The blanching process has the main objective of inactivation of the endogenous enzymes in fruits and vegetables that lead to the natural degradation of the product. It is always processed previously to vegetable or fruit sterilization, dehydration and freezing processes.
Enzymes such as lipases, lipoxygenases, polyphenol oxidases, pectinases, chlorophyllases and ascorbate oxidase must be inactivated for the preservation of the colour, aroma, flavour, texture and nutritional value of these processed foods.
The enzymes catalase and peroxidase are more heat-resistant than the other referred endogenous enzymes. The determination of a zero peroxidase activity can be an indicator of the effectiveness of the blanching process. The time required for the blanching process (at given pH and T) is that necessary for complete catalase or peroxidase inactivation.