Effects of microwave energy on the relative stability of vitamin E in animal fats

The relative stabilities of individual tocopherols during microwave heating were evaluated in purified animal fats. Each tocopherol (α, β, γ and δ) was added to the purified beef tallow and lard at 0.25 μmol g−1 fat immediately before use. During microwave heating the highest rate of loss was shown by α‐tocopherol, followed by γ‐, β‐ and δ‐tocopherols. This order did not depend on the types of fats present. The indices such as peroxide value, carbonyl value and anisidine value for assessing quality of fats showed a significant difference (P < 0.05) in the final stage (12–20 min) of heating. It is therefore necessary that particular attention be paid to the loss of vitamin E when cooking pork or beef in a microwave oven.