Characterization of Mandarin (Citrus deliciosa Ten.) essential oil. determination of volatiles, non-volatiles, physico-chemical indices and enantiomeric ratios.

An investigation of 27 samples of mandarin essential oils (Citrus deliciosa Tenore), industrially produced in Sicily during the 2007-2008 season, was performed to determine the composition of the volatile fraction by GC/FID and GC/MS-LRI, the enantiomeric distribution of some monoterpene hydrocarbons and linalol by Es-GC, the non-volatile oxygen heterocyclic components by RP-HPLC/PDA and the physicochemical indices (relative density, refractive index, optical rotation, residue on evaporation, and UV spectroscopic CD value). This study up-dates the information available in the literature on Sicilian mandarin (C. deliciosa Ten.) essential oils, and provides information on the composition and quality parameters for the evaluation of this product

Composition of Egyptian Nerolì Oil

The bitter orange flower oil (or nerolì) is an essential product, largely used in perfumery. Nerolì is obtained by hydrodistillation or steam distillation, from the flowers of bitter orange ( Citrus aurantium L.). Since a long time nerolì production is limited and its cost on the market is considerably high. The annual production in Tunisia and Morocco is ca. 1500 Kg, representing more than 90% of the worldwide production. A small amount of nerolì is also produced in Egypt, Spain and Comorros (not exceeding 150 kg totally). Due to the high cost, the producers and the users have tried to obtain less expensive products, with odor characters close to that of nerolì oil to be used as substitute and sometimes as adulterants of the genuine oil. In this study are investigated five samples of Egyptian nerolì oils produced in 2008 and 2009, in the same industrial plant, declared genuine by the producer. For all the samples the composition was determined by GC/FID and by GC/MS-LRI; the samples were also analyzed by esGC to determine the enantiomeric distribution of twelve volatiles and by GC-C-IRMS for the determination of the δ 13CVPDB values of some mono and sesquiterpene hydrocarbons, alcohols and esters. The analytical procedures allowed to quantitatively determining 86 components. In particular the variation of the composition seems to be dependent on the period of production. In fact, the amount of linalool decreases from March to April while linalyl acetate presents an opposite trend, increasing in the same period. The RSD determined for the δ 13CVPDB are very small (max. 3.89%), ensuring the authenticity of all samples. The results are also discussed in function of the limits provided by the European Pharmacopoeia (EP) (2004), AFNOR (1995) and ISO (2002) regulations for genuine nerolì oils

Reliable identification and quantification of volatile components of sage essential oil using ultra HRGC.

Salvia officinalis (common sage) essential oil was chemically characterized by means of GC-MS, using 100 meter capillary columns with two different stationary phases. Identification of the analytes was carried out by means of the FFNSC mass spectrum library and the use of the Linear Retention Index (LRI) as an extra criterion of library searching. Quantitative analysis was also carried out by means of GC-FID with the internal standard method and the use of relative response factors determined for each chemical class of components. A total of 45 compounds were identified and quantified and reported with their experimental LRI values

Determination of bioactive compounds in the juice of pummelo (Citrus grandis Osbeck).

The juice of pummelo (Citrus grandis Osbeck) was analyzed to determine its composition of flavonoids, polymethoxyflavones, coumarins and psoralens. The analyses were carried out by HPLC using columns packed with small diameter Fused-Core® C18 particles to achieve high resolution in short analysis time. In addition, the profile of the native carotenoids present in the juice was determined using a C30 column. Identification of flavonoids was achieved by MS with ESI in negative mode; the MS acquisition of oxygenated heterocyclic compounds was performed in positive APCI; carotenoids were detected with a PDA detector. Nineteen native carotenoids were determined in pummelo juice for the first time. The composition of this juice is also discussed in comparison with other Citrus juices, especially grapefruit

Autenticazione degli alimenti

Il capitolo si occupa delle problematiche legate all'assicurazione della autenticità degli alimenti descrivendo brevemente le più moderne tecniche analitiche a disposizione del chimic

Blood orange (Citrus sinensis) as a rich source of nutraceuticals: investigation of bioactive compounds in different parts of the fruit by HPLC-PDA/MS

: This study is part of a wider investigation aimed to sustain the economical value of the by-products generated by the Citrus industry. In particular, the protected geographic indication (PGI) red orange of sicily (known as blood orange) has been analysed by HPLC and by the enzymatic AOAC method. All the by-products contain significant amounts of biologically active compounds (limonoids and flavonoids). The decanted pulps were the most abundant, with the highest amount of flavonoids (130 g/kg) and high amount of limonoids (5.5 g/kg). Seeds were the best source of limonoids with about 10 g/kg. Low amount of anthocyanins were found only in coarse pulps and waste water. The total, the insoluble and the soluble dietary fibre (TDF, IDF and SDF respectively) were also determined. The pulps resulted to be the best source of dietary fibre, based on the amount and on the best insoluble/soluble ratio

Purification and characterization of recombinant Caulobacter crescentus Cu,Zn superoxide dismutase

Recombinant Cu,Zn Superoxide Dismutase from Caulobacter crescentus has been expressed in Escherichia coli and characterized. The corresponding recombinant protein has a molecular weight typical of a homodimeric Cu,ZnSODs and an activity comparable to that of other prokaryotic enzymes. The copper active site is characterized by a peculiar axial geometry as evidenced by its electron paramagnetic resonance spectrum, moreover, the copper atom displays a low accessibility toward external chelating agents indicating a lower solvent accessibility when compared to other prokaryotic enzymes. Investigation of the enzyme thermal stability through differential scanning calorimetry indicates the occurrence of two transitions at low and higher temperature that are found to be due to the apo and holo protein, respectively, confirming that the metals have a crucial role in the stabilization of this class of enzymes. © 2005 Elsevier B.V. All rights reserved