Desarrollo de sistemas microestructurados de sílice como soporte con función antimicrobiana sobre Staphylococcus aureus

[EN] Caprylic acid is a saturated fatty acid characterized as a natural antimicrobial compound. Conventional antibiotics can produce resistant antimicrobial, and therefore, consumers demand the development of natural alternatives, which do not produce a food safety problem. The aim of this work was the study of a new alternative, the use of Mesoporous Silica Particles functionalized with the antimicrobial compound, carrying out the test of determination of the minimum bactericidal concentration and its comparison with the free compound on a collection strain of Staphylococcus aureus. The result showed particles functionalized with caprylic acid had proper functionalization process, because the structure of the particle was maintained, but the inhibition of the microorganism S. aureus was notlethal compared with the free compound. These results highlight the value the use of free caprylic acid as antimicrobial compound and the research for other alternatives to improve its potential of antimicrobial inhibition[ES] El uso inapropiado de los antibióticos puede producir microorganismos resistentes y favorece su aparición, propagación y persistencia. Además, la resistencia a antibióticos requiere la administración de elevadas dosis de los mismos, generando en ocasiones toxicidad. Por todo ello, los consumidores están demandando el desarrollo de sistemas alternativos para prevenir y tratar las enfermedades bacterianas. La nanotecnología ha surgido en el campo de la biodetección de microorganismos, así como en el área de la inhibición bacteriana como agentes antimicrobianos. Las partículas mesoporosas de sílice pueden ser usadas en este ámbito mediante su cargado y/o funcionalización con compuestos antimicrobianos. El objetivo de este trabajo será el estudio de las propiedades antibacterianas de dichos materiales funcionalizados con compuestos antimicrobianos naturales mediante la determinación de la concentración mínima bactericida y su comparación con el compuesto libre en un microorganismo patógeno alimentario como Staphylococcus aureus.Abril Gisbert, B. (2015). Desarrollo de sistemas microestructurados de sílice como soporte con función antimicrobiana sobre Staphylococcus aureus. http://hdl.handle.net/10251/54185.TFG

Ultrasound intensification of Ferrochelatase extraction from pork liver as a strategy to improve ZINC-protoporphyrin formation

[EN] The enzyme Ferrochelatase (FeCH), which is naturally present in pork liver, catalyses the formation of Zincprotoporphyrin (ZnPP), a natural pigment responsible for the typical color of dry-cured Italian Parma ham. The aim of this study was to evaluate the feasibility of using high power ultrasound in continuous and pulsed modes to intensify the extraction of the enzyme FeCH from pork liver. US application during FeCH extraction led to an improved enzymatic activity and further increase in the formation of ZnPP. The optimal condition tested was that of 1 min in continuous US application, in which time the enzymatic activity increased by 33.3 % compared to conventional extraction (30 min). Pulsed US application required 5 min treatments to observe a significant intensification effect. Therefore, ultrasound is a potentially feasible technique as it increases the catalytic activity of FeCH and saves time compared to the conventional extraction methodThe authors acknowledge the financial support from the "Ministerio de Economia y Competitividad (MINECO) and Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA)" in Spain (Project RTA2017-00024-C04-03). The authors acknowledge the contribution of the undergraduate student Jose V. Pedrero-Gonzalez to the experimental work.Abril-Gisbert, B.; Sanchez-Torres, E.; Bou, R.; Garcia-Perez, J.; Benedito Fort, JJ. (2021). Ultrasound intensification of Ferrochelatase extraction from pork liver as a strategy to improve ZINC-protoporphyrin formation. Ultrasonics Sonochemistry. 78:1-7. https://doi.org/10.1016/j.ultsonch.2021.105703S177

Water desorption isotherms of pork liver and thermodynamic properties

[EN] For the first time, the relationship between equilibrium moisture content and water activity is reported for the desorption process in pork liver. For that purpose, a standardized conductivity hygrometer was used at four different temperatures (0, 10, 30 and 50 degrees C) over a wide range of water activity (0.999-0.103). Five models frequently found in the literature (GAB, Oswin, Henderson, Hasley and Ratti) were considered for the purposes of describing the experimental desorption. The GAB model emerged as the best option (explained variance 96.6%) for the physical and mathematical description of the water desorption isotherms in pork liver. The computed isosteric heat, entropy and Gibbs energy illustrated the high water-sorbent affinity, because of a considerable availability of strong sorption sites at low moisture contents. The reported experimental desorption isotherms, and modeling results, are essentials for the optimal design of the drying process of pork liver, which is a necessary step for the further research addressing the extraction of the protein fraction from the dried product. Extraction and isolation of the protein fraction from pork liver could be considered a reasonable strategy considering the demand of protein materials and the high-environmental impact of the meat industry.The authors acknowledge the financial support from the "Ministerio de Economia y Competitividad (MINECO)" and "Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA)" in Spain (Project RTA 2017-00024-C04-03). Eduardo A. Sanchez-Torres acknowledges the FPU PhD contract (FPU18/01439) granted by the Spanish Ministry of Science, Innovation and Universities.Sanchez-Torres, E.; Abril-Gisbert, B.; Benedito Fort, JJ.; Bon Corbín, J.; Garcia-Perez, J. (2021). Water desorption isotherms of pork liver and thermodynamic properties. LWT - Food Science and Technology. 149:1-10. https://doi.org/10.1016/j.lwt.2021.11185711014

Aplicación de tecnologías emergentes para la obtención de Zinc-protoporfirina y proteínas funcionales a partir de co-productos cárnicos

Tesis por compendio[ES] El hígado de cerdo es un coproducto de origen animal que contiene una elevada cantidad de proteínas, así como otros compuestos de interés, entre los que destacan las enzimas como la ferroquelatasa (FeQ). La FeQ actúa como catalizadora en la formación del pigmento zinc protoporfirina (ZnPP), responsable del color característico del jamón de Parma y que puede resultar relevante en la elaboración de productos cárnicos crudo-curados. Así, en la presente Tesis Doctoral se va a estudiar la aplicación de tecnologías emergentes, como los ultrasonidos (US), para favorecer la extracción de la enzima FeQ y para la mejora de la formación del pigmento ZnPP. Asimismo, con el objetivo de la valorización del hígado como fuente de proteínas, en primer lugar se estudiará su estabilización mediante el secado convectivo, a un amplio rango de temperaturas, para optimizar el producto (fracción proteica). Posteriormente, el hígado deshidratado se desgrasará y desodorizará utilizando técnicas convencionales como el arrastre por vapor con aplicación de vacío (AVV) y CO2 supercríticos (CO2-SC), para lograr un producto rico en proteínas que sea aceptable organolépticamente por el consumidor. Los resultados experimentales mostraron que la aplicación de US intensificó en gran medida la extracción de la enzima FeQ del hígado de cerdo. Así, la aplicación de US durante la extracción de FeQ condujo a una mejora de la actividad enzimática y consecuentemente a un aumento de la formación de ZnPP. En cuanto a la formación de ZnPP asistida por US a partir hígado homogeneizado (Hhc) e hígado homogeneizado, con adición de oxihemoglobina (Hhc+OxiHb), el máximo de ZnPP formado cuando se aplicaron US a baja potencia (7.05 W/L) fue de 0.405 mmol ZnPP/L en Hhc y 0.449 mmol ZnPP/L en Hhc+OxiHb, alcanzándose este valor a las 12 h, mientras que sin aplicación de US el máximo se alcanzó a las 24 h, siendo éste de 0.322 mmol ZnPP/L en Hhc y 0.430 mmol ZnPP/L en Hhc+OxiHb. Sin embargo, cuando se aplicaron US a moderada potencia (36.53 W/L) fue solo de 0.037 mmol ZnPP/L a 24 h de incubación, debido a que el sistema de control de temperatura no pudo ser controlado. En relación al secado de hígado de cerdo a diferentes temperaturas (de -10 a 70ºC), los resultados revelaron que el aumento de la temperatura de secado influyó tanto en la actividad enzimática como en la concentración de FeQ aparente. Así, la condición óptima se encontró en el rango de 10 a 20ºC. Además, la temperatura de secado y el desgrasado también influyó en las propiedades fisicoquímicas y tecno-funcionales del hígado de cerdo, siendo la temperatura de 40ºC la que conllevó una menor degradación de proteínas en comparación con el deshidratado a 70ºC. En cuanto a la desodorización, los resultados mostraron que ambas técnicas (AVV y CO2-SC) fueron eficaces en la reducción y eliminación compuestos volátiles (COVs) característicos del hígado del cerdo. A través del AVV se redujo el contenido de COVs se redujo en su conjunto un 67.5%, mientras que mediante CO2-SC se redujo un 81.2%, con respecto al hígado de cerdo deshidratado sin desodorizar. Además, tras la aplicación de CO2-SC se eliminaron COVs característicos del olor desagradable del hígado de cerdo. Asimismo, mediante la extracción con CO2-SC se redujo el contenido de grasa un 24.9%, en comparación con la muestra sin desodorizar. Así pues, se puede concluir que las tecnologías emergentes como los US mejoraron el proceso de extracción de FeQ, así como su actividad enzimática en la formación de ZnPP. Además, mediante el secado y desgrasado del hígado, es posible alargar la vida útil del hígado. Así, a partir del hígado deshidratado se extrajo FeQ con actividad catalítica para la formación del pigmento ZnPP, y a partir del hígado deshidratado-desgrasado se recuperó la fracción proteica, la cual presentaba excelentes propiedades fisicoquímicas y tecno-funcionales. La extracción mediante CO2-SC resultó ser una alternativa a la técnica AVV para la desodorización.[CA] El fetge de porc és un coproducte d'origen animal que conté una elevada quantitat de proteïnes, així com altres compostos d'interès, entre els quals destaquen els enzims com la ferroquelatasa (FeQ). La FeQ actua com a catalitzadora en la formació del pigment zinc protoporfirina (ZnPP), responsable del color característic del pernil de Parma i que pot resultar rellevant en l'elaboració de productes carnis crucurats. Així, en aquesta Tesi Doctoral s'estudiarà l'aplicació de tecnologies emergents, com els ultrasons (US), per afavorir l'extracció de l'enzim FeQ i per a la millora de la formació del pigment ZnPP. Així mateix, amb l'objectiu de la valorització del fetge com a font de proteïnes, en primer lloc se n'estudiarà l'estabilització mitjançant l'assecatge convectiu, a un ampli rang de temperatures, per optimitzar el producte (fracció proteica). Posteriorment, el fetge deshidratat es desgreixarà i desodoritzarà utilitzant tècniques convencionals com l'arrossegament per vapor amb aplicació de buit (AVV) i CO2 supercrítics (CO2-SC), per aconseguir un producte ric en proteïnes que sigui acceptable organolèpticament pel consumidor. Els resultats experimentals van mostrar que l'aplicació US va intensificar en gran mesura l'extracció de l'enzim FeQ del fetge de porc. Així, l'aplicació US durant l'extracció de FeQ va conduir a una millora de l'activitat enzimàtica i conseqüentment a un augment de la formació de ZnPP. Quant a la formació de ZnPP assistida per US a partir fetge homogeneïtzat (Hfp) i fetge homogeneïtzat, amb addició de oxihemoglobina (Hfp+OxiHb) , el màxim de ZnPP format quan es van aplicar US a baixa potència (7.05 W/L) va ser de 0.405 mmol ZnPP/L a Hhc i 0.449 mmol ZnPP /L a Hhc+OxiHb, assolint-se aquest valor a les 12 h, mentre que sense aplicació d'US el màxim es va assolir a les 24 h, sent aquest de 0.322 mmol ZnPP/L a Hhc i 0.430 mmol ZnPP/L a Hhc+OxiHb . Tot i això, quan es van aplicar US a moderada potència (36.53 W/L) va ser només de 0.037 mmol ZnPP/L a 24 h d'incubació, pel fet que el sistema de control de temperatura no va poder ser controlat. Pel que fa a l'assecatge de fetge de porc a diferents temperatures (de -10 a 70ºC), els resultats van revelar que l'augment de la temperatura d'assecatge va influir tant en l'activitat enzimàtica com en la concentració de FeQ aparent. Així, la condició òptima es va trobar al rang de 10 a 20ºC. A més, la temperatura d'assecatge i el desgreixat també va influir en les propietats fisicoquímiques i tecnofuncionals del fetge de porc, sent la temperatura de 40ºC la que va comportar una menor degradació de proteïnes en comparació del deshidratat a 70ºC. Pel que fa a la desodorització, els resultats van mostrar que ambdues tècniques (AVV i CO2-SC) van ser eficaces en la reducció i eliminació compostos volàtils (COVs) característics del fetge del porc. A través de l'AVV es va reduir el contingut de COVs es va reduir en conjunt un 67.5%, mentre que mitjançant CO2-SC es va reduir un 81.2%, respecte al fetge de porc deshidratat sense desodoritzar. A més, després de l'aplicació de CO2-SC es van eliminar COV característics de l'olor desagradable del fetge de porc. Així mateix, mitjançant l'extracció amb CO2-SC es va reduir el contingut de greix un 24.9%, en comparació de la mostra sense desodoritzar. Així doncs, es pot concloure que les tecnologies emergents com els US van millorar el procés d'extracció de FeQ, així com la seva activitat enzimàtica a la formació de ZnPP. A més, mitjançant l'assecatge i desgreixatge del fetge, és possible allargar la vida útil del fetge. Així, a partir del fetge deshidratat es va extreure FeQ amb activitat catalítica per a la formació del pigment ZnPP, ia partir del fetge deshidratat-desgreixat es va recuperar la fracció proteica del fetge, la qual presentava excel·lents propietats fisicoquímiques i tecnofuncionals. L'extracció mitjançant CO2-SC va resultar ser una alternativa a la tècnica de AVV per a la desodorització.[EN] Pork liver is a co-product of animal origin that contains a high amount of protein, as well as other compounds of interest, among which enzymes such as ferrochelatase (FeCH). FeCH acts as a catalyst in the formation of the pigment zinc protoporphyrin (ZnPP), responsible for the characteristic color of Parma ham and which may be relevant in the production of raw-cured meat products. Thus, in this Doctoral Thesis, the application of emerging technologies, such as ultrasound (US), will be studied to favor the extraction of the FeCH enzyme and to improve the formation of the ZnPP pigment. Likewise, with the aim of valorizing the liver as a source of protein, its stabilization by means of convective drying will first be studied, at a wide range of temperatures, to optimize the product (protein fraction). Subsequently, the dehydrated liver will be defatted and deodorized using conventional techniques such asvacuum steam distillation (VSD) and supercritical CO2 (SC-CO2), to achieve a protein-rich product that is organoleptically acceptable to the consumer. The experimental results showed that the application of US greatly enhanced the extraction of FeCH enzyme from pork liver. Thus, the application of US during the FeCH extraction led to an improvement in the enzymatic activity and consequently to an increase in the ZnPP formation. Regarding US-assisted ZnPP formation from homogenized pork liver (HLi) and homogenized pork liver, with the addition of oxyhemoglobin (HLi+OxyHb, the maximum ZnPP formed when US was applied at low power (7.05 W/L) was 0.405 mmol ZnPP/L in Hhc and 0.449 mmol ZnPP /L in Hhc+OxyHb, reaching this value at 12 h, while without application of US the maximum was reached at 24 h, being 0.322 mmol ZnPP/L in Hhc and 0.430 mmol ZnPP/L in Hhc+OxyHb. However, when US was applied at moderate power (36.53 W/L) it was only 0.037 mmol ZnPP/L at 24 h of incubation, because the temperature control system could not be controlled. Regarding the drying of pig liver at different temperatures (from -10 to 70ºC), the results revealed that the increase in the drying temperature influenced both the enzymatic activity and the apparent FeCH concentration. Thus, the optimal condition was found in the range of 10 to 20ºC. In addition, the drying temperature and defatting also influenced the physicochemical and techno-functional properties of pork liver, being the temperature of 40ºC the one that led to less protein degradation compared to that dehydrated at 70ºC. Regarding deodorization, the results showed that both techniques (VSD and SC-CO2) were effective in reducing and eliminating volatile compounds (VOCs) characteristic of pig liver. Through AVV the content of VOCs was reduced as a whole by 67.5%, while through SC-CO2 towas reduced by 81.2%, with respect to dried pork liver without deodorizing. In addition, after the application of SC-CO2, VOCs characteristic of the unpleasant odor of pig liver were eliminated. Likewise, by extraction with SC-CO2, the fat content was reduced by 24.9%, compared to the sample without deodorization. Thus, it can be concluded that emerging technologies such as US improved the FeCH extraction process, as well as its enzymatic activity in the ZnPP formation. Furthermore, by drying and defatting the liver, it is possible to extend the lifespan of the liver. Thus, from the dehydrated liver, FeCH was extracted with catalytic activity for the formation of the ZnPP pigment, and from the dried-defatted liver, the protein fraction of the liver was recovered, which presented excellent physicochemical and techno-functional properties. The SC-CO2 extraction turned out to be an alternative to the VSD technique for the deodorization.The authors acknowledge the financial support from the “Ministerio de Economía y Competitividad (MINECO)” and “Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)” in Spain (Projects RTA2017-00024-C04-03 and RTA2017-00024-C04-02).Abril Gisbert, B. (2023). Aplicación de tecnologías emergentes para la obtención de Zinc-protoporfirina y proteínas funcionales a partir de co-productos cárnicos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/192244Compendi

Supercritical CO2 deodorization of dried pork liver

[EN] Pork liver has excellent nutritional properties but is a highly perishable product often rejected by consumers due to its strong unpleasant flavour. The objective of this study was to analyze the feasibility of the deodorization , defatting of dried pork liver by means of supercritical CO2 (SC-CO2) and conventional vacuum steam distillation (VSD).The results showed that both deodorization techniques were effective at reducing volatile organic compounds (VOCs). Through VSD, the VOC content was reduced by 67.6% UA, while an 81.3% UA reduction was achieved by SC-CO2, with respect to dried pork liver. In addition, 3 characteristic compounds of raw pork liver were completely eliminated by applying SC-CO2, which could potentially reduce the characteristic mushroom (1-octen-3-ol), fatty and green (1-nonanol) , fishy ((E,E)- 2,4-heptadienal) off-flavours. Therefore, SC-CO2 could be considered a promising technique for the elimination of VOCs, and furthermore it leads to a reduction in the fat content (24.9%).The authors acknowledge the financial support from the "Ministerio de Economia y Competitividad (MINECO) and Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA)" in Spain (Project RTA2017-00024-C04-03). The authors acknowledge the contribution of the slaughterhouse "Carnes de Teruel S.A.", (D.O. Jamon de Teruel, Spain) for the supply of pork livers.Abril-Gisbert, B.; Lorenzo, J.; Garcia-Perez, J.; Contreras-Ruiz, M.; Benedito Fort, JJ. (2023). Supercritical CO2 deodorization of dried pork liver. Journal of CO2 Utilization. 70:1-10. https://doi.org/10.1016/j.jcou.2023.1024551107

Influence of ultrasonic application on the enzymatic formation of zinc protoporphyrin

[EN] Ferrochelatase (FeCH), present in pork liver, catalyses the formation of zinc-protoporphyrin (ZnPP), a stable purple-red pigment found in Parma ham. Kinetics of ZnPP formation is especially slow. Thus, the aim of this study was to improve the ZnPP production using power ultrasound (US) at low (7.05 W/L) and moderate power (36.53 W/L) in homogenised pork liver (HLi) and with added oxyhemoglobin (HLi + OxyHb). ZnPP formation was performed at 37 degrees C, under anaerobic conditions, for different reaction times (6-48 h). When US was applied at low power, it shortened the time needed to reach maximum ZnPP formation by 50% and increased the yield by 25.77% in the case of HLi and by 4.42% in that of HLi + OxyHb, when compared to the control experiments; however, for the moderate power, ZnPP formation was hindered. Therefore, low power US proved to be an effective method with which to intensify enzymatic ZnPP production.The authors acknowledge the financial support from the "Ministerio de Economia y Competitividad (MINECO) and Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA)" in Spain (Project RTA 2017-00024-C04-03). The authors acknowledge the contribution of the slaughterhouse "Carnes de Teruel S.A." (D.O. Jamon de Teruel, Spain) for the supply of pork livers.Abril-Gisbert, B.; Contreras-Ruiz, M.; Bou, R.; Llauger, M.; Garcia-Perez, J.; Benedito Fort, JJ. (2023). Influence of ultrasonic application on the enzymatic formation of zinc protoporphyrin. Journal of Food Engineering. 347:1-7. https://doi.org/10.1016/j.jfoodeng.2023.1114491734

Physicochemical and Techno-Functional Properties of Dried and Defatted Porcine Liver

[EN] Porcine liver has a high nutritional value and is rich in proteins, minerals, and vitamins, making it an interesting co-product to alleviate the growing global demand for protein. The objective of this study was to analyze how the drying and defatting processes of porcine liver affect the physicochemical and techno-functional properties of its proteins. Two drying temperatures (40 and 70 °C) were studied, and dried samples were defatted using organic solvents. The drying process turned out to be an effective method for the stabilization of the protein fraction; however, when the drying temperature was high (70 °C), greater protein degradation was found compared to drying at a moderate temperature (40 °C). Regarding the defatting stage, it contributed to an improvement in certain techno-functional properties of the liver proteins, such as the foaming capacity (the average of the dried and defatted samples was 397% higher than the dried samples), with the degree of foaming stability in the liver dried at 40 °C and defatted being the highest (13.76 min). Moreover, the emulsifying capacity of the different treatments was not found to vary significantly (p > 0.05). Therefore, the conditions of the drying and defatting processes conducted prior to the extraction of liver proteins must be properly adjusted to maximize the stability, quality, and techno-functional properties of the proteins.This research was financially supported by the "Ministerio de Economia y Competitividad (MINECO)" and the "Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA)" in Spain (Projects RTA2017-00024-C04-03 and RTA2017-00024-C04-02).Abril-Gisbert, B.; Sanchez-Torres, E.; Toldrà Alegret, M.; Benedito Fort, JJ.; Garcia-Perez, J. (2022). Physicochemical and Techno-Functional Properties of Dried and Defatted Porcine Liver. Biomolecules. 12(7). https://doi.org/10.3390/biom1207092612

Airborne ultrasonic application on hot air-drying of pork liver. Intensification of moisture transport and impact on protein solubility

[EN] Nowadays, there is increasing interest in developing strategies for the efficient and sustainable use of animal byproducts, such as pork liver. In order to stabilize the product, a prior dehydration stage may be required due to its high perishability. The water removal process of pork liver is energy costly and time consuming, which justifies its intensification using novel technologies. In this sense, the aim of this study was to assess the effect of the airborne application of power ultrasound on the hot air-drying of pork liver. For that purpose, drying experiments were carried out at 30, 40, 50, 60 and 70 ?C on pork liver cylinders at 2 m.s(-1) with (US) and without ultrasonic application (AIR). The drying process was modeled from the diffusion theory and, in the dried pork liver, the protein solubility was analyzed in order to determine the effect of drying on the protein quality. The ultrasound application increased the drying rate, shortening the drying time by up to 40% at 30 ?C. The effect of power ultrasound at high temperatures (60 and 70 ?C) was of lesser magnitude. Drying at 70 ?C involved a noticeable reduction in the protein solubility for dried liver, while the impact of ultrasound application on the solubility was not significant (p > 0.05).The authors acknowledge the financial support from the "Ministerio de Economia y Competitividad (MINECO)" and "Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA)" in Spain (Project RTA2017-00024-C04-03) . Eduardo A. Sanchez-Torres acknowledges the FPU PhD contract (FPU18/01439) granted by the Spanish Ministry of Science, Innovation and Universities. Funding for open access charge: Universitat Politecnica de Valencia.Sanchez-Torres, E.; Abril-Gisbert, B.; Benedito Fort, JJ.; Bon Corbín, J.; Toldrà, M.; Parés, D.; Garcia-Perez, J. (2022). Airborne ultrasonic application on hot air-drying of pork liver. Intensification of moisture transport and impact on protein solubility. Ultrasonics Sonochemistry. 86:1-10. https://doi.org/10.1016/j.ultsonch.2022.1060111108