DESTRUCTION OF POTATO PEEL TRYPSIN-INHIBITOR BY PEELING AND EXTRUSION-COOKING

Potato peels, a by-product of potato processing, can serve as a source of concentrated dietary fiber, but potato trypsin inhibitors (TI) in peels could reduce nutritional quality. Peels prepared by two methods (abrasion or steam) were extruded at 110C or 150C with feed moistures of either 30% or 35%. Prior to extrusion, abrasion and steam peels con tained 45.57 and 8.06 TIU/g, respectively. Extrusion reduced TI activi ty by 75-85% in abrasion peels, but no reductions were observed for st eam peels. TI may not pose a nutritional problem for steam peels with or without extrusion. Abrasion peels should be extruded, or processed by another thermal method, prior to use in foods.