This study aims to investigate the
stability of soybean oil (SO)
using natural antioxidantsspecifically inherent and added
tocopherols, alongside carnosic acid and carnosol from rosemary (Salvia rosmarinus) acetone extracts. By employing
a series of selective oxidation assays, we determined that the strongest
synergistic effect of the antioxidant combination was achieved with
a 1.5:1 ratio of tocopherol to carnosic acid plus carnosol. Furthermore,
this combination was tested in SO, as evidenced by various metrics
such as the induction period (IP) value, peroxide value (PV), free
fatty acids (FFA), kinetic parameters, and antioxidant depletion tracking.
The findings highlight the potential of natural antioxidants as a
viable strategy for food preservation, emphasizing their bioavailability
and overall benefits. The kinetic changes of antioxidants during thermal
oxidation in soybean oil revealed that their interaction involved
the regeneration of tocopherol by carnosic acid, which degrades into
a carnosol.