Partial least squares discriminant analysis: A dimensionality reduction method to classify hyperspectral data

The recent development of more sophisticated spectroscopic methods allows acquisition of high dimensional datasets from which valuable information may be extracted using multivariate statistical analyses, such as dimensionality reduction and automatic classification (supervised and unsupervised). In this work, a supervised classification through a partial least squares discriminant analysis (PLS-DA) is performed on the hy- perspectral data. The obtained results are compared with those obtained by the most commonly used classification approaches

Partial least squares discriminant analysis: A dimensionality reduction method to classify hyperspectral data

The recent development of more sophisticated spectroscopic methods allows acqui- sition of high dimensional datasets from which valuable information may be extracted using multivariate statistical analyses, such as dimensionality reduction and automatic classification (supervised and unsupervised). In this work, a supervised classification through a partial least squares discriminant analysis (PLS-DA) is performed on the hy- perspectral data. The obtained results are compared with those obtained by the most commonly used classification approaches

Application of nuclear magnectic resonance (NRM) to study of grape dehydration cv. bombino

[SPA] Actualmente Italia ha experimentado un importante crecimiento en la producción de vinos dulces o de postre de calidad. Asimismo, se han modificado las técnicas de secado de sistemas tradicionales a sistemas más tecnificados. El incremento de la demanda por una mejor calidad de los productos, ha provocado la investigación y desarrollo de técnicas de medida y evaluación no destructiva. La técnica de deshidratación consiste en un túnel de secado dotado de ventiladores que trabajan en régimen de aspiración donde se controlan las variables de velocidad de aire, temperatura y humedad relativa. Se seleccionaron 100 bayas numeradas y se dispusieron en el interior del túnel a una velocidad de aire de 1,5 m/s, una temperatura de 20ºC y una humedad relativa 45-50%. El tiempo de secado fue de 13 días hasta alcanzar aproximadamente el 30% de peso perdido. Se tomaron diferentes imágenes de resonancia magnética (RMI) a lo largo del proceso de secado, pudiendo visualizar el movimiento del agua durante el proceso de deshidratación, que ocurre desde las capas más superficiales hacia el centro geométrico de la baya. [ENG] Now days, Italy has experimented an important development in the production of quality sweet wines or dessert wines. In this way, it has modified the systems of drying techniques. The increase of the need of a better quality of products, has caused the research and the development of non destructive measurement and evaluation techniques. The dehydration technique consists of drying tunnel with funs working in a regime of aspiration where the air variation, temperature and relative humidity are controlled.100 berries numbered were selected and they were set into the tunnel at an air speed of 1,5 m/s, a temperature of 20ºC and the relative humidity 45-50%. The time of drying was 13 days until reaching 30% of weight loss. It takes different nuclear magnetic imagining during grape drying. We can observe the water movement during the dehydration process which happens from the superficial tissue below the skin towards to the centre by concentric circles.Trabajo de investigación financiado por el Ministerio de Agricultura Italiano (MUVON Project). Al programa Sócrates /Erasmus de la UPCT la ayuda financiera para la estancia de Alejandro Tomás en Italia

Application of near infrared spectroscopy to study of grape dehydration cv. montepulciano

[SPA] Actualmente Italia ha experimentado un importante crecimiento en la producción de vinos dulces o de postre de elevada calidad. Asimismo, se han modificado las técnicas de secado de sistemas tradicionales a sistemas más tecnificados. El incremento de la demanda por una mejor calidad de estos vinos, ha provocado la investigación y desarrollo de técnicas de medida y evaluación no destructiva. La técnica de deshidratación consiste en un túnel de secado dotado de ventiladores que trabajan en régimen de aspiración donde se controlan las variables de velocidad de aire, temperatura y HR. Para el trabajo experimental, se seleccionaron 50 bayas numeradas y se dispusieron en el interior de un túnel de secado a una velocidad de aire de 1,5 m s-1 a una temperatura de 20ºC y HR del 45-50%. El tiempo de secado fue de 13 días hasta alcanzar aproximadamente el 30% de peso perdido. Diariamente se calculó la pérdida de peso y el espectro en el infrarrojo cercano (NIR) de cada baya. Los resultados de la espectroscopía NIR son reflejados como un espectro de absorbancia en la región infrarroja de longitud de onda, donde se pueden identificar los picos correspondientes a la absorbancia del agua (1400-1440 nm y 1900-1950 nm). La aplicación de la espectroscopía NIR al proceso de secado permite la observación de la variación del espectro en el tiempo así como la predicción de los tiempos de secado. [ENG] Nowadays, Italy has experimented an important development in the production of high quality sweet wines. In this way, the berry drying system has been modified to more sophisticated techniques . Consumer demands of better quality products, have induced the research and development of non destructive measurement and evaluation techniques. The dehydration system consists of a drying tunnel with funs working in an aspiration regime where the air variation, temperature and RH are controlled. Fifty numbered berries were selected and disposed into the tunnel at an air speed of 1,5 m s-1, temperature of 20ºC and RH of 45-50%. The drying time was 13 days until weight loss in berries reached 30%. Weight loss and NIR spectrum of each berry were dayly monitored. The spectroscopy results reports an absorbance spectrum in the infrared region, where it is possible to identify water absorbance (1400-1440 nm and 1900-1950 nm). The application of NIR spectroscopy for grape drying allowed the observation of the spectre variation and drying time prediction.Trabajo de investigación financiado por el Ministerio de Agricultura Italiano (MUVON Project). Al programa Sócrates /Erasmus de la UPCT la ayuda financiera para la estancia de Alejandro Tomás en Italia

Bacterial Populations Related to Gerbera (Gerbera jamesonii L.) Stem Break

Bacterial distribution, both external (epiphytic) and internal (endophytic), on Gerbera jamesonii L. cv. Provence and its relationship to gerbera stem break and ethylene production were investigated. The greatest number of epiphytic bacteria was found at capitulum level and 20 cm below. Three genera of bacteria were identified: Acinetobacter, Bacillus and Pantoea. A silver-nitrate solution greatly reduced ethylene production in cut flowers. The use of acid fuchsin solution revealed an occlusion of the xylem vessels, probably due to bacterial cells. The bacteria Acinetobacter, Pantoea and Bacillus appeared to be involved in stem break once their populations reached 105 cfu g-1 of stem tissue

Postharvest dehydration and defoliation

Background and Aims: Sfursat is an Italian wine produced with partially dehydrated Nebbiolo grapes in the Valtellina region which is located at high altitude. The research aims to understand the influence of fruit exposure on the rate of water loss by harvested fruit and the influence of exposure and dehydration on the content of phenolic substances and anthocyanins in the wine. Methods and Results: Clusters of Nebbiolo grapes from control vines (ND) and from vines that were defoliated at fruitset (DFS) or post-veraison (DPV) were harvested at a sugar concentration of about 230 g/L (there was no significant difference among the treatments), and dehydrated at 10, 20 or 30°C and at 60% relative humidity (RH), and air flow. Fruit were sampled at 10 and 20% weight loss (WL). Leaf removal had little effect on the physical characteristics of bunches and on the anthocyanins content and profile of harvested Nebbiolo grapes but affected dehydration. At 10 and 20°C, DFS fruit lost mass more slowly than DPV and ND fruit. In ND fruit, 20% WL reduced anthocyanins from 554 mg/kg fresh mass (FM) at harvest to 458, 432 and 396 mg/kg FM at 10, 20 and 30°C, respectively. In DFS and DPV berries, anthocyanins increased during dehydration at 10°C. At harvest, ND berries had a lower content of total stilbenes than those from defoliated vines. Dehydration (10°C, 20% WL) increased stilbene concentration in ND and DPV fruit. Dehydration at 10°C induced a rise in the flavonol concentration in fruit from defoliated vines. Catechin concentration was 106.5 mg/kg DM (dry mass), the highest value in ND berries at harvest. Wine was produced only from grapes dehydrated at 10°C. Wine from DFS fruit had a higher content of phenolic substances (2704.8 mg/L) and anthocyanins (104 mg/L) than that from DPV (2454.9 and 96.2 mg/L, respectively) and ND (2301.9 and 100.5 mg/L, respectively) fruit. Conclusions: Postharvest dehydration was slower where vines had been defoliated and resulted in changes in the ratios among groups of phenolic substances as well as among single phenolic components. Significance of the Study: In Nebbiolo grapes for Sfurzat wine production, defoliation at fruit set enables fruit to reach phenolic maturity at a lower sugar concentration allowing dehydration to increase sugar concentration without producing excessively alcoholic wines

Effects of treatments with ozonated water in the vineyard (cv Vermentino) on microbial population and fruit quality parameters

Ozone (O3) is currently employed in wineries as a sanitizing agent and is used to control microbial growth and infection. This molecule decomposes spontaneously to oxygen upon application and the use of ozonated water can represent an alternative for the control of pathogens in the vineyard. Entire canopies of Vitis vinifera (cv Vermentino) plants have been sprayed throughout the vegetative growth with water saturated with O3 to assess the effects of these treatments in reducing the microorganism population, and to evaluate if and how the oxidative stress, induced in the plant by this strong oxidizing agent, affects fruit development, the activity of the cellular antioxidant system, and the production of aromas by the grape berries at ripening. Ozonated water treatments resulted in a partial control of microorganism population, especially considering fungi. Furthermore, the treatments induced a slight delay in the technological maturity of grapes, a significant increase in antioxidant capacity and changes of aroma profile of the grapes at harvest, with an accumulation of monoterpenes. In general, ozonized water treatments showed promising results and seem to be a feasible protocol to be applied in the vineyard in order to reduce the use of chemicals

Distinct transcriptome responses to water limitation in isohydric and anisohydric grapevine cultivars

Background: Grapevine (Vitis vinifera L.) is an economically important crop with a wide geographical distribution, reflecting its ability to grow successfully in a range of climates. However, many vineyards are located in regions with seasonal drought, and these are often predicted to be global climate change hotspots. Climate change affects the entire physiology of grapevine, with strong effects on yield, wine quality and typicity, making it difficult to produce berries of optimal enological quality and consistent stability over the forthcoming decades. Results: Here we investigated the reactions of two grapevine cultivars to water stress, the isohydric variety Montepulciano and the anisohydric variety Sangiovese, by examining physiological and molecular perturbations in the leaf and berry. A multidisciplinary approach was used to characterize the distinct stomatal behavior of the two cultivars and its impact on leaf and berry gene expression. Positive associations were found among the photosynthetic, physiological and transcriptional modifications, and candidate genes encoding master regulators of the water stress response were identified using an integrated approach based on the analysis of topological co-expression network properties. In particular, the genome-wide transcriptional study indicated that the isohydric behavior relies upon the following responses: i) faster transcriptome response after stress imposition; ii) faster abscisic acid-related gene modulation; iii) more rapid expression of heat shock protein (HSP) genes and iv) reversion of gene-expression profile at rewatering. Conversely, that reactive oxygen species (ROS)-scavenging enzymes, molecular chaperones and abiotic stress-related genes were induced earlier and more strongly in the anisohydric cultivar. Conclusions: Overall, the present work found original evidence of a molecular basis for the proposed classification between isohydric and anisohydric grapevine genotypes