Marcello Saitta

Gas chromatographic–tandem mass spectrometric identification of phenolic compounds in Sicilian olive oils

Phenolic compounds in Sicilian olive oils were analyzed by GC–MS and GC–MS/MS after extraction with methanol:water 80:20 and derivatization with bis(trimethylsilyl)trifluoracetamide and trimethylchlorosilane (BSTFA:TMCS 99:1). Numerous compounds were detected and 23 were identified. Tyrosol, hydroxytyrosol and the decarbomethoxy ligstroside and oleuropein aglycons in the dialdehydic forms were the most abundant compounds. 4-(Acetoxyethyl)-1-hydroxybenzene, 3,4-dihydroxyphenylacetaldehyde, syringaldehyde and the cis form of ferulic acid were identified: these compounds were not found in olive oils before. The presence of the dialdehydic form of elenolic acid (without carbomethoxy group) linked to 3-methoxy-4-hydroxyphenylethanol was hypothesized. There were quantitative differences in oils from the varieties Nocellara del Belice, Santagatese and Cerasuola; these differences could depend on the olive varieties and ripeness.

High performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry for sensitive determination of bioactive amines in donkey milk

In the present study we report on the optimization and validation of a sensitive high performance liquid chromatography atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) method for the determination of 8 bioactive amines (histamine, tyramine, tryptamine, 2-phenylethylamine, cadaverine, putrescine, spermidine and spermine) in donkey milk samples. The method involves donkey milk pre-treatment to remove proteins and pre-column dansylation of the amines. HPLC in reversed phase mode has been used for bioactive amines separation and the operating condition of the APCI-MS system proved to be powerful and very efficient for peak assignment. The separation was accomplished in a short time with an excellent resolution for all the amine peaks. Quantification was carried out by monitoring the characteristic [M+H](+) ion of each amine derivative. The method sensitivity, linearity and repeatability were assayed with satisfactory results. The detection limits of the analysed amines ranged from 0.5 microg L(-1) to 15 microg L(-1); the highest LOD was for spermine. Also remarkably good recovery values were obtained; at the lowest spiking level (1 microg L(-1)) the percent mean recoveries ranged from 77.7 to 109.7. Furthermore, as the investigations relate to a complex matrix as donkey milk, suitable studies on matrix effect were performed. Finally, the developed and validated method was applied to analyse 13 donkey milk samples. Among the identified bioactive amines, putrescine, spermine and spermidine proved to be the main amines in donkey milk. Their concentration levels in the present study were lower than the values determined in mature human, cow and sow milk.

Principal component analysis in fast atom bombardment-mass spectrometry of triacylglycerols in edible oils

Positive-ion fast atom bombardment-mass spectrometry, withm-nitrobenzyl alcohol as matrix and a methanolic sodium iodide (Nal) solution, was used to characterize edible oils by their triacylglycerol composition. Cationized triacylglycerols gave characteristic spectra for olive (57 samples), sunflower (9 samples), soybean (9 samples), corn (12 samples), and peanut (10 samples) oils. Relative abundance of [M + Na]+ ions showed relevant differences among the oils. The obtained data were analyzed with the aid of chemometrics by using principal component analysis (PCA) to evaluate the differentiation. Twelve variables were reduced to two principal components, accounting for 82% of the total variance. A two-dimensional plot of 97 PCA scores allowed the separation of the edible oils. The analysis is both fast and reproducible.

Chemometric analysis of minerals and trace elements in Sicilian wines from two different grape cultivars

Abstract Chemometric analysis are used for food authenticity evaluation, correlating botanical and geographical origins with food chemical composition. This research was carried out in order to prove that it is possible linked red wines to Nero d’Avola and Syrah cultivars of Vitis vinifera according to their mineral content, while the values of the physical and chemical parameters do not affect relevantly this discrimination. The levels of mineral elements were determined by ICP-OES and ICP-MS. Samples from cv Nero d’Avola had the highest content of Zn, Cr, Ni, As and Cd, whereas the highest mineral concentration in cv Syrah samples was represented by K, Mg, Cu, and Sb. The research highlights that it is possible linked red wines to Nero d’Avola and Syrah cultivars of V. vinifera according to their mineral contents, adding knowledge to the determination studies of the wine botanical origin.

Contamination of Citrus Essential Oils: The Presence of Phosphorated Plasticizers

Abstract Organophosphorus insecticides are common pollutants of the citrus oils. Unknown phosphorated compounds, different from organophosphorus pesticides, were detected during GC analyses of citrus oils; the chromatographic profile was similar to a triarylphosphate mixture. Standard mixtures of triarylphosphates were analyzed and mass spectra were obtained; the results showed that the contamination was due to triphenylphosphate and tritolylphosphate isomers essentially. The contaminants were found to probably originate from contact of the oils with plastic materials from which they leached on oil storage.

Gas chromatography-tandem mass spectrometry multi-residual analysis of contaminants in Italian honey samples

ABSTRACT Contaminants belonging to various classes, including polychlorobiphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs), pyrethroid insecticides (PYRs), fungicides (Fs), herbicides (Hs), synergists (SYNs) and insect growth regulators (IGRs) were analysed simultaneously in honey samples using a new simultaneous, easy and rapid method based on a liquid–liquid extraction with a mixture of n-hexane and ethyl acetate. It allowed recoveries in the range 80–137%, with limits of detection (LODs) between 0.10 and 5.21 ng g–1, showing a good sensitivity and accuracy. All the analysed Italian honeys showed the presence of residues of OPPs; PAHs were in 46.8% of the samples and PCBs were always below the LODs; 53.2% of the samples were contaminated by OCPs, PYRs, SYNs and IGRs. In addition, 46.8% of the samples exceeded the maximum residue limits (MRLs) established by the European Community in honey for chlorfenvinphos (cis + trans), TPP, γ-HCH, tebuconazole, coumaphos and τ-fluvalinate (cis + trans). GRAPHICAL ABSTRACT

4.22 – Sample Preparation for the Determination of Metals in Food Samples

The main aspects of sample preparation for the determination of metals in food samples are here described. The need for a correct sampling and sample pretreatment, the choice of high purity reagents, and the control of possible sources of contamination are taken into account. Sample digestion techniques are treated: dry ashing, open wet digestion, closed wet digestion, microwave assisted digestion, and UV photolysis digestion. Metal extraction by ultrasonic assistance and direct analysis of solid (or slurry) sampling are considered too. Several examples of sample preparation for the determination of metals in different foods, regarding all the highlighted techniques, are reported and compared.

Compounds with Antioxidant Properties in Pistachio (Pistacia vera L.) Seeds

Publisher Summary This chapter outlines the antioxidants found in pistachio seeds and their benefits to human health. Different antioxidant classes are present in pistachio seeds: anthocyanins, tocopherols, carotenoids, chlorophylls, flavonoids, isoflavones, proanthocyanidins, anacardic acids, and cardanols, as well as resveratrol and vitamin C. These antioxidants can interact in very different ways: the synergistic effects can improve the protection against oxidative damage and play an important role in the biological antioxidant network. Hydrophilic extracts of pistachio nuts inhibited both the metal-dependent and the metal-independent lipid oxidation of bovine liver microsomes and also the Cu2+-induced oxidation of human low density lipoproteins. Studies of the benefits of pistachio consumption in humans show that the mean plasma total cholesterol and malondialdehyde levels, total cholesterol/high density lipoprotein ratio, and low density lipoprotein/high density lipoprotein ratio significantly decrease. The use of antioxidants as chemopreventive agents by inhibiting radical generation has been suggested, since free radicals are responsible for DNA damage and scavengers are probably important in cancer prevention.

Pesticides and plasticizers in Citrus essential oils: An ordinary history of research

The history of the research on pesticides and plasticizers presence in Citrus essential oils is resumed. The determinations of organophosphorus pesticides, organochlorine pesticides, and some class of plasticizers (triarylphosphates, phthalate esters, chloroparaffins, adipate esters, sebacate esters) are described, and the evolution of the contamination over the years and according to the type of Citrus essential oil is highlighted.

Low-level Free Phenols in Sicilian Olive Oils

Publisher Summary The phenolic fraction of olive oils can be analyzed in different manners: the simple total quantitative determination is carried out by a colorimetric method, and the single phenols qualitative and quantitative analysis by using chromatographic or electrophoretic methods. Many methods have been set by high-performance liquid chromatography (HPLC); the quantification is simple and derivatizing reagents are not necessary, as in gas chromatography. GC methods do however have some advantages with respect to HPLC: lower detection limits and better separations. Hyphenated methods like GC-MS or GC-MS/MS add a direct qualitative information and further sensitivity due to ion current analysis or selected ion monitoring. Even trace compounds can be detected and identified with this technique; the aglycons of ligstroside and oleuropein can be detected too; only the whole glycosides, ligstroside and oleuropein, cannot be detected in GC. The importance of the analysis of the phenols is due to their antioxidant action, but their amount depends on many factors, like the growth and maturation of the olives, the oil preparation, the variety and the climate. The determination of low-level free phenols in olive oils is an aid to evaluate differences among samples from different varieties and some compounds can be related to the autoxidation stages of olive oils. This chapter reports the chromatographic and spectroscopic approach to GC-MS and GC-MS/MS analysis and the results obtained on 76 Sicilian monovarietal virgin olive oils (six different cultivars), produced in the years 1998–2000.