Micropropagation of grape rootstocks of interest for Misiones province

Con el objeto de micropropagar portainjertos de vid de interés para la provincia de Misiones (Paulsen 1103 y Vr 04343) se cultivaron segmentos nodales y ápices meristemáticos. Para el establecimiento de segmentos nodales se evaluaron diferentes concentraciones del medio propuesto por Murashige y Skoog (MS) -¼, ½, 1- adicionando diferentes concentraciones de benciladenina (0; 1; 3 y 5 mg.L-1) y ácido naftalenacético (0 y 0,01 mg.L-1). Se evaluaron estado fisiológico y topófisis de yemas. En fase de multiplicación se evaluaron ápices, segmentos uni y binodales con o sin hoja desplegada. Para el establecimiento de ápices se evaluó el medio MS ½ suplementado con bencilaminopurina (0; 0,5; 1; 2 mg.L-1). Los mejores resultados para el establecimiento de segmentos nodales se obtuvieron con yema despierta en medio MS ¼ sin adición de reguladores. La multiplicación de los mismos puede realizarse partiendo de un explanto uni o binodal con o sin hoja. Al utilizar ápices como explanto, se debe adicionar al medio MS ½ bencilaminopurina en una concentración de 0,5 mg.L-1. En la aclimatación de las plantas, se obtuvieron valores de supervivencia de 80 a 90%.In order to develop a micropropagation system for different grape rootstock of interest for Misiones Province (Paulsen 1103 and Vr 04343), nodal segments and root tips were culturated. Different concentrations of the medium proposed by Murashige and Skoog (MS) -¼, ½ , 1- adding different concentrations of benzyladenine (0; 1; 3 and 5 mg.L-1) and naphthylacetic acid (0 and 0.01 mg.L-1) were evaluated for the establishment of nodal segments. Topofisis and physiological state of the buds were also evaluated. Shoot tips and one-node and twonode segments with or without leave were evaluated in the multiplication stage. For the establishment of shoot tips the medium MS ½ supplemented with benzylaminopurine (0; 0.5; 1; 2 mg.L-1) was evaluated. The best results for establishment phase of nodal segments with the bud were obtained with the medium MS ¼ without regulator’s addition. Multiplication phase can start from an one or two-node explant with or without leaf. When using shoot tips as explant, the medium MS ½ should be added with benzyladenine at 0.5 mg.L-1. In acclimated plants, we obtained survival values between 80 and 90%.Fil: Guerrero, Diego R.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Mroginski, Luis A.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Krivenky, Mario A.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro AzulFil: Domínguez, Martín C.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro Azu

Volatile organic compounds and consumer preference for meat from suckling goat kids raised with natural or replacers milk

Most of European Union goats are slaughtered with carcase weights between 5 kg and 11 kg. Some farmers rear kids with milk replacers to produce cheese with the dams’ milk. The aim of this experiment was to study the volatile compounds (VOCs) of meat of suckling light kids reared with natural milk or milk replacers and to study the influence of consumers’ psychographic characteristics on the sensory preference for meat. Gas chromatography-mass spectrometry was performed to identify the VOCs and consumers evaluated the flavour, juiciness and overall acceptability. Thirty-five VOCs were detected and 44.3%, 25.1%, 6.9% and 2.3%, were aldehydes, hydrocarbons, ketones and alcohols, respectively. The influence of the rearing system on VOCs clearly depended on the breed. The use of milk replacers did not affect the percentage of linear aldehydes compared to the use of natural milk. However, the major aldehyde, hexanal (34.8%), was related to the use of natural milk and correlated positively with both the flavour (r = 0.21) and overall acceptability (r = 0.24). On the other hand, hydrocarbons such as hexane were related to MR, and 2-methyl-pentane and 3-methyl pentane were correlated with the acceptability of flavour (r = −0.22 and −0.25, respectively) and with the overall acceptability (r = −0.21 and −0.24). The 2-penthyl furan and 2-ethyl-1-hexanol were correlated with the overall acceptability (r = −0.22 and −0.22, respectively). Therefore, the acceptability of meat from suckling kids fed natural milk was greater for older consumers and people with a moderate consumption of meat.Unión Europea, Ministerio de Economía y Competitividad (MINECO). [RTA2012-0023-C03]; CYTED [116RT0503

Determination of 2,4,6-trichloroanisole by cyclic voltammetry

The electrochemical reduction of 2,4,6-trichloroanisole (TCA), a chlorinated arene with electron-donating substituents, was evaluated by cyclic voltammetry (CV). TCA is a major concern for the winery industry since it is related with “cork taint”, a wine defect. The results obtained showed that CV could be used to detect and quantify TCA in standard solutions. Linear relationships could be set between the current amplitude and TCA concentrations (R>0.990) with detection and quantification limits of 0.08 and 0.26 ppm. Although, these preliminary limits are higher than the human sensory threshold (5 ppt in wine), the simplicity of the methodology confers this study a possible role in the development of more efficient and less expensive process for TCA detection in the industry.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia

THE EFFECT OF PRODUCTION SYSTEM INFORMATION ON CONSUMER EXPECTATION AND ACCEPTABILITY OF LECCESE LAMB MEAT

Twenty lamb meat’s habitual consumers (eight females and twelve males, from 25 to 62 yrs of age) took part in a centrallocation test, organised to assess consumers’ expectations generated by information on animal feeding system, lambs fedwith maternal milk from mothers reared on grass (T1) versus lambs fed with maternal milk from mothers reared on stall(T2), and to assess the effect of this knowledge on the hedonic ratings of lamb meat from the Leccese breed. Using anone-point hedonic scale, first blind and then informed scores were collected on two types of Leccese meat. The blind testprovided information which was different from informed test; in fact, T2 meat receiving higher hedonic scores than T1 meat. Onthe contrary, with the label information on animal feeding system, meat from T1 lambs was liked more than meat from T2lambs. The lamb meat’s habitual consumers showed a higher interest in extrinsic quality attributes which referred to the origin orproduction system

Effect of sponge volume fraction on the performance

A novel fluidized bed bioreactor (FBBR) was designed by integration of anaerobic granular activated carbon and aerobic sponge reactors. This FBBR was evaluated at different sponge volume fractions for treating a synthetic wastewater. Polyester urethane sponge with cube size of 1 × 1 × 1 cm and density of 28-30 kg/m3 with 90 cells per 25 mm was used as biomass carrier. The results indicate that the FBBR could remove more than 93% of dissolved organic carbon (DOC). The highest nutrient removal efficiencies (58.2% PO4 -P and 75.4% NH4-N) were achieved at 40% sponge volume fraction. The system could provide a good condition for biomass growth (e.g. 186.2 mg biomass/g sponge). No significant different performance in specific oxygen uptake rate was observed between 30, 40, and 50% sponge volume fractions. © IWA Publishing 2013 Water

Development and evaluation of tools to improve the texture and quality of dry-cured ham

El jamón curado es considerado un producto típico de la región mediterránea elaborado con las patas traseras del cerdo, las cuales se salan y curan durante un período largo. Sin embargo, existen otros productos curados como el jamón curado de cordero, el Fenalår, típico de Noruega, que se sala, se ahúma y se cura durante un período más corto de tiempo. La textura de los productos curados es un criterio de calidad importante para los consumidores. Sin embargo, el desarrollo de la textura, así como también de los defectos de textura de los productos curados tanto de cerdo como de cordero son un tema complejo puesto que hay muchos factores involucrados. Por este motivo, hay un interés creciente de la industria alimentaria en encontrar soluciones para reducir la incidencia de productos con texturas blandas y/o defectuosas.El principal objetivo de esta Tesis es desarrollar y evaluar herramientas para mejorar el proceso de elaboración y la calidad de dos productos curados: el jamón curado y el Fenalår. Para ello, se han llevado a cabo diferentes estudios los cuales se presentan en esta Tesis en diferentes artículos científicos. El artículo I aborda los principales factores que afectan al desarrollo de la textura y a la modelización de la textura. El segundo artículo muestra los resultados de la microbiología predictiva utilizada para estudiar la seguridad alimentaria en relación con el proceso de elaboración y la reducción del contenido de sal, así como también la omisión de nitrificantes (artículo II). En el artículo III se investigó un método para evaluar de manera no destructiva el punto final del proceso en función de las medidas obtenidas en la superficie del jamón. En el artículo IV,se presentan los resultados obtenidos de un primer intento para el desarrollo de un método para evaluar la pastosidad con el reómetro y evitar así los tediosos análisis sensoriales. Finalmente, el uso de un tratamiento de altas presiones como acción correctora para productos con texturas defectuosas se presenta en el artículo V.Con la finalidad de estudiar de forma más detallada el desarrollo de la textura, se desarrolló un modelo matemático (artículo 1), que relaciona las condiciones de procesado y las características de la materia prima con la textura del producto. Este modelo no sólo permite evaluar el efecto de estos factores, sino que también podría permitir una optimización del proceso de elaboración a nivel industrial. Los resultados mostraron que el contenido de sal, el pH, las características de la materia prima y las condiciones de procesado (temperatura de secado y merma final) son factores importantes que afectan al desarrollo de la textura, tal y como se presenta en el artículo I, y a la vez comprometen la seguridad del producto. En el artículo II, la reducción del contenido de sal no sólo dio como resultado texturas más blandas, sino que también produjo un incremento de los riesgos microbiológicos, especialmente cuando se omitieron los nitrificantes, tal y como muestran los resultados obtenidos mediante los modelos de microbiología predictiva. Además, los defectos de textura en ambosproductos curados representan un importante desafío para la industria.A pesar de los esfuerzos realizados para mejorar el proceso de elaboración, es posible que algunos productos sigan siendo defectuosos, evidenciando así la necesidad de nuevas herramientas y/o tecnologías con potencial para su aplicación a nivel industrial. En esta Tesis, se estudió una metodología para evaluar si el producto tenía o no la textura adecuada para su comercialización (artículo III), así como también un análisis para evaluar instrumentalmente el defecto de pastosidad en jamón curado loncheado (papel IV). Los resultados presentados en el artículo III muestran que el método ITAS permitió evaluar de manera no destructiva el punto final del proceso; esta metodología consiste ensimular la valoración táctil en la superficie del jamón realizada actualmente por los expertos. La máxima precisión de clasificación fue del 82,1%, obtenida al combinar las mediciones junto con el espesor de la grasa subcutánea. La implantación de esta tecnología a nivel industrial no sólo mejoraría la calidad del producto, sino que también supondría un ahorro económico, energético y de espacio, ya que permitiría un mejor ajuste del tiempo de secado necesario para cada jamón.En el artículo IV se presentan los resultados obtenidos en un primer estudio para el desarrollo de un método para evaluar la pastosidad utilizando un reómetro. Los resultados obtenidos mostraron un aumento de la viscosidad de los extractos a medida que aumentaba la intensidad del defecto de pastosidad, mostrando así la posibilidad de detectar instrumentalmente este defecto utilizando el reómetro. Sin embargo, hay otros factores a parte de la viscosidad que pueden afectar/alterar los resultados y el reómetro sólo permite discriminar las muestras con una pastosidad intensa de aquellas que tienen un defecto medio o que no son pastosas.También se han llevado a cabo acciones correctoras en lonchas de jamón curado utilizando tratamientos mediante altas presiones a diferentes temperaturas (artículo V).Los resultados obtenidos muestran que, si bien las temperaturas de 7 ºC y 20 ºC son útiles para corregir el defecto en las lonchas con pastosidad media, se necesita una temperatura superior (35 ºC) para las de pastosidad intensa. Por lo tanto, conocer las características iniciales de textura del producto es clave para definir las condiciones óptimas para su procesado mediante altas presiones cuando se busca mejorar la textura sin deteriorar el color ni el aroma.Las metodologías desarrolladas y evaluadas en esta Tesis pueden utilizarse para mejorar el proceso de elaboración y la calidad del jamón curado. Además, representan un primer paso en el desarrollo de nuevas herramientas para uso industrial.Dry-cured ham is considered a typical product of the Mediterranean area made of pig¿s hind leg which is dry-salted and has a long maturation period. However, there are other typical dry-cured products such as the dry-cured lamb ham, Fenalår, from Norway, which is dry-salted and smoked followed by a short maturation period. The texture of dry-cured products is an important quality criterion for the consumers. However, texture development and also texture defects of dry cured products from both pork and lamb are a complex issue since many factors are involved. For this reason, there is an increasing interest of the industry in finding solutions to reduce the incidence of products with soft and/or defective textures. The main objective of this PhD Thesis dissertation was to develop and evaluate tools to improve the manufacturing process and the quality of two examples of dry-cured products; dry-cured ham and Fenalår. For this reason, different studies were conducted and herein presented as different papers. First one addresses the main factors affecting texture development and texture prediction modelling (presented in paper I). The second paper presents the results of predictive microbiology used to study food safety in relation to manufacturing process with reduced salt and nitrites addition (in paper II). Next study investigated a method to non-destructively evaluate the end of process based on the measurements taken at the surface of the ham (in paper III). The results of an attempt to develop a method to evaluate pastiness with a rheometer to avoid the tedious sensory analysis are presented in paper IV. Finally, the use of high pressure treatments as a corrective action for products with defective textures is presented in paper V. In order to study texture development in more detail, mathematical models were developed (paper I), that relate processing conditions and raw material characteristics to the texture of the product. These models not only allow the effect of these factors to be evaluated but could also enable further optimisation of the process in the industry. The results showed that salt content, pH, raw material characteristics and processing conditions (drying temperature and final weight loss) are important factors affecting texture development, as shown in paper I, while affecting product safety. In paper II, reduced salt content not only resulted in softer textures but also in an increase of microbiological hazards especially when no nitrite was used as evaluated by predictive microbiology models. Furthermore, texture defects in both dry-cured products represent an important challenge for the industry. Despite the efforts to improve the manufacturing process, some products may still be defective and the need for new tools and/or technologies with potential for industrial application is emerging. In this Thesis, a methodology to evaluate whether the product had the appropriate texture to be sent to the market or not (paper III) and an analysis to instrumentally evaluate pastiness defect in sliced dry-cured ham (paper IV) were studied. Results presented in paper III show that ITAS method allowed to non-destructively assess processing end point; this methodology consist of simulating the tactile assessment of ham surface as currently made by the experts. The maximum classification accuracy was 82.1% obtained when combining measurements with subcutaneous fat thickness. The implementation of this technology in industry would not only improve the quality of the product but also economic, energy and space savings, as it would enable better adjustment of required drying time for each ham. Results of the study in paper IV represent a first attempt for the development of a method to evaluate pastiness using a rheometer to avoid the tedious sensory analysis. An increase in viscosity of water extracts with an increase in pastiness intensity, show the ability to instrumentally detect this defect using the rheometer. However, there are factors other than viscosity that can affect/alter the results and this method allows discriminating only samples with high pastiness intensity from those with medium or non-pastiness defect. Corrective actions for dry-cured ham slices using HPP treatments at different temperatures were also analysed (paper V). The obtained results show that while temperatures of 7 ºC and 20 ºC are useful to correct ham slices with medium pastiness, higher temperature (35 ºC) is needed in the case of high pastiness. Therefore, knowing textural properties of the product is key information to define optimal HP processing conditions when aiming to improve texture without deteriorating colour and aroma. The methodologies developed and evaluated in the present work can be used to improve the manufacturing process and quality of dry-cured ham. They represent a first step in development of new tools for industrial use. <br /

Situaciones problema de la vida cotidiana y su representación con funciones de la forma f(t) = (x(t), y(t))

En este proyecto se emplean situaciones problema de la vida cotidiana para que el alumno con el apoyo del video digital, el Tracker y Geogebra, aproximen las funciones que describen el movimiento de una burbuja en una manguera flexible llena de agua, el giro de una rueda de bicicleta sobre su eje y rodando sin resbalar y un tren eléctrico de juguete. Las actividades se realizaron en distintos talleres y tuvieron como propósito relacionar el movimiento de objetos con una función paramétrica de la forma f(t)=(x(t), y(t)) y como un elemento motivador para aprender matemáticas

Changes in aromatic compounds of cabernet sauvignon wines during ageing in stainless steel tanks

The influence of age on the volatile composition of cabernet sauvignon red wines, aged in stainless steel tanks during different years was studied. For this purpose, the evolution of volatile compounds: alcohols, esters, fatty acids, aldehydes and ketones, of the four wines were determined using headspace solid phase microextraction (HS-SPME) and gas chromatography mass spectrometry (GCMS). Quantitatively, alcohols formed the most abundant group in the aromatic components of the four wines studied, followed by esters and acids. The sum of the individual aroma compounds studied increased progressively, and the compounds that changed significantly were alcohols and esters. The profiles of all the aroma compounds for cabernet sauvignon wines were increasingly diverse. The ability to distinguish the aroma of the four wines was probably due to the dominance of alcohols, ethyl esters of fatty acids, and their contributions to the global aroma.Key words: Cabernet sauvignon, stainless steel tanks, aromatic compounds, headspace/solid-phase microextraction, gas chromatography-mass spectrometry (GC/MS)