315 research outputs found
Regiões agrícolas, mercado de trabalho e migrações: novas áreas produtivas de frutas, casos do Brasil e da Argentina.
El objetivo del artículo es analizar cómo el proceso de valorización de espacios para a agricultura intensiva produce impactos en la estructura agraria, en el mercado de trabajo y en los centros urbanos regionales como consecuencia de la movilización territorial de trabajadores, y cómo este proceso influye en la organización do trabajo agrícola en regiones productoras de frutas frescas en Argentina y en Brasil, atendiendo a mercados segmentados y exigentes según estrategias específicas. La cuestión que se enfatiza es: Cuáles son las diferencias y las semejanzas que se constituyen en regiones distantes, pero sujetas a los mismos imperativos del mercado de productos frescos, haciendo hincapié en los procesos migratorio
PRELIMINARY CHEMICAL CHARACTERIZATION OF TUNISIN MONOVARIETAL VIRGIN OLIVE OILS AND COMPARISON WITH SICILIAN ONES.
Work was carried out on the characterization of monovarietal virgin olive oils (VOO)
from Tunisia and Sicily (Italy). The two main Tunisian VOO (cvv. Ch\ue9toui of the North and
cv. Chemlali grown in the Center and some regions of the South) and three principal
Sicilian VOO (cvv. Nocellara del Belice, Biancolilla and Cerasuola) were studied.
Moreover, the Ch\ue9toui oils were tested in a rain-fed control and an irrigation regime. All
olive samples were picked at three different stages of ripeness. Analyses of major
components (fatty acids and triacylglycerols) and minor ones (squalene, tocopherols
and phenolic compounds) were carried out. Ch\ue9toui oils had a higher level of phenolic
compounds followed by Chemlali. Generally, in the Sicilian oils these natural antioxidant
contents were lower. These preliminary results indicate that it was possible to
classify the Tunisian and Sicilian oils tested in their original growing area based on their
chemical composition
Investigación preliminar sobre los posibles efectos del tratamiento con arcilla mineral aplicado a aceites producidos a partir de aceitunas: enfoque sobre la eliminación de humedad y cambios en la composición
In this preliminary study, two non-filtered virgin olive oils (one freshly produced VOO-N; one VOO-O stored for one year) were subjected to moisture removal with mineral clay (raw or activated) and analyses were performed to attest possible effects on the quality of the product. The results demonstrated that the treatment of oil with mineral clay at 36-38 °C had no negative effect on the basic quality parameters or on the volatile comound profile. On the other hand, a significant decrease in the water amount as well as in pigments was observed in the samples subjected to this kind of treatment, in particular with raw clay. Regarding the colour measurement, the lightness (L) as well as the consumers’ acceptability exhibited a marked increase when oils were treated with raw clay.En este estudio preliminar, dos aceites de oliva vírgenes no filtrados (uno VOO-N recién producido y el otro, VOO-O almacenado durante un año) fueron sometidos a la eliminación del contenido de humedad con arcilla mineral (cruda o activada) y se realizaron análisis para atestiguar posibles efectos sobre la calidad del producto. Los resultados demostraron que el tratamiento del aceite con arcilla mineral, realizado a 36-38 °C, no tuvo consecuencias negativas en los parámetros básicos de calidad y en el perfil de los compuestos volátiles. Por otro lado, se observó una disminución significativa en la cantidad de agua y en los pigmentos en las muestras sometidas a este tipo de tratamiento, en particular con arcilla cruda. Con respecto a la medida del color, luminosidad (L) y aceptabilidad de los consumidores mostraron un aumento notable cuando los aceites se trataron con arcilla cruda
Preliminary investigation of possible effects of mineral clay treatment applied to oils produced from olives: Focus on moisture removal and compositional changes
In this preliminary study, two non-filtered virgin olive oils (one freshly produced VOO-N; one VOO-O stored for one year) were subjected to moisture removal with mineral clay (raw or activated) and analyses were performed to attest possible effects on the quality of the product. The results demonstrated that the treatment of oil with mineral clay at 36-38 °C had no negative effect on the basic quality parameters or on the volatile comound profile. On the other hand, a significant decrease in the water amount as well as in pigments was observed in the samples subjected to this kind of treatment, in particular with raw clay. Regarding the colour measurement, the lightness (L) as well as the consumers' acceptability exhibited a marked increase when oils were treated with raw clay
Characterization of virgin olive oils obtained from minor Tunisian varieties for their valorization
Several compositional parameters (fatty acids, tocopherols, polar phenols and volatiles) in virgin olive oils from varieties located at the center of Tunisia, namely Baldi, Chemchali, Neb Jmel, Tounsi and Besbessi from Gafsa and Chemchali and Sehli cultivated in Sidi Bouzid, were studied. To the best of our knowledge, this is the first study focusing on the chemical composition of virgin olive oils (VOO) from Sidi Bouzid. Significant differences were found between varieties from Sidi Bouzid and Gafsa in monounsaturated saturated fatty acid levels, some volatile compounds and γ-tocopherol amounts. Notably, Tounsi and Baldi VOOs showed the highest six carbon atoms alcohol contents, whereas Neb Jmel VOO revealed the highest aldehyde six carbon atoms content. Fatty acid composition, as well as tocopherol content, showed differences among different VOO. Principal component analysis and hierarchical component analysis on polar phenols, fatty acids, tocopherols and volatiles data evidenced a good discrimination among oils from the different investigated varieties
Design and in-house validation of a portable system for the determination of free acidity in virgin olive oil
Nutritional and healthy values are well known properties of virgin olive oil (VOO). The product quality, in terms of belonging to a specific quality grade (extra virgin, virgin, lampante), is defined by a set of chemical-physical and sensory measurements. According to the official regulation of the European Union (EU Reg. 1348/2013)the free acidity is the first parameter that has to be determined by analysts; it gives information about the quality of the olives used to produce the VOO as well as the hydrolytic state of VOO just produced and stored. The official procedure is based on an acid-base titration that needs to be carried out in a chemical laboratory. In this paper a portable battery-operated electronic system to measure olive oil free acidity is presented: the system can be used for quick \u201cin situ\u201d tests in a production environment (olive oil mills or packaging centers)by people without particular training. The working principle of the system is based on the creation of an emulsion between oil and a hydroalcoholic solution: the free acidity is estimated on the value of the emulsion electrical conductance. The proposed system has been calibrated and in-house validated showing good results in terms of limit of detection and quantification, precision and accuracy. Moreover, a good correlation (R 2adj = 0.97)with free acidity data obtained applying the official method on 30 olive oil samples belonging to different commercial categories (extra virgin, virgin and lampante olive oil)has been evidenced
Simulating International Shipments of Vegetable Oils: Focus on Quality Changes
This investigation evaluated the quality changes of commercial vegetable oils after
different simulated shipments. In particular, the oils were placed in containers with or
without thermal insulation and subjected to two simulated shipments, from Italy to Los
Angeles and to Quebec. The temperature profiles were monitored to simulate the real
shipments conditions in laboratory through properly developed climate chambers.
Different quality parameters were evaluated before and after the simulations, showing a
high degree of oxidation for samples shipped to Los Angeles in standard containers. In
this study, the thermal insulation container was effective in protecting samples from
potential oxidative damage during simulated shipping.The authors would like to thank Enhancement of the Palestinian University System (E- PLUS) for PhD scholarship grants
financed by the Italian Ministry of Foreign Affairs-Directorate General for Cooperation and Development (coordinated
by the University of Pavia)
Incidence and predictors of heart failure hospitalization and death in permanent pacemaker patients: a single-centre experience over medium-term follow-up
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Segmentation of optical remote sensing images for detecting homogeneous regions in space and time.
With the amount of multitemporal and multiresolution images growing exponentially, the number of image segmentation applications is recently increasing and, simultaneously, new challenges arise. Hence, there is a need to explore new segmentation concepts and techniques that make use of the temporal dimension. This paper describes a spatio-temporal segmentation that adapts the traditional region growing technique to detect homogeneous regions in space and time in optical remote sensing images. Tests were conducted by considering the Dynamic Time Warping measure as the homogeneity criterion. Study cases on high temporal resolution for sequences of MODIS and Landsat-8 OLI vegetation indices products provided satisfactory outputs and demonstrated the potential of the spatio-temporal segmentation method.Também publicado na Revista Brasileira de Cartografia, v. 70, n. 5, p. 1779-1801, 2018. Special Issue XIX Brazilian Syposium on GeoInformatics, 2018. DOI: 10.14393/rbcv70n5-45227
Modelo para análise de risco de ocorrência da sigatoka negra em bananais do Vale do Ribeira-SP, baseado no uso de classificação de dados organizados em distribuições polinomiais.
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