine, toxic ion removal and water purification inter alia. On the other ha...

Broad beans (Vicia faba) and lupin seeds (Lupinus albus) are legumes rich in a wide range of compounds, which may represent a useful dietary approach for modulating the human gut microbiome. In this work, after in vitro digestion, legume samples were used as carbon sources in anaerobic batch cultures to evaluate their impact on the intestinal micro...

Eight tropical fruit pulps from Brazil were simultaneously characterised in terms of their antioxidant and antimicrobial properties. Antioxidant activity was screened by DPPH radical scavenging activity (126–3987 mg TE/100 g DW) and ferric reduction activity power (368–20819 mg AAE/100 g DW), and complemented with total phenolic content (329–12466...

Aloe vera mucilage is reported to be rich in acemannan that is a polysaccharide with a backbone of β-(1→4)-D-mannose residues acetylated at the C-2 and C-3 positions and contains some side chains of galactose and arabinose attached to the C-6 carbon. The evaluation of the prebiotic potential of Aloe vera mucilage was carried out by in vitro ferment...

Arabinoxylans (AX) consumption has been related to the treatment and prevention of cardiovascular diseases, type II diabetes, colorectal cancer and obesity. The beneficial health effects are conferred through gut microbiota modulation, and therefore, they have been proposed as potential slowly fermentable prebiotic candidates. As the mechanisms are...

The major chemical features of the hemicellulosic polymers present in biomass (xylans, mannans, xyloglucans, arabinogalactans, and mixed linkage β-glucans) are discussed, as well as their conversion into oligosaccharides by physicochemical, chemical and/or enzymatic processing. Selected strategies for the manufacture of purified oligosaccharide con...

Xylooligosaccharides (XOS) obtained by autohydrolysis of rice husks were demonstrated in a previous study to act as fermentable substrates by the intestinal microbiota in human fecal slurry cultures, leading to the generation of acetic and lactic acids and supporting the growth of bifidobacteria (Gullón et al. 2011). The purpose of the present stud...

Pinus pinaster wood samples were subjected to double hydrothermal processing. The liquors coming from the second stage, containing soluble saccharides of polymeric or oligomeric nature from hemicelluloses (POHs), were subjected to membrane processing (operating in discontinuous diafiltration) for refining and fractionation. Refined POH fractions we...

The aqueous fractionation of native lignocellulosic materials with hot, compressed water (also known as hydrothermal processing or autohydrolysis) has been proposed as a fractionation method for biorefineries, as it enables the simultaneous removal of water‐soluble extractives and the solubilization of hemicelluloses, yielding a solid phase enriche...

Apple pomace samples were subjected to Simultaneous Saccharification and Fermentation (SSF) to yield a medium containing mainly lactic acid and oligosaccharides. After lactic acid removal by ion exchange, the SSF medium was refined by a two-step (diafiltration-concentration) membrane treatment. Limited losses of glucooligosaccharides, galactooligos...

Rice husks were subjected to processing with hot, compressed water under selected conditions to cause the partial breakdown of xylan into soluble products (mainly xylooligosaccharides, XOS). The reaction media were subjected to membrane processing, endoxylanase treatment and ion exchange to obtain purified XOS concentrates. Human fecal slurry cultu...

The importance of human intestinal microbiota in maintaining host health is well known. Pectin-derived oligosaccharides (POS) have been proposed as excellent candidates in the development of new-generation prebiotics due to their functional properties.

The role of biorefineries in the production of energy and chemicals from biomass of lignocellulosic nature is reviewed. Special attention is devoted to biorefinery schemes dealing with the fractionation of lignocellulosic raw materi-als by chemical treatments. The potential of hydrothermal treatments as the first stage of future biorefineries is di...

Lignocellulosic materials, particularly the ones of residual nature generated in agricultural and industrial activities, represent a renewable, abundant and cheap source of raw materials for multiple purposes. Barley husks belong to this type of materials. Aqueous fractionation of a solid byproduct from malting industries (denoted MSW), mainly made...

This work provides an assessment on the hydrothermal processing (or autohydrolysis treatments) of two lignocellulosic wastes: mixed herbs (denoted MH, mainly belonging to the Lolium species), and sunflower seed shells (denoted SS). Compositional data were obtained for both raw materials (which contained cellulose, heteroxylan and Klason lignin as m...