Effect of antioxidants on losses of tocopherols during deep-fat frying

The changes in tocopherol content of oil used for deep-fat frying of potatoes have been studied. It has been found that α-tocopherol is lost much faster than β-, γ- or δ tocopherol, with a reduction of 50% α-tocopherol after 4–5 frying operations compared with values of about 7 and 7–8 frying operations for β- and γ-tocopherol, respectively, in the absence of added antioxidants. However, the presence of a rosemary extract or ascorbyl palmitate in the frying oil caused a marked reduction in the rate of loss of the tocopherols.