1. flash steam peeling
2. knife peeling
3. abrasion peeling
4, caustic peeling
5. flame peeling.
3.4.1 Flash steam peeling
Foods (for example root crops) are fed in batches into a pressure vessel which is rotated at 4-6 rpm. High-pressure steam (1500 x 103 Pa) is introduced and all food surfaces are exposed to the steam by the rotation of the vessel for a predetermined time, which differs according to the type of food. The high temperatures cause rapid heating of the surface layer (within 15-30 s) but the low thermal conductivity of the product prevents further heat penetration, and the product is not cooked. Texture and colour are therefore preserved. The pressure is then instantly released which causes steam to form under the skin, and the surface of the food "flashes off Most of the peeled material is discharged with the team, and water sprays are needed only to remove any remaining traces. This