Inactivation of polyphenoloxidase from Litopenaeus vannamei by High Pressure Carbon Dioxide

Póster presentado en: 17th European Meeting on Supercritical Fluids. 2019, 8-11 de abril, Ciudad Real(MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-

Derivados de inosina y triazolopirimidinas con propiedades terapéuticas de interés. Síntesis y evaluación biológica

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Orgánica. Fecha de lectura: 22-11-201

Structural changes of a protein extract from apple with polyphenoloxidase activity obtained by cationic reversed micellar extraction induced by high-pressure carbon dioxide and thermosonication

Polyphenoloxidase from apple was extracted and further concentrated by cationic reversed micellar extraction. Previous to reversed micellar extraction a crude protein extract was obtained using AG2-X8 as adsorbent of phenolic compounds and the detergent Triton X-100. Forward and backward extraction conditions were optimized by using dodecyl trimethyl ammonium bromide as surfactant in the organic phase. Optimization was carried out to obtain the highest value of PPO activity recovery and the purification fold at the different experimental conditions. Under the optimum extraction conditions, PPO activity recovery was 99% and purification fold reached a value of 17, showing that reversed micellar extraction was a good technique as a first step to concentrate on a targeted enzyme. After removing some impurities by centrifuge ultrafiltration, the protein extract with PPO activity was treated by pressurized carbon dioxide and thermosonication achieving residual PPO activity values of 16 ± 3 and 9 ± 1%, respectively. Quenching experiments by iodide performed in the non-treated extract and in the treated extracts revealed conformational changes of this protein fraction reflected in the greater exposure of the fluorophore to the quencher.Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI’s contract, and to Junta de Castilla y León and ERDF for financial support of project BU301P18

High pressure CO2 solubility in food model solutions and fruit juices

Measurements of CO2 solubility were performed in different media, pure water, model citrate buffer solutions at different pH values and in the presence of different sugar content and in real apple and carrot juices. Solubility was determined in the pressure range from 8 to 20 MPa and in the temperature range from 308 to 318 K. CO2 solubility in citrate buffer solutions at pH = 3.8 and pH = 6.2 was slightly lower than CO2 solubility in pure water. A Chrastil-type equation according to Fornari’s approach was used to fit CO2 solubility data in pure water and model solutions. A new term was introduced in this equation to account for the decrease in solubility of CO2 in the presence of sugar in the liquid media.Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-

Effect of High Pressure Carbon Dioxide on polyphenoloxidase from Litopenaeus vannamei

The extraction of polyphenoloxidase (PPO) from Litopenaeus vannamei was studied at different temperatures, pH and ionic strength conditions. Optimum extracts at pH = 7.2 were treated by hiph pressure carbon dioxide (HPCD) technology at 20 MPa and in a temperature range from 35 to 50 °C. Inactivation kinetics for PPO extracts were determined and fitted to the Weibull model. The effect of HPCD on PPO activity was also evaluated in shrimps in vivo, finding that PPO could be easier inactivated than in the crude PPO extract. Color of Litopenaeus vannamei was visually followed right after HPCD treatment and thermal treatment at the same temperature and during storage at 4 °C during a week, showing good results when shrimps were treated with HPCD in the absence of water.Spanish Government (MINECO) and the European Regional Development Fund for financial support of project CTQ2015-64396-

Efecto del tratamiento por ultrasonidos en el zumo de manzana no clarificado

Póster presentado en: I Congreso CyTA Junior: 19 de mayo de 2017. IX Congreso CyTA-CESIA, Ayer, hoy y mañana de la Ciencia y Tecnología de los Alimentos, 16-19 de mayo de 2017, MadridMINECO y FEDER por la financiación del proyecto CTQ2015-64396-

High voltage atmospheric cold plasma decontamination of Salmonella enteritidis on chicken eggs

Salmonella enteritidis (SE) accounts for more than 70% of Salmonella spp. infections in humans with a primary source being chicken eggs, that can result from post-lay SE cross-contamination of the shell from contaminated equipment or the environment. The objective of this study was to apply a HVACP treatment that can achieve a minimum 5-log reduction in SE on the surface of artificially inoculated shell eggs with an initial bacterial load of 108 CFU/egg, after a previous disinfection. Optimized HVACP treatment conditions were an indirect treatment with air at 60% humidity at 100 kV for one minute treatment and six hours post-treatment or alternatively, five minutes of treatment and four hours post-treatment. Egg quality parameters of Haugh unit (HU), pH, color, and vitelline membrane and shell strength were tested under the optimized conditions and showed no significant difference (p > 0.05) between treated and untreated eggs. Industrial relevance: Missing information for a possible scale up of a cold plasma system for egg surface decontamination has been addressed by an optimization of HVACP treatment focused on treatment and posttreatment time, essential parameters to have into account in the food industry. These results demonstrate that HVACP is an effective decontamination method for SE on chicken shell eggs and provides a baseline for a future scale up of the process, showing that different combinations of treatment variables can achieve the desired decontamination without affecting to key quality parameters of the egg such as Haugh Unit or vitelline membrane strength.This work was supported by Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), and the Barrett Family Foundation Chair in Sustainable Food Engineering

High pressure carbon dioxide technology: application to orange juice

Ponencia presentada en: 16th European Meeting on Supercritical Fluids, 25 a 28 de abril de 2017, LisboaHigh pressure carbon dioxide (HPCD) treatment has been applied to orange juice as alternative non-thermal treatment. Kinetics inactivation for pectin methyl esterase has been determined at different operating conditions. PME residual activity was correlated succesfully to the two-fraction model. Some quality parameters such as colour, pH, calcium content, turbidity and particle size distribution (PSD) were also determined right after HPCD treatment. PSD shows that HPCD treatment results in a homogenization effect with a volume increase of small particles and a volume decrease of large particles regarding the non-treated orange juice.MINECO (CTQ2015-64396-R). R. Melgosa acknowledges MINECO for a grant (BES-2013-063937).Spanish Government through MINECO (CTQ2015-64396-R). R. Melgosa acknowledges MINECO for a grant (BES-2013-063937

Supercritical CO2 assisted synthesis and concentration of monoacylglycerides rich in omega-3 polyunsaturated fatty acids

Supercritical carbon dioxide (SC−CO2) has been used as solvent in the ethanolysis of fish oil rich with omega-3 polyunsaturated fatty acids (n-3 PUFAs) by Lipozyme 435. The effect of experimental conditions: initial ethanol-to-oil molar ratio (MR, 6:1-76:1), pressure (10–30 MPa), and temperature (323–343 K) on the reaction performance has been studied. Experimental results have been fitted to a kinetic model based on a Ping Pong Bi Bi mechanism. High accumulation of monoacylglycerides (MAGs) has been observed in short reaction times (90 min at MR = 76:1, 10 MPa, 323 K). Subsequent purification of reaction products by supercritical fluid extraction (SFE) in the experimental range 10–28 MPa and 298–333 K yielded an extract rich with fatty acid ethyl esters (FAEE) (up to 99.46%wt.), and a raffinate with up to 82.25%wt. MAG and 49.5%wt. n-3 PUFAs.Spanish Government through MINECO and the European Regional Development Fund (ERDF) for financial support [grant number CTQ2012-39131-C02-01] and RM’s and AEI’s contracts [BES-2013-063937, CTQ2015-64396-R]. To Junta de Castilla y León and ERDF for financial support [grant number BU055U16] and ÓBR’s post-doctoral contract

Enzymatic inactivation of apple and tomato juices using HPCD (high pressure carbon dioxide) technology and its effect on the quality parameters of the juice

Póster presentado en: 6th International Congress on Green Process Engineering (GPE 2018), 3 a 6 de junio de 2018, ToulouseMINECO and ERDF for financial support of AEI's contract through project CTQ2015-64396-R To JCyL and ERDF for financial support of project BU055U16 and O.Benito-Román’s Post-doctoral contract To MINECO for RM's pre-doctoral contract (BES-2013-063937)