Fac-simile Scheda Linee di Ricerca - Federalimentare

Dati pubblicati inerenti il tema di ricerca:1. Calligaris S., Sovrano S., Manzocco L., Nicoli M.C., 2006, Influence of crystallization on theoxidative stability of extra virgin olive oil. J. Agric. Food Chem., 54, 2, 529-535,The aim of this study was to evaluate the influence of extra virgin olive oil (EVOO) physical state on the kineticsof oxidative reactions. To this purpose, EVOO was stored at increasing temperatures from 3 to 60 °C and theoxidation was followed by measuring both primary and secondary oxidation products. Results highlighted thatcrystallization plays an important role in determining EVOO stability. Below the melting point, the oxidationrate was found to be higher than that expected on the basis of the Arrhenius equation. The observed deviationfrom the Arrhenius equation was attributed to the physico-chemical changes occurring as a consequence of phasetransitions. In particular, the increase in unsaturated triacylglycerol concentration and the decrease of polyphenolcontent in the liquid phase surrounding fat crystals was indicated as the main factor causing the deviation. Bytaking into account these changes it was possible to describe the temperature dependence of oxidation rate in theentire range of temperatures considered. This model appears promising in the challenge to find out mathematicalmodels able to predict the stability and, hence, the shelf-life of lipid containing foods.2. Calligaris S., Manzocco L., Nicoli M.C., 2007, Modelling the temperature dependence ofoxidation rate in water-in-oil emulsions stored at sub-zero temperatures. Food Chem., 101 (3),1019-1024,.The aim of the present research was to model the temperature dependence of lipid oxidation rate in water-in-oilemulsions stored at sub-zero temperatures. In fact, the application of the well-known Arrhenius equation resultedprecluded in such conditions. To this purpose, the physical state and the oxidation rate of sunflower oil-wateremulsions were evaluated from –30 to 60 °C. Results indicate that the rate of oxidation could be considered as aresultant of a complex interplay between the physico-chemical changes occurring in the hydrophilic and hydrophobicphases as a consequence of phase transitions. By taking into account the changes in oil viscosity and inthe reactant concentration in both lipid and water phase it was possible to set up a mathematical model able todescribe the temperature dependence of oxidation rate in multiphase systems in the entire range of temperaturesconsidered.3. Calligaris S., Arrighetti G., Barba L., Nicoli M.C., 2008, Phase transition of sunflower oil asaffected by oxidation level. J. Am. Oil Chem. Soc., 85(7), 591-598.The influence of the oxidation level on the phase transition behavior of sunflower oil was evaluated by differentialscanning calorimetry (DSC) and Synchrotron X-Ray Diffraction (XRD) at both small and wide angles. Thecrystallization was monitored at cooling/heating rate of 2 °C/min from 20 to -80 °C and vice versa applying bothtechniques. The triacylglycerols organize in two double-chain length structures: α 2L (61.87 Å) and β’ 2L(82.89Å). The crystalline structure changes upon oxidation. In particular, the intensity of the XRD peak associatedwith the double chain structure of β’, as well as its crystallization and melting enthalpy, significantly decreasesas oxidation level increases.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.it497