摘要

18 samples of different products by olive processing (6 refined olive oils, 2 lampante olive oils, 4 repaso oils obtained from second centrifugation step and 6 extra virgin olive oils) were characterized by means of cooling and heating thermogram profiles and their thermal properties were related to fatty acid compositions. Deconvolution was also applied to crystallization transition. Enthalpy of cooling transition was found to not significantly differ among samples. More differences were found for other thermal parameters: repaso samples exhibited high T(on) and low T(off) of crystallization with a large range of transition than the others.
Heating profiles of repaso oils appeared to be quite different from the others as the minor exothermic event peaking at the highest temperature region of the thermograms, was almost absent, probably due to the formation of quite different polymorphic forms of crystals among samples.
Linear discriminate analysis was performed with predictors corresponding to cooling and heating thermal properties and parameters obtained by deconvolution of crystallization transition giving an excellent resolution among categories. In particular, the parameters obtained by the two deconvoluted events peaking at lowest temperature and representing the majority of lipid crystallization in the oils seemed to be very useful to discriminate among analysed categories.

  • 出版日期2011-9