Optimization of an Extraction Procedure for the Quantification of Vitamin E in Tomato and Broccoli using Response Surface Methodology

Response surface methodology (RSM) was applied to optimize the extraction procedure for the determination of vitamin E in tomato and broccoli samples. The effects of varying the amount of 60% potassium hydroxide (KOH), saponification time, and final ethanol concentration (EtOH) on the tocopherol contents were evaluated to optimize extraction and saponification steps by RSM. The optimized parameters were obtained by ridge analysis. Based on the ridge analysis, optimum conditions found were: ml 60% KOH, 8.4–8.9; saponification time (min), 50.7–54.3 at 70°C; and %EtOH, 30.1–35.0. Under the optimized conditions, the experimental values agreed with values predicted by ridge analysis. The analytical method validation parameters such as accuracy, precision, limit of detection, limit of quantification, and specificity were calculated to ensure the methodʹs validity.