Study On Extraction Process Optimization Using Response Surface Methodology And Extraction Kinetics Of Essential Oil From Pogostemon Cahlin (Blanco) Benth And Pericarpium Citri Reticulatae

Pogostemon cahlin?Blanco?Benth?patchouli?and Pericarpium Citri Reticulatae?tangerine peel?,as traditional Chinese herbal medicines,are widely distributed in China.The essential oils of patchouli and tangerine peel include complex chemical components and have abundant bioactive substance significantly applied in medicine,agricultural production,food and health care,flavors and fragrances,cosmetics and so on.In this work,the response surface methodology?RSM?was employed to optimize extraction conditions for hydro-distillation and supercritical CO₂ extraction of essential oils from patchouli and tangerine peel.The yield and chemical compositions of essential oils were compared with different extraction methods.Finally,a kinetic model for supercritical CO₂ extraction of essential oils from patchouli and tangerine peel was explored.This study mainly includes the following contents:?1?The essential oils of patchouli and tangerine peel were extracted by traditional hydro-distillation,respectively.The optimum extraction conditions were determined by single factor experiment and box-behnken design?BBD?in response surface methodology.The maximum experimental yield of patchouli essential oil was 1.21%under the optimal conditions of extraction time 130 min,solid-liquid ratio 1:18 and soaking time 88 min.The highest yield of tangerine peel oil was 0.59%under the conditions of extraction time 97 min,solid-liquid ratio 1:18 and soaking time 51 min.?2?The supercritical CO₂ extraction was used to separately extract the essential oils of patchouli and tangerine peel,and the optmized extraction conditions were also determined by single factor experiment and box-behnken design?BBD?in response surface methodology.The maximum experimental yield of patchouli essential oil was 2.44%at extraction temperature 48?,extraction pressure 24MPa and exrraction time 119 min,and the highest yield of tangerine peel oil was 1.34%when extraction temperature is 45?,and extraction pressure is 14MPa and exrraction time is 147 min.?3?The yield and chemical compositions of patchouli and tangerine peel oil individually obtained by hydro-distillation and supercritical CO₂ extraction were compared.The results indicated that the yield and chemical composition of patchouli and tangerine peel oil obtained by supercritical CO₂ extraction were better than those of hydro-distillation.?4?Based on the Brunauer-Emmett-Teller?BET?theory of adsorption,a mathematical modeling was applied to simulate the process of supercritical CO₂ extraction of essential oil from patchouli and tangerine peel.The model has been solved by simulated annealing algorithm.The average absolulte relative deviation?AARD?between the calculated value of the model and the experimental value does not exceed 4.00%.The results show that the mathematical model can describe the extraction process of essential oil from patchouli and tangerine peel well.