Effects of different cooking techniques on bioactive contents of leafy vegetables

Domestic cooking is based on common techniques, which include boiling, microwaving, frying, and steaming. Most leafy vegetables are commonly consumed after cooking which may improve palatability by softening the food matrix, inactivate the anti-nutritional compounds, and toxic materials. However, cooking may or may not affect the bioavailability of the vital compounds like phenolic compounds, carotenoids, and ascorbic acid contents of vegetables. In this review, the available literature revealed that steaming is safer way of cooking in terms of retention of bioactive contents of vegetables as compared to boiling, frying, and microwaving. The boiling method has a very adverse effect on bioactive contents, especially on ascorbic acid contents. Microwaving and frying have moderate effects on bioactive contents of vegetables, however, the frying technique may improve the lutein (more than 60%) and beta-carotene. Among the cooking techniques, a safer technique should be adopted, with priority on taste, and safety of the leafy vegetables.