Effects of different cooking methods on the vitamin C content of selected vegetables

Vegetables are rich in vitamin C, but most of them are commonly cooked before being consumed. The objective of the present study was to evaluate the effects of three common cooking methods (i.e. steaming, microwaving, and boiling) on the vitamin C content of broccoli, spinach, and lettuce.

100 g of homogeneous pieces of broccoli, spinach, and lettuce was separately processed for 5 minutes by steaming, microwaving, and boiling. A simple UV analytical method was employed to determine the vitamin C content of the vegetables.

Loss of vitamin C in broccoli, spinach, and lettuce during steaming was 14.3, 11.1, and 8.6 per cent, respectively, while the loss of vitamin C during boiling was 54.6, 50.5, and 40.4 per cent, respectively. During microwaving, loss of vitamin C in broccoli, spinach, and lettuce was 28.1, 25.5, and 21.2 per cent, respectively.

This study shows that any raw vegetable contains the highest content of vitamin C compared to that of cooked one. Eating raw vegetables is the best way to obtain vitamin C. Cooking methods (i.e. steaming, microwaving, and boiling) have huge impacts on the vitamin C content of vegetables. Steaming is the best cooking method for retaining the vitamin C content in vegetables.

This study evaluates for the first study the effects of three common cooking methods (i.e. steaming, microwaving, and boiling) on the vitamin C content of broccoli, spinach, and lettuce.