Application of differential scanning calorimetry-chemometric coupled procedure to the evaluation of thermo-oxidation on extra virgin olive oil

In this work, the opportunity of adopting a differential scanning calorimetry (DSC)-principal component analysis (PCA) coupled procedure to measure the degree of thermal stress for extra virgin olive oil (EVOO) was presented. Oil was subjected to thermal stress under convectional or microwave heating treatments at different heating times up to 1,440 and 15 min, respectively, and p-anisidine values (PAV) were obtained on all samples to measure their oxidative degradation. The entire DSC profiles obtained on the oil upon cooling in the range from 30 °C to –80 °C and subsequent re-heating to 30 °C at different times and under cooking procedures have been subjected to PCA data analysis. PCA discriminated samples by means of profile changes in DSC transition both upon cooling and heating not only according to treatment times (which accounted for the degree of thermo-oxidation) but also considering different heating process. The proposed procedure may be useful to measure oil thermal stress and to select appropriate heating condition to be applied for EVOO both in industrial and/or in food-catering sectors.