2,882 research outputs found
Efectos de la maduración y el procesamiento sobre la calidad nutricional y sensorial de las aceitunas de mesa Itrana
In the present study, we evaluated the nutritional and sensory characteristics of table olives of the Italian doubleaptitude olive cultivar (Olea europaea L. cv. Itrana) processed as green (Oliva bianca di Itri) and black (Oliva di Gaeta) table olives with modified Greek methods of preparation. One method provides an initial step of immersion in water to stimulate the growth of specific microflora which contributes to the debittering of the fruits. After 15-45 days, salt is added to the liquid in quantities not exceeding 8 kg per 100 kg of fresh olives. Another method entails the immersion of fruits directly in brine utilizing double-salting (half the amount of NaCl was added immediately and the remaining part after 15 days). All the information derived from chemico-physical, nutritional and sensory data have separated the samples into four groups according to techno-processings, ripening stage and storage. Double-salting is the method which assures the best results.En el presente estudio se evalúan las características nutricionales y sensoriales de la variedad Itrana de aceituna (Olea europaea L.) de doble uso, elaborada en verde (Oliva Bianca di Itri) y en negro (Oliva di Gaeta), utilizando métodos griegos modificados al efecto. Un método consiste en una etapa inicial de inmersión en agua para favorecer el crecimiento de una flora específica que contribuye al endulzado de los frutos. Después de 15-45 días se añade sal a la solución en una cantidad que no exceda 8 kg por 100 g de fruto fresco. Otro procedimiento consiste en colocar directamente las aceitunas en salmuera utilizando un sistema de adición de la sal en dos etapas (la mitad de la sal se añade inmediatamente y el resto a los 15 días). Toda la información derivada de los análisis fisico-químicos, nutricionales y sensoriales ha permitido la separación de las muestras en cuatro grupos según la tecnología de elaboración, el estado de madurez y el almacenamiento. El proceso de adición de sal en dos etapas (“double salting”) fue el procedimiento que dio mejores resultados
Zirconocene-based catalysts for the ethylene-styrene copolymerization: reactivity ratios and reaction mechanism
A kinetic study of the ethylene-styrene copolymerization in the presence of rac-(ethylenebis- (1-indenyl)zirconium dichloride activated by MAO shows the peculiar behavior of this catalytic system that is known to produce crystalline nearly alternating copolymers. Some inferences on the monomer- metal interactions are made on the basis of this study. The parallel investigation on the catalyst based on isopropylidene(1-cyclopentadienyl)(9-fluorenyl)zirconium dichloride allows us to produce a stereoregular nearlyalternatingethylene-styrenecopolymeralsowiththiscatalyticsystem. Thesamemaintacticity seems to characterize the copolymers obtained with the C2 and Cs symmetric catalysts in accordance with the generally accepted mechanism of stereocontrol in the 1-alkene polymerizations
Identification and characterization of citrus concave gum-associated virus infecting citrus and apple trees by serological, molecular and high-throughput sequencing approaches
Citrus concave gum-associated virus (CCGaV) is a negative-stranded RNA virus, first reported a few years ago in citrus trees from Italy. It has been reported in apple trees in the USA and in Brazil, suggesting a wider host range and geographic distribution. Here, an anti-CCGaV polyclonal antiserum to specifically detect the virus has been developed and used in a standard double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) that has been validated as a sensitive and reliable method to detect this virus both in citrus and apple trees. In contrast, when the same antiserum was used in direct tissue-blot immunoassay, CCGaV was efficiently detected in citrus but not in apple. Using this antiserum, the first apple trees infected by CCGaV were identified in Italy and the presence of CCGaV in several apple cultivars in southern Italy was confirmed by field surveys. High-throughput sequencing (HTS) allowed for the assembling of the complete genome of one CCGaV Italian apple isolate (CE-c3). Phylogenetic analysis of Italian CCGaV isolates from apple and citrus and those available in the database showed close relationships between the isolates from the same genus (Citrus or Malus), regardless their geographical origin. This finding was further confirmed by the identification of amino acid signatures specific of isolates infecting citrus or apple hosts. Analysis of HTS reads also revealed that the CE-c3 Italian apple tree, besides CCGaV, was simultaneously infected by several viruses and one viroid, including apple rubbery wood virus 2 which is reported for the first time in Italy. The complete or almost complete genomic sequences of the coinfecting agents were determined
Identification, full-length genome sequencing, and field survey of citrus vein enation virus in Italy
Citrus vein enation virus (CVEV) was described in Spain and then it has been reported in several citrus growing areas of Asia, America and Australia. Here, the occurrence of CVEV in Italy has been documented for the first time. The full genome sequence of a CVEV Italian isolate (14Q) was determined by high-throughput sequencing and the presence of the virus was confirmed by RT-PCR and graft-transmission to indicator plants, from which the virus was recovered six-months post-inoculation. Phylogenetic analysis based on the full-length genome of CVEV isolates from different countries showed that they are phylogenetically related to each other based on their geographic origin, rather than on their host and that the Italian isolate is more closely related to the Spanish isolate than to the other ones. A field survey revealed the presence of CVEV in some areas of Campania region (southern Italy), prevalently infecting lemon trees. In the frame of this survey, kumquat was identified for the first time as a host of CVEV. No symptoms were observed in the field so far. The infection of asymptomatic hosts and the transmission by aphid species present in Italy increase the risk that the virus could further spread
Flow discharge measurement by a linear width contraction device
In this paper, the outflow process of a linear width contraction device for a free-flow condition is modeled using the dimensional analysis and the incomplete self-similarity condition. The proposed theoretical stage-discharge relationship is tested using measurements available in the literature. The proposed power stage-discharge equation is characterized by a value of the exponent close to 2 and a coefficient depending on the angle of the device sides with the channel bank. The proposed flume is characterized by simple construction, easy installation, low cost, and a good accuracy of the measured discharge (errors in the estimate ranging from - 3.84 to 1.9%). The deduced stage-discharge equation is characterized by errors in the estimate of discharge lower than or equal to & PLUSMN; 3% for 93.7% of the investigated cases. The main result of this paper is a stage-discharge relationship giving an accurate estimate of discharge but, at the same time, having the advantage of working regardless of the discharge coefficient estimate
Assessing a transitional and turbulent overland flow resistance law for surfaces with different roughness
The control and management of soil erosion phenomena caused by rainfall and runoff is a significant issue in sloping landscapes, especially if they are scarcely or not vegetated. The study of the relationship between soil roughness and flow resistance is a fundamental step in improving the knowledge of erosion processes. In this study, the suitability of a theoretically deduced flow resistance law, based on a power-velocity profile, was assessed by transitional and turbulent overland flow data obtained in laboratory and available in the literature. These measurements were obtained in a sloping (slope in the range 1-40 %) rectangular flume, testing the effects of six different roughness conditions. At first, for each investigated roughness condition, the available measurements were used to calibrate and test the equation relating the Gamma function of the velocity distribution, the flow Froude number, and the channel slope. For all the investigated conditions, this analysis allowed for demonstrating that the flow resistance law gives a reliable estimate of the Darcy-Weisbach friction factor, with errors <=+/- 5 % for 89.8-100 % of the examined cases with reference to the considered roughness condition. Then, using coefficients b (1.05) and c (0.562) of the Gamma function available in the literature, the roughness effect was exclusively attributed to the a coefficient. In this case, the friction factor values calculated by the flow resistance law, with b = 1.05 and c = 0.562 and the a values corresponding to the different roughness conditions, are characterized by errors <=+/- 5% for 70.4-100 % of the cases. Finally, the power relationships between the calibrated a, b, and c coefficients of the Gamma function, and Manning's n values, corresponding to the roughness of the investigated surfaces, pointed out that the a coefficient is the most affected by the roughness conditions, as the exponent of Manning's assumes the highest value. The significance of this research is due to the fact that a relevant issue in modeling overland flow is to define the resistance coefficient for variable roughness, especially the vegetated ones
Ésteres alquílicos de ácidos grasos en aceitunas de mesa en relación con fermentaciones anormales y tratamientos tecnológicos mal realizados
There are several methods to prepare table olives, and each of the steps and conditions during this processing can affect the composition and nutritional value of the product. The influence of abnormal fermentation and poorly conducted technological treatments was examined here in terms of the lipid fraction of table olives. In ‘Greek style’ olives, a low concentration of brine can allow the growth of spontaneous microflora and consequent organoleptic defects (‘putrid/butyric fermentation’, ‘winey-vinegary’). Here, the ‘Kalamata’ and ‘Moresca’ cultivars can produce methyl esters (methyl oleate/ linoleate: 553 and 450 mg·kg-1 oil, respectively) and ethyl esters (ethyl oleate/ inoleate: 4764 and 4195; palmitate: 617 and 886 mg·kg-1 oil, respectively). In ‘Sevillan style’ olives, a high NaOH concentration influences the fatty-acid composition less, but is difficult to eliminate, for a ‘soapy’ defect. The ‘Giarraffa’ and ‘Nocellara del Belice’ cultivars produce only ethyl esters (ethyl oleate/ linoleate: 222 and 289 mg·kg-1 oil, respectively). With this production of ethyl and methyl esters from the principal fatty acids in the lipid fractions of table olives, methods that provide only biological treatments (i.e., Greek style) pose more risk than methods that provide only chemical treatments (i.e., Sevillan style).H�a�y� �v�a�r�i�o�s� �m�ét�o�d�o�s� �p�a�r�a� �p�r�e�p�a�r�a�r� �l�a�s� �a�c�e�i�t�u�n�a�s� �d�e� �m�e�s�a�,� �y� �c�a�d�a� �u�n�o� �d�e� �l�o�s� �p�a�s�o�s� �y� �c�o�n�d�i�c�i�o�n�e�s� �d�u�r�a�n�t�e� �e�s�t�e� �p�r�o�c�e�s�a�m�i�e�n�t�o� �p�u�e�d�e�n� �a�f�e�c�t�a�r� �a� �l�a� �c�o�m�p�o�s�i�c�i�ón� �y� �a�l� �v�a�l�o�r� �n�u�t�r�i�c�i�o�n�a�l� �d�e�l� �p�r�o�d�u�c�t�o�.� �L�a� �i�n�f�l�u�e�n�c�i�a� �d�e� �l�a� �f�e�r�m�e�n�t�a�c�i�ón� �a�n�o�r�m�a�l� �y� �t�r�a�t�a�m�i�e�n�t�o�s� �t�e�c�n�o�l�ó�g�i�c�o�s� �m�a�l� �r�e�a�l�i�z�a�d�a�s� �s�e� �e�x�a�m�i�nó� �a�q�u�í� �e�n� �t�é�r�m�i�n�o�s� �d�e� �l�a� �f�r�a�c�c�i�ó�n� �l�i�p�í�d�i�c�a� �d�e� �a�c�e�i�t�u�n�a�s� �d�e� �m�e�s�a�.� �E�n� �l�a�s� �a�c�e�i�t�u�n�a�s� �p�r�o�c�e�s�a�d�a�s� �m�e�d�i�a�n�t�e� �e�s�t�i�l�o� �g�r�i�e�g�o�,� �l�a� �b�a�j�a� �c�o�n�c�e�n�t�r�a�c�i�.�n� �d�e� �s�a�l�m�u�e�r�a� �p�e�r�m�i�t�e� �e�l� �c�r�e�c�i�m�i�e�n�t�o� �e�s�p�o�n�tá�n�e�o� �d�e� �m�i�c�r�o�f�l�o�r�a� �y� �l�a� �c�o�n�s�i�g�u�i�e�n�t�e� �a�p�a�r�i�c�i�ó�n� �d�e� �d�e�f�e�c�t�o�s� �o�r�g�a�n�o�l�é�p�t�i�c�o�s� �(‘�f�e�r�m�e�n�t�a�c�i�ó�n� �b�u�t�í�r�i�c�a� �y� �a�v�i�n�a�g�r�a�d�o’ )�.� �L�o�s� �c�u�l�t�i�v�a�r�e�s� �d�e� �‘K�a�l�a�m�a�t�a’� �y� ‘M�o�r�e�s�c�a’� �p�u�e�d�e�n� �p�r�o�d�u�c�i�r� �é�s�t�e�r�e�s� �m�e�t�í�l�i�c�o�s� �(�o�l�e�a�t�o� �y� �l�i�n�o�l�e�a�t�o�:� �5�5�3� �y� �4�5�0� �m�g·�k�g�-1� �d�e� �a�c�e�i�t�e�,� �r�e�s�p�e�c�t�i�v�a�me�n�t�e�)� �y� �é�s�t�e�r�e�s� �e�t�í�l�i�c�o�s� �(�o�l�e�a�t�o� �y� �l�i�n�o�l�e�a�t�o�:� �4�7�6�4� �y� �4�1�9�5�;� �p�a�l�m�i�t�a�t�o�:� �6�1�7� �y� �8�8�6� �m�g·k�g�-1�,� �r�e�s�p�e�c�t�i�v�a�m�e�n�t�e�)�.� �E�n� �l�a�s� �a�c�e�i�t�u�n�a�s� �p�r�o�c�e�s�a�d�a�s� �m�e�d�i�a�n�t�e� �e�s�t�i�l�o� �s�e�v�i�l�l�a�n�o�,� �l�a� �a�l�t�a� �c�o�n�c�e�n�t�r�a�c�ió�n� �d�e� �N�a�O�H� �i�n�f�l�u�y�e� �m�e�n�o�s� �e�n� �l�a� �c�o�m�p�o�s�i�c�ión� �d�e� �ác�i�d�o�s� �g�r�a�s�o�s�,� �p�e�r�o� �e�s� �d�i�fíc�i�l� �d�e� �e�l�i�m�i�n�a�r� �e�l� �d�e�f�e�c�t�o� �j�a�b�ón�.� �L�o�s� �c�u�l�t�i�v�a�r�e�s� �d�e� �‘G�i�a�r�r�a�f�f�a’� y� �‘N�o�c�e�l�l�a�r�a� �d�e�l� �B�e�l�i�c�e’ �p�r�o�d�u�c�e�n� �s�o�l�a�m�e�n�t�e� é�s�t�e�r�e�s� �e�t�éíl�i�c�o�s� �(�o�l�e�a�t�o� �y� �l�i�n�o�l�e�a�t�o�:� �2�2�2� �y� �2�8�9� �m�g�·�k�g-1� �d�e� �a�c�e�i�t�e�,� �r�e�s�p�e�c�t�i�v�a�m�e�n�t�e�)�.� �C�o�n� �e�s�t�a� �p�r�o�d�u�c�c�ión� �d�e� �é�s�t�e�r�e�s� �e�t�í�l�i�c�o�s� �y� �m�e�t�í�l�i�c�o�s� �d�e� �l�o�s� �á�c�i�d�o�s� �g�r�a�s�o�s� �p�r�i�n�c�i�p�a�l�e�s� �e�n� �l�a�s� �f�r�a�c�c�i�o�n�e�s� �l�i�pí�d�i�c�a�s� �d�e� �l�a�s� �a�c�e�i�t�u�n�a�s� �d�e� �m�e�s�a�,� �l�o�s� �mét�o�d�o�s� �q�u�e� �p�r�o�p�o�r�c�i�o�n�a�n� �t�r�a�t�a�m�i�e�n�t�o�s� �u�n�i�c�a�m�e�n�t�e� �b�i�o�ló�g�i�c�o�s� �(�e�s� �d�e�c�i�r�,� �d�e� �e�s�t�i�l�o� �g�r�i�e�g�o�)� �p�l�a�n�t�e�a�n� �má�s� �r�i�e�s�g�o�s� �q�u�e� �l�o�s� �m�ét�o�d�o�s� �q�u�e� �p�r�o�p�o�r�c�i�o�n�a�n� �t�r�a�t�a�m�i�e�n�t�o�s� �q�uí�m�i�c�o�s� �(�e�s� �d�e�c�i�r�,� �d�e� �e�s�t�i�l�o� �s�e�v�i�l�l�a�n�o�)�
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