Tissue damage in heated carrot slices. Comparing mild hot water blanching and infrared heating

Mild heat treatment of carrot slices as a pre-treatment for frozen storage was accomplished by exposure of slices to radiant heat to maximise thermal exposure of the cells at the surface while preserving the integrity of cells within the slices. Cell damage as a consequence of this treatment on texture was evaluated. Carrot slices treated for 7 s with radiant energy in the far-infrared region from a radiant surface at 810 K were evaluated for cell damage by relative electrolyte leakage and microscopic observations. Cell damage caused by heating in boiling water from 5 to 30 s was used for comparison. Carrot slices heated by far-infrared radiation contained damaged cells only in the first half millimetre from the surface and exhibited the texture characteristic of the raw tissue.