Browsing by Author "Villarán, M. Carmen"
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Item Effect of the unsaturation degree and concentration of fatty acids on the properties of WPI-based edible films(2007-02) Fernández, Laura; De Apodaca, Elena Díaz; Cebrián, Marta; Villarán, M. Carmen; Maté, Juan I.; Alimentación SostenibleThe incorporation of lipids into hydrophilic protein films allows the modification of their barrier properties, improving its commercial application as preservation medium on different foods. The main objective of this study was to develop films from Whey Protein Isolate (WPI) together with saturated and unsaturated fatty acids and to determine the effect of concentration and unsaturation degree on surface tension of the coating solution and on water vapor permeability (WVP), mechanical properties (tensile strength and elongation at break), and opacity, of the films. The results obtained showed that surface tension was significantly decreased by adding unsaturated fatty acids (oleic and linoleic acid), whereas the greatest effect on WVP reduction was achieved with stearic acid. The addition of stearic acid resulted in a decrease of elongation and an increase of tension strength; however unsaturated fatty acid content did not modify the elongation and slightly reduce a tensile strength.Item Giving credit to residual bioresources: From municipal solid waste hydrolysate and waste plum juice to poly (3-hydroxybutyrate)(2020-12) Izaguirre, Jon Kepa; da Fonseca, M. Manuela R.; Castañón, Sonia; Villarán, M. Carmen; Cesário, M. Teresa; Alimentación SostenibleMunicipal solid waste (MSW) is massively generated all over the world. Its organic fraction (OFMSW), which represents a high percentage of MSW, mainly contains biodegradable materials, namely food waste, paper and garden waste. The social cost of OFMSW treatment and/or disposal is a serious and widespread problem, particularly in highly populated areas. Thus, effective and innovative solutions, which include the upgrading of OFMSW, are being currently sought. In fact, the OFMSW abundance, availability and average composition suggest its considerable potential within the circular economy desideratum, paving the way to valorisation approaches. In this context, an OFMSW sugar-rich hydrolysate and its validation as a substrate for the production of the polyester poly(3-hydroxybutyrate) (P(3HB)), to date the only bioplastic easily biodegradable in marine environment, were successfully obtained in a previous study. Based on those results, this work addresses the upscaling of the fermentative production, in fed-batch mode, of P(3HB) by Burkholderia sacchari. The OFMSW hydrolysate was used as cultivation medium due to its balanced nutrient composition, while a plum waste juice, also rich in sugars, was applied as feed to the bioreactor. By implementing this strategy, a maximum P(3HB) production of 30 g·L−1 with an accumulation of 43% g (P(3HB))/g cell dry weight (CDW) after 51 h, was achieved. The use of the hydrolysate as initial medium resulted in higher CDW (71 g·L−1) than that of the simulated hydrolysate (62 g·L−1 in average), probably because the OFMSW hydrolysate favours biomass growth in detriment of P(3HB) production.Item High yield production of monomer-free chitosan oligosaccharides by pepsin catalyzed hydrolysis of a high deacetylation degree chitosan(2007-12-28) Roncal, Tomás; Oviedo, Alberto; de Armentia, Iratxe López; Fernández, Laura; Villarán, M. Carmen; BIOECONOMÍA Y CO2; Alimentación SostenibleThe high molecular weight of chitosan, which results in a poor solubility at neutral pH values and high viscosity aqueous solutions, limits its potential uses in the fields of food, health and agriculture. However, most of these limitations are overcome by chitosan oligosaccharides obtained by enzymatic hydrolysis of the polymer. Several commercial enzymes with different original specificities were assayed for their ability to hydrolyze a 93% deacetylation degree chitosan and compared with a chitosanase. According to the patterns of viscosity decrease and reducing end formation, three enzymes-cellulase, pepsin and lipase A-were found to be particularly suitable for hydrolyzing chitosan at a level comparable to that achieved by chitosanase. Unlike the appreciable levels of both 2-amino-2-deoxy-d-glucose and 2-acetamido-2-deoxy-d-glucose monomers released from chitosan by the other enzymes after a 20 h-hydrolysis (4.6-9.1% of the total product weight), no monomer could be detected following pepsin cleavage. As a result, pepsin produced a higher yield of chitosan oligosaccharides than the other enzymes: 52% versus as much as 46%, respectively. Low molecular weight chitosans accounted for the remaining 48% of hydrolysis products. The calculated average polymerization degree of the products released by pepsin was around 16 units after 20 h of hydrolysis. This product pattern and yield are proposed to be related to the bond cleavage specificity of pepsin and the high deacetylation degree of chitosan used as substrate. The optimal reaction conditions for hydrolysis of chitosan by pepsin were 40 °C and pH 4.5, and an enzyme/substrate ratio of 1:100 (w/w) for reactions longer than 1 h.Item Occurrence of ochratoxin A in Rioja Alavesa wines(2011-05-01) Quintela, Silvia; Villarán, M. Carmen; Armentia, Iratxe López De; Elejalde, Edurne; Alimentación SostenibleIn this survey the influence of the geographical location and the kind of wine in the concentration of ochratoxin A (OTA) was studied. Forty percent of the Spanish wine market belongs to the Rioja Qualified Designation of Origen (DOCa Rioja) wines, which are already worldwide known. A total of 100 wines from the Rioja Alavesa (RA) production area of the DOCa Rioja were analysed, using immunoaffinity column clean-up and high-performance liquid-chromatography with fluorimetric detection (detection limit 0.002 μg/l). The presence of OTA was greater in wines produced in low rainfall and high temperature regions. The geographical location and kind of wine did not seem to have influence on the OTA concentration. The mean OTA concentration of RA wines was 0.035 μg/l and its contribution to mean daily OTA intake could be considered negligible, representing a 0.07% of the latest tolerable weekly intake (TWI) established in 2006 by EFSA.Item Ochratoxin A removal in wine: A review(2013-04-01) Quintela, Silvia; Villarán, M. Carmen; López de Armentia, Iratxe; Elejalde, Edurne; Alimentación SostenibleOchratoxin A (OTA) is a mycotoxin mainly produced in wine grapes by Aspergillus carbonarius fungal species. This mycotoxin is a potent nephrotoxin with immunosuppressive, teratogenic and carcinogenic properties and has been classified as a possible carcinogen to humans. Reports on OTA in wine revealed that its occurrence is worldwide and that red wine generally contains a higher OTA amount than white and rosé wine. The European Commission sets in 2005 the limit of OTA in wine at 2 μg/l. In the world trade the wine is an important beverage and the OTA presence in it could represent a risk to the wine economy. In this paper the physical, chemical and microbiological methods employed for the purpose of removal OTA in wine are reviewed. Among the several physical methods that may be applied, the dilution with non contaminated food-stuffs is forbidden in the European Union. The OTA may be practically reduced through the remove of mouldy grapes or bunches before entering in the winemaking process, but sometimes this may not be economically feasible for the wine industry. Chemical methods are the most widely used to remove OTA in wine. Several oenological fining agents have been tested with different degrees of success, depending on the fining agent used, its type and dosage applied, as well as the OTA concentration in the wine. Allergen free and non toxic biodegradable chitin adsorbents are good alternatives to reduce OTA in wine in comparison with the most widely adsorbents used in the winemaking process. Microbiological methods may be a good alternative to OTA detoxification in wines. The OTA degradation by microbiological methods has not been yet achieved, though it is known that can be adsorbed by some yeast and bacteria strains.Item Protein hydrolysate from organic fraction of municipal solid waste compost as nitrogen source to produce lactic acid by Lactobacillus fermentum ATCC 9338 and Lactobacillus plantarum NCIMB 8826(2020-01) Izaguirre, Jon Kepa; Dietrich, Thomas; Villarán, M. Carmen; Castañón, Sonia; Alimentación SostenibleIn this work a strategy for obtaining free amino-acids concentrate from an organic fraction of municipal solid waste compost and its use as a nitrogen source for lactic acid production, a compound widely used in different industries, using L. fermentum ATCC 9338 and L. plantarum NCIMB 8826 strains is described. Enzymatic digestion is based on the combined action of endoprotease Alcalase 1.5 MG and exoprotease Flavourzyme 500 MG. The highest degree of hydrolysis obtained under the optimal conditions was 41%. The use of glucanase Viscozyme L prior to protein hydrolysis helped to reduce the viscosity of the solution and promote the action of proteases, increasing its hydrolysis degree by 76%. The hydrolysate contained all 21 amino-acids, making it ideal for lactic acid bacteria growth. During shake flask cultivations the culture media was complemented with glucose as carbon source. Finally, with the hydrolysate, a maximum lactic acid concentration of 9.0 ± 0.2 g·L−1 and 11.1 ± 0.1 g·L−1 for L. fermentum ATCC 9338 and L. plantarum NCIMB 8826 respectively was obtained after 27 h. The innovation of the approach lies in exploiting the overproduction of compost for the production of lactic acid.Item Removal of cooper (II) ions from aqueous solution by the use of biopolymers(2005) Villarán, M. Carmen; Valle, Beatriz; Bilbao, Ainhoa; Lorenzo, Leire; De Apodaca, Elena Díaz; Gugliotta, Vito; Gaballah, I.; Mishra, B.; Solozabal, R.; Tanaka, M.; Alimentación Sostenible; Tecnalia Research & InnovationChelation with bio-polymers is recognized as an emerging technique for the treatmente os wastewater containing heavy metals. In a first step of this study, the chelatmg kinetics of bio-polymers as alginic acid, calcium alginate, carrageenan and chitosan in relation with the Cu(II) at different pH and metal concentration, has been investigated. The chitosan was crosslinked with different chemicals and at different concentrations, to improve its stability at several pH. The used technologies for the regeneration of each polymer were ionic exchange and electrodeposition. Only with a combination of both technologies has been possible to obtain values of regeneration up to 95%.Item Upgrading the organic fraction of municipal solid waste to poly(3-hydroxybutyrate)(2019-10) Izaguirre, Jon Kepa; da Fonseca, M. Manuela R.; Fernandes, Pedro; Villarán, M. Carmen; Castañón, Sonia; Cesário, M. Teresa; Alimentación SostenibleThe organic fraction of municipal solid waste was studied as feedstock for the production of poly(3-hydroxybutyrate) (P(3HB)). To release the monosaccharides, a diluted acid pre-treatment followed by an enzymatic hydrolysis was applied. A sugar yield of 49% was achieved using a pre-treated waste and an enzyme cocktail of Pentopan 500 BG and Celluclast BG. The addition of Glucoamylase NS 22035 helped to hydrolyze the starch fraction, improving the hydrolysis yield to 56%. The hydrolysate was used as culture medium to produce P(3HB) by Burkholderia sacchari DSM 17165. Assays at shaking flask scale showed that when the hydrolysate was used as substrate, the attained cell concentration was slightly higher than in the control medium. It was necessary to supplement the hydrolysate with extra glucose to increase the C/N ratio and with a mineral solution to overcome the nutritional deficiencies. The P(3HB) accumulation using the supplemented hydrolysate was 58% (g polymer/g biomass).