Oxidative stability of sunflower-chia oil blends with addition of antioxidants

GUIOTTO. ESTEFANIA N.; IXTAINA, VANESA Y.; NOLASCO, SUSANA M.; TOMÁS, MABEL C.

Montreal

Congreso; 104th AOCS Annual Meeting & Expo.; 2013

AOCS

The oxidative stability of sunflower oil, chia oil -rich in ω-3 fatty acids- and their blends (sunflower-chia 80:20 and 90:10 wt/wt) with the addition of ascorbyl palmitate (AP, 2000ppm), rosemary extract (ER, 5000ppm) and AP:ER (2000:2000ppm) was evaluated periodically during their storage (t: 360 days) at two temeperatures (T: 4±1 and 20±2ºC,).  An accelerated test (Rancimat), was carried out at 98 ºC with an  air flow of 20 L/h using 5 g of oil, and the oil stability was expressed in terms of  induction time (ti). Oils stored at 4±1°C exhibited higher ti than those stored at 20±2°C. Thus, the temperature is an important parameter in the stability of vegetable oils. Sunflower oil had the highest initial ti value (13.0h) while chia oil recorded the lowest due to its high PUFAs content.The 80:20 and 90:10wt/wt blends showed​​initial ti of 7.6 and 9.2h, respectively. The addition of antioxidants increased the ti in all cases. In the initial time (t:0 day), ER produced the best antioxidant effect, increasing the ti values until 18.1 and 22.5 h for sunflower-chia 80:20 and 90:10 wt/wt, respectively. However, AP:ER was the most effective antioxidant during the storage at both temperatures.