1,721,157 research outputs found
Semi-industrial ultrasound-assisted virgin olive oil extraction: impact on quality
No full textThis is the first effort to implement a continuous VOO ultrasound-assisted extraction system on a semi-industrial scale, studying its impact on product quality. Four sets of control/treated monovarietal VOOs were produced from Carolea and Ottobratica cultivars, at two maturation stages, in a low-scale mill plant (W-cap = 150 kg/h). Thirty minutes of traditional malaxation were set for control trials, whereas UAE tests underwent 15min of traditional malaxation and 15 min of sonication, performed in a continuous ultrasonic reactor placed between the malaxer and decanter. Basic VOO quality parameters, antioxidant content, and volatile profiles were studied. In the tested conditions, UAE treatment did not affect free acidity or peroxide values. A consistent and significant increase in the content of minor compounds, namely phenols (lignans, secoiridoids) and C-6 and C-5 volatile compounds, was generally observed when UAE was applied. However, UAE may have been responsible for a reduction in tocopherol content. UAE generally lead to higher extraction yields and higher intensities of positive sensory notes of fruity, bitter, and pungent. The results of semi-industrial trials support the application of UAE for VOO production, rendering its industrial implementation tangible. Practical applications: UAE allows enrichment of VOO in minor compounds with nutritional and sensory relevance, therefore, improving the quality and the commercial value of the VOO. It also appears to increase the extraction yield, thus, overcoming the need for employing extreme kneading conditions. Therefore, VOO-UAE seems to be a promising process that could represent a genuine innovation for the milling industry. The UAE-enrichment of VOOs in antioxidant content - in particular secoiridoids, which play a key role in VOO's health properties - assumes special relevance with the possibility to stake the labeled health claim, as in EU Reg. No. 432/2012. This is positive both for the consumer, who stands to gain added nutritional benefits, and for the oil miller, who could market a product with added value. Furthermore, the application of US to VOO production, as a non-thermal and continuous production method, provides an answer to the current trend toward healthy and nutritionally enriched products.info:eu-repo/semantics/publishedVersio
Effetto della filtrazione e della chiarificazione con gas inerti sulla qualità di oli vergini di oliva
No full textGoing 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
Changes in the composition of a cold-pressed hemp seed oil during three months of storage
No full textSeveral analytical parameters were evaluated to investigate changes in the composition of a cold-pressed hemp seed oil over a period of 3 months of storage. The environmental conditions applied for the conservation were 12 h of light and 12 of darkness at room temperature, to mime a grocery or supermarket shelf, and the oil was stored in amber glass bottles. The peroxide value was quite low on freshly produced oil (2.66 ± 0.29 mEqO2/kg of oil) and decreased after 3 months (1.35 ± 0.08 mEqO2/kg of oil), as confirmed by free radical concentration, while no other statistically significant (one-way ANOVA, Tukey’s HSD test, p < 0.05) differences were observed (e.g. conjugated diene and triene systems, Oxidative Stability Index and free acidity). The fatty acid, cannabinoids and tocopherols composition did not statistically change; expect for δ-tocopherol, for which a decrease was observed. The overall results did not show a strong effect of photooxidation on the oil, despite its high degree of unsaturation
Macro and micro functional components of a spreadable olive by-product (pâté) generated by new concept of two-phase decanter
No full textIn this research, the potential use of a spreadable olive by-product, so called “pâté,” generated during a modern two-phase centrifugal processing technique as a natural source of bioactive compounds has been evaluated using advanced separation techniques. For this purpose, the qualitative and quantitative characterization of the lipophilic and hydrophilic fractions were performed to establish the fatty acid composition and phenolic profile of the new spreadable olive by-product. A typical olive oil fatty acid profile and very high oxidative stability was found for lipid fraction, whereas hydrophilic fraction was characterized by the presence of hydroxytyrosol, ß-hydroxyverbascoside, oleoside derivative, luteolin, among other. This kind of compounds are well-known for their beneficial effects in the human health. These results suggest that the spreadable olive by-product could be used as functional ingredients, in the production of nutraceuticals or for feed industry. Practical applications: Application of analytical chemistry aimed at utilizing a new olive-oil by-product, either through conversion into an affordable source of bioactive compounds and in promoting their overall sustainable management. The obtained results indicate that this by-product is a potential source of bioactive compounds with applications in the pre-formulation of functional ingredient for human and animal feeding. The modern two-phase centrifuge generates a new spreadable olive by-product which consists of lipophilic and hydrophilic fractions. The analysis of lipophilic compounds showed a typical olive oil fatty acid profile and very high oxidative stability. Hydrophilic fraction was characterized by the presence of hydroxytyrosol, ß-hydroxyverbascoside, oleoside derivative, luteolin, among other. This kind of compounds are well-known for their beneficial effects in the human health. These results suggest that the spreadable olive by-product could be used as functional ingredients, in the production of nutraceuticals or for feed industry
COMPLIANCE WITH EU VS. EXTRA-EU LABELLED GEOGRAPHICAL PROVENANCE IN VIRGIN OLIVE OILS: A RAPID UNTARGETED CHROMATOGRAPHIC APPROACH BASED ON VOLATILE COMPOUNDS [VERIFICA DELLA CONFORMITÀ DELL’INDICAZIONE DI ORIGINE EUROPEA ED EXTRA-EUROPEA NEGLI OLI VERGINI DI OLIVA: UN APPROCCIO RAPIDO CROMATOGRAFICO DI TIPO UNTARGETED BASATO SUI COMPOSTI VOLATILI]
No full textComparison of three different methodologies for the quantification of hydroxytyrosol and tyrosol in olive oils, in relation to the health claim
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