The factors that affect rosemary extraction efficiency include: selection of extractant, dosage, extraction times, standing time, emulsification, etc. When an aqueous solution of solute A is extracted with an organic solvent, the extraction efficiency is equal to the percentage of the total content of A in the organic phase to the total content of A in the two phases. There is a certain relationship between extraction efficiency and distribution ratio.

Extraction refers to the use of the difference in solubility or distribution coefficient of a compound in two mutually immiscible (or slightly soluble) solvents to transfer a compound from one solvent to another. After repeated extractions, most of the compounds are extracted.