Optimization of parameters influencing the hydrodistillation of Rosmarinus officinalis L. by response surface methodology [Optimisation des paramètres influençant l'hydrodistillation de Rosmarinus officinalis L. par la méthodologie de surface de réponse]

In order to optimize the factors affecting the extraction of rosmarinus officinalis l. essential oil by hydrodistillation,a study by response surface design type central composite was conducted. after an appropriate choice of four variables,27 experiments led to a mathematical second degree model relating the response function (yield) to factors and allowing a good control of the extraction process. later than the realization of the experiments and data analysis,the study has allowed the knowledge of the optimal conditions necessary to obtain a better essential oil yield. these operating conditions are: an hydrodistillation time of 210 min,a drying for about 8 days,a water/plant material ratio of approximately 10,5 (x 100ml/100g) and a heating temperature of 250°c. our study proved the great efficiency to applying the experiments design methodology for optimizing the operational parameters affecting the hydrodistillation of rosmarinus officinalis. it is about a relevant and economical way which allows to obtain the maximum of information in a short time and,especially,with a minimum of experiments.