FACTORS INFLUENCING THE FRICTION OF RAISINS DURING PROCESSING AND HANDLING

Our study on the friction of Sultana and Corinth raisins indicates tha t there is a linear increase of the static and the kinetic friction fo rce when the sample was loaded with added weights. An increase in the moisture content, up to 18%, reduces the friction of Sultana raisins, but increases that of Corinth raisins. For moistures larger than 30%, the friction of both types of raisins remains constant. Anti-sticking substances, reduce the friction but increase the stick-slip effect. Th e friction of raisins increases with sugar loss. The friction coeffici ents of raisins, sliding on Teflon-coated surfaces, are reduced by mov e than 30%, compared to PVC surfaces. (C) 1997 Elsevier Science Limite d. All rights reserved.