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

Role of Enzymatic Reactions in Meat Processing and Use of Emerging Technologies for Process Intensification

Meat processing involves different transformations in the animal muscle after slaughtering, which results in changes in tenderness, aroma and colour, determining the quality of the final meat product. Enzymatic glycolysis, proteolysis and lipolysis play a key role in the conversion of muscle into meat. The accurate control of enzymatic reactions in meat muscle is complicated due to the numerous influential factors, as well as its low reaction rate. Moreover, exogenous enzymes are also used in the meat industry to produce restructured products (transglutaminase), to obtain bioactive peptides (peptides with antioxidant, antihypertensive and gastrointestinal activity) and to promote meat tenderization (papain, bromelain, ficin, zingibain, cucumisin and actinidin). Emerging technologies, such as ultrasound (US), pulsed electric fields (PEF), moderate electric fields (MEF), high-pressure processing (HPP) or supercritical CO2 (SC-CO2), have been used to intensify enzymatic reactions in different food applications. This review aims to provide an overview of the enzymatic reactions taking place during the processing of meat products, how they could be intensified by using emerging technologies and envisage potential applications.This research was financially supported by the “Ministerio de Economía y Competitividad (MINECO)” and the “Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)” in Spain (Projects RTA2017-00024-C04-03 and RTA2017-00024-C04-02).info:eu-repo/semantics/publishedVersio

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

Enhancement of immune maturation in suckling rats by leptin and adiponectin supplementation

Leptin and adiponectin, adipokines present in breast milk, have shown immunomodulatory properties. The current study aimed to ascertain whether a nutritional supplementation with leptin or adiponectin in neonatal rats was able to infuence the maturation of the systemic immune response in early life. To achieve this, suckling Wistar rats were supplemented with either leptin (0.7μg/kg/day) or adiponectin (35μg/kg/day) during the whole suckling period. Plasmatic immunoglobulins were quantifed, and spleen lymphocyte composition and their ability to proliferate and release cytokines were evaluated during (day 14) and at the end (day 21) of the suckling period. Rats fed with either adipokine showed higher plasma IgM and IgG1 concentrations and adiponectin supplementation also increased IgG2a at both studied days (P<0.05). With regard to the lymphocyte composition, both adipokine supplementations increased T cell proportion and both CD4+ and CD8+ T cell subsets after two weeks of supplementation (P<0.05). Moreover, only leptin administration increased NK and NKT cell proportions at the end of the suckling period. Finally, both adipokines infuenced the cytokine secretion pattern by splenocytes. In conclusion, these results suggest that leptin and adiponectin play a role in the maturation of the systemic immune response during the suckling period

Leptin and adiponectin supplementation modifies mesenteric lymph node lymphocyte composition and functionality in suckling rats

At birth, when immune responses are insufficient, there begins the development of the defence capability against pathogens. Leptin and adiponectin, adipokines that are present in breast milk, have been shown to play a role in the regulation of immune responses. We report here, for the first time, the influence of in vivo adipokine supplementation on the intestinal immune system in early life. Suckling Wistar rats were daily supplemented with leptin (0·7 μg/kg per d, n 36) or adiponectin (35 μg/kg per d, n 36) during the suckling period. The lymphocyte composition,proliferation and cytokine secretion from mesenteric lymph node lymphocytes (on days 14 and 21), as well as intestinal IgA and IgM concentration (day 21), were evaluated. At day 14, leptin supplementation significantly increased the TCRαβ+ cell proportion in mesenteric lymph nodes, in particular owing to an increase in the TCRαβ+ CD8+ cell population. Moreover, the leptin or adiponectin supplementation promoted the early development CD8+ cells, with adiponectin being the only adipokine capable of enhancing the lymphoproliferative ability at the end of the suckling period. Although leptin decreased intestinal IgA concentration, it had a trophic effect on the intestine in early life. Supplementation of both adipokines modulated the cytokine profile during (day 14) and at the end (day 21) of the suckling period. These results suggest that leptin and adiponectin during suckling play a role in the development of mucosal immunity in early life

Leptin and adiponectin variations in rat’s milk and plasma throughout the lactation period

Podeu consultar el III Workshop anual INSA-UB complet a: http://hdl.handle.net/2445/118993Sessió 1. Pòster núm. 1

Modulation of the Systemic Immune Response in Suckling Rats by Breast Milk TGF-β2, EGF and FGF21 Supplementation

Breast milk is a rich fluid containing bioactive compounds such as specific growth factors (GF) that contribute to maturation of the immune system in early life. The aim of this study was to determine whether transforming growth factor- 2 (TGF- 2), epidermal growth factor (EGF) and fibroblast growth factor 21 (FGF21), compounds present in breast milk, could promote systemic immune maturation. For this purpose, newborn Wistar rats were daily supplemented with these GF by oral gavage during the suckling period (21 days of life). At day 14 and 21 of life, plasma for immunoglobulin (Ig) quantification was obtained and spleen lymphocytes were isolated, immunophenotyped and cultured to evaluate their ability to proliferate and release cytokines. The main result was obtained at day 14, when supplementation with EGF increased B cell proportion to reach levels observed at day 21. At the end of the suckling period, all GF increased the plasma levels of IgG1 and IgG2a isotypes, FGF21 balanced the Th1/Th2 cytokine response and both EGF and FGF21 modified splenic lymphocyte composition. These results suggested that the studied milk bioactive factors, mainly EGF and FGF21, may have modulatory roles in the systemic immune responses in early life, although their physiological roles remain to be established

Rat Milk and Plasma Immunological Profile throughout Lactation

The composition of bioactive factors with immune activity in human breast milk is widely studied. However, the knowledge on rat milk immune factors during the whole lactation period is still scarce. This study aimed to analyze rat breast milk's immunoglobulin (Ig) content and some critical adipokines and growth factors throughout the lactation period, and to assess relationships with corresponding plasma levels. During lactation, milk concentration of the transforming growth factor (TGF)-β2 and -β3 showed a punctual increase in the first week, whereas adiponectin and leptin remained stable. In the second period of lactation (d14-21), despite the increase in the milk epidermal growth factor (EGF), a decrease in fibroblast growth factor 21 (FGF21) was detected at day 21. Milk IgA concentration had a progressive increase during lactation, while no significant changes were found in IgM and IgG. Regarding plasma levels, a decrease in all studied adipokines was observed in the second period of lactation, with the exception of IgA and TGF-β1, which reached their highest values at the end of the study. A positive correlation in IgM, IgG, and adipokine concentration was detected between milk and plasma compartments. In summary, the changes in the pattern of these bioactive compounds in rat milk and plasma and their relationships during lactation are established

A Preterm Rat Model for Immunonutritional Studies

Neonates are born with an immature immune system, which develops during the first stages of life. This early immaturity is more acute in preterm newborns. The aim of the present study was to set up a preterm rat model, in which representative biomarkers of innate and adaptive immunity maturation that could be promoted by certain dietary interventions are established. Throughout the study, the body weight was registered. To evaluate the functionality of the intestinal epithelial barrier, in vivo permeability to dextrans was measured and a histomorphometric study was performed. Furthermore, the blood cell count, phagocytic activity of blood leukocytes and plasmatic immunoglobulins (Ig) were determined. Preterm rats showed lower erythrocyte and platelet concentration but a higher count of leukocytes than the term rats. Although there were no changes in the granulocytes' ability to phagocytize, preterm monocytes had lower phagocytic activity. Moreover, lower plasma IgG and IgM concentrations were detected in preterm rats compared to full-term rats, without affecting IgA. Finally, the intestinal study revealed lower permeability in preterm rats and reduced goblet cell size. Here, we characterized a premature rat model, with differential immune system biomarkers, as a useful tool for immunonutritional studies aimed at boosting the development of the immune system