VARIEDAD DE MICROFLORA PRESENTE EN VAINILLA (Vanilla planifolia Jacks. ex Andrews) RELACIONADOS CON PROCESOS DE BENEFICIADO

The safety indicators groups, such as Total Aerobic bacterial count (TAB), Total Coliform (TC), and Fungi and Yeast (F&Y), to determine the diversity of enterobacteria present in green (Vv) and cured (Vb) vanilla siliques (Vanilla planifolia) from four curing processes, considering that the microbiological information of the fruits and their relationship with the types of curing is limited. The processes evaluated were: rustic (BR1, BR2), traditional (BT) and semi-technified (BST). The microbiological analyses identified enterobacteria using selective, differential cultivation media, and confirming tests with the VITEK system. With the species identified, the Simpson (D), Shannon-Wiener (H’) and Chao (SChao1) diversity indices were used. The microbe recounts reflected high levels of microbiological contamination; AMB did not present significant differences (p>0.05) in both states of the silique, in contrast with TC whose values decreased notably (?10 UFC/g). The F&Y decreased significantly with curing (101 to 103 UFC/g), except in BR1 fruits. The species isolated with highest frequency in Vv and Vb were E. aerogenes, E. cloacae and Klebsiella pneumoniae, while E. coli and Citrobacter freundii were identified only in Vb. The D, H and SChao1 indices reflected a higher diversity in the BR1 and BR2 processes. The results obtained are focused on the design of preventive actions for the safety of vanilla curing process in vanilla curing.Se evaluaron grupos indicadores de inocuidad tales como: Bacterias Mesófilas Aerobias (BMA), Coliformes Totales (CT) y Hongos y Levaduras (HyL) para determinar la diversidad de enterobacterias presentes en silicuas verdes (Vv) y beneficiadas (Vb) de vainilla (Vanilla planifolia) provenientes de cuatro procesos de beneficiado, considerando que la información microbiológica de los frutos y su relación con tipos de beneficiado es limitada. Los procesos evaluados fueron: rústico (BR1, BR2), tradicional (BT) y semitecnificado (BST). Los análisis microbiológicos identificaron enterobacterias utilizando medios de cultivo selectivos, diferenciales y pruebas confirmatorias con el sistema VITEK. Con las especies identificadas se calcularon los índices de diversidad Simpson (D), Shannon-Wiener (H’) y Chao (SChao1). Los recuentos microbianos reflejaron altos niveles de contaminación microbiológica, las BMA no presentaron diferencias significativas (P>0.05) en ambos estados de la silicua, a diferencia de CT cuyos valores disminuyeron notablemente (?10 UFC/g). Los H y L se redujeron significativamente con el beneficiado (101 a 103 UFC/g) excepto en frutos de BR1. Las especies aisladas con mayor frecuencia en Vv y Vb fueron E. aerogenes, E. cloacae y Klebsiella pneumoniae; mientras que E. coli y Citrobacter freundii fueron identificadas únicamente en Vb. Los índices D, H y SChao1 reflejaron mayor diversidad en procesos BR1 y BR2. Los resultados obtenidos se enfocan al diseño de acciones preventivas para la inocuidad en el beneficiado de vainilla

MEDIDAS Y LÍMITES DE CONTROL DURANTE EL PROCESO DE BENEFICIADO DE Vainilla planifolia Jacks. ex Andrews

El proceso de beneficiado de vainilla (Vainilla planifolia Jacks. ex Andrews) debe cumplir con requerimientos de calidad e inocuidad, y factores como la actividad de agua (cantidad de agua disponible), contenido de humedad y temperatura a las que se exponen los frutos (“vainas”), determinan la inocuidad de la vainilla, ya se puede favorecer el desarrollo de especies de bacterias y hongos de riesgo potencial para la salud del consumidor

A novel barley β-glucan extract (Glucagel TM) in combination with flax or coconut oil influences cholesterol and triglyceride levels in growing rats

A 2 x 2 factorial arrangement of treatments was used to test the hypothesis that inclusion of a novel P-glucan extract (GlucagelTM) in cholesterol-free synthetic diets containing coconut oil or flax oil would lower circulating total cholesterol (TC) and triglyceride (TG) levels in growing rats. Inclusion of Glucagel™ (100 g/kg) tended to decrease TC levels (P=0.07), however TC level was not influenced by oil type (P>0.05). A significant interaction (P0.05), respectively. Faecal digestibility of fat was reduced by 7% (P=0.08) in rats fed coconut oil plus P-glucan. These data suggest that reduced TG levels caused by addition of p-glucan may be mediated in part by reduced fat digestion in the small intestine, an effect most likely caused by the unique gel-forming properties of Glucagel

Study of encapsulation parameters to improve content of lycopene in tomato (Solanum lycopersicum L.) powders

The aim was to examine conditions of convective drying and spray-drying to improve preservation of lycopene content in tomatoes. The weight, size, colour, pH and °Brix values were evaluated in fresh fruit (FF) and colour (L, a, b), hue, and chrome indices were analysed from dried tomatoes, too. Tomato paste was dried (40, 50, 60, and 80 °C with times of 540, 390, 270, and 240 min) under convection conditions and pulverized. In the encapsulation treatments core material with tomato powders of 50, 60, and 70%, shell solution of maltodextrin/gum arabic 1:1, flow rate of 4, 6, 9, and 12 ml min–1, and inlet air T of 160, 170, and 180 °C were used. The physicochemical properties of FF corresponded to a degree of ripeness for consumption. The a, a/b, and hue values of dried tomatoes at 50 °C significantly correlated to red colouring and higher lycopene content (47.98±1.49 mg/100 g). The encapsulation with 50% and 60% of tomato powders, 170 °C and 9 ml min–1 treatments increased lycopene contents to 10.41 mg/100 g, 10.20 mg/100 g, and 11.51 mg/100 g, respectively. The results demonstrated that the physicochemical and functional properties were influenced by drying conditions, providing useful information for increasing the stability of lycopene in dried tomatoes

Multiple-path Quantum Interference Effects in a Double-Aharonov-Bohm Interferometer

We investigate quantum interference effects in a double-Aharonov-Bohm (AB) interferometer consisting of five quantum dots sandwiched between two metallic electrodes in the case of symmetric dot-electrode couplings by the use of the Green’s function equation of motion method. The analytical expression for the linear conductance at zero temperature is derived to interpret numerical results. A three-peak structure in the linear conductance spectrum may evolve into a double-peak structure, and two Fano dips (zero conductance points) may appear in the quantum system when the energy levels of quantum dots in arms are not aligned with one another. The AB oscillation for the magnetic flux threading the double-AB interferometer is also investigated in this paper. Our results show the period of AB oscillation can be converted from 2π to π by controlling the difference of the magnetic fluxes threading the two quantum rings

Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta|<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\rm T}$, out to $p_{\rm T}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\rm T}>8$ GeV/$c$. The small $p_{\rm T}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\rm T}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\rm T}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\rm T}$.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

The inclusive transverse momentum ($p_{\rm T}$) distributions of primary charged particles are measured in the pseudo-rapidity range $|\eta|<0.8$ as a function of event centrality in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=2.76$ TeV with ALICE at the LHC. The data are presented in the $p_{\rm T}$ range $0.15<p_{\rm T}<50$ GeV/$c$ for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor $R_{\rm{AA}}$ using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-$p_{\rm T}$ particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with $R_{\rm{AA}}\approx0.13$ at $p_{\rm T}=6$-7 GeV/$c$. Above $p_{\rm T}=7$ GeV/$c$, there is a significant rise in the nuclear modification factor, which reaches $R_{\rm{AA}} \approx0.4$ for $p_{\rm T}>30$ GeV/$c$. In peripheral collisions (70-80%), the suppression is weaker with $R_{\rm{AA}} \approx 0.7$ almost independently of $p_{\rm T}$. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284

Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

The $p_{\rm T}$-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D$^0$, D$^+$, and D$^{*+}$ in the rapidity range $|y|<0.5$, and for transverse momentum $1< p_{\rm T} <12$ GeV/$c$, were measured in proton-proton collisions at $\sqrt{s} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D$^0 \rightarrow$K$\pi$, D$^+ \rightarrow$K$\pi\pi$, D$^{*+} \rightarrow$D$^0\pi$, and their charge conjugates, and was performed on a $L_{\rm int} = 1.1$ nb$^{-1}$ event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at $\sqrt{s} = 2.76$ TeV and at 7 TeV was evaluated by extrapolating to the full phase space the $p_{\rm T}$-differential production cross sections at $\sqrt{s} = 2.76$ TeV and our previous measurements at $\sqrt{s} = 7$ TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307

Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

The yield of charged particles associated with high-$p_{\rm T}$ trigger particles ($8 < p_{\rm T} < 15$ GeV/$c$) is measured with the ALICE detector in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jet-like correlation peaks in azimuthal di-hadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta $p_{\rm T}> 3$ GeV/$c$ on the away-side drops to about 60% of that observed in pp collisions, while on the near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/350

Whole genome sequencing of Shigella sonnei through PulseNet Latin America and Caribbean: advancing global surveillance of foodborne illnesses

Objectives Shigella sonnei is a globally important diarrhoeal pathogen tracked through the surveillance network PulseNet Latin America and Caribbean (PNLA&C), which participates in PulseNet International. PNLA&C laboratories use common molecular techniques to track pathogens causing foodborne illness. We aimed to demonstrate the possibility and advantages of transitioning to whole genome sequencing (WGS) for surveillance within existing networks across a continent where S. sonnei is endemic. Methods We applied WGS to representative archive isolates of S. sonnei (n = 323) from laboratories in nine PNLA&C countries to generate a regional phylogenomic reference for S. sonnei and put this in the global context. We used this reference to contextualise 16 S. sonnei from three Argentinian outbreaks, using locally generated sequence data. Assembled genome sequences were used to predict antimicrobial resistance (AMR) phenotypes and identify AMR determinants. Results S. sonnei isolates clustered in five Latin American sublineages in the global phylogeny, with many (46%, 149 of 323) belonging to previously undescribed sublineages. Predicted multidrug resistance was common (77%, 249 of 323), and clinically relevant differences in AMR were found among sublineages. The regional overview showed that Argentinian outbreak isolates belonged to distinct sublineages and had different epidemiologic origins. Conclusions Latin America contains novel genetic diversity of S. sonnei that is relevant on a global scale and commonly exhibits multidrug resistance. Retrospective passive surveillance with WGS has utility for informing treatment, identifying regionally epidemic sublineages and providing a framework for interpretation of prospective, locally sequenced outbreaks