196,455 research outputs found
Ottimizzazione dell’ambientamento di microtalee radicate in vitro di mirto (Myrtus communis L.)
No full textApplicazione di metiljasmonato in colture di callo di mirtillo per indurre la produzione di composti fenolici
No full textLo studio dei metaboliti secondari ha registrato un crescente interesse negli ultimi anni, in quanto essi
rappresentano un’importante fonte di molecole con attività biologica; ad esempio, alla base di molti
farmaci ci sono composti naturali chimicamente modificati. L’interesse per i prodotti bioattivi di origine
vegetale ha favorito l’identificazione di numerosi composti con potenziali attività farmacologiche.
Recentemente, sono state notevolmente implementate le tecnologie di produzione di metaboliti secondari
basate sulle colture in vitro (Lila, 2004; Ruffoni et al., 2009a e referenze incluse). I vantaggi
offerti dalle colture in vitro riguardano principalmente la produzione di elevate quantità di materiale
ottenuto da uno stesso espianto, la garanzia di protezione dall’attacco di funghi e batteri attraverso lo
svolgimento delle operazioni in ambienti controllati, la ripetibilità di tale processo e la possibilità di
automatizzarlo. Tuttavia, numerosi aspetti sono ancora da studiare e da chiarire sia a livello tecnologico
che biologico. Molti lavori sono presenti in bibliografia riguardanti l’incremento della produzione di
molecole bioattive in piante coltivate in pieno campo o in ambiente protetto, mentre gli studi su piante
o cellule coltivate in vitro sono limitati e spesso riguardano una sola classe di metaboliti. Le difficoltà
nascono dalla definizione delle condizioni colturali più idonee per la crescita delle colture e dalla
messa a punto di appropriati trattamenti di elicitazione abiotica per incrementare la produzione di
molecole bioattive.
Qui descriviamo un protocollo per indurre produzione di composti fenolici, in particolare antociani e
acido ellagico, in colture di callo di mirtillo americano
Supercritical carbon dioxide extraction of phospholipids from dried egg yolk without organic modifier
No full textPhospholipids (PL) were successfully extracted from dried egg yolk by using neat supercritical carbon dioxide (SC-CO2) on a microscale. The spray-dried egg yolk powder was extracted with SC-CO2 at a density of 1.06 g/ml (517 bar, 40 degreesC), which was the maximum of density achievable with the apparatus. The extraction yield obtained by SC-CO2 (67 g of extract per 100 g of sample) can be compared with the conventional Bligh and Dyer extraction method (63 g of extract per 100 g of sample), which involves a chloroform/methanol/water mixture as an extraction solvent. The solvent extract contained 29% of PL, while the neat SC-CO2 extract consisted of 26% PL. HPLC analysis coupled with an evaporative light scattering detector (ELSD) showed no significant selectivity in the SC-CO2 extraction of the PL components. The extraction with neat SC-CO2 appears to be a valid alter-native for the extraction of PL for analytical purpose. (C) 2000 Elsevier Science B.V. All rights reserved
Vecchi e nuovi indicatori per valutare il trattamento termico e lo stato di conservazione del miele
No full textGli indicatori di produzione, trasformazione e conservazione, ampiamente utilizzati nel controllo della qualità del miele, ne permettono la caratterizzazione e la valorizzazione sul mercato. Agli indicatori classici, quali attività diastasica e idrossimetilfurfurolo, influenzabili dalle caratteristiche chimico-fisiche del miele, possono essere affiancati dei “nuovi indicatori” proposti recentemente (furosina, furoilmetil derivati, 1,-2 dicarbonili, maltulosio) che da utilizzare da soli o in combinazione con i vecchi consentono una migliore caratterizzazione e tutela del miele
On-line Commerce and Town Centre Retailers’ Experience
No full textThis paper is an attempt to develop a new way to sell products or services for retailers within town centres. An analysis of the literature revealed that the use of the Internet and digital commerce strategies are rarely used as tools to revitalize urban retail and develop a multidimensional experience of place. Thus, this paper aims to highlight which new modes of online commerce—e-commerce, s-commerce and m-commerce—are more suitable than others to help town centre retailers revitalize the place where they work. The research questions are as follows: 1) What are the origins of the growth and development of new forms of selling? and 2) How might town centre retailers integrate new forms of selling with traditional retailing? In answering the previously stated questions, this paper provides a proposed model that, by combining physical and virtual means to sell products and services, can provide specific strengths in revitalizing town centres
On-line Commerce and Town Centre Retailers' Experience
No full textThis paper is an attempt to develop a new way to sell products or services for retailers within town centres. An analysis of the literature revealed that the use of the Internet and digital commerce strategies are rarely used as tools to revitalize urban retail and develop a multidimensional experience of place. Thus, this paper aims to highlight which new modes of online commerce—e-commerce, s-commerce and m-commerce—are more suitable than others to help town centre retailers revitalize the place where they work. The research questions are as follows: 1) What are the origins of the growth and development of new forms of selling? and 2) How might town centre retailers integrate new forms of selling with traditional retailing? In answering the previously stated questions, this paper provides a proposed model that, by combining physical and virtual means to sell products and services, can provide specific strengths in revitalizing town centres
Cryopreservation of Italian cultivars of hazelnut
No full textThe present study was performed to optimise the cryopreservation protocol in Italian cultivars of Corylus avellana L. Lateral buds excised from in vitro grown plantlets of ‘Tonda Gentile Romana’ (TGR) and ‘Montebello’ (MB) were cryopreserved by the encapsulation-dehydration technique. The effect of dehydration of beads with sucrose (0.5, 0.75 or 1 M) for 1 or 3 days, of desiccation with silica gel for 6 or 8 h and of application of two cytokinins (N6-benzyladenine or meta-Topolin) in the regrowth phase was evaluated. The highest regrowth was obtained dehydrating alginate beads with 0.75 M sucrose applied for 1 day and with desiccation for 8 h with silica gel in both cultivars. On the other hand, the regrowth response to the type of cytokinins in the recovery medium was different in the two cultivars: in TGR the highest regrowth, 40% with N6-benzyladenine and 47% with meta-Topolin, was reached without significant differences between the two cytokinins, while in MB meta-Topolin induced significant higher regrowth (40%) than N6-benzyladenine
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