Fac-simile Scheda Linee di Ricerca - Federalimentare

did not account for the differences observed in chemical compositions. On the contrary, a higher degree of unsaturationin the lipid profile induced a shift of the crystallization onset towards lower temperatures and narrowingof the crystallization temperature range. The presence of triacylglycerol lysis and lipid oxidation productsshifted the crystallization towards higher temperatures and the phase transition developed over a larger temperaturerange. Differential scanning calorimetry thermograms were deconvoluted into three constituent exothermicpeaks for all samples. The area of the two lower-temperature exotherms was found to be statistically correlatedwith the amount of triunsaturated and monosaturated triacylglycerols present in the oil. Thermal properties of extravirgin olive oil were found to be affected by oil chemical composition.2. Chiavaro E., Vittadini E., Rodriguez-Estrada M.T., Cerretani L., Bendini A. (2008)Monovarietal Extra Virgin Olive Oils. Correlation Between Thermal Properties and ChemicalComposition: Heating Thermograms. J Agric Food Chem. 56, 496-501.Extra virgin olive oils from drupes of three Sicilian varieties (Biancolilla, Cerasuola and Nocellara del Belice)and collected at three different harvesting periods, were analyzed upon heating by means of DSC and thermalproperties were related to the chemical composition of the samples. All thermograms exhibited multiple transitionswith a minor exothermic peak, followed by a major endothermic event. Cerasuola samples showed higheroverall enthalpy and narrower range of transition at all harvesting periods, as compared to the other oils. A moreordered crystal structure originating from a more uniform chemical composition, with higher triolein content, inCerasuola, may be hypothesized. At different harvesting periods, thermal transitions started at lower temperaturesand developed over a narrower range in all cultivars, probably due to the insertion of molecules derivedfrom triacylglycerols lysis (diacylglycerols and free fatty acids) and lipid oxidation products into the triacylglycerolcrystal lattice. All heating thermograms were deconvoluted into one exothermic and five endothermic constituentpeaks and the effect of chemical components on thermal properties of the peaks was evaluated. DSC applicationupon heating appears to be very promising in discriminating among oil samples from olives of differentcultivars and/or harvesting periods.3. Chiavaro E., Vittadini E., Rodriguez-Estrada M.T., Cerretani L., Bendini A. (2008). DifferentialScanning Calorimeter Application to the Detection of Refined Hazelnut Oil in Extra VirginOlive Oil”, Food Chem, 110, 248-256.The potential application of Differential Scanning Calorimetry (DSC) to verify adulteration of extra virgin oliveoil with refined hazelnut oil was evaluated. Extra virgin olive oil and hazelnut oil were characterized by significantlydifferent cooling and heating DSC thermal profiles. Addition of hazelnut oil significantly enhanced crystallizationenthalpy (at hazelnut oil ≥ 20%) and shifted the transition towards lower temperatures (at hazelnut oil≥ 5%). Lineshape of heating thermograms of extra virgin olive oil was significantly altered by hazelnut oil addition:a characteristic exothermic event originated at – 27 °C and progressively disappeared with increasing hazelnutoil content, while the major endothermic peak at – 3.5 °C broadened (at hazelnut oil ≥ 40%) and the minorendothermic peak at 8 °C shifted towards lower temperatures (at hazelnut oil ≥ 5%). The results presented in thisstudy suggest that DSC analysis may be a useful tool to detect adulteration of extra virgin olive oil with refinedhazelnut oil.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it338