Improving the oxidative stability of virgin olive oil using microformulated vitamin-C.

This study aims to improve the oxidative stability of olive oil using microformulated vitamin-C (Vit-C). The microemulsion containing 10,000 µg/ml Vit-C with a droplet size of 1,000 ± 68 nm was first prepared. Free radical scavenging of olive oil and olive oil containing blank microemulsion, different amounts of formulated Vit-C (100-500 µg/ml), and TBHQ (100 and 200 µg/ml as a standard antioxidant) was around 90% during 21 days of incubation at 60°C. The oxidative stability of the mentioned samples during incubation was investigated using the rancimat test, and their quality criteria analysis was studied by peroxide and the acid values. Results showed that the sample's acid value containing 500 µg/ml of Vit-C did not show significant differences ( < .05) with samples containing TBHQ. However, samples containing TBHQ's peroxide value were significant ( < .05) lower than samples containing 500 µg/ml of Vit-C. Furthermore, the induction time of samples containing 500 µg/ml of Vit-C was significantly ( < .05) higher than other treatments during incubation. Thus, the prepared microemulsion could be used as a natural antioxidant in the oil industry instead of harmful synthetic TBHQ.