Optimization o ig Juice Concentrate Production rom Estahban's 3th Grade Dried ig ruits

ig has a great signiicance due to its nutritional value and the amount o energy. In this project, according to the unique eatures o this product, the considerable amount o ig's production in Iran, reduction o ruit losses, best consumption and its increased additional value, the production isibility o the concentrate and ig syrup was studied and dierent aspects o these products were evaluated. ig ruits were soaked in three temperatures 25, 50 and 75 ΊC in order to ascertain the best temperature and time. Ater passing the required time, the ig juice extracts were iltered. The temperature o 75 ΊC was selected or the next experiments. Three methods were used to concentrate the ig juice with the initial brix value o 10 including: microwave heating, rotary vaccum evaporator and evaporating at atmospheric pressure respectively in 10, 25, 63 min to reach the inal brix 63. The color changes during concentration processes were investigated. Total color dierences, Hunter L, a and b parameters were used to estimate the extent o color loss. L and b parameters decreased with time but a and total color dierence increased. It was observed that the severity o color loss was lower in microwave heating process than the others. Dierent types o kinetic models were also applied to the changes in color parameters. The combined model itted very well with all parameters. Then the production o syrup was perormed by adding pectin and sugar. To assess the main and interaction eects o pectin and sugar on physical and chemical eatures o ig syrup, a central composite rotational design was applied. To reach this goal, dierent combinations o pectin and sugar were added to extract. Panel tests were accomplished or more complete distinction between syrups. DSC studies showed no cold crystallization or melting endotherm in thermograms o ig juice concentrate, while thermograms o syrups with dierent concentration o sucrose showed these peaks. This study conirms the presence o amorphous sugars in the ig juice concentrate. Addition o 0.8% pectin prevented cold crystallization in ig syrup. It can be cocluded that due to dierent physicochemical properties o ig juice concentrate and syrups, they can be utilized as a proper product in dierent ood industries as a coloring agent, a sugar substituent in bakery, and a sweetner in dairy products etc.