100 research outputs found
Uso de de almidón de papa andina nativa y deshidratada (chuño) como estabilizantes en la elaboración de yogur firme reducido en grasa
El yogur es el alimento lácteo fermentado de mayor consumo a nivel internacional, debido tanto a sus propiedades nutricionales y sensoriales distintivas como por su impacto positivo en la salud del consumidor. Así, el mercado de yogur es uno de los más dinámicos del sector lácteo, con propuestas novedosas, entre las cuales se destaca las variedades con contenido reducido en grasas. Sin embargo, la omisión de la grasa introduce problemas de calidad que conducen al rechazo por el consumidor. La principal estrategia empleada para superar estas limitaciones es el agregado de hidrocoloides (HC) como estabilizantes. El objetivo del presente trabajo fue evaluar la influencia del agregado de almidón de papa andina nativa y de "chuño" (papa andina congelada y deshidratada) como estabilizantes en la elaboración de yogur firme bajo en grasas. Se prepararon tres formulaciones de yogures a partir de leche descremada reconstituida (10%, p/v) añadida con almidón de papa nativo (AN) o "chuño" (ACH) [2,5% (p/v) final en producto]. Los HC previamente disueltos en leche (en proporción 1:10) se agregaron previo al tratamiento térmico (90°C, 5 min con agitación). La fermentación de la leche se llevo a cabo a 45ºC en baño de agua hasta pH 4,5. El grado de sinéresis, propiedades de flujo y viscoelásticas de los yogures fueron evaluados y comparados con los de un yogur control preparado sin almidón, en los días 1, 7, 14 y 28 de almacenamiento. Para la obtención de las curvas de flujo y las medidas oscilatorias se utilizó un reómetro (AR 2000; TA Instruments, New Castle, DE, EE. UU.) geometría plato-plato de 40 mm.
El agregado de almidones de AN y ACH modificó significativamente los parámetros evaluados en relación al yogur control. En relación a la sinéresis, los mayores valores se observaron en el YC, efecto que incrementó significativamente con el tiempo de almacenamiento. Se observa que las formulaciones con almidones no mostraron diferencias significativas entre ellas hasta el día 7. Sin embargo, el YCH incrementó paulatinamente los valores de sinéresis luego del día 14, mientras que en la formulación YN no se observaron diferencias hasta el final del ensayo.
Además, las muestras mostraron claras diferencias en cuanto a sus propiedades reológicas. En términos generales, los yogures que contienen almidones exhibieron valores de viscosidad aparente más altos que los observados en el YC después de 1 día de almacenamiento, tendencia que se mantuvo hasta el final del ensayo. Por otra parte, los valores de los módulos viscoso (G'), elástico (G'') y complejo (G*) incrementaron proporcionalmente a la frecuencia angular, siendo G' superior a G'' en todos los casos.
G* también mostró diferencias entre las muestras, siendo significativamente mayores en las muestras con AN, seguida de ACH, en relación al control para todos los tiempos evaluados. Nuestros resultados demostraron que la incorporación de almidones de papa andina y chuño en la formulación de yogur firme reducido en grasas permitió reducir el grado de sinéresis proporcionando mejores características reológicas al producto final.Centro de Investigación y Desarrollo en Criotecnología de Alimento
Production and Characterization of Antifungal Compounds Produced by Lactobacillus plantarum IMAU10014
Lactobacillus plantarum IMAU10014 was isolated from koumiss that produces a broad spectrum of antifungal compounds, all of which were active against plant pathogenic fungi in an agar plate assay. Two major antifungal compounds were extracted from the cell-free supernatant broth of L. plantarum IMAU10014. 3-phenyllactic acid and Benzeneacetic acid, 2-propenyl ester were carried out by HPLC, LC-MS, GC-MS, NMR analysis. It is the first report that lactic acid bacteria produce antifungal Benzeneacetic acid, 2-propenyl ester. Of these, the antifungal products also have a broad spectrum of antifungal activity, namely against Botrytis cinerea, Glomerella cingulate, Phytophthora drechsleri Tucker, Penicillium citrinum, Penicillium digitatum and Fusarium oxysporum, which was identified by the overlay and well-diffusion assay. F. oxysporum, P. citrinum and P. drechsleri Tucker were the most sensitive among molds
Protective action of N-acetyl-L-cysteine associated with a polyvalent antivenom on the envenomation induced by Lachesis muta muta (South American bushmaster) in rats
In this study, we examined the potential use of N-acetyl-L-cysteine (NAC) in association with a polyvalent antivenom and as stand-alone therapy to reduce the acute local and systemic effects induced by Lachesis muta muta venom in rats. Male Wistar rats (300–350 g) were exposed to L. m. muta venom (1.5 mg/kg – i.m.) and subsequently treated with anti-Bothrops/Lachesis serum (antivenom:venom ratio 1:3 ‘v/w’ – i.p.) and NAC (150 mg/kg – i.p.) separately or in association; the animals were monitored for 120 min to assess changes in temperature, locomotor activity, local oedema formation and the prevalence of haemorrhaging. After this time, animals were anesthetized in order to collect blood samples through intracardiac puncture and then euthanized for collecting tissue samples; the hematological-biochemical and histopathological analyses were performed through conventional methods. L. m. muta venom produced pronounced local oedema, subcutaneous haemorrhage and myonecrosis, with both antivenom and NAC successfully reducing the extent of the myonecrotic lesion when individually administered; their association also prevented the occurrence of subcutaneous haemorrhage. Venom-induced creatine kinase (CK) release was significantly prevented by NAC alone or in combination with antivenom; NAC alone failed to reduce the release of hepatotoxic (alanine aminotransferase) and nephrotoxic (creatinine) serum biomarkers induced by L. m. muta venom. Venom induced significant increase of leucocytes which was also associated with an increase of neutrophils, eosinophils and monocytes; antivenom and NAC partially reduced these alterations, with NAC alone significantly preventing the increase of eosinophils whereas neither NAC or antivenom prevented the increase in monocytes. Venom did not induce changes in the erythrogram parameters. In the absence of a suitable antivenom, NAC has the potential to reduce a number of local and systemic effects caused by L. m. muta venom
Active Whey Protein Edible Films and Coatings Incorporating Lactobacillus buchneri for Penicillium nordicum Control in Cheese
Fungal contamination of food is responsible for health issues and food waste. In this work, the incorporation of a lactic acid bacteria (LAB) with antifungal properties (Lactobacillus buchneri UTAD104) into whey protein-based films and coatings was tested for the control of an ochratoxigenic fungi (Penicillium nordicum) in a cheese matrix. The incorporation of L. buchneri cells resulted in thicker films with less luminosity than control films and colour alteration. Nevertheless, cells inclusion did not alter moisture content, water vapour permeability, mechanical properties, hydrophobicity and chemical structure of the films. Whey protein films were able to maintain the viability of L. buchneri UTAD104 cells in 105 CFU/mL after 30 days of storage at 25 \textdegreeC. When applied in cheese, films and coatings containing L. buchneri cells prevented fungal contamination for at least 30 days, while control cheeses with films and coatings either without LAB or with Lactobacillus casei UM3 (a strain without antifungal ability) showed fungal contamination during that period. Ochratoxin A was not found in cheeses treated with films and coatings containing L. buchneri UTAD104. Results showed that the inclusion of a LAB with antifungal properties in edible films and coatings can help to reduce or eliminate P. nordicum contamination in cheeses.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ana Guimarães received support through grant SFRH/BD/103245/2014 from the Portuguese FCT.info:eu-repo/semantics/publishedVersio
The crossroads of anxiety: distinct neurophysiological maps for different symptomatic groups
Montserrat Gerez,1–3 Enrique Suárez,2,3 Carlos Serrano,2,3 Lauro Castanedo,2 Armando Tello1,3 1Departamento de Neurofisiología Clínica, Hospital Español de México, Mexico City, Mexico; 2Departamento de Psiquiatría, Hospital Español de México, Mexico City, Mexico; 3Unidad de Postgrado, Universidad Nacional Autónoma de México, Mexico City, Mexico Background: Despite the devastating impact of anxiety disorders (ADs) worldwide, long-lasting debates on causes and remedies have not solved the clinician’s puzzle: who should be treated and how? Psychiatric classifications conceptualize ADs as distinct entities, with strong support from neuroscience fields. Yet, comorbidity and pharmacological response suggest a single “serotonin dysfunction” dimension. Whether AD is one or several disorders goes beyond academic quarrels, and the distinction has therapeutic relevance. Addressing the underlying dysfunctions should improve treatment response. By its own nature, neurophysiology can be the best tool to address dysfunctional processes.Purpose: To search for neurophysiological dysfunctions and differences among panic disorder (PD), agoraphobia-social-specific phobia, obsessive–compulsive disorder (OCD) and generalized anxiety disorder.Methods: A sample population of 192 unmedicated patients and 30 aged-matched controls partook in this study. Hypothesis-related neurophysiological variables were combined into ten independent factors: 1) dysrhythmic patterns, 2) delta, 3) theta, 4) alpha, 5) beta (whole-head absolute power z-scores), 6) event-related potential (ERP) combined latency, 7) ERP combined amplitude (z-scores), 8) magnitude, 9) site, and 10) site of hyperactive networks. Combining single variables into representative factors was necessary because, as in all real-life phenomena, the complexity of interactive processes cannot be addressed through single variables and the multiplicity of potentially implicated variables would demand an extremely large sample size for statistical analysis.Results: The nonparametric analysis correctly classified 81% of the sample. Dysrhythmic patterns, decreased delta, and increased beta differentiated AD from controls. Shorter ERP latencies were found in several individual patients, mostly from the OCD group. Hyperactivities were found at the right frontorbital-striatal network in OCD and at the panic circuit in PD.Conclusions: Our findings support diffuse cortical instability in AD in general, with individual differences in information processing deficits and regional hyperactivities in OCD and PD. Study limitations and the rationale behind the variable selection and combination strategy will be discussed before addressing the therapeutic implications of our findings. Keywords: anxiety disorders, dysrhythmic, epileptiform, ERP, EEG, LORET
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