Microstructural Changes During Steam Peeling of Fruits and Vegetables

ABSTRACT Microstructural changes of the fruit tissue during a steam‐peeling process were studied and critically evaluated using pimiento pepper ( Capsicum annum L. cv.‘Truhart’) as a model commodity. The high temperature of the steam resulted in melting and reorganization (phase transition) of the cuticular waxes on the surface of the fruit. Heat transfer increased the temperature inside the fruit, which in turn caused vaporization of the cell fluids, increased internal pressure, occurrence of various biochemical reactions (hydrolysis of carbohydrates, breakdown of pectins) and finally rupture of cell walls and separation of the skin. A possible mechanism of peeling is discussed and a multistage peeling process is introduced to improve product yields and reduce peeling losses.