INVESTIGADORES
GUIOTTO Estefania Nancy
congresos y reuniones científicas
Título:
A DSC study of the autoxidation of chia - sunflower oil blends
Autor/es:
GUIOTTO. ESTEFANIA N.; IXTAINA, VANESA Y.; NOLASCO, SUSANA M.; TOMÁS, MABEL C.
Lugar:
California
Reunión:
Congreso; 103rd AOCS Annual Meeting & Expo.; 2012
Institución organizadora:
AOCS
Resumen:
Differential scanning calorimetry (DSC) was applied to study the thermoxidation
of chia - sunflower oil blends. The
thermoxidation of sunflower oil, chia oil -rich in omega-3 fatty acids- and
their mixtures (sunflower:chia 80:20 and 90:10 wt/wt) were investigated under
non-isothermal conditions (10 - 350°C)
under an oxygen atmosphere at different heating rates (β = 2.5; 5.0; 10.0; 15.0
and 20.0ºC/min). The
thermograms showed two peaks associated with the primary and secondary lipid
oxidation products. Temperatures of the extrapolated start of oxidation (Te)
and the maximum heat flow (Tp1 and Tp2) were determined from
each thermogram and used to calculate the activation
energy (Ea) and the Arrhenius kinetic parameters of
thermal-oxidative decomposition of these oils, using the Ozawa-Flynn-Wall (OFW)
method. Chia and sunflower oils recorded the lowest and the highest values of Te,
Tp1 and Tp2, respectively. Activation energy (Ea)
of the thermoxidation of chia seed oil (onset) was 79.78 kJ/mol and increased
up to 88.22 and 89.41 kJ/mol in case sunflower:chia
oil blends (80:20 and 90:10), respectively, and up to 99.48 kJ/mol for
sunflower oil. This information shows the
more susceptibilty associated
with chia seed oil in terms of oxidation mainly due to its fatty acid
composition.