Effects of ultraviolet radiation on the microbiological, physicochemical, and sensory properties of Rangpur lime juice

Rangpur lime juice was subjected to ultraviolet (UV) radiation as a non-thermal technology and changes in/on quality characteristics (microbiological, physicochemical and sensorial) were determined in order to extend its shelf life. UV-C treated juice resulted in 2.33 log and 2 log reductions in aciduric microorganisms and yeast and mould count, respectively. After UV-C treatment, there were no significant changes (p > 0.05) in pH, acidity and soluble solids;however antioxidant activity and the ascorbic acid content were affected by this process. The losses in ascorbic acid were 27.5 and 42% after UV-C treatment necessary to decrease 95 and 99% of the microbial load, respectively. Based on sensory analysis results, no significant differences were detected between fresh and UV-C treated juices. UV-C treatment extended the shelf life of fresh juice to 5 days during storage at 4°C.Fil: Acevedo, Belén Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Sgroppo, Sonia Cecilia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Dellacassa, Eduardo. Universidad de la República; Urugua

Mixed cultures of Hanseniaspora vineae and Saccharomyces cerevisiae: the compromise between completing fermentation and increasing wine flavor complexity

Introduction. In winemaking is traditional that some technical interventions implicate losing or gaining some quality characteristics of the final wine in terms of color or flavor. Among nonSaccharomyces species, Hanseniaspora vineae has been successfully used at winery scale and is now available to winemakers as an active dry yeast. This species only tolerates moderate levels of ethanol (around 10% v/v). The implementation of a mixed culture with S. cerevisiae is a useful strategy to obtain complete fermentations, increasing flavour complexity. Methods. H vineae HV205 and four conventional Saccharomyces strains were utilized for the mixed cultures and as pure control cultures. Fermentation rate and yeast growth were measured in different experiments using a synthetic grape must or natural grape musts of Chardonnay, Petit Manseng, Glera, Tannat and Termantis. Flavor compounds were studied by GCMS analysis, and other non-volatile compounds by HPLC or NIR. Results. The co-fermentations inoculated with a combination of 80% H. vineae and 20% of different Saccharomyces strains, resulted in intense flavor compounds over their threshold values. Olfactory aroma values obtained in these conditions even below those corresponding to pure fermentations of HV205, were still significantly higher than conventional fermentations. Fermentation rates in these conditions were like pure Saccharomyces performance in real wine pilot scale with Glera and Termantis grapes. Co-inoculation 80%-20% produced significant higher concentrations of 2phenylethanol, tyrosol and tryptophol acetates compared to 50%-50% proportions and other tested combinations. Similar results were also obtained in high alcohol content wines such as Tannat and Petit Manseng of about 15% of alcohol. Conclusions. Co-inoculation of HV205 80% and Saccharomyces 20% showed to be the ideal strategy to solve the compromise between completing fermentations and increasing flavor complexity within a reasonable process time. These results will facilitate the more effective application of HV205, simplifying its use in large-scale fermentation facilities

Improving honey identification: stable isotope ratios variability of mono and polyfloral honeys from the citrus growing area of Salto/Concordia and from Uruguayan coastal areas

Concordia in Argentina and Salto in Uruguay are two neighbouring regions famous for the production of a precious citrus honey, whose valorisation passes through the ability to guarantee its geographical origin. In this study the influence of the different botanical origins (monofloral and polyfloral) within the same region of origin on the different stable isotope ratios was evaluated. Moreover, the effectiveness of the stable isotope ratio parameters δ13Choney, δ13Cprotein, δ15Nprotein, δ34Sprotein, δ2 Hprotein and δ18Oprotein to discriminate between honeys produced in the internal border regions between Argentina and Uruguay (namely, Concordia and Salto) and honeys sampled in the two different Uruguayan coastal regions (Canelones and Maldonado) was tested on 82 monofloral and polyfloral honey samples. The results show that the different stable isotope ratios, except that of nitrogen, are not significantly influenced by the botanical origin of the samples. The sulphur isotopic ratio of proteins and carbon of honey are the most significant parameters for discriminating the geographical origin of the honeys considered. Applied a Principal Component Analysis, the first two factors overall explain 63.5% of the total variance, while the Discriminant Analysis provided optimal discrimination between the three origins, reaching a minimum of 96.7% correct reclassification

Multivariate analysis discrimination of various cold-pressed lemon oils from different geographical regions.

The main objective of present study was to investigate the influence of geographical region on the flavour compounds of various cold-pressed lemon oils, i.e. Argentinean, Ivory Cost, Italian, Spanish and Uruguayan. Among the flavor compounds, the major volatile flavour compounds from different chemical classes namely monoterpene hydrocarbons (i.e. limonene, sabinene plus β-pinene, γ-terpinene, myrcene, α-pinene and α-terpinolene), esters (i.e. neryl acetate and geranyl acetate), alcohol (i.e. α-terpineol) and aldehyde compounds (i.e. geranial and neral) were composed of > 90% of total volatile flavor compounds of target cold pressed lemon oils. Uruguayan essential oil had the least concentration level of all major classes of flavor compounds except for alcohol compounds; while the highest content of all chemical classes of flavor compounds identified in this study. The principle component analysis (PCA) allowed us to discriminate various cold-pressed lemon oil based on their origin resource, thereby classify their sensorial attributes

Protección del ácido clorogénico frente a lesiones inducidas por benzo[a]pireno en Saccharomyces cerevisiae

El objetivo del presente estudio fue analizar el efecto del ácido clorogénico, uno de los compuestos polifenólicos con mayor concentración en la infusión de Ilex paraguariensis, sobre el daño celular y molecular inducido por el benzo[a]pireno. La infusión de Ilex paraguariensis (“mate”) es bebida por la mayoría de los habitantes de Argentina, Paraguay, sur de Brasil y Uruguay. La levadura Saccharomyces cerevisiae (cepas SC7K lys2-3; SX46A y SX46A rad14Δ) se utilizó como modelo eucariota. Las células en crecimiento exponencial se expusieron a concentraciones crecientes de benzo[a]pireno y a tratamientos combinados con una concentración de 250 ng/mL de benzo[a]pireno y ácido clorogénico a una concentración igual a la encontrada en la infusión de yerba mate. Luego de los tratamientos se determinaron fracciones de sobrevida, frecuencia mutagénica y roturas de doble cadena de ADN así como la modulación en la expresión de la proteína Rad14 a través de un análisis de Western Blot. Se observó un aumento significativo en las fracciones de sobrevida así como una disminución en la frecuencia mutagénica después de la exposición combinada con benzo[a]pireno y ácido clorogénico en comparación con los tratamientos con benzo[a]pireno como único agente. En la cepa mutante deficiente en la proteína Rad14 se observó un aumento significativo en la sensibilidad a benzo[a]pireno en comparación con la cepa SC7K lys2-3. En los tratamientos combinados de benzo[a]pireno y ácido clorogénico se observó una importante disminución de la letalidad. Con respecto a la determinación de roturas de doble cadena de ADN no se observó fraccionamiento cromosómico a la concentración de benzo[a]pireno utilizada en los experimentos. Los análisis de Western Blot mostraron un aumento en la expresión de la proteína Rad14 en las muestras tratadas con benzo[a]pireno como único agente en comparación con la muestra control. Adicionalmente se observó una disminución en la expresión de la proteína cuando en los tratamientos se utilizaron benzo[a]pireno y ácido clorogénico combinados. Los resultados indican que el ácido clorogénico disminuye significativamente la actividad mutagénica producida por el benzo[a]pireno, la cual no se encuentra relacionada con un incremento en la remoción de las lesiones inducidas por el sistema de reparación por escisión de nucleótidos

Estudio del envejecimiento acelerado del aroma, el color y los parámetros fisicoquímicos de vinos Tannat

En este trabajo se evaluaron diferentes técnicas para lograr un envejecimiento acelerado del vino: ultrasonido (US), radiaciones gamma (RG) y altas presiones (AP). Las condiciones experimentales para cada tratamiento fueron: US, se aplicaron secuencias de 30 y 60 minutos a 20 kHz; RG, se analizaron tres dosis (1, 3 y 6 kGy); AP, se sometieron las muestras a una presión constante de 650 MPa variando el tiempo de aplicación (15, 30, 60 y 120 minutos). Los vinos fueron caracterizados por sus parámetros fisicoquímicos básicos, su perfil volátil (GC-MS) y el análisis de color (CIELAB). Se utilizó como testigo el mismo vino sin tratar. Los resultados mostraron que el tratamiento de US no produjo diferencias significativas respecto al control en ninguna de las condiciones ensayadas. Aplicando AP se obtuvieron diferencias significativas respecto al control en el color (disminución de todos los parámetros cromáticos) y en el contenido de compuestos volátiles (aumento del contenido de terpenos y ésteres). El tratamiento GR produjo los mayores cambios respecto al vino control, con un incremento de todos los Parámetros cromáticos al aumentar la dosis de radiación. Mientras que en el perfil volátil se observó un aumento del contenido de 3-oxo-α-ionol, ho-diol y lactato de etilo, todos cambios deseables durante el envejecimiento natural

In Vitro bioaccessibility of bioactive compounds from Citrus pomaces and orange pomace biscuits

The present investigation aimed to provide novel information on the chemical composition and in vitro bioaccessibility of bioactive compounds from raw citrus pomaces (mandarin varieties Clemenule and Ortanique and orange varieties Navel and Valencia). The effects of the baking process on their bioaccessibility was also assessed. Samples of pomaces and biscuits containing them as an ingredient were digested, mimicking the human enzymatic oral gastrointestinal digestion process, and the composition of the digests were analyzed. UHPLC-MS/MS results of the citrus pomaces flavonoid composition showed nobiletin, hesperidin/neohesperidin, tangeretin, heptamethoxyflavone, tetramethylscutellarein, and naringin/narirutin. The analysis of the digests indicated the bioaccessibility of compounds possessing antioxidant [6.6–11.0 mg GAE/g digest, 65.5–97.1 µmol Trolox Equivalents (TE)/g digest, and 135.5–214.8 µmol TE/g digest for total phenol content (TPC), ABTS, and ORAC-FL methods, respectively; significant reduction (p < 0.05) in Reactive Oxygen Species (ROS) formation under tert-butyl hydroperoxide (1 mM)-induced conditions in IEC-6 and CCD-18Co cells when pre-treated with concentrations 5–25 µg/mL of the digests], anti-inflammatory [significant reduction (p < 0.05) in nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 macrophages], and antidiabetic (IC50 3.97–11.42 mg/mL and 58.04–105.68 mg/mL for α-glucosidase and α-amylase inhibition capacities) properties in the citrus pomaces under study. In addition, orange pomace biscuits with the nutrition claims “no-added sugars” and “source of fiber”, as well as those with good sensory quality (6.9–6.7, scale 1–9) and potential health promoting properties, were obtained. In conclusion, the results supported the feasibility of citrus pomace as a natural sustainable source of health-promoting compounds such as flavonoids. Unfractionated orange pomace may be employed as a functional food ingredient for reducing the risk of pathophysiological processes linked to oxidative stress, inflammation, and carbohydrate metabolism, such as diabetes, among other

In vitro bioaccessibility of extractable compounds from tannat grape skin possessing health promoting properties with potential to reduce the risk of diabetes

Diabetes pathogenesis encompasses oxidative stress, inflammation, insulin malfunctioning and partial or total insulin secretion impairment, which leads to a constant hyperglycemia. Polyphenols are known to possess bioactive properties, being Tannat grape skin a natural and sustainable source of these compounds. The present study aimed to find out the bioaccessibility of health-promoting molecules composing a multifunctional extract from Tannat grape skin obtained under hydro-alcoholic-acid conditions. The identification of phenolic compounds in the samples was performed by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Subsequently, the samples were in vitro digested mimicking the human oral gastrointestinal conditions and the bioactivity of the digest (antioxidant, anti-inflammatory and modulation of glucose metabolism) was assessed. Effect on glucose metabolism was estimated by measuring carbohydrases activity and the functionality of glucose transporters of small intestine cells in presence and absence of the digested extract. Flavonoids, phenolic acids and phenolic alcohols were the major phenol compounds detected in the extract. The bioaccessible compounds protected the intestinal cells and macrophages against the induced formation of reactive oxygen species (ROS) and nitric oxide (NO). In addition, glucose transporters were inhibited by the digested extract. In conclusion, the bioaccessible compounds of the extract, including phenols, modulated key biochemical events involved in the pathogenesis of diabetes such as oxidative stress, inflammation and glucose absorption. The extract was effective under prevention with co-administration conditions supporting its potential for either reducing the risk or treating this diseas

Molecular diversity within clones of cv. Tannat (Vitis vinifera)

DNAs from 9 clones of cv. Tannat (Vitis vinifera) were analyzed at 89 microsatellite loci. Only one, VMCNg 1d12, showed a differential pattern that separated the clones in two groups. The statistical analysis of concentrations for aroma compounds from microvinifications also resulted in the same two groupings of clones. Many analyzed microsatellite loci amplified only one allele, implying that Tannat is a highly homozygous variety. For a given set of 15 microsatellites the level of homozygosity was 53 % for Tannat, in contrast to 6 % for Pinot, 20 % for both Cabernet Franc and Chardonnay and 33 % for Cabernet Sauvignon. We provide molecular data for Tannat, originating from southwestern France and nowadays becoming the emblematic cultivar of Uruguayan fine red wines. We also report a correlation between aroma-related compounds and molecular markers within clones of a cultivar.