Spice Oleoresin and Extracts as Natural Antioxidants for Improving Thermal Stability of Vegetable Oils.

A study on effect of spice oleoresin and extracts
on high temperature stability of some vegetable oils
namely, soybean, sunflower and groundnut oils was
carried out. Vegetable oils containing added chilli and
pepper oleoresins or extracts at 0.01, 0.05, and
0.10% (wt/wt) were subjected to heating at 120°C for
various time periods of 0, 2, 4, 8, 12, 16, 20, and 24
hr. Afterwards, samples were investigated for changes
in color, peroxide formation and fatty acid composition
using standard methods. Chilli and pepper oleoresin
and extracts showed antioxidant effect in commercial
soybean oil. There was a mild antioxidant effect in
refined sunflower oil and unrefined groundnut oil.
The extracts showed synergism with α-tocopherol
when tested in sunflower oil. However, for deep frying
purposes, the spice oleoresin or extracts may prove
beneficial as antioxidants instead of the synthetic
antioxidants.