1,720,974 research outputs found
ESTRAZIONE DI ANTOCIANINE MEDIANTE CO2 SUPERCRITICA DA SUBSTRATI VEGETALI. PON 2001
No full textObiettivo del progetto di ricerca industriale è la messa a punto di un sistema di estrazione di antocianine (estratti totali) da substrati vegetali (carote, uva rossa, more, mirtilli, basilico rosso, ciliegie, cereali scuri, etc..) mediante un impianto d’estrazione che fa uso di tecnologie innovative, CO2 supercritica, a basso impatto ambientale.
Il progetto si propone:
a) la selezione di substrati vegetali ad alto contenuto di antocianine;
b) la caratterizzazione chimico-fisica delle matrici di interesse individuate al punto precedente; estrazione delle antocianine con solventi.
c) il pretrattamento delle matrici vegetali individuate in precedenza ai fini dell’ottimizzazione del processo di estrazione con CO2 supercritica;
d) prove di estrazione di antocianine dai matrici vegetali mediante CO2 supercritica, utilizzando un impianto sperimentale esistente; volume dell’estrattore 10 l.
e) ottimizzazione del processo di estrazione tramite :
individuazione dei parametri fisico-chimici ottimali;
eventuali modifiche e/o adattamenti dell’impianto di estrazione esistente;
f) la caratterizzazione degli estratti e la messa a punto della formulazione del prodotto finito secondo le esigenze commerciali.
La realizzazione di questo progetto di ricerca metterà a disposizione dell’industria di trasformazione un know how innovativo per la produzione di antocianine con caratteristiche di:
• resa elevata
• bassi costi di produzione
• assenza di solventi
• inalterata attività biologica
L’ottenimento di un estratto con un elevato contenuto di antocianine e privo di solventi chimici contaminanti renderà questo prodotto competitivo sul mercato internazionale e permetterà il suo utilizzo come additivo colorante / antiossidante nei settori dell’industria alimentare, farmaceutica e cosmetica
Supercritical CO2 extraction of lycopene from tomatoes: a procedure for obtaining a unique natural product.
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Estrazione di licopene con CO2 supercritica da matrici biologiche preparate da bacche mature di pomodoro
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Durum wheat by-products as natural sources of valuable nutrients.
No full textThis review reports the use of wheat milling by-products for the extraction of high quality oil and vitamin E including our results on the exploitation of durum wheat bran as a valuable source of important healthful compounds. Wheat oil can be used as an ingredient in food, pharmaceutical or cosmetic preparations because it contains important bioactive compounds such as vitamin E, carotenoids and unsaturated fatty acids. Different methods are used for oil recovery from plant materials, such as
solvent extraction, mechanical pressing or the ecofriendly supercritical carbon dioxide (SC-CO2) extraction technology. By using SC-CO2, we obtained an oil from durum wheat (Triticum durum Desf.) bran and optimized the extraction conditions to increase oil and vitamin E yields. Wheat bran, which is composed of pericarp, aleurone layer and germ, is discarded during the early stages of durum wheat milling processes to obtain a final product (semolina) that is stable over time. Maximum oil and vitamin E yields were obtained when a durum wheat bran matrix with particle size of *30 mesh and a moisture content of
2.6 % was used. The optimal conditions for oil extraction were: 300–350 bar, 60–70 C, and 4 l min-1 gaseous CO2 flow rate for 1 h. The chemical composition (vitamin E forms, carotenoids, quinones, lipids and fatty acids) of the SC-CO2 extracted oil was
analyzed and compared to that of the oil extracted by Soxhlet using hexane as solvent. The findings here reported highlight the importance of durum wheat bran as a rich source of valuable natural nutrients
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