Addition of rice bran oil to soybean oil during frying increases the oxidative stability of the fried dough from rice flour during storage

The effect of proportion of soybean oil to rice bran oil on lipid peroxidation inhibition in fried dough with rice flour during storage was investigated. Rice flour dough was fried in 100% soybean oil and mixtures with 25, 50 and 75% of rice bran oil at 160 °C for 1 min, then stored in the dark at 60 °C for 10 days. During 10-day storage, polyunsaturated fatty acid decreased rapidly in fried dough frying in 100% soybean oil and mixtures with 25% rice bran oil, while saturated fatty acid increased. Furthermore, total tocopherol content (p ⩽ 0.05) and headspace oxygen concentration in vial headspace (p ⩽ 0.05) were significantly rapidly decreased in fried dough frying in 100% soybean oil and mixtures with 25% rice bran oil, while peroxide and p-anisidine values were significantly lower in fried dough with using oil mixtures (50%, 75% and 100% rice bran oil) during storage (p ⩽ 0.05). However, an increase of FFA was significantly higher in fried dough with frying in 100%, 75% and 50% of rice bran oil during storage (p ⩽ 0.05). There was no significant difference in decreasing gamma-oryzanol contents of fried dough during storage (p > 0.05). These results demonstrated the effect of soybean oil mixtures with 50% and 75% rice bran oil on retardation of oxidative rancidity and hydrolytic rancidity in fried dough during storage.