Atividade antioxidante total da polpa de tomate submetida ao processamento térmico doméstico em diferentes tempos

Abstract

The beneficial effect of tomatoes is attributed to the high antioxidant potential of fruit, which is the result of the presence of antioxidant compounds such as lycopene, phenolics and vitamin C. Heat processing can significantly affect the level of antioxidants in tomatoes, which may reduce or increase its beneficial effects to human health. The objective of this study was evaluating the effect of cooking time under domestic conditions upon the content of the main antioxidant compounds and the total antioxidant activity in vitro (AAT) of the tomato pulp. The tomatoes from cultivar Débora were cooked in stainless steel containers in domestic stove by 0, 15, 30, 45, 60, 75 and 90 minutes. The contents of total phenolics, vitamin C, licopene and β-carotene in the tomato pulp were determined. AAT was determined by using the DPPH and β- carotene/linoleic methods. The cooking of the tomato pulp increased its AAT and the increase was more marked till the 15 minutes in the β-carotene/linoleic acid system and till 30 minutes in the DPPH method. The results showed a significant increase of the contents of licopene, β-carotene and total phenolics and a decrease in the vitamin C content. In general, the heat treatment reduces the nutritive value of foods, but, this study showed an increase in the antioxidant properties of tomato, allowing the consumer to obtain greater benefits in the cooking of tomatoes prior to consumption.