At present, the main methods of extracting ginger oil from ginger include pressing, molecular distillation, and supercritical extraction.
(1) Press method is to directly process the cleaned ginger by mechanical means to obtain the ginger oil. The amount of ginger oil obtained by this method is not only related to the quality of ginger itself but also related to the operation of ginger pretreatment and squeezing facilities. In addition, the pressing product can be treated by precipitation separation method to obtain two different products, namely, supernatant and sediment. The mixture of ginger oil obtained by the pressing method includes non-volatile and volatile ginger oil.
(2) Molecular distillation can better separate the terpenes and gingerol phenols in ginger oil by using the new technology of molecular distillation and can increase the relative content of gingerol phenols to more than 85%. Therefore, molecular distillation is more suitable for the refining process of ginger essential oil.
(3) Supercritical CO2 extraction supercritical, ginger oil produced by Changsha Shanghe Biological is prepared by this method. CO2 extraction can obtain volatile and non-volatile ginger oil at the same time. Because the inertia of CO2 and the extraction and separation are carried out at room temperature, the ginger essential oil extracted by supercritical fluid has more chemical components, a more transparent fragrance and a more pure fragrance. Therefore, this method can reduce the decomposition of unstable components in ginger during the separation process, and its practical application effect is better than that extracted by traditional steam distillation, Moreover, the residue after extraction is more conducive to comprehensive utilization.
