1,721,113 research outputs found
Tecnologie di estrazione, conservazione, packaging e loro riflessi sulla qualità dell'olio vergine di oliva
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I fattori di variabilità genetici, ambientali e colturali della composizione dell'olio d'oliva
Full text linkThe compositon of olive oil results from a multivariate interaction in which genotype, environment, and agronomic-dependent factors are involved. The genotype controls genetic traits accounting for the rate pattern of fruit growth, oil accumulation in mesocarp cells and fruit ripening, while the genotype x environment interaction changes the rate of fruit growth, oil accumulation and fruit ripening pattern. The latter accounts for large changes in oil composition and sensorial features. The influence of genotype is linked to differences in the fruit growth and ripening patterns, though all those factors that may have an influence on fruit size, flesh/pit ratio and relative growth rate have a lower and more erratic influence on the olive oil composition. The genotype is the principal source of sensorial differences and this has been proved for most of the cultivars, giving them a specific role in gastronomy. The influence on olive oil composition of environmental factors, such as temperatures during fruit growth and ripening or water availability, may also be a function of changes in the fruit growth and ripening patterns and of the oil accumulation rate pattern. Some facts have been generally recognized, such as the changes of saturated vs insaturated fatty acids ratio in relation to temperature and latitude or the progressive reduction of polyphenols content in the oil along with fruit ripening or with the increase of water availability. Crop load influences the fruit ripening rate pattern and the rate pattern of oil accumulation and this may account for differences in oil composition, related to polyphenols and fatty acid content. This review covers different sources of variability of olive oil composition and overall quality, such as genotype, environment, bearing capacity, stage of fruit ripening during harvest and cultural management (irrigation, fertilization, harvest). None of these aspects can be underestimated in order to reduce the site- and year-dependent fluctuactions of olive oil quality of specific genotype
Strategie d'impresa e qualità nel comparto degli oli extra - vergini di oliva molisani
No full textRecent approaches about food quality have stressed the social processes by which “quality conventions” prevailing on the market are achieved. The present work investigates
these conventions on the supply side, focusing on the “styles” characterizing the management of a group of firms.
More specifically, the research analyzes a group of oil-press plants localized in Molise, an Italian region the name of which is also the “brand-name” of a PDO recently registered
by EU. In the first part the essay outlines the scenario of both olive oil market and local context. In the second section the paper shows the results of a direct survey.
Applying factorial analysis to the data collected in the survey, four main “quality factors” were identified: safety and health; localization and scale; product differentiation; technological heritage. On the basis of these factors it was
possible to point out three main styles characterizing the sample firms: the “endogenous”, the local, and the “fordistic”
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Investigation on the Effects of a Pulsed Electric Field (PEF) Continuous System Implemented in an Industrial Olive Oil Plant
Full text linkThe aim of this study was to investigate how the treatment of olive paste of the Picholine variety with pulsed electric fields (PEF) under real operating conditions in a large-scale olive oil extraction plant affects the extractability, chemical composition and sensory profile of the oils. The application of pulsed electric fields (PEF) as a non-thermal food processing technology is interesting for many food extraction processes. The results of this study show that pulsed electric fields can be used as a pretreatment before oil separation to increase the extractability of the process and improve the content of functional components. The application of pulsed electric field (PEF) treatment (2.4 kV/cm, 4 kJ/kg, 6 μs pulse width) to olive paste through a continuous system significantly increased the extractability and total concentration of phenols (especially oleuropein derivatives) compared to the control. In addition, the volatile compounds, α-tocopherol, the fatty acid profile and the main legal quality parameters of extra virgin olive oil (EVOO), including free acidity, peroxide values, extinction indices and sensory analysis, were evaluated. The pulsed electric fields (PEF) treatment did not modify these EVOO quality parameters, neither the α-tocopherol content nor the volatile profile. The sensory properties of EVOO were not affected as well as the PEF treatment showed a similar intensity of fruity and pungent attributes without any off-flavor according to the European Union legal standards. An increase in the bitter taste attribute was observed in the PEF oils. Consequently, this study demonstrates that pulsed electric fields (PEF) processing could be implemented in olive oil processing as pretreatment for improving the efficiency of the process
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Oil quality of olive cv. Leccino grown under irrigated or dry-farmed conditions
No full textOlive trees (cv. `Leccino') were grown in Tuscany (Italy) to assess the effect of irrigation on oil yield and quality. Fruits were harvested at the stage of full pigmentation of the epicarp only (black skin) or at green-black skin color. Free acidity, peroxide number, K(232), K(270) and fatty acid composition were measured using official methods of analysis and volatile compounds by SPME-GS-MS; phenolic compounds were assayed colorimetrically. Irrigation did not affect free acidity, peroxide number and fatty acid composition of oils. The oleic acid ranged from 74.3 to 77.5% of total fatty acids in oils from dry-farmed and irrigated trees, respectively. Irrigation decreased total phenols and ortho-diphenols of oils from black ripe fruits (but not of those from green-black fruits) and increased several volatile compounds related to oil flavours. Irrigation decreased pungency and bitterness and increased flavours, such as fruity-apple or hay-like, of oils from black fruits
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