Effect of Natural Antioxidants on the Oxidative Stability of chia seed oil (Salvia hispanica L.)

IXTAINA, V.Y. ; NOLASCO, S.M. ; TOMAS, M.C.

Phoenix

Congreso; 101th AOCS Annual Meeting & Expo; 2010

Amercian Oil Chemists¢¥ Society (AOCS)

Chia seed oil exhibits a high susceptibility to lipid oxidation, due to its high level of PUFAs (~80%), mainly ¥á-linolenic acid. This work evaluates the effect of the addition of tocopherols, rosemary and green tea extracts and their blends on the oxidative stability of chia seed oil. Concentrations ranged between 250 to 5000 ppm of these natural antioxidants were added to the chia oil and an oxidative accelerated test (98 ¨¬C; 20 l/h) was performed. The addition of antioxidants increased the induction time (ti) of this oil in all cases, depending on their type and concentration. Rosemary and green tea extracts produced the best antioxidant effect at the maximum concentration (5000 ppm), with an increase of 3.4 and 2.6 in ti, with respect to control, respectively while their blends (1:1) exhibited a higher antioxidant activity than each one of them. Tocopherols produced positive changes in ti up to 1500 ppm but with a lower effect than those previously described. This fact could be explained considering the ¡°polar paradox¡± due to the hydrophilic nature of the polyphenolic compounds present in both herbal and tea extracts assayed.