The incorporation of alpha-tocopherol and functional doses of phytosterol esters during cheesemaking does not affect DNA or mRNA dynamics of Streptococcus thermophilus and Lactococcus lactis throughout and after the end of ripening

Tocopherols and phytosterols are lipid-soluble molecules which have been widely used in the food industry. Nevertheless, the influence of these compounds on the performance of starter lactic acid bacteria (SLAB) in fermented foods has received little attention. Here, we assessed the behavior of Streptococcus thermophilus and Lactococcus lactis during the ripening of a functional Port Salut light cheese elaborated with these SLAB and with alpha-tocopherol and phytosterol esters as bioactive molecules. Functional and control cheeses were manufactured at an industrial plant and sampled at 7, 21, 40, 60 and 90 days after elaboration for real-time quantitative PCR (qPCR) or reverse transcription-qPCR (RT-qPCR) experiments. Target DNA and mRNA from both SLAB were detected after 90 days of elaboration in both functional and control cheeses, supporting their potential role in generating flavor metabolites. Furthermore, here we showed for the first time that the addition of alpha-tocopherol and functional doses of phytosterols did not affect DNA or mRNA dynamics of these SLAB during cheesemaking, throughout and after the end of ripening. Therefore, our results support the use of cheese manufactured with both S. thermophilus and L. lactis as an optimal delivery system for these beneficial bioactive compounds.Inst. de Tecnol. de los Alimentos- ITAFil: Pega, Juan Franco. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA).LABINTEX. Centre de Coopération Internationale en Recherche Agronomique pour le Déeveloppement. Déepartement PERSYST, UMR Qualisud; FranciaFil: Nanni, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Diaz, Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Ruzal, Sandra Monica Consejo Nacional de Investigaciones Científicas y Téecnica; ArgentinaFil: Perez, Carolina Daiana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rossetti, Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Rizzo, Sergio Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentin

Comparative analysis of the diet of arctocephalus gazella (Pinnipedia), at two localities of the south Shetland Islands, with emphasis on the fish component

Se estudió la dieta de ejemplares macho no reproductivos de lobo fino antártico, Arctocephalus gazella (Peters, 1875) en dos localidades de las Islas Shetland del Sur: Cabo Funes/Punta Stranger, Isla 25 de Mayo/Isla Rey Jorge y Punta Duthoit, Isla Nelson; por medio del análisis de 65 muestras de materia fecal colectadas en Febrero de 2012. En general, el krill antártico Euphausia superba (Dana, 1850) y los peces fueron los taxa presa más consumidos, seguidos por pingüinos y cefalópodos. Entre los peces, los mictófidos fueron dominantes; Gymnoscopelus nicholsi (Gilbert, 1911) fue la especie más importante en ambos apostaderos, seguido por Electrona antarctica (Gunther, 1878) en Punta Stranger y por el nototénido Pleuragramma antarctica (Boulenger, 1902) en Punta Duthoit. La similitud hallada en la composición dietaria de los agrupamientos de lobo estudiados sugiere áreas de alimentación en común. Nuestros resultados fueron comparados con aquellos reportados en la literatura para diferentes localidades de las Islas Shetland del Sur y la región del Mar de Scotia. La ausencia de especies de nototenoideos demersales históricamente diezmadas en la dieta del lobo fino podría estar reflejando el impacto negativo que las pesquerías comerciales han tenido sobre algunas poblaciones de peces y enfatizar la necesidad de realizar un monitoreo a largo plazo de los hábitos alimentarios de A. gazella en el archipiélago de las Islas Shetland del Sur.We studied the diet of non-breeding male Antarctic fur Seals Arctocephalus gazella (Peters, 1875) at two different localities of the South Shetland Islands: Stranger Point, King George Island/Isla 25 de Mayo and Duthoit Point, Nelson Island, by the analysis of 65 faecal samples collected in February 2012. Overall, Antarctic krill Euphausia superba (Dana, 1850) and fish were the main prey taxa followed by penguins and cephalopods. Myctophids were dominant among fish; Gymnoscopelus nicholsi (Gilbert, 1911) was the most important prey species at both sampling sites, followed by Electrona antarctica (Gunther, 1878) at Stranger Point and by the nototheniid Pleuragramma antarctica (Boulenger, 1902) at Duthoit Point. The relative similarity found in the dietary composition of fur seals from both locations suggest they might have been sharing common feeding areas. Our results were compared with those reported in the literature for different localities of the South Shetland Islands and the Scotia Sea region. The absence of formerly harvested demersal notothenioid species in the diet of fur seals may reflect the negative impact that commercial fisheries had on some fish populations and supports the importance of implementing long-term monitoring studies on the feeding habits of A. gazella in the area.Fil: Descalzo, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Daneri, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Negrete, Javier. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Corbalán, Aldo. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Barrera Oro, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Combination of organic acids and low-dose gamma irradiation as antimicrobial treatment to inactivate Shiga toxin-producing Escherichia coli inoculated in beef trimmings: Lack of benefits in relation to single treatments

The aim of this study was to assess the efficacy of lactic acid (LA), caprylic acid (CA), high- (HDI) and low- (LDI) dose gamma irradiation and LDI combined with LA or CA on the inactivation of a pool of Shiga toxin-producing Escherichia coli (STEC) strains inoculated on beef trimmings. The three most efficacious treatments were selected to study their effect on meat quality parameters and sensory attributes. The inoculum included five native STEC serogroups (O26, O103, O111, O145 and O157). The treatments applied were 0.5% LA, 0.04% CA, 0.5 kGy LDI, 2 kGy HDI, LDI+LA and LDI+CA. Beef trimmings were divided into two groups; one was inoculated with high (7 log CFU/g) and the other with low (1 log CFU/g) level of inoculum. Efficacy was assessed by estimating log reduction and reduction of stx- and eae-positive samples after enrichment, respectively. Results showed that treatments with organic acids alone were not effective in reducing STEC populations. For high inoculum samples, the most effective treatment was HDI followed by LDI+LA and LDI alone or combined with CA. For low inoculum samples, the most effective treatment was HDI followed by LDI alone or combined with organic acids. Concerning meat quality parameters and sensory attributes, irradiation treatments (LDI and HDI) caused minimal changes, while LDI+LA modified them significantly compared with the control. Therefore, based on our results, no benefits were observed after combining organic acids with gamma irradiation.Fil: Cap, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Cingolani, Celeste. Comisión Nacional de Energía Atómica (CNEA). Centro Atómico Ezeiza; Argentina.Fil: Lires, Carla. Comisión Nacional de Energía Atómica (CNEA). Centro Atómico Ezeiza; Argentina.Fil: Mozgovoj, Marina Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Soteras, Trinidad. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Sucari, Adriana. Laboratorio de Alimentos Stamboulian. División Higiene y Seguridad Alimentaria y Ambiental; Argentina.Fil: Gentiluomo, Jimena. Laboratorio de Alimentos Stamboulian. División Higiene y Seguridad Alimentaria y Ambiental; Argentina.Fil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Grigioni, Gabriela Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina. Universidad de Morón; Argentina.Fil: Signorini, Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Horak, Celina. Comisión Nacional de Energía Atómica (CNEA). Centro Atómico Ezeiza; Argentina.Fil: Vaudagna, Sergio Ramon. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina. Universidad de Morón; Argentina.Fil: Leotta, Gerardo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias UNLP, IGEVET — (UNLP-CONICET LA PLATA). Instituto de Genética Veterinaria “Ing. Fernando N. Dulout ”; Argentina

Impacto de la incorporación de lípidos vegetales y antioxidantes sobre el comportamiento del starter durante la producción industrial de un queso funcional evaluado por técnicas independientes de cultivo

Los fitoesteroles son un conjunto de lípidos vegetales que han sido utilizados para el diseño de productos lácteos funcionales debido a su capacidad para reducir el colesterol sérico. No obstante, su efecto sobre el comportamiento del cultivo starter en la elaboración de quesos no ha sido estudiado. En este trabajo se monitoreó la cinética del DNA y RNA de la bacteria Streptococcus thermophilus, un starter lácteo ampliamente utilizado y con potencial probiótico, durante la producción industrial de un queso funcional conteniendo esteres de ftoesteroles y alfa-tocoferol como compuestos bioactivos. Para este propósito, se optimizaron técnicas de PCR cuantitativa (qPCR) y qPCR con transcriptasa reversa (RT-qPCR). Asimismo, se utilizó un diseño experimental ad hoc para evaluar el umbral de detección de ácidos nucleicos libres. En nuestro conocimiento, este abordaje provee la primera evidencia experimental indicando que el DNA no es un indicador confiable de integridad celular cuando se detecta por qPCR, mientras que el RNA permitiría estimar de modo más preciso integridad bacteriana. El starter S. thermophilus se detectó por qPCR y RT-qPCR durante la producción del queso hasta los 81 días de madurado. Asimismo, se observó por primera vez que la adición de alfa-tocoferol y concentraciones funcionales de fitoesteroles correlacionó con un aumento significativo en los niveles de DNA y cDNA específicos.Phytosterols are plant lipophilic triterpenes that have been used for the design of functional dairy products because of their ability to lower serum cholesterol levels. However, their effect on the starter culture behavior during cheesemaking has not yet been studied. Here, we followed DNA and RNA kinetics of the bacterium Streptococcus thermophilus, an extensively used dairy starter with probiotic potential, during industrial production of a functional cheese containing phytosterol esters and alpha-tocopherol as bioactive compounds. For this purpose, real-time quantitative PCR (qPCR) and reverse transcription-qPCR (RT-qPCR) assays were optimized. An experimental set-up was used to evaluate the detection threshold of free nucleic acids. To our knowledge, this approach provides the first experimental evidence indicating that DNA is not a reliable marker of cell integrity, whereas RNA may constitute a more accurate molecular signature to estimate bacterial integrity. The starter S. thermophilus was detected by qPCR and RT-qPCR during cheese production until 81 days of ripening. We also showed for the first time that the addition of alpha-tocopherol and phytosterols at functional concentrations correlated with a significant increase in target DNA and cDNA levels.Fil: Pega, Juan Franco. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Rizzo, Sergio Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina.Fil: Rossetti, Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina.Fil: Perez, Carolina Daiana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Diaz, Gabriela Esther. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Ruzal, S.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina.Fil: Nanni, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina

Impact of extracellular nucleic acids from lactic acid bacteria on qPCR and RT-qPCR results in dairy matrices: Implications for defining molecular markers of cell integrity

In this study, we evaluated whether quantitative PCR (qPCR) and reverse transcription-qPCR (RT-qPCR) results could be affected by extracellular (free) DNA or RNA, respectively, obtained either from isolated bacteria or from fermented dairy foods manufactured with these microorganisms. These experimental set-ups involved two starter lactic acid bacteria (SLAB), Streptococcus thermophilus and Lactococcus lactis, as models across their most common technological environments: yoghurt, milk and cheese. The presence of free DNA modified qPCR results in levels sufficient to bias SLAB determinations, indicating that DNA may be a poor measure of cellular integrity. Furthermore, we showed for the first time that an order of magnitude more of free RNA than of DNA had to be used to modify RT-qPCR results. Importantly, the interference produced by free DNA and RNA was maintained across all the dairy matrices evaluated, independently of the SLAB and of the source of nucleic acids used, in both negative and positive samples. This study suggests that, contrary to DNA molecules, mRNA from dead microorganisms or from other extracellular sources may not be a determinant factor in skewing molecular quantifications. Therefore, our results support the potential use of mRNA as a molecular signature of cell integrity in dairy matrices.Fil: Pega, Juan Franco. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rizzo, Sergio Anibal. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Rossetti, Luciana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Pérez, Carolina Daiana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Díaz, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Centre de Coopération Internationale en Recherche Agronomique pour le Développerment; FranciaFil: Nanni, Mariana Sandra. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The relevance of fish in the summer diet of the Antarctic fur seal (Arctocephalus gazella) at Hope Bay, Antarctic Peninsula and Stranger Point, South Shetland Islands

The fish incidence, particularly notothenioids and myctophids, in the diet of non-breeding male Arctocephalus gazella in the western Antarctic Peninsula (AP) region is widely variable according to the studied locality. We made a comparative diet analysis on 158 fecal samples collected in summer 2005 at Hope Bay (HB), AP and at Stranger Point (SP), South Shetland Islands (SSI). The frequency of occurrence of Antarctic krill Euphausia superba and fish as prey was similar at HB, whereas krill was predominant at SP. For each fish species identified based on the otoliths found, their relative importance in the diet was evaluated using the IRI index. Notothenioid fish prevailed at HB, Pleuragramma antarctica being the most important prey. Contrarily, the myctophids Gymnoscopelus nicholsi and Electrona antarctica predominated at SP. Both benthopelagic and pelagic fish species were represented at HB, while the latter were more important at SP. Demersal nototheniid species (e.g., Trematomus spp.) were scarcely represented and only at HB, which might be related to a preference of fur seals for the more abundant pelagic prey there. At SP, demersal nototheniids were not represented in the scats. The fish species consumption was higher in diversity at SP in comparison with HB but low in overlap between the two sites. We surmise that the differences found in the dietary composition of fur seals from both sites could be related to 1—different topographical and hydrological conditions associated to the study areas; 2—historical finfish fisheries, which took place during the late 1970s at the SSI, but not in the AP. Our findings are compared with studies from other localities of the AP and the Scotia Arc.Fil: Descalzo, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Daneri, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Harrington, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Negrete, Javier. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Negri, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Corbalán, Aldo. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Barrera Oro, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Effect of the addition of phytosterols and tocopherols on Streptococcus thermophilus robustness during industrial manufacture and ripening of a functional cheese as evaluated by qPCR and RT-qPCR

The quality of functional food products designed for the prevention of degenerative diseases can be affected by the incorporation of bioactive compounds. In many types of cheese, the performance of starter microorganisms is critical for optimal elaboration and for providing potential probiotic benefits. Phytosterols are plant lipophilic triterpenes that have been used for the design of functional dairy products because of their ability to lower serum cholesterol levels in humans. However, their effect on the starter culture behavior during cheesemaking has not yet been studied. Here, we followed DNA and RNA kinetics of the bacterium Streptococcus thermophilus, an extensively used dairy starter with probiotic potential, during industrial production of a functional, semi-soft, reduced-fat cheese containing phytosterol esters and alpha-tocopherol as bioactive compounds. For this purpose, real-time quantitative PCR (qPCR) and reverse transcription-qPCR (RT-qPCR) assays were optimized and applied to samples obtained during the manufacture and ripening of functional and control cheeses. An experimental set-up was used to evaluate the detection threshold of free nucleic acids for extraction protocols based on pelleted microorganisms. To our knowledge, this straight-forward approach provides the first experimental evidence indicating that DNA is not a reliable marker of cell integrity, whereas RNA may constitute a more accurate molecular signature to estimate both bacterial viability and metabolic activity. Compositional analysis revealed that the bioactive molecules were effectively incorporated into the cheese matrix, at levels considered optimal to exert their biological action. The starter S. thermophilus was detected by qPCR and RT-qPCR during cheese production at the industrial level, from at least 30 min after its inoculation until 81 days of ripening, supporting the possible role of this species in shaping organoleptic profiles. We also showed for the first time that the addition of phytosterols at functional concentrations, not only did not affect starter performance but also correlated with a significant increase in target DNA and cDNA levels in most of the time points evaluated throughout cheesemaking. Therefore, these findings suggest that the growth and metabolism of S. thermophilus may be enhanced by the incorporation of these biologically active molecules during cheese production, providing important information for the industrial design of novel fermented foods.Fil: Pega, Juan Franco. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rizzo, Sergio Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Perez, Carolina Daiana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rossetti, Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Diaz, Gabriela Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Ruzal, Sandra Mónica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Nanni, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA).LABINTEX-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD). Département PERSYST; Franci

Impact of storage on the functional characteristics of a fermented cereal product with probiotic potential, containing fruits and phytosterols

The aim of this work was to study the changes in the functional characteristics of a fermented maize product containing fruits, and enriched with phytosterols. Functional characteristics (natural antioxidants and phytosterols content, in vitro antioxidant capacity and probiotic viability), lipid oxidation, and physicochemical parameters were investigated during 4 weeks of storage at 4 °C. The differences between one formulation elaborated with semi-skimmed powdered milk (Basic Product) and another with whey protein isolate (WPI Product) were evaluated. The content of polyphenols, carotenoids and tocopherols remained unchanged during the storage of both formulations. These compounds increased the antioxidant capacity in both products compared to the control formulation (without fruits), which was displayed along the whole storage period. The doses of phytosterols and the probiotic potential were maintained to the end of the storage period for both formulations. Basic and WPI products represent novel foods with desirable functional characteristics preserved during commercial storage. Resumen: El objetivo de este trabajo fue estudiar los cambios en las características funcionales de un producto de maíz fermentado que contiene frutos y está enriquecido con fitoesteroles. Características funcionales (contenido de antioxidantes naturales y fitoesteroles, in vitrocapacidad antioxidante y viabilidad probiótica), oxidación de lípidos y parámetros fisicoquímicos se investigaron durante 4 semanas de almacenamiento a 4 ° C. Se evaluaron las diferencias entre una formulación elaborada con leche en polvo semidesnatada (Producto Básico) y otra con aislado de proteína de suero (Producto WPI). El contenido de polifenoles, carotenoides y tocoferoles se mantuvo sin cambios durante el almacenamiento de ambas formulaciones. Estos compuestos aumentaron la capacidad antioxidante en ambos productos en comparación con la formulación de control (sin frutas), que se mostró durante todo el período de almacenamiento. Las dosis de fitoesteroles y el potencial probiótico se mantuvieron hasta el final del período de almacenamiento para ambas formulaciones. Los productos básicos y WPI representan nuevos alimentos con características funcionales deseables que se conservan durante el almacenamiento comercial.Instituto de Investigación de Tecnología de AlimentosFil: Lingua, Mariana Soledad. Consejo Nacional de Investigaciones Cientìficas y Técnicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina. Universidad Nacional de Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina.Fil: Gies, Magali. Centro de Cooperación Internacional en Investigación Agronómica para el Desarrollo (CIRAD). UMR QualiSud Montpellier; Francia.Fil: Gies, Magali. La Unidad de Investigación (QualiSud). Cirad - Montpellier SupAgro - Universidad de Montpellier - UAPV Aviñón - Universidad de La Reunión - IRD; Francia.Fil: Descalzo, Adriana María. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina.Fil: Servent, Adrien. Centro de Cooperación Internacional en Investigación Agronómica para el Desarrollo (CIRAD). UMR QualiSud Montpellier; Francia.Fil: Servent, Adrien. La Unidad de Investigación (QualiSud). Cirad - Montpellier SupAgro - Universidad de Montpellier - UAPV Aviñón - Universidad de La Reunión - IRD; Francia.Fil: Paez, Roxana Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina.Fil: Baroni, María Verónica. Consejo Nacional de Investigaciones Cientìficas y Técnicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina. Universidad Nacional de Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina.Fil: Blajman, Jesica Evelyn. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea; Argentina. Consejo Nacional de Investigaciones Cientìficas y Técnicas. Instituto de Investigación de la Cadena Láctea; ArgentinaFil: Dhuique-Mayer, Claudie. La Unidad de Investigación (QualiSud). Cirad - Montpellier SupAgro - Universidad de Montpellier - UAPV Aviñón - Universidad de La Reunión - IRD; Francia.Fil: Dhuique-Mayer, Claudie. Centro de Cooperación Internacional en Investigación Agronómica para el Desarrollo (CIRAD). UMR QualiSud Montpellier; Francia

Coupling Virus-Induced Gene Silencing to Exogenous Green Fluorescence Protein Expression Provides a Highly Efficient System for Functional Genomics in Arabidopsis and across All Stages of Tomato Fruit Development1[C][W]

Since the advent of the postgenomic era, efforts have focused on the development of rapid strategies for annotating plant genes of unknown function. Given its simplicity and rapidity, virus-induced gene silencing (VIGS) has become one of the preeminent approaches for functional analyses. However, several problems remain intrinsic to the use of such a strategy in the study of both metabolic and developmental processes. The most prominent of these is the commonly observed phenomenon of “sectoring” the tissue regions that are not effectively targeted by VIGS. To better discriminate these sectors, an effective marker system displaying minimal secondary effects is a prerequisite. Utilizing a VIGS system based on the tobacco rattle virus vector, we here studied the effect of silencing the endogenous phytoene desaturase gene (pds) and the expression and subsequent silencing of the exogenous green fluorescence protein (gfp) on the metabolism of Arabidopsis (Arabidopsis thaliana) leaves and tomato (Solanum lycopersicum) fruits. In leaves, we observed dramatic effects on primary carbon and pigment metabolism associated with the photobleached phenotype following the silencing of the endogenous pds gene. However, relatively few pleiotropic effects on carbon metabolism were observed in tomato fruits when pds expression was inhibited. VIGS coupled to gfp constitutive expression revealed no significant metabolic alterations after triggering of silencing in Arabidopsis leaves and a mild effect in mature green tomato fruits. By contrast, a wider impact on metabolism was observed in ripe fruits. Silencing experiments with an endogenous target gene of interest clearly demonstrated the feasibility of cosilencing in this system; however, carefully constructed control experiments are a prerequisite to prevent erroneous interpretation