Compositional Changes of the Jujube Fruit During Solar and Tray Drying

Abstract

This study aims to determine the changes in some components of jujube fruit after drying in the solar and tray dryer, and to choose the appropriate drying method in terms of component loss. In this study, jujube fruit (Zizyphus jujuba Mill.) was used as material and were obtained from producers in the Çivril-Denizli regions of Turkey. Firstly, we analysed the total soluble solids, dry matter, titratable acidity, pH, total phenolic content, organic acids (malic, citric, succinic and tartaric acid), sugars (glucose, fructose and sucrose) and water-soluble vitamins (ascorbic acid, riboflavin, niacin, pyridoxine and thiamine) in fresh jujube fruit. Secondly, the fresh jujube fruits were dried in the solar and tray dryer (50, 60 and 70 °C). Following the drying processes, changes of the above-mentioned parameters were evaluated. The total phenolic content was determined using the spectrophotometric method. Sugars, organic acids and water-soluble vitamins content were determined using a high-performance liquid chromatography (HPLC) instrument. The solar drying of the jujube fruit resulted in glucose and sucrose content decrement and in fructose content increment, while tray drying resulted in decrement in glucose, fructose and sucrose content. A high decrement in organic acids and water-soluble vitamins content of the jujube fruit both in the solar and tray drying process was determined. In addition, solar drying resulted in more vitamin content decrement compared to the tray drying. ©️ 2023 The Author(s).