Effects of thermal treatment on colour and texture of Typha latifolia L.

Through the analysis of the residual activity of peroxidase (POD), chromatic aberration, shear intensity and shear power, the effects of different thermal treatment times at 100 degrees C on the POD, surface colour and texture of Typha latifolia L. were evaluated. The results showed that the activity of POD decreased with the increasing thermal treatment time at 100 degrees C. The regeneration amount of POD increased first for some time and then started to decrease with the treatment time. Thermal treatment times 1.0 and 1.5 min at 100 degrees C exhibited maximum regeneration of POD for the samples stored at 20 and 37 degrees C, respectively. The sample had acceptable texture and surface colour when they were treated at 100 degrees C for 4 min because the POD in the sample was inactivated to an acceptable level.