Volatile emerging contaminants in melon fruits, analysed by HS-SPME-GC-MS

<p>The aim of this research was to develop and validate a headspace-solid phase micro-extraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS) method for the determination of volatile emerging contaminants in fruit. The method showed good precision (RSD ≤ 14%) and satisfactory recoveries (99.1–101.7%) and LOD and LOQ values ranging between 0.011–0.033 μg kg⁻¹ and 0.037–0.098 μg kg⁻¹, respectively. The method was applied to investigate the content of volatile emerging contaminants in two varieties of melon fruit (<i>Cucumis melo</i> L.) cultivated adjoining high-risk areas. Glycol ethers, BHT, BHA and BTEX (benzene, toluene, ethylbenzene and xylene) were determined in melon fruit pulps for the first time, with different sensitivities depending on sample and variety. Although the amount of the volatile contaminants in the melon samples were in the order of µg kg⁻¹, the safety of vegetable crops cultivated near risk areas should be more widely considered. The results showed that this accurate and reproducible method can be useful for routine safety control of fruits and vegetables.</p

Mt-DNA RFLP patterns obtained at the end of fermentation from Nero d'Avola (lane 3) and Frappato (lane 4), inoculated with B2–48 (A), B2–25 (B), ICV-D254 (C) and QD-145 (D).

<p>Control RFLP patterns obtained with DNA from the pure cultures of each isolate are shown in lane 2 of each panel. Lane 1, molecular marker (1 kb ladder, BDH).</p

Mt-DNA RFLP patterns of 14 isolates (indicated) used for the 100 liter fermentations of 2004.

<p>A. Patterns obtained with the <i>RsaI</i> enzyme. B. patterns obtained with the <i>HinfI</i> enzyme. M, molecular marker (1 kb ladder, BHD).</p

Analysis of fermentation vigor (top) and sulfite tolerance (bottom) after two days (left) and seven days (right) of 129 <i>Saccharomyces</i> strains isolated from spontaneous fermentations.

<p>A large number of isolates show values higher than the control strain L404.</p

CO₂ production (as derived from the measured weight loss) of 129 <i>Saccharomyces</i> strains, upon 300 g/l sugar supplementation.

<p>The weight loss of L404 is indicated by an arrow (12.48 g). The number of strains per each frequency class is indicated.</p

Results of the sensory analyses performed on the Nero d'Avola (A) and Frappato (B) wines.

<p>See text for further explanation.</p

Growth curves of <i>Saccharomyces</i> and non-<i>Saccharomyces</i> yeasts in B2–25-inoculated Nero d'Avola must.

<p>The relative sugar consumption (expressed as °Baumé) is indicated.</p

Research area (A) and location of the wineries (B) where must sampling was carried out (collection sites are indicated by capital letters).

<p>Research area (A) and location of the wineries (B) where must sampling was carried out (collection sites are indicated by capital letters).</p

Wine tasting results for the 14 experimental wines.

<p>The name of each starter is indicated.</p