Optimizing conditions for E-and Z-ajoene formation from garlic juice using response surface methodology

The optimum conditions for the formation of E- and Z-ajoene from garlic juice mixed with soybean oil were determined using response surface methodology. A central composite design was used to investigate the effects of three independent variables temperature (°C, X(1)), reaction time (hours, X(2)), and oil volume (multiplied by weight, X(3)). The dependent variables were Z-ajoene (Y(1)) and E-ajoene (Y(2)) in oil-macerated garlic. The optimal conditions for E- and Z-ajoene using ridge analysis were 98.80°C, 6.87 h, and weight multiplied by weight 2.57, and 42.24°C, 9.71 h, and weight multiplied by weight 3.08, respectively. These conditions resulted in E- and Z-ajoene compound predicted values of 234.17 and 752.62 μg/g from garlic juice, respectively. The experimental values of E- and Z-ajoene were 222.75 and 833.59 μg/g, respectively. The estimated maximum values at the predicted optimum conditions were in good agreement with experimental values.