Total antioxidant capacity of stewed tomato and onion flavoured with parsley: effect of thermal household processing

Abstract

Fruit and vegetables are the major antioxidant contributors to the diet Antioxidants assist in the prevention of oxidative damage in the body and may as a result prevent the causation of degenerative diseases. Thermal household processing plays an integral part in South African consumers' lives, as most fruit and vegetables consumed are processed at home. Consumers' perceptions that food processing causes nutrient losses, especially of vitamin C, have been corroborated by studies that investigated thermal household processing of single foods or that of industrial processing. No studies have determined the effect of thermal household processing on mixed dishes. A popular consumed South African mixed dish, namely, stewed tomato and onion flavoured with parsley, was investigated by using three recipes, each using a different preparation method. The traditional recipe for the preparation of stewed tomato and onion was modified (control recipe) to contain parsley. Two other recipes (Recipe 1 and 2) were compiled based on the recipe formulation of the control recipe but differed in the preparation methods used. In Recipe 1, raw onion was added to cooked tomato and in Recipe 2, sauteed onions were added to cooked tomato.