Resumen
The aim of this research was to determine the action of peroxidase (POD) and polyphenoloxidase (PPO) as well as mineral contents into natural and blanched broccoli, Brassica oleracea L. (Brassicaceae), - the latter was submitted to thermal treatment at 95,0oC during 10 to 12 minutes. Extracts containing POD and PPO were prepared using sodium phosphate buffer 100mmol/L in different pH (5.0, 5.5, 6.0, 6.5, 7.0 and 7.5). The procedure was followed in order to extract the soluble fraction and the fraction ionically linked to the cellular wall. Among the extracted fractions from both natural and blanched broccoli a strong distinction on the soluble fraction was noticed, being POD and PPO activity more intense on natural broccoli. The same variation, however, was not detected in ionically linked fractions. The thermal treatment used in the blanching process did not affect mineral contents: Fe (152.3ppm e 149.0ppm); Cu (15.5ppm e 9.6ppm); Zn (104.3ppm e 104.3ppm); Mn (59.8ppm e 59.6ppm); Ca (0.69% e 0.59%); Mg (0.29% e 0.29%); K (2.58% e 3.04%) - for natural and blanched broccoli, respectively.