Abstract:
This work tries to evidence, comparativelly, the evolution of the iodine
index of some maize and sunflower nonrefined oil samples stored under
certain conditions (temperature, light, addition of carroten) during 60 days.
The material for experiment was represented by raw oil samples, whose
iodine index has been determined at once after processing, as well as at 5, 30
and 60 days of keeping at +4ºC (in dark) and at +20-22ºC (in dark and
light). Beside thermal and light regime, in some oil samples has been also
used an addition of carroten (10% carrot fresh juice) to evidence if these
provitamins have an antioxydant role. The analyse of iodine index values in
all samples stored 5, 30 şi 60 days, under above mentioned conditions, has
evidenced the least decrease of this index in samples stored at +4C, and the
highest ones in samples kept at +20-22C, 60 days, in light conditions and with
carroten addition. 30 days of storage at +20-22C has led to very close values of
iodine index in the both types of oil. After 60 days, this index has registered higher
values (a less decrease) in sunflower oil kept in dark conditions. After 60 days of
exposure to light, the sunflower crude oil has registered a more marked decrease of
iodine index than maize oil. The carroten addition, to avert or to slow down the
oxydation process of fatty acids from the both types of oils, has had good results
only at +4C, and less at +20-22C, under dark conditions.
