Effect of traditional thermal treatment on the antioxidant activity and carotenoids content of nopalitos

The effect of the temperature and duration of thermal treatments of nopalitos on the carotenoid content, phenolic compound content and antioxidant activity was evaluated. The nopalitos were roasted or fried at three temperatures and six time intervals. HPLC and spectroscopic methods to evaluate the modification on the carotenoids, phenolic compounds content and antioxidant activity were used. No correlation between antioxidant activity and carotenoids content in nopalitos, either fried or roasted, was found. The highest antioxidant activity was found in roasted nopalitos (125 ºC; 30 min), however at these conditions, the lowest concentration of carotenoid was obtained. The highest content of phenolic compounds was obtained from roasted nopalitos (75 ºC; 20 min). Both thermal treatments, fried and roasted modified the nutraceutical characteristics of nopalitos.

Keywords: Opuntia ficus, nopalito, antioxidant, thermal treatment.