BLANCHING
Blanching is a mild heat treatment used to inactivate the oxidative enzymes in fruits and vegetables, and given prior to further processing (canning, freezing and dehydration), which otherwise will result in undesirable changes in color, flavor, and nutritive value of the porduct during handling and storage. Apart from enzyme inactivation, blanching also serves several additional functions. It removes the noncondensible tissue gases (which achieves a better vacuum in cans, reduces the strain on can closures during processing, and results in reduced oxygen levels in the can), increases the bulk temperature of the tissue, cleanses the tissue, wilts the tissue to facilitate in packing, and in some instances assists in improving (fixing) the color and texture of green vegetables.