Optimization of grape juice clarification using bentonite, for the maximal removal of turbidity and the minimal reduction of antioxidant compounds by response surface methodology

Response surface methodology was applied to produce Grape juice with high nutritional properties and low mycotoxin. The experiments were planned using the central composite design (CCD) with two independent variables: bentonite concentration (۰.۲۵-۰.۷۵% w/v), and clarification time (۲–۴ hour). To assess samples, polyphenol, flavonoid and turbidity were determined and optimized. The reduction amount of turbidity and flavonoid followed the linear mode. However, the decreased phenolic acid followed the quadratic model. There was adirect linear correlation between the reduction amounts of turbidity and antioxidant compounds with the concentration of bentonite and the clarification time.The bentonite concentration and clarification time significantly affected the reduce of the turbidity and the antioxidant content of grape juice. In general, the results of the current study indicated the addition of ۰.۵۳% bentonite into grape juice could result in a safe food product with ۰.۵۷۳ desirability that it is needed Contact time for approximately ۲.۲۸ hours.

کلیدواژه ها:

turbidity ، grape juice ، clarification ، antioxidant compounds ، optimization.