Q1. Explain the principle of blanching.
Based on (De Corcuera, Cavalieri and Powers) says that the inactive enzymes that are present in vegetables and fruit have maintained through blanching i.e. pretreatment. I agree with the statement that blanching is an operation which has activated, “before the stage of freezing, canning or drying.” For preservation of vegetables and fruits blanching has used temperature that is below 100 *C i.e. pre-set time, “which has utilized for cooling.”
According to (Fellows) statement that tells Blanching preservation procedure starts with heating process i.e. use of steam or water. Further, steps that have presented in the book are Blanching | Pasteurisation | Heat sterilisation | Evaporation & Distillation | Extrusion.
Q2. Explain the effects of blanching on the sensory and nutritional qualities of foods and on microorganisms.
According to (Fellows) introduction about heat treatment in food processing varies on step by step method. Blanching is a best way to maintain eating quality. It helps in keeping up the preservation, along with processing conditions. Moreover, maintaining shelf stable food and many other quality stages being used in the blanching process.
Chapter 11 of Blanching says that less use of water soluble components have made for undermining Blanching procedure. Author further, says that it has lower capital cost and provides better energy speed than a normal steam blanchers. It requires small space and systematic way that has used for product heating. Moreover new methods have introduced in the blanching procedure that are Microwave Heating, Ohmic Heating and High Pressure Processing.
De Corcuera, Jos\'e I Reyes, Ralph P Cavalieri, and Joseph R Powers. 'Blanching Of Foods'. (2004): n. page.
Fellows, P. Food Processing Technology. 1st ed. Boca Raton, Fla.: CRC Press, 2009.