Clarification of pomegranate juice with chitosan: Changes on quality characteristics during storage

Abstract

In this study, for the first time, the use of chitosan as a clarifying agent in the production of clear pomegranate juice was evaluated and its effects on quality characteristics of juice were investigated. A central composite face centered design was used to establish the optimum conditions for clarification of pomegranate juice (PJ) using response surface methodology. The three factors were concentration of chitosan (10–120mg/100ml), process temperature (10–20°C), and process time (30–90min) and their effects on turbidity and a∗ values were investigated. Using a desirability function method, the optimum process conditions were found to be 68.93mg/100ml chitosan at a process temperature and time of 10°C and 30min, respectively. PJ was produced using the optimum conditions and the quality characteristics such as turbidity, colour characteristics (L∗, a∗, b∗, C∗), titratable acidity, total phenolic, monomeric anthocyanin, and protein contents were evaluated during storage at 4 and 20°C for 6months.