Effect of anti-rancidity of ethanolic crude extracts from fifteen local edible plants
were evaluated in palm oil containing 5 ppm ferric ion. Each plant extract was added into
oil sample to obtain the concentration of 350 ppm and stored at 40C for 28 days. The
anti-rancidity was evaluated using Conjugated diene hydroperoxides (CD), Peroxide value
(PV) and Thiobarbituric acid reactive substance (TBARS). After adding the plant extracts
(day 0), some samples had statistically higher in initial CD, PV or TBARS (p>0.05). After
incubation, the increases in CD, PV and TBARS were significantly observed in all samples
including control and oil sample with BHT 200 ppm. In addition, the oil samples with
different plant extracts showed different results either inhibit or activate the lipid
oxidation. Oil samples with 2 plant extracts, Gymnema inodorum (Lour.) Decne and
Micromelum minutum Wight & Arn showed lower values of CD, PV or TBARS compared to
oil sample with BHT (p<0.05). These results suggest that both plants are a promising
source for supplement synthetic antioxidant in oil.