分子蒸馏技术纯化柠檬精油工艺研究

Study on Purification of Lemon Essential Oil by Molecular Distillation

采用分子蒸馏技术对柠檬精油进行浓缩精制,分别考察了蒸馏温度、刮膜转速和蒸馏压力对浓缩精油中柠檬醛浓度的影响。在单因素试验基础上,通过L9(3^4)正交设计试验确定了柠檬精油分子蒸馏的最佳工艺参数。结果表明,柠檬精油分子蒸馏的最佳工艺参数为:进料速度1 mL/min,分子蒸馏温度45℃,刮膜转速240 r/min,蒸馏压力40 Pa。浓缩精油经过气相色谱仪(GC)测定,柠檬醛浓度由1.41 mg/mL上升至11.17 mg/mL,浓缩倍数达7.9。经过分子蒸馏后的浓缩精油呈深棕色,质地浓稠,气味浓郁、醇厚。

Lemon essential oil was concentrated and refined by molecular distillation technology.The effects of distillation temperature,rotation speed of wiped film,distillation pressure on the concentration of citral in condensed essential oil was studied respectively.The optimal technological parameters of molecular distillation for lemon essential oil were determined by single factor and L9(3^4)orthogonal tests.The results showed that the optimum conditions of molecular distillation of lemon essential oil were as follows:feed speed 1 mL/min,distillation temperature 45℃,wiped film rotation speed 240 r/min,distillation pressure 40 Pa.Gas chromatograph(GC)analysis showed that the concentration of citral in concentrated essential oil increased from 1.41 mg/mL to 11.17 mg/mL,about 7.9 folds.The concentrated essential oil had dark brown color,thick texture,and strong and mellow odor.