Efecto de la emulsificación sobre la actividad antimicrobiana del carvacrol

Este trabajo se basa en la emulsificación del carvacrol para su incorporación a jugos con el objetivo de retener su actividad antimicrobiana y mejorar la estabilidad del aceite en sistemas acuosos. El carvacrol se emulsificó (CA-E) utilizando capsul® (emulsión1:2) y la actividad antimicrobiana se determinó sobre Escherichia coli y Lactobacillus plantarum. El efecto combinado de CA-E y la reducción del pH a 4,5 se evaluó en diferentes jugos. La emulsión no afectó la sensibilidad de L. plantarum al carvacrol; sin embargo, E. coli presentó mayor concentración mínima inhibitoria. Los tratamientos combinados incrementaron el efecto, 0,5 µL/mL CA-E aumentó desde 0,2 a 2,1 reducciones log de E. coli. La emulsión de carvacrol (1,0 µL/mL) inactivó exitosamente a E. coli en jugos de manzana y naranja, alcanzando niveles indetectables (<1 log UFC/mL). La eficacia de la emulsión de carvacrol aumentó por la acidificación, permitiendo su uso en bajas dosis en alimentos ácidos, constituyendo una alternativa para múltiples aplicaciones en alimentos.This work focuses on the emulsification of carvacrol for its incorporation into juices with the aim of retaining antimicrobial activity while enhancing the stability of the oil in aqueous systems. Carvacrol was emulsified (CA-E) using capsul® (1:2 emulsion) and its antimicrobial activity was determined on Escherichia coli and Lactobacillus plantarum. The combined effect of CA-E and pH reduction to 4.5 was assessed on different juices. The sensitivity of L. plantarum to carvacrol was not affected by emulsification, whereas E. coli presented higher minimal inhibitory concentrations. Combined treatments improved the effect: 0.5 µL/mL CA-E increased from 0.2 to 2.1 log reductions of E. coli. Carvacrol emulsion (1.0 µL/mL) successfully inactivated E. coli in apple and orange juices, attaining undetectable levels (<1 log CFU/mL). The efficacy of carvacrol emulsion was improved by acidification; therefore, its incorporation at low doses in acidic foods may be a useful alternative for multiple applications.Fil: Char, Cielo Dolores. Universidad de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cisternas, Lorena. Universidad de Chile; ChileFil: Perez, Francisco. Universidad de Chile; ChileFil: Guerrero, Sandra N.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Study of Pulsed Light-Induced Damage on Saccharomyces cerevisiae in Apple Juice by Flow Cytometry and Transmission Electron Microscopy

This work analyzed the pulsed light (PL) (0.0-71.6 J/cm2)-induced damage on Saccharomyces cerevisiae KE162 cells in peptone water (pH 3.5 or 5.6) and apple juice (pH 3.5) by applying flow cytometry (FCM) and transmission electronic microscopy. Cells were labeled with fluorescein diacetate (FDA) for detecting membrane integrity and esterase activity and with propidium iodide (PI) for monitoring membrane integrity. S. cerevisiae inactivation curves reached 6-7 log reductions (peptone water systems) and 3.9 log reductions (apple juice) after 60 s (71.6 J/cm2) of PL exposure. FCM revealed the same damage pattern (although at different doses) in all media: at low doses, there was an increase in population in PI+-FDA+ quadrant, while at high doses, most of the population was located at quadrant PI+-FDA-, indicating that PL provoked rupture of the cytoplasm membrane allowing PI to penetrate cells and there was progressive loss of esterase activity. Comparison of conventional culture technique with FCM revealed the occurrence of certain cell subpopulations in peptone water with pH 3.5 which were stressed and lost their ability to grow in agar but still showed metabolic activity. Transmission electron microphotographs of PL-treated cells clearly indicated that various cell structures other than plasma membranes were altered and/or destroyed in a different degree depending on exposure time and type of medium.Fil: Ferrario, Mariana Inés. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Ministerio de Educación, Cultura, Ciencia y Tecnología. Secretaria de Gobierno de Ciencia Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica. Fondo Argentino Sectorial; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Guerrero, Sandra N.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; ArgentinaFil: Alzamora, Stella Maris. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentin

Development and quality assessment of a turbid carrot-orange juice blend processed by UV-C light assisted by mild heat and addition of Yerba Mate (Ilex paraguariensis) extract

Carrot-orange juice processed by UV-C (10.6 kJ/m 2 ) assisted with mild heat (H, 50 °C) and yerba mate addition (E) was obtained. UV-C/H + E treated juice was examined for native flora, polyphenol content (PC), total antioxidant activity (TAA), colour, turbidity, °Brix and pH along storage (4 °C). Consumer profiling studies were performed. UV-C/H + E provoked 2.6–5.7 native flora log reductions, preventing from recovery during 24 day-storage. The UV-C/H + E juice exhibited a significant increase in PC (720.2 µg/mL) and TAA (5.5 mg/mL) compared to untreated (PC = 205.0 µg/mL/TAA = 0.7 mg/mL) and single treated juices (PC = 302.1–408.0 µg/mL/TAA = 0.7–2.4 mg/mL), remaining constant throughout storage. UV-C/H + E juice exhibited scarce changes in colour. Nevertheless, increases in °Brix and turbidity were observed compared to single treatments. A cluster sensory analysis revealed that one group showed a marked interest in UVC/H + E beverages with herbal taste and strong aroma. CATA question revealed that some improvements should be introduced in order to satisfy the consumers’ ideally beverage.Fil: Ferrario, Mariana Inés. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: Schenk, Marcela Liliana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: García Carrillo, Mercedes. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: Guerrero, Sandra N.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; Argentin

Relationships between rheological properties, texture and structure of apple (Granny Smith var.) affected by blanching and/or osmotic dehydration

The objective of this work was to evaluate and correlate rheological properties (small-scale dynamic oscil- latory and creep/recovery measurements and large-scale compression force-deformation testing), texture (sensory evaluation by trained panel) and structure (optical and transmission electronic microscopy observations) of apples osmotically dehydrated to water activity (aw) 0.97 with glucose, with or without previous blanching. All apple samples showed a solid behavior (G′ > G′′) dominating the viscoelastic response, but both dynamic moduli were reduced due to processing. The instantaneous elastic compliance (J0) and the retarded compliances (J1 and J2) increased for treated tissues and the steady-state viscosity (ηN) was approximately 15% to 29% of the value of fresh apple. In general, compression parameters decreased for all treated tissues. Changes in structural features were mainly evidenced in heated samples. Partial least squares regres- sion analysis regression models revealed that texture could be well predicted by rheological properties (compression and creep parameters). Juiciness, crispness and sensory hardness were negatively correlated to J0, J1 and J2, and ηN was negatively correlated to sensory fracturability. Some mechanical parameters (fracturability, hardness 2, area 2, modulus of deformability and cohesiveness) were positively related to sensory fracturability, crispness and sensory hardness; and juiciness was negatively correlated to hardness. Compression and creep parameters showed ability to evidence structure differences (rupture of membranes, swelling of cells and degradation of cell walls) and to explain texture of treated apples.Fil: Garcia Loredo, Analia Belen. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Industrias; Argentina;Fil: Guerrero, Sandra N.. Universidad de Buenos Aires. Prog.id Fuentes Altern.de M.primas y Energia(p). Departamento de Industrias; Argentina;Fil: Gómez, Paula Luisina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Industrias; Argentina;Fil: Alzamora, Stella Maris. Universidad de Buenos Aires. Prog.id Fuentes Altern.de M.primas y Energia(p). Departamento de Industrias; Argentina

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

Risk factors for hepatitis C virus infection among blood donors in southern Brazil: a case-control study

BACKGROUND: In Brazil, it is estimated that between 2.5 and 4.9% of the general population present anti-hepatitis C virus (HCV) antibodies, which corresponds to as many as 3.9 to 7.6 million chronic carriers. Chronic liver disease is associated with HCV infection in 20% to 58% of the Brazilian patients. The objective of this case-control study was to investigate the risk factors for presence of anti-HCV antibody in blood donors in southern Brazil. METHODS: One hundred and seventy eight blood donors with two positive ELISA results for anti-HCV were cases, and 356 controls tested negative. A standardized questionnaire was used to collect data concerning demographic and socioeconomic aspects, history of previous hepatitis infection, social and sexual behaviors, and number of donations. Variables were grouped into sets of hierarchical categories. Cases and controls were compared using logistic regression, odds ratios, and 95% confidence intervals. The statistical significance of the associations was assessed through likelihood ratio tests based on a P value < 0.05. RESULTS: The prevalence of anti-HCV among blood donors was 1.1%. Most of the donors were white and males. In the multivariate analysis, independent predictors of anti-HCV positivity were: intravenous drug use, blood transfusion >10 years earlier, having had two to four sexually transmitted diseases, incarceration, tattooing, sex with a hepatitis B or C virus carrier or with intravenous drug users. CONCLUSION: Intravenous drug use, blood transfusion, and tattooing were the main risk factors for anti-HCV positivity among blood donors from southern Brazil, but sexual HCV transmission should also be considered

Measurement of the Y(1S) pair production cross section and search for resonances decaying to Y(1S)μ⁺μ⁻ in proton-proton collisions at √s = 13 TeV

The fiducial cross section for Y(1S) pair production in proton-proton collisions at a center-of-mass energy of 13 TeV in the region where both Y(1S) mesons have an absolute rapidity below 2.0 is measured to be 79±11(stat)±6(syst)±3(B) pb assuming the mesons are produced unpolarized. The last uncertainty corresponds to the uncertainty in the Y(1S) meson dimuon branching fraction. The measurement is performed in the final state with four muons using proton-proton collision data collected in 2016 by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9fb⁻¹. This process serves as a standard model reference in a search for narrow resonances decaying to Y(1S)μ⁺μ⁻ in the same final state. Such a resonance could indicate the existence of a tetraquark that is a bound state of two b quarks and two b antiquarks. The tetraquark search is performed for masses in the vicinity of four times the bottom quark mass, between 17.5 and 19.5 GeV, while a generic search for other resonances is performed for masses between 16.5 and 27 GeV. No significant excess of events compatible with a narrow resonance is observed in the data. Limits on the production cross section times branching fraction to four muons via an intermediate Y(1S) resonance are set as a function of the resonance mass

Measurement of the Y(1S) pair production cross section and search for resonances decaying to Y(1S)μ⁺μ⁻ in proton-proton collisions at √s = 13 TeV

The fiducial cross section for Y(1S) pair production in proton-proton collisions at a center-of-mass energy of 13 TeV in the region where both Y(1S) mesons have an absolute rapidity below 2.0 is measured to be 79±11(stat)±6(syst)±3(B) pb assuming the mesons are produced unpolarized. The last uncertainty corresponds to the uncertainty in the Y(1S) meson dimuon branching fraction. The measurement is performed in the final state with four muons using proton-proton collision data collected in 2016 by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9fb⁻¹. This process serves as a standard model reference in a search for narrow resonances decaying to Y(1S)μ⁺μ⁻ in the same final state. Such a resonance could indicate the existence of a tetraquark that is a bound state of two b quarks and two b antiquarks. The tetraquark search is performed for masses in the vicinity of four times the bottom quark mass, between 17.5 and 19.5 GeV, while a generic search for other resonances is performed for masses between 16.5 and 27 GeV. No significant excess of events compatible with a narrow resonance is observed in the data. Limits on the production cross section times branching fraction to four muons via an intermediate Y(1S) resonance are set as a function of the resonance mass

Search for dijet resonances using events with three jets in proton-proton collisions at root s=13 TeV

A search for a narrow resonance with a mass between 350 and 700 GeV, and decaying into a pair of jets, is performed using proton-proton collision events containing at least three jets. The data sample corresponds to an integrated luminosity of 18.3 fb(-1) recorded at root s = 13 TeV with the CMS detector. Data are collected with a technique known as "data scouting", in which the events are reconstructed, selected, and recorded at a high rate in a compact form by the high-level trigger. The three-jet final state provides sensitivity to lower resonance masses than in previous searches using the data scouting technique. The spectrum of the dijet invariant mass, calculated from the two jets with the largest transverse momenta in the event, is used to search for a resonance. No significant excess over a smoothly falling background is found. Limits at 95% confidence level are set on the production cross section of a narrow dijet resonance and compared with the cross section of a vector dark matter mediator coupling to dark matter particles and quarks. Translating to a model where the narrow resonance interacts only with quarks, upper limits on this coupling range between 0.10 and 0.15, depending on the resonance mass. These results represent the most stringent upper limits in the mass range between 350 and 450 GeV obtained with a flavor-inclusive dijet resonance search. (C) 2020 The Author(s). Published by Elsevier B.V.Peer reviewe

A measurement of the Higgs boson mass in the diphoton decay channel

A measurement of the mass of the Higgs boson in the diphoton decay channel is presented. This analysis is based on 35.9 fb(-1) of proton-proton collision data collected during the 2016 LHC running period, with the CMS detector at a centre-of-mass energy of 13 TeV. A refined detector calibration and new analysis techniques have been used to improve the precision of this measurement. The Higgs boson mass is measured to be m(H) = 125.78 +/- 0.26GeV. This is combined with a measurement of m(H) already performed in the H -> ZZ -> 4l decay channel using the same data set, giving m(H) = 125.46 +/- 0.16GeV. This result, when further combined with an earlier measurement of m(H) using data collected in 2011 and 2012 with the CMS detector, gives a value for the Higgs boson mass of m(H) = 125.38 +/- 0.14GeV. This is currently the most precise measurement of the mass of the Higgs boson. (C) 2020 The Author(s). Published by Elsevier B.V.Peer reviewe