Skip to content

Who’s optimization? 9 Rosemary Antioxidants and Oil Extraction Methods


Rosemary EXTRACT

Antioxidants, rosemary essential oil, etc. can be extracted from rosemary.

  • The main components of antioxidants are diterpenoids, flavonoids, triterpenoids and other compounds with antioxidant functions;
  • Rosemary essential oil is a liquid oil composed of more than 30 volatile components.
Rosemary oil CO2 extraction process

Rosemary extract

Rosemary and its extract can well prevent oxidation reactions in meat food processing, and protect the flavor of processed food. This kind of property has very good stability and is not easy to volatile. At the same time, it has a certain control effect on taste and aroma.

Rosemary extract has strong dissolving power.

It can be made into fat-soluble products or water-soluble products. Therefore, it has strong adaptability in food applications and has the function of stabilizing fats and essential oils in food processing.

rosemary oil extraction method

  1. Steam distillation
  2. Solvent extraction method
  3. Influencing factors
  4. Ultrasonic extraction
  5. Supercritical co2 extraction process
  6. Subcritical co2 extraction method
  7. Microwave extraction
  8. Mnzymatic hydrolysis
  9. Microcapsule aqueous two-phase extraction method

Steam distillation

Extracted substance: volatile components of rosemary


According to the vapor pressure of each component of the volatile oil, the essential oil is extracted from the raw material by using water vapor

Influencing factors

Degree of crushing, soaking time, amount of water added, extraction time


Simple operation, low cost, and can reduce the distillation temperature of perfume ingredients, prevent the decomposition or deterioration of the extract, the extraction process is relatively mature, the output is large, and it does not pollute the environment.


The steam distillation extraction process takes a long time and the system is open. The process will cause thermal instability and the loss of easily oxidizable components, which will damage some components. Therefore, it is only suitable for extracting essential oils.

If other active ingredients need to be extracted, other extraction methods need to be combined, and the process will become complicated and costly.

Solvent extraction method

Extract material

Effective substances in rosemary


Use organic solvents such as petroleum ether, n-hexane, ethyl acetate, acetone, ethanol as extraction solvents to dissolve the effective substances.

Taking into account factors such as safety, effectiveness, economy, etc., rosemary extraction generally uses ethanol as an organic solvent. Ethanol is suitable for extraction within 2 h, with a liquid-to-material ratio of 10:1.

The concentration of ethanol should not be too high, so as not to dissolve non-polar substances in rosemary, such as chlorophyll. And this method is often combined with microwave shaking and other methods to achieve higher yields.

Influencing factors

Ethanol concentration, extraction temperature, material-to-liquid ratio, extraction time and extraction times, etc.


The solvent method is used to analyze the extraction of medicinal materials rich in carnosic acid. The extraction process has high extraction rate and good stability, and is suitable for industrial applications;

Ursolic acid is extracted from rosemary, the extraction rate is 92.38%, its purity is high, and many antioxidant components in rosemary can be extracted at the same time. The method is safe, effective, environmentally friendly, easy to operate, and relatively low cost.


Carnosic acid is greatly affected by operating conditions during the separation process, and is easily converted into carnosol, an oxidation intermediate product, which reduces the antioxidant effect and makes it difficult for the product to meet the requirements of the international market.

Supercritical co2 extraction process

Extracted substances

Essential oils and antioxidants (rosmarinic acid, carnosic acid, etc.).

CO2 Extraction process One

BIT assisted the laboratory of a university in China to extract the antioxidant components of natural rosemary by supercritical carbon dioxide extraction. The optimization extraction parameters were 40MPa pressure, 80°C temperature, 20% water addition, and 2.5h access time. Rosmarinic acid, carnosic acid, and other ingredients are mainly extracted.

CO2 Extraction process Two

Another university’s laboratory concluded that the optimization process conditions are: extraction pressure of 32.6 MPa, temperature of 56.5 ℃, entrainer dosage of 0.6 mL/g, and extraction time of 1 h. In addition, the choice of the composite carrier co-solvent “E6K-10ET” not only significantly improved the physical and chemical properties of the extracted product, but also had a very significant solubilizing effect. The extraction yield of carnosic acid increased from 25.83% to 62.14%.


The method is simple, fast, and efficient, and the obtained essential oil is of pure quality and high in antioxidant active ingredients. Due to the low cost, no pollution, energy-saving, simple operation, environmental protection, and the advantages of simultaneous separation and purification, the method has been widely used in the extraction and separation of natural antioxidants.

Subcritical CO2 fluid extraction

Extracted substances

Flavonoids, saponins, terpenes, antioxidants and volatile oils


Using subcritical fluid as the extractant, in a low-pressure, oxygen-free, airtight container, according to the principle of similar compatibility, through the molecular diffusion process of the extraction material and the extractant in the soaking process, the product and the extraction are extracted through vacuum evaporation Agent separates out.

Influencing factors

Temperature, time, organic solvent, surfactant addition, extraction times, etc.


The choice of solvents is wide, the source of fluid is wide, the price is lower, the dissolution consumption is low, the extraction quality is high, environmental protection, is fast, suitable for heat-sensitive ingredients, etc.

Ultrasonic extraction

Extract material

Rosmarinic acid, carnosic acid, carnosol, ursolic acid, oleanolic acid, etc.

With the increase of time in the ultrasonic extraction process, the yield of carnosic acid and rosmarinic acid gradually increased. After 50 min, the yield of carnosic acid tends to decrease. It is speculated that carnosic acid will be partially degraded or dissimilar under long-term ultrasound. Structured. The material-to-liquid ratio has no significant effect on the yield of rosmarinic acid, but has a significant effect on the yield of carnosic acid.

Advantages and disadvantages

Although ultrasonic extraction takes a long time to extract, there are few impurities in the liquid medicine, and the effective ingredients are easy to separate and purify; the extraction temperature is low, and the effective ingredients are not easily deteriorated; the operation cost of the extraction process is low, and the comprehensive economic benefits are significant; the operation is simple and easy, equipment maintenance, Easy maintenance, etc.

Microwave extraction

Extracted substances

oils and alkaloids of rosemary.


Microwave has different effects on different parts of plants and different tissues, and the release of intracellular products has a certain selectivity. Therefore, different treatment methods should be adopted according to the characteristics of plant products and their different parts.

Microwave can penetrate the extraction medium and heat directly, which can shorten the extraction time and improve the extraction efficiency.

In a paper, the author microwave-assisted extraction of rosemary volatile oil, the optimization process conditions are: the material-to-liquid ratio is 12.3 mL/g, the extraction time is 125s, the microwave power is 500W, and the extraction rate is 4.05%.


Microwave extraction is less limited by the affinity of the solvent, and there are more solvents to choose from, reducing the amount of solvent.

It is safe, reliable, pollution-free, and belongs to a green project. Microwave extraction does not require pretreatment such as drying, which simplifies the process, reduces investment, and the result of extraction is not affected by the water content of the substance and can be recycled

It has the advantages of strong selectivity, short operating time, low solvent consumption, easy control, simple equipment, environmental protection, and low investment.

Enzymatic hydrolysis

According to the composition of the plant cell wall, using the high specificity of the enzyme, the corresponding enzyme is selected to hydrolyze and degrade the constituent components of the cell wall, destroy the cell wall structure, and dissolve, suspend or peptize the effective components in the cell into the solution, thereby To achieve the purpose of extraction.

Extraction time can be shortened, and the purity of the active ingredients is high, but the technical requirements are high.

Microcapsule aqueous two-phase extraction method

The combined use of microcapsules and two-phase water technology not only improves the extraction efficiency and purification degree of volatile oil, but also effectively protects the transformation of unstable components during the extraction process.