Optimization of acid hydrolysis conditions for total isoflavones analysis in soybean hypocotyls by using RSM

The optimum hydrolysis conditions of soybean hypocotyls with HCl For a quan titative HPLC determination of total isoflavones (TI) were studied by using response surface methodology (RSM). HCl concentration (HC), hydrolysis tim e (HT) and reaction temperature (RT) were assumed to be the most important factors affecting hydrolysis for the determination of TI. Optimum hydrolysi s conditions for maximizing the determination of TI were: HC = 3.42N, HT = 205.5 min and RT = 44.6 degreesC. The model had a satisfactory coefficient of R-2 (=0.967) and was verified experimentally. Furthermore, the recovery of individual isoflavones was 97-100% under the optimum hydrolysis conditio ns. The results suggested that the conditions were mild and useful for maxi mizing a quantitative HPLC determination of TI in soybean hypocotyls. (C) 2 001 Elsevier Science Ltd. All rights reserved.