Effect of different cooking methods on the nutritional value of some African indigenous leafy vegetables in Kenya

A study to determine the effect of four cooking methods, on the nutritional value of three African indigenous leafy vegetables, Solanum nigrum, Gynandropsis gynandra and Amaranthus hybridus was carried out between October 2011 and March 2012. Levels of eight nutrients, Beta carotene, Ascorbic acid, calcium, copper, magnesium, manganese, zinc and iron were determined. Cooking methods significantly influenced the nutrient composition of vegetables. The raw samples were of higher nutritional value than the cooked samples. The best cooking method retaining most nutrients across the three vegetables was boiling for 5 minutes. Amaranthu hybridus had an overall higher nutritional value. Data was analyzed using SPSS version 16.