Antioxidant components of Brassica vegetables including turnip and the influence of processing and storage on their anti-oxidative properties.

Brassica vegetables, particularly turnip, are a rich source of natural antioxidants. This review focuses on antioxidant components and the effect of processing and storage conditions on antioxidant activities of some Brassica vegetables including turnip. Long storage times had an adverse effect on antioxidant value of turnip. Also during cooking, the antioxidant activity of Brassica vegetables might be influenced by qualitative changes, antioxidant breakdown and leaching into surrounding water. Heat treatment influences the antioxidant activity of Brassica vegetables and it has been observed lower antioxidant capacity in processed samples versus raw vegetables. Industrial processing such as blanching, canning, sterilizing and freezing, as well as cooking methods probably affect the yield, chemical composition and bioavailability of antioxidants in Brassica vegetables. Cooking methods such as steaming and microwaving are proper methods for a short time. Consumption of raw or slightly blanched turnip is an appropriate way to maximize its health benefits.