Suchergebnisse

This work provides experimental fluid phase equilibrium data of the pseudo-ternary mixture CO2 + ethanol + fish oil, a system of interest in pharmaceutical and food-industry applications such as the production of omega-3-enriched lipid derivatives at mild, non-oxidative conditions. Experimental tie-lines were obtained by means of an analytical isothermal method with recirculation of the vapour phase. Measurements were carried out in the temperature range 323.15 K–343.15 K and at pressures from 10 MPa to 30 MPa. The Peng-Robinson equation of state coupled with the conventional van der Waals mixing rules with two adjustable parameters was used for experimental data correlation. ; Spanish Government through MINECO and Junta de Castilla y León for financial support of the projects CTQ2012-39131-C02-01 and BU055U16, respectively, 16 both co-financed by the European Regional Development Fund (ERDF)

Ponencia presentada en: 16th European Meeting on Supercritical Fluids, 25 a 28 de abril de 2017, Lisboa ; This work provides experimental phase equilibrium data of the pseudo-ternary system CO2 + ethanol + fish oil, a system of interest in pharmaceutical and food-industry applications such as the enzymatic production of fatty acid ethyl esters at mild, non-oxidative conditions. Measurements were carried out in a high-pressure variable-volume view cell in the temperature range 323.15-343.15 K and at pressures from 10 to 30 MPa. The Peng-Robinson equation of state was used to satisfactorily correlate experimental data. ; European Regional Development Fund (ERDF), Spanish Government (MINECO) and Junta de Castilla y León for financial support (projects CTQ2012-39131-C02-01 and BU055U16). RM acknowledges MINECO (BES-2013-063937)

The production of polyunsaturated fatty acids (PUFAs) concentrates by enzymatic catalysis has gained interest due to their stereospecificity and the milder conditions employed compared to the use of inorganic catalysts. The enzymatic glycerolysis of sardine oil by Lipozyme 435 to get PUFA concentrates in the forms of di‐ and monoacylglycerols (DAGs, MAGs) in an optimized amount of tert‐butanol as the organic solvent was studied. First, mass transfer limitation of the reaction system was analyzed. The effects of different operating variables such as lipase loading, temperature and feed composition were investigated. A semi‐empirical kinetic model based on the reversible elementary reactions of glycerolysis and hydrolysis of the glycerides was employed to correlate the experimental kinetic data. A molar ratio glycerol:oil of 3:1 was the optimum, which produced more than 84 wt% of MAG at 323 K. A comparison with other glycerolysis systems was performed using MAG yield, reaction rate and significance of kinetic parameters. ; Spanish Government through MINECO (CTQ2012‐39131‐C02‐01)

Production of monoacylglycerols (MAGs) rich in x-3 polyunsaturated fatty acids (n-3 PUFAs) was conducted through short path distillation (SPD) of an acylglycerol mixture (containing 67% MAGs) produced by enzymatic glycerolysis of sardine oil with glycerol. A stepwise SPD process in a UIC KDL 5 system (vacuum 10 3 mbar, feeding flow 1.0 mL/min) was proceeded: the first distillation performed at evaporator temperature (TE) of 110 C to remove glycerol completely and most of FFAs; and the second distillation at optimized TE 155 C; resulting in a stream distillate with 91% purity and 94% overall recovery of MAGs. This work also demonstrated that SPD is able to concentrate n-3 PUFAs in MAG form by distilling at proper TE e.g. 125 C, where n-3 PUFAs are concentrated in the residues. Moreover, this work mapped out a complete processing diagram for scalable production of n-3 PUFAs enriched MAGs as potential food emulsifier and ingredient. ; Spanish Government through MINECO and the European Regional Development Fund (ERDF) for financial support to the project CTQ2012-39131-C02-01.

Ponencia presentada en: 16th European Meeting on Supercritical Fluids, 25 a 28 de abril de 2017, Lisboa ; High 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)

Ponencia presentada en: 16th European Meeting on Supercritical Fluids, 25 a 28 de abril de 2017, Lisboa ; The quality of cloudy apple juice seems to be better than the clarified juice due to the loss of phenolic compounds during processing. Enzymatic browning and cloud stability are the main problems in processing and storage of the juice. In this work, HPCD is proposed as an alternative to the traditional heat treatments that can degrade the quality of the juice. Polyphenol oxidase (PPO) and pectin methylesterase (PME) inactivation by HPCD were determined for both enzymes. The effect of stirring speed on PPO inactivation was studied; obtaining that at higher speed inactivation was also higher. Other quality parameters in the juice were also determined after HPCD treatment, such as particle size distribution, colour, turbidity and total phenolic compounds. ; (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI's contract. R. Melgosa acknowledges MINECO for a grant (BES-2013-063937). ; Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI's contract. R. Melgosa acknowledges MINECO for a grant (BES-2013-063937)

The production of monoacylglycerol rich in polyunsaturated fatty acids (PUFA) via enzymatic glycerolysis of sardine oil in a homogeneous system was evaluated. Reactions were conducted in two different tert-alcohols. Based on the phase equilibrium data, the amount of solvent added to create a homogeneous system has been calculated and optimized. The immobilized lipase used in this work was Lipozyme RM IM from Rhizomucor miehei, a water dependent lipase. The amount of water added as well as other reaction parameters were studied to evaluate the optimum conditions for monoacylglycerol obtencion. An initial reactant mole ratio glycerol to sardine oil 3:1, 12 wt% of water based on glycerol content and 10 wt% of lipase loading (based on weight of reactants), achieved a MAG yield of around 70%, with nearly 28 wt% PUFA, with low free fatty acid content (lower than 18 wt%). ; En este trabajo se ha estudiado la producción de monoacilglicéridos, ricos en ácidos grasos poliinsaturados (AGPI), mediante glicerolisis enzimática de aceite de sardina. La reacción se ha llevado a cabo en dos tert-alcoholes para conseguir de esta forma un medio homogéneo de reacción. La cantidad de disolvente añadida al medio de reacción se ha optimizado y calculado en base al equilibrio de fases de los componentes del sistema. La lipasa empleada como biocatalizador ha sido la enzima inmovilizada Lipozyme RM IM de Rhizomucor miehei, una lipasa dependiente de agua. Se ha estudiado el efecto de distintos parámetros cinéticos, así como de la cantidad de agua añadida al medio de reacción, en la producción de monoacilglicéridos. De los resultados obtenidos, se puede concluir que, para una relación molar inicial de reactantes glicerol:aceite de sardina de 3:1, un 12 % en peso de agua en base al glicerol y un 10 % en peso de lipasa, en base al peso de reactantes; se puede llegar a conseguir un rendimiento en monoacilglicéridos alrededor del 70 % en peso, con casi un 28 % en peso de AGPI y un bajo contenido en ácidos grasos libres (menor del 18 % en peso). ; Spanish Government through MINECO and the European Regional Development Fund (ERDF) for financial support to the project CTQ2012-39131-C02-01. They wish to thank Novozymes A/S for kindly supplying the enzymes. RM acknowledges MINECO for an FPI grant (reference BES-2013-063937).

Cloudy apple juice has been treated by high pressure carbon dioxide (HPCD) as non-thermal technology to inactive polyphenoloxidase and pectinmethylesterase in batch mode. Stirring speed (from 200 to 600 rpm) induced an increase in the enzyme inactivation rate while a triple cycle of pressurization/depressurization led to the same enzyme inactivation efficiency. Enzyme inactivation kinetics were determined at different temperatures (from 35 to 45 °C) and pressures (from 10 to 20 MPa). Data were described by the first order kinetic model and the Weibull model. For the first order kinetic model, decimal reduction time for HPCD treatment was found to be smaller than for mild heating, in the same temperature range. The same tendency was observed for the first decimal reduction time in the Weibull model. HPCD treatment resulted in a homogenization effect reflected in the shifting of the particle size distribution towards smaller diameters after treatment. HPCD treatment did not result in a change of water and oxalate soluble pectin content, total phenolic compounds and hidroxymethylfurfural content. ; Spanish Government (MINECO) and the European Regional Development Fund for financial support of project CTQ2015-64396-R and AEI's contract.

The supercritical fluid extraction (SFE) of wheat bran alkylresorcinols has been studied. Extractions were carried out at 40.0 MPa. The effect of particle size, static extraction pretreatment with supercritical CO2 (SC-CO2) and extraction temperature on the extraction kinetics was investigated. The extraction yield increased as the particle size decreased and with temperature. Extraction curves present a faster and linear initial extraction period followed by a slower extraction period. Based on these results the approximate mathematical model of Sovová was successfully applied to describe the extraction curves. The total content of alkylresorcinols was determined and compared with the alkylresorcinol content obtained by conventional organic solvent extraction. Due to the amphiphilic nature of these resorcinolic lipids, the extraction yield was higher for polar organic solvents than for SC-CO2. Characterization of supercritical extracts was also performed by determining the fatty acid composition and antioxidant activity. ; GALANG project (Ref.: ITC-20113029) financed by the Spanish Government through CDTI

Ponencia presentada en: 16th European Meeting on Supercritical Fluids, 25 a 28 de abril de 2017, Lisboa ; Among the recent non-thermal technologies developed, HPCD treatment has been shown to be effective for the inactivation of microorganisms and enzymes avoiding food exposure to the adverse effects of high temperatures. Processing of tomato juice can result in a modification of its consistency and a decrease of its viscosity due to the activity of enzymes such as pectinmethylesterase (PME), polygalacturonase (PG). Peroxidase (POD) catalyzes oxidation reactions related to the production of undesirable flavours and colours. The main objective of this work was to study the effect of the HPCD technology on tomato juice. The influence of HPCD process parameters such as pressure (8.5 - 20 MPa) and temperature (35 and 45 ºC) on the inactivation kinetics of PME, PG and POD and physical parameters such as pH and particle size distribution was evaluated. Results showed that increasing pressure and temperature decreased the residual activity of the enzymes evaluated. The results obtained showed a higher efficiency of the HPCD technology regarding the high pressure processing (HPP) technology since the pressure required to achieve enzymatic inactivation by HPCD (8.5 – 20 MPa) are well below the pressure required by HPP (600-800 MPa) for the same purpose. HPCD technology uses much softer processing conditions that modify the tomato juice to a lesser extent and achieve a greater degree of enzymatic inactivation. The tomato juice pH value (4.1 ± 0.1) did not change significantly (p ≤ 0.05) before and after HPCD treatment. The particle size distribution (PSD) of the tomato juice was bimodal, with a particle diameter that shifted towards lower sizes after HPCD treatment, indicating that homogenization is favoured by this treatment. ; (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI's contract. To MINECO for RM's pre-doctoral contract (BES-2013-063937). ; Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI's contract

Supercritical carbon dioxide (SC-CO2) has been used as green solvent in the lipase-catalyzed ethanolysis of fish oil by Lipozyme RM IM at mild, non-oxidative conditions and with no solvent residues. The effect of experimental conditions, initial substrate ethanol/oil molar ratio (2–38), pressure (7.5–30 MPa), and temperature (323.15–353.15 K) on equilibrium conversion, reaction rate and oxidative status of the products has been studied. No ethanol inhibition has been observed at high concentrations of ethanol, when putting in contact first the fish oil with the enzyme avoiding direct contact between the biocatalyst and ethanol. Operating pressure affected positively the reaction performance in the range investigated. Visual observation of the phase behaviour of the initial reaction mixture showed an "expanded liquid phase" that helped enhancing reaction rate, and a gas phase. Raising temperature accelerated the reaction up to a limit (343.15 K), observing higher enzyme thermal stability than in other reaction media (313.15 K). However, lipid oxidation increases with temperature. Up to 86 ± 1% FAEE yield has been found at MR = 6:1, 30 MPa and 323.15 K. Kinetic data have been correlated by using a mathematical model based on the elementary reactions of the 3-step transesterification. Kinetic rate constants, apparent activation volumes and energies are reported for the first time for a lipase-catalyzed ethanolysis reaction in SC-CO2. ; Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of the project CTQ2012-39131-C02-01. Financial support from the Junta de Castilla y León and European Regional Development Fund (ERDF) through project BU055U16

tLiquid and supercritical CO2has been used to extract the remaining fat content from rendered fish meal.The effect of pressure (10–40 MPa) and temperature (25–80◦C) on the extraction kinetics and extractionyield has been investigated as well as the effect on the rendered fish meal. The extraction curves areinitially linear with a slope close to the oil solubility value in pressurized CO2. Based on previous fishoil solubility data reported in the literature, a general equation has been proposed to correlate fish oilsolubility data as a function of temperature and density of CO2. Fish meal has been characterized beforeand after extraction by determining the fat and protein content and its colour. Toxic trace elements havebeen also determined by ICP-MS in the fish meal showing that most of the toxic elements remained inthe fish meal after extraction. Characterization of extracted oil was also performed by determining thefatty acid group composition and some physical parameters such as colour ; Spanish Government through MINECO (CTQ2012-39131-C02-01). To SARVAL for supplying the fish meal. S.L.B.acknowledges support by the Secretary of Education Public ofMexico for the fellowship through PROMEP program and Tech-nological University of Morelia

Cloudy apple juice has been treated by thermosonication in batch mode as an alternative processing to thermal treatment. Thermosonication was found to be effective to inactivate polyphenol oxidase; however, pectinmethylesterase was found to be more resistant. An increase of the working ultrasound amplitude and the amount of energy supplied to the juice led to lower enzyme residual activities. Enzyme inactivation kinetics were determined at different temperatures (from 44 to 67 °C). Inactivation data were described by the first order kinetic model and the Weibull model, both models yielding good fitting. Thermosonication treatment caused a homogenization effect reflected in the shifting of the particle size distribution towards smaller diameters. The effect of the nature of dissolved gases in the juice on enzyme inactivation was studied by displacing the air dissolved in the juice by bubbling nitrogen or carbon dioxide, previous to the thermosonication experiments. Higher inactivation rates were obtained by displacing the air with nitrogen. Industrial relevance Consumers demand of natural and fresh-like products has driven the food industry to investigate alternative technologies to replace conventional food heat treatments that may affect food quality. Among these technologies, thermosonication treatment is an attractive technology that can inactivate microorganisms and enzymes. This work shows that some enzymes that cause deleterious effect on cloudy apple juice can be more effectively inactivated by thermosonication than by thermal treatment, in the same temperature range, reducing the damages caused by heating. ; Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015- 64396-R and AEI's contract. To MINECO for RM's pre-doctoral contract (BES-2013-063937). To University of Burgos for AGS's pre-doctoral contract. To Consejería de Educación, Junta de Castilla y León and ERDF for financial support of project BU055U16 and O. Benito Román´s Post-doctoral contract.