Optimization of extraction process in production of juniper molasses using response surface methodology

This study reports on the optimization of extraction process in production of juniper molasses. For this purpose Box-Behnken design, which is a widely used form of Response Surface Methodology was used. The effect of three independent variables including temperature (°C), dilution rate (w/v) and time (min) on the total soluble solids (TSS) content were studied. For this, extraction temperature 50 ? 90 ° C, dilution rate 1:4 ? 1:9 (w/v) and extraction time 30 ? 180 min was selected as the minimum and maximum points. In addition total phenolic content, pH and titratable acidity, antioxidant activity and sucrose, glucose and fructose contents of extracts of juniper fruit were determined. The highest value (9,2 °Bx) of soluble solids were obtained at 90 °C of extraction temperature, 1:4 of dilution rate and 105 minutes of extraction time. In addition an optimization model was calculated using soluble solids content values of extracts. To verify the optimization model, extracts were obtained at 90 °C of extraction temperature, 1:4 of dilution rate and 180 minutes of extraction time. According to the prediction model, 9,22 °Bx of TSS content is estimated using these conditions. Verification experiments were performed under these conditions and 9,23 °Bx of TSS content were determined. A 99,92 % of correlation rate was calculated between the predicted and observed values in terms of TSS content. In addition, the lowest and highest values of the results of analyses were found to be 892,57 ? 3968,37 mg/L for total phenolic content, 0,07 % ? 0,18 % for titratable acidity, 4,82 ? 4,95 for pH, 6,15 ? 25,05 mM/mL for antioxidant capacity determined with the ABTS test, 7,96 ? 124,70 mL/mg for antioxidant capacity determined with DPPH test. Sucrose, glucose and fructose contents were determined as 5,78 ? 18,07 g/L, 8,33 ? 23,78 g/L, 9,15 ? 26,12 g/L, respectively.