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

• Appropriate conditions for clarification of PJ with chitosan were determined using RSM.
• Quality characteristics of PJ clarified using chitosan were analyzed.
• Clarification with chitosan was compared to traditional method of clarification.

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 (10–120 mg/100 ml), process temperature (10–20 °C), and process time (30–90 min) and their effects on turbidity and a∗ values were investigated. Using a desirability function method, the optimum process conditions were found to be 68.93 mg/100 ml chitosan at a process temperature and time of 10 °C and 30 min, 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 6 months.