Giuseppe Avellone

Study of green Sicilian table olive fermentations through microbiological, chemical and sensory analyses

The production of five different green table olive cultivars was studied by a combined strategy consisting of chemical, microbiological and sensory analyses. Cultivable microflora of samples collected during processing was monitored by plate counts on seven synthetic culture media. In all samples Enterobacteriaceae, Pseudomonaceae, staphylococci, lactic acid bacteria and spore-forming bacteria were undetectable. Yeasts and moulds were countable from the day 42 (2 log CFU/ml) till the end of fermentation (6 log CFU/ml). The use of three different approaches for microorganism detection, including a culture-independent methodology, revealed the presence of barely three yeast species during the entire fermentation period: Candida parapsilosis, Pichia guilliermondii and Pichia kluyveri. Biochemical features of technological interest were evaluated for 94 strains in order to investigate their potential role in fermentation of green Sicilian table olives. Olive drupes sampled at picking and periodically during fermentation were also carpologically analyzed, revealing that all the cultivars were suitable for table olive fermentation process. After 120 days of fermentation all products met acceptable commercial standards, although GC-MS analysis evidenced several differences among varieties in terms of aroma components. Results from sensory evaluation led to the conclusion that a revision of technological procedures may improve the final quality of product.

Distribution of volatile organic compounds in Sicilian groundwaters analysed by head space-solid phase micro extraction coupled with gas chromatography mass spectrometry (SPME/GC/MS)

This work presents the results of an assessment of the existence and concentration of 13 volatile organic compounds (VOCs) in groundwaters from 14 hydrological basins in Sicily (25,710km (2)). On the basis of hydrological, hydrogeochemical and geological studies, 324 sampling points were selected. All groundwater sampled were collected twice, from October to December 2004 and from February to May 2005, and were analysed to determine the concentration and spatial distribution of the VOCs in the aquifers. The need to analyze a large number of samples in a short space of time so as to obtain quantitative analyses in trace concentration levels spurred us to create a new analytical method, both simple and sensitive, based on HS-SPME/GC/MS. The concentrations of VOCs measured in industrial and intensive agricultural unconfined aquifers were greater than those found in other aquifers. Tetrachloroethylene, chloroform, trichloroethylene and 1,2-dichloropropane were the most frequently detected VOCs. However, they exceeded the guideline values proposed by the EU in only three aquifers located near to industrial and intense agricultural areas.

Halogenated Anesthetics Determination in Urine by SPME/GC/MS and Urine Levels Relationship Evaluation with Surgical Theatres Contamination

In this work, a new sensitive analytical method has been developed and evaluated for the determination of the most commonly used gaseous anesthetics, desflurane, sevoflurane, and this latters hepatic metabolite hexafluoroisopropanol (HFIP) in the urine. In addition, an evaluation of anesthetics exposition on the urine levels of a small population of surgical operators has been performed and results are briefly discussed.

Melatonin: structural characterization of its non-enzymatic mono-oxygenate metabolite

Abstract: Oxidation of melatonin by Fenton reagents as well as with hypochlorous acid or oxoferryl hemoglobin has been investigated. Analysis of products by low resolution/mass spectra (MS), high resolution/MS, 1H‐nuclear magnetic resonance (NMR), 13C‐NMR, correlated spectroscopy (COSY) and heterocorrelated spectroscopy (HETCOR) 2D NMR reveals the formation of a single mono‐oxygenated product under all conditions and unequivocally assigns the N‐[2‐(5‐methoxy‐2‐oxo‐2,3‐dihydro‐1H‐indol‐3‐yl)‐ethyl]‐acetamide structure, which had not been previously considered.

Genotoxicity of citrus wastewater in prokaryotic and eukaryotic cells and efficiency of heterogeneous photocatalysis by TiO2

The presence of (±)α-pinene, (+)β-pinene, (+)3-carene, and R-(+)limonene terpenes in wastewater of a citrus transformation factory was detected and analyzed, in a previous study, by using Solid Phase Micro-extraction (SPME) followed by GC analyses. Purpose of that research was to compare the genotoxic responses of mixtures of terpenes with the genotoxicity of the individual compounds, and the biological effects of actual wastewater. Genotoxicity was evaluated in the Salmonella reversion assay (Ames test) and in V79 cells by Comet assay. Ames tests indicated that the four single terpenes did not induce an increase of revertants frequency. On the contrary, the mixtures of terpenes caused, in the presence of metabolic activation, a highly significant increase of the revertants in TA100 strain in comparison to the control. The Comet assay showed a significant increase in DNA damage in V79 cells treated for 1h with single or mixed terpenes. Moreover, the actual wastewater was found highly genotoxic in bacterial and mammalian cells. Photocatalytic tests completely photodegraded the pollutants present in aqueous wastewater and the initial high genotoxicity of samples of wastewater collected during the photocatalytic run, was completely lose in 3h of irradiation.

Spectrophotometric investigation of the binding of vitamin E to water-containing reversed micelles.

The distribution constants of vitamin E partitioned between apolar organic phase and water-containing reversed micelles of sodium bis (2-ethylhexyl) sulfosuccinate (AOT), didodecyldimethylammonium bromide (DDAB), soybean phosphatidylcholine (lecithin) and tetraethylene glycol monododecyl ether (C12E4) have been evaluated by a spectrophotometric method. The results suggest that in the presence of domains from apolar organic solvent to surfactant and to water, vitamin E is partitioned between the micellar palisade layer and the organic solvent and also that its binding strength to reversed micelles depends mainly by specific interactions between the head group of vitamin E and that of the surfactant. Moreover, in addition to the advantageous interactions between vitamin E and water, the dependence of the distribution constants upon the molar ratio R (R=[water]/[surfactant]) indicates a competition between water and vitamin E for the binding sites at the water/surfactant interface. The biological implications of the preferential location and confinement of vitamin E in water-containing reversed micelles are discussed.

Natural co-occurrence of ochratoxin A, ochratoxin B and aflatoxins in Sicilian red wines

The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 (OTA, OTB, AFB1, AFB2, AFG1, AFG2) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l–1, well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG1, present in 57.9% of samples, while the other aflatoxins were rarely present. Recovery experiments were carried out on eight mycotoxin-free red wines spiked with OTA, OTB, AFB1, AFB2, AFG1 and AFG2 at two different levels. The limits of detection (LODs) in wines were 0.02 µg l–1 for OTA, 0.04 µg l–1 for OTB, 0.03 µg l–1 for AFG1, AFG2 and AFB2, and 0.05 µg l–1 for AFB1. A good correlation was found, with good performances in term of precision for the method.

Determination of the cultivar and aging of Sicilian olive oils using HPLC-MS and linear discriminant analysis

A large number of certified samples (84) of Sicilian olive oils arising from the eight cultivars most represented in Sicily (Biancolilla, Cerasuola, Moresca, Nocellara del Belice, Nocellara Etnea, Oglialora Messinese, Brandofino and Tonda Iblea) have been collected and analyzed by HPLC/MS using an atmospheric pressure chemical ionization (APCI) source. The sample preparation is very simple; in fact, the oil samples are diluted without any chemical derivatization. A following statistical data treatment by general discriminant analysis (GDA) allows the determination of the olive oil cultivar. Furthermore, changes in the composition of glyceridic components of the olive oils lead to easy discrimination between fresh oils and 1-year-old samples.

Determination of Aflatoxins and Ochratoxins in Sicilian Sweet Wines by High-Performance Liquid Chromatography with Fluorometric Detection and Immunoaffinity Cleanup

Ochratoxin A is the only mycotoxins with legal limits in the European Union for wine, by contrast, there is no EU legislation imposed for Aflatoxins and Ochratoxin B. A reproducible and sensitive analytical method for six mycotoxins: Ochratoxin A, Ochratoxin B, Aflatoxins B1, Aflatoxin B2, Aflatoxin G1 and Aflatoxin G2 was developed by using immunoaffinity column cleanup and HPLC-FLD method in 30 sweet wines produced in Sicily. This typical type of wine is manufactured from grapes grown in warmer climates, which have a higher sugar content; also, the over-ripening and the drying process of the grapes before fermentation conditions are responsible for the particular susceptibility of these berries to contamination by mycotoxins producing fungi. Results revealed the presence of Ochratoxin A in 96.6xa0% and of Ochratoxin B in 83.3xa0% of the samples examined (mean 0.246 and 0.168xa0μg/l, respectively). None of the samples showed a contamination exceeding the EU limit (2xa0μg/kg). Nine of tested wines were found to contain Aflatoxins with concentrations ranging from below LOD values to 0.068xa0μg/l. The results showed a very low incidence of Ochratoxins and Aflatoxins in analyzed wines, confirming the high degree of quality and safety of Sicilian sweet wines.

Triacylglycerols in edible oils: Determination, characterization, quantitation, chemometric approach and evaluation of adulterations

Vegetable oils are a dietary source of lipids that constitute an essential component of a healthy diet. The commonly used vegetable oils differ significantly for their triacylglycerol (TAG) profile. TAGs represent the principal components of oils and may contain different fatty acids (FA) esterified with glycerol leading to several positional isomers. To differentiate individual TAGs species in edible oils, advanced analysis systems and innovative methods are therefore required. TAGs can be considered as good fingerprints for quality control and many studies have been performed to develop rapid and low cost analytical methods to determinate the authenticity, origin and eventually evidence frauds or adulterations. The present manuscript provides a general overview on the most common vegetable oils TAGs compositions and on the related analytical methodologies recently used. Finally, the chemometric applications developed to assess the authenticity, quality and botanical origin of various edible oils are discussed.