Minimization of peroxide formation rate in soybean oil by antioxidant combinations

The objective of this work was to minimize peroxide formation rates in refined soybean oil packaged in PVC bottles. The experiment was conducted according to a central composite design for four variables, namely, concentrations of TBHQ, beta-carotene and citric acid in the oil, and Tinuvin P(R) (UV-absorber) in the bottles. The samples were stored at 1720 1x and 25 degreesC during 6 months. Peroxide values were measured monthly, and the mean peroxide formation rate (PFR) during storage time was calculated. PFR was highly correlated to odor changes, measured as differences-from-control at the end of storage time. TBHQ was the most effective antioxidant, followed by Tinuvin P(R). beta-Carotene impaired the color acceptance of the oil. The following antioxidant ranges were suggested to decrease PFR without promoting oil rejection: 150-200 mg kg(-1) of TBHQ, not more than 11 mg kg(-1) of beta-carotene, 30 mg kg(-1) of citric acid, and 3-4 g kg(-1) of Tinuvin P. (C) 2004 Elsevier Ltd. All rights reserved.