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Mazzarrino G.,University of Teramo | Paparella A.,University of Teramo | Chaves-Lopez C.,University of Teramo | Faberi A.,Laboratorio Centrale Of Rome | And 4 more authors.
Food Control | Year: 2015

Twenty one essential oils (EOs) were screened against 10 Salmonella enterica and 10 Listeria monocytogenes strains, by Disk Diffusion and Minimal Inhibitory Concentration (MIC) determination. The most effective EOs were: Origanum vulgare (oregano)>. Cinnamomum zeylanicum (cinnamon)~. Caryophillus aromaticus (clove)>. Thymus vulgaris (red thyme)>. Melaleuca alternifolia (tea tree), with MIC values ranging from 0.6 for oregano and 20.0μL/mL for tea tree.The survival/inactivation dynamics of S. Typhimurium S4 and L.monocytogenes ATCC 7644, selected as the most resistant strains, in presence of increasing concentrations (MIC/4, MIC/2, MIC value, MIC×2, MIC×4) of the five most active EOs were determined. All EOs were effective, showing bacteriostatic or bactericidal effects, depending on concentration. Overall, when cells survived in presence of sub-MIC concentrations, lag phase was significantly extended, while cells death was promptly evidenced, immediately after exposure to the highest EOs concentrations. Particularly oregano showed the best antimicrobial activity on both bacteria at low concentrations (0.15-5.0μL/mL).The five EOs showed a total phenols concentration between 1.85 (tea tree) and 17.75mg GAE/g for clove, which gave also the highest radical-scavenging activity, with 1362μM Trolox equivalent/mL. Phenols, terpenes and aldehydes were the major compounds detected by double GC/MS, evidencing carvacrol, borneol, eugenol, terpinen-4-ol and trans-cinnamaldehyde as principal components.In conclusion, our results highlighted a good activity of the five selected EOs on S.enterica and L.monocytogenes, with bactericidal or bacteriostatic effect at very low concentrations and were particularly encouraging, with regard to the Gram negative pathogen. Information on the inactivation dynamics provided useful details to be taken into account with the aim of developing control strategies based on natural antimicrobial agents. © 2014 Elsevier Ltd. Source

Bontempo L.,Research and Innovation Center | Ceppa F.A.,Research and Innovation Center | Perini M.,Technology Transfer Center | Tonon A.,Research and Innovation Center | And 5 more authors.
Food Control | Year: 2014

Tomato passata, one of the 'pillars' of the Mediterranean diet, is a typical Italian product that by law must be obtained exclusively from fresh tomatoes. For this reason Italian law provides for use of the δ18O of vegetal water to determine whether passata (Brix of up to 12) is genuine or has been obtained by diluting tomato paste (Brix higher than 12), although without any indication of reference limits. In this study an extensive dataset of over 1000 samples collected along the Italian tomato product production chain (tap waters, juices, passata, pastes) in different years (2004-2012), was investigated on the content of water δ18O. This parameter was shown to be statistically different in the four classes of products, increasing from water to juice and paste, in relation to the different degree of evaporation taking place during the preparation phase. Moreover, the δ18O of vegetal water, due to the contribution of the lower δ18O values of tap water during dilution, was highly effective in distinguishing genuine passata from watered down paste, also in the case of passata previously concentrated up to 11.9 Brix. In particular, two lower threshold values are proposed:-1.4‰ for 'raw' passata and-2.9‰ for passata previously concentrated up to 11.9 Brix. Although the use of δ18Owater alone does not make it possible to discriminate between Italian and foreign products, an increasing trend in δ18Owater values was shown in juices and passata samples as well as in tap waters, when moving from northern to southern Italian products, making it possible to predict good geographical discrimination for this parameter. © 2013 Elsevier Ltd. Source

Tripaldi C.,Italian Agricultural Research Council | Palocci G.,Italian Agricultural Research Council | Longo L.,Laboratorio Centrale Of Rome | Fuselli F.,Laboratorio Centrale Of Rome | Catillo G.,Italian Agricultural Research Council
Italian Journal of Food Science | Year: 2014

Pecorino Romano protected designation of origin (PDO) cheese was subjected to traditional (TS) and reduced (RS) dry salting methods. TS cheese was analyzed from 2 to 581 d of ripening and RS cheese was analyzed from 2 to 258 d of ripening. RS cheese had a significantly lower salt to moisture (S/M) ratio than TS cheese (4.48 vs 7.20%; 9.04 vs 12.09% in the inner and outer sections, respectively). A significant difference in S/M was obtained between the inner and outer sections of TS cheese. RS cheese had higher moisture content than TS cheese (41.02 vs 38.91%; 39.80 vs 37.29% in the inner and outer sections, respectively). RS cheese had higher pH 4.6 soluble N/total N ratios and total and individual amino acid contents. However, proteolysis was not significantly different between RS and TS. In TS and RS, total amino acid content was significantly higher in the inner than in the outer sections. Total free fatty acid content was higher in RS than in TS. Lipolysis was not significantly different between RS and TS. Source

Perini M.,Fondazione Edmund Machinery FEM | Rolle L.,University of Turin | Franceschi P.,Fondazione Edmund Machinery FEM | Simoni M.,Fondazione Edmund Machinery FEM | And 5 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

In this study we investigated the effect of the grape withering process occurring during the production of Italian passito wines on the variability of the (D/H)I, (D/H)II, δ13C, and δ18O of wine ethanol and the δ18O of wine water. The production of PDO Erbaluce di Caluso Passito in five different cellars in Piedmont (Italy) was considered in two successive years. Moreover, samples of 17 different traditional Italian passito wines taken at different stages of maturation were taken into account. We found that the δ18O of must and wine water and the δ18O of ethanol decrease in the case of passito wines produced in northern and central Italy using postharvest drying of the grapes in dedicated ventilated or unventilated fruit drying rooms (fruttaio), during autumn-winter. For passito wines produced in southern Italy, where the main technique involves withering on the plant (en plein air), δ18O tends to increase. The (DH)I of wine ethanol did not change during withering, whereas the (DH)II and δ13C values changed slightly, but without any clear trend. Particular attention must be therefore paid in the evaluation of the δ18O data of passito wines for fraud detection. © 2015 American Chemical Society. Source

Fuselli F.,Laboratorio Centrale Of Rome | Guarino C.,Laboratorio Of Conegliano | La Mantia A.,Laboratorio Centrale Of Rome | Longo L.,Laboratorio Centrale Of Rome | And 2 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2012

The incorrect use of preservatives in cheeses may compromise food safety and damage consumers. According to the law, more than one preservative may be contemporarily used in cheeses. So a method for their contemporary detection may be useful for both manufacturers and control agencies quality control. In this research a liquid chromatography-tandem mass spectrometric with electrospray ionization method for the multi-determination of seven preservatives (benzoic acid, citric acid, hexamethylenetetramine, lysozyme, natamycin, nisin and sorbic acid) in cheese was developed. The preservatives were contemporarily extracted from cheese by a single procedure, and analyzed by RP-LC/ESI-MS/MS (Ion Trap) in positive ionization mode, with single reaction monitoring (SRM) acquisition. Three sample types (hard, pasta filata and fresh cheese) were used for method evaluation. Recoveries were mostly higher than 90%; MDLs ranged from 0.02 to 0.26mgkg-1, and MQLs were included between 0.07 and 0.88mgkg-1. Due to matrix effect, quantitation was performed by referring to a matrix matched calibration curve, for each cheese typology. This method was also applied to commercial cheese samples, with good results. It appears fast, reliable and suitable for both screening and confirmation of the presence and quantitation of the preservatives in a single, multi-detection analysis. © 2012 Elsevier B.V. Source

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