ANTIOXIDANT ACTIVITY OF PASILLA PEPPERS HEATED WITH MICROWAVES

摘要

Peppers are a relevant ingredient in traditional Mexican foods, and also contain interesting phytochemicals such as carotenoids and phenolics. The aim of the present work was to study the effects of microwave treatment on the antioxidant activity and the concentration of carotenoids, lutein, □-cryptoxanthin, lycopene and □-carotene. Four different samples were prepared using dry Pasilla peppers, which were previously re-hydrated to 80% moisture, as follows: Sample 1 Pasilla peppers, Sample 2 peppers + water (1:2 w/w), Sample 3 peppers + corn oil (1:2 w/w), Sample 4 peppers + cream (1:2 w/w). 100 g of each sample were heated in a domestic microwave oven LG MS-1742 (650Watts) for 60, 120 and 150 s. Results show that microwave processing increases the concentration of carotenoids and antioxidant activity. The content of □-carotene increases significantly from 500 to 1500 μg carotenoid/g pepper on a dry basis when heated for 150 s and mixed with oil. Lutein and □-cryptoxanthin doubled their concentration in the sample with water. These differences may be due to the different solubilities of carotenoids in water and oil, according to their functional groups. The antioxidant activity expressed as μMol Trolox/g of pepper on dry basis increased significantly on Sample 1 from 27 to 91, on Sample 2 from 43 to 119 and on Sample 3 from 50 to 93. It was concluded that microwave processing may improve the antioxidant activity of Pasilla peppers.