Dipping effect on drying kinetics of plum fruits

Abstract

Drying of plums is a slow and time-consuming process since their skin is covered with waxy bloom and the fruits dried as a whole. In order to increase the drying rate, various pre-treatments are applied, among which most commonly used operation is dipping. The work presents results of dipping effect on drying kinetics of the plum cultivars Čačanska lepotica, Mildora, Čačanska Rodna and Stanley. Dipping is carried out in laboratory conditions by immersing the fruits in boiling water. Examinations are performed at the drying temperature 70°C in an experimental drier for testing convective drying technological procedure, until reaching 75% of total dry matter in a dried fruit. By dipping at the drying temperature 70 °C, drying time is reduced by 10%, in relation to the control (undipped fruits) for all examined cultivars except Mildora where drying process is decreased by 5,5%.