ABSTRACT
Oils and fats when exposed to air or light and stored for a period of time, are oxidized and deteriorate to produce rancidity. Antioxidants are the compounds, which slow down or hinder the oxidation reaction. The present study was aimed to investigate the effects of different single antioxidant or a mixture of antioxidants on the storage of soybean oil. The single antioxidants used were TBHQ, BHT, BHA and mixture of BHT and BHA. Four samples of oil were stored for 15 weeks with the addition of antioxidants, and a control sample [without antioxidant] was run side by side. The determination was examined periodically, measuring refractive index, saponification value and unsaponifiable matter. The results indicate that synthetic antioxidants tested with soybean oil like TBHQ>BHT>BHT and BHA>BHA were ranked in decreasing order of effectiveness. There was a significant decline of peroxide value and FFA value of the oil with the addition of antioxidant as compared to the oil without any antioxidant. There was also found a slight change in the colour of the oil without antioxidant as compared to oil with antioxidant. No significant change was observed in the saponification value, iodine value and unsaponifiable matter with the addition of antioxidant