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

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/100ml), 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/100ml 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.