In fact,
red value (a) decreased when the steam blanching times were increased. Furthermore the chroma and the browning index de-
creased from 5 to 7 min steam blanching, indicating the effect of
long time heat inactivation as mentioned by Matinez and Whitaker
(1995). There was also non-significant fluctuation after one week
in the total colour variation (DE) when steam blanching was ap-
plied for 3, 5 and 7 min. However, in the other cases the colour
change was obvious because of the PPO and POD action.