Transfer of metal ions at the soil-root interface: role of VO²⁺ on Fe³⁺ mobilization from a Fe(III)-network

This note reports the role of VO(IV) on Fe(III) mobilization from a Fe(III)-polygalacturonate network. The effect of the reaction on the physical properties of the system is also considered

Role of the polygalacturonate network on the iron (III) reduction by caffeic acid

This communication reports the role of polygalacturonate network on the Fe(III) reduction by caffeic acid. The effect of phosphate ions on the redox reaction is also considered

Variazioni dell'olio essenziale di <i>Citrus grandis</i> L. x <i>Citrus paradisi</i> macf. a differenti stadi di maturazione

Nel presente lavoro ci siamo interessati agli oli essenziali della cultivar Oroblanco che ha avuto origine nel 1958 da un incrocio tra un pummelo ed un pompelmo bianco. I frutti delle cultivar più precoci vengono commercializzati con il nome di Sweetie mentre le cultivar tardive come Golden Sweetie

Analisi di oli essenziali di <i>Citrus</i> durante il periodo di maturazione del frutto

Gli oli essenziali del genere Citrus costituiscono un’importante classe di prodotti il cui utilizzo è molteplice. Nel campo alimentare sono utilizzati come aromatizzanti, nella profumeria per la formulazione di profumi con particolari “note di testa”, in campo farmaceutico come aromatizzanti. Vista l’importanza di questi oli abbiamo ritenuto interessante valutare la variabilità del loro contenuto in rapporto al grado di maturazione del frutto. La nostra indagine ha riguardato gli oli essenziali di due cultivar pigmentate: Moro e tarocco ed una cultivar bionda locale: San vito

Influence of different drying parameters on the composition of volatile compounds of thyme and rosemary cultivated in Sardinia

The shelf life of spices is traditionally extended by drying. Fresh herbs, due to their high water content, undergo microorganism growth and adverse biochemical reactions. On the other hand drying may result in a lot of physical and chemical alterations. Air and oven-dehydration are the main methods used to stabilize spices. During oven drying, in general, losses of volatile compounds are directly dependent on the temperature and time used. This paper deals with the effect of different drying temperatures and air fluxes on the volatiles in rosemary (Rosmarinus officinalis L.) and thyme (Thymus officinalis L.) cultivated in Sardinia. Fresh leaves were collected and soon divided in two batches, which were subjected to hydro distillation and GC-MS analysis, the first batch as fresh, the second one after drying in a laboratory pilot dryer. Three drying temperatures were used, 30, 38 and 45°C, and for each one two airflow rates were set. The fresh and dried plant material were hydro distilled for 4 hours using a Clevenger-type apparatus (Italian Official Pharmacopeias X). The oils (liquid and light yellow) were recovered directly from above the distillate without adding any solvent and stored at –20°C before analyses, which were carried out on two replicates of each sample by gas chromatography, using a flame ionization detector. The diluted samples were injected using a split/splitless automatic injector (using 2,6-dimethylphenol as internal standard). Qualitative analysis was done by GC/Mass and mass units were monitored from 10 to 450 at 70 eV. Results of the influence of the different drying conditions on volatile compounds of the two herbs will be reported

Isolamento ed analisi di molecole bioattive da estratti di <i>Pistacia Terebinthus L.</i> vegetante in Sardegna

Il genere Pistacia (Anacardiacee) include P. Terebinthus, piccolo albero a foglie decidue presente in Sardegna solo in una ristretta area calcarea della costa est, Cala Gonone (NU). Le specie del genere Pistacia hanno un largo uso in etnobotanica; venivano usati come antiinfiammatori, antibatterici, nel trattamento dell’eczema. Questo ci ha portato a pensare, anche in base alla letteratura presente, che nelle piante appartenenti a questo genere ci siano delle molecole particolarmente importanti dal punto di vista farmaceutico. Partendo dalle osservazioni di etnobotanica abbiamo voluto investigare la composizione chimica di questa specie con lo scopo di trovare, eventualmente, dei nuovi nutraceutici

Variabilità dei principi attivi in <i>Hypericum perforatum</i> L. vegetante in Sardegna

Vista la grande importanza farmacologica che sta rivestendo l’estratto d’iperico nella cura della depressione (2-3) abbiamo ritenuto interessante indagare la specie spontanea presente in Sardegna. Le analisi sono state effettuate via HPLC

Determinazione dei residui di Deltametrina nelle ciliegie

This paper describes the determination of residues of the insecticide Deltamethrin in cherries growing in the Bonnanaro area near Sassari (Sardinia - Italy). The analytical procedure for the isolation of the insecticide was developed. The quantitative determinations were carried out by HPLC, with UV detector at 220 nm, on a Perkin-Elmer C18-HS3 column with acetonitrile - water (75: 25) as the mobile phase. A rapid decrease of the concentration of the insecticide with ti me was ascertained; three days after from the treatment the values were significantly lower than those required by the italian law

Variabilità dell'olio essenziale di <i>Helichrysum italicum</i> (Roth) G. Don

Per lo studio dell'olio essenziale di Helichrysum italicum, sono state prese in considerazione varie stazioni di E. italicum (Roth) G. Don subsp. microphyllum (Willd.) Nyman vegetante allo stato spontaneo sia nel Nord che nel Sud della Sardegna. Le analisi sono state condotte via Gas-massa e ci hanno permesso di identificare 69 costituenti per un totale compreso tra il 92.9% ed il 99.9% dei costituenti totali

Influence of different stabilizing operations and storage time on the composition of essential oil of thyme (Thymus officinalis L.) and rosemary (Rosmarinus officinalis L.)

Abstract The effect of different stabilizing techniques on the composition of essential oil of rosemary (Rosmarinus officinalis L.) and thyme (Thymus officinalis L.) during one year of storage is reported. The study was aimed to know what is the stabilizing technique to keep at the best the original essential oil composition. The fresh samples were collected and treated as follows: air-dried in a laboratory scale pilot dryer, frozen in a forced-air freezer and freeze-dried in a laboratory freeze-dryer. The fresh sample served as control. The treated samples were packaged with appropriate packaging material and stored at 20 °C or −20 °C for 12 months. All the samples were hydrodistilled every three months and the oils composition was obtained by means of gas chromatography/mass spectrometry (GC/MS). Quantification of known compounds was done with the use of an internal standard. Freezing best maintained the composition of rosemary and thyme essential oil. Appropriate packaging of air-dried and freeze-dried herbs resulted in negligible quality loss up to one year of storage. The frozen and stored thyme samples showed the best retention of thymol, the most important compound, as well as of γ-terpinene and carvacrol