The oil extraction technologies of vegetable oil mainly include: squeezing method, leaching method, water substitution method, supercritical CO2 extraction method, subcritical extraction method and so on.

pressing method is a method of extracting tea oil from camellia oleifera seeds by physical pressing, which originated from the traditional oil-making method in workshops and is a traditional extraction process.

leaching method is a method of extracting tea oil from camellia oleifera seeds by using the principle of solvent extraction.

water substitution method, "water substitution method" is short for replacing oil with water, which does not require pressure squeezing or solvent leaching. Under certain conditions, the affinity between water and protein is greater than that between oil and protein, so the water soaks into the oil to replace the oil.

supercritical CO2 extraction, supercritical fluid leaching technology, is a method to obtain components from fluid or solid materials under critical temperature and pressure conditions with supercritical fluid as solvent. Commonly used supercritical solvent is CO2.

subcritical extraction method: subcritical extraction refers to leaching at low temperature and desolventizing at normal temperature. Butane or a mixture of butane and propane is used as the solvent, which has a low boiling point and is gaseous at normal temperature and is easy to volatilize.

Extended information

Camellia oil is suitable for storage in a cool, dry and dark place, and the optimum temperature is 1-25℃. There will be milky white flocculent crystals at low temperature, which is a normal phenomenon and will not affect eating. When the outside temperature is high, it will naturally disappear (note: refined camellia oil will not have this phenomenon after freezing treatment). Because camellia oil contains a lot of antioxidants, its shelf life can be as long as two years at room temperature, which is much longer than that of ordinary edible oil.

after each use, the bottle cap should be tightened to reduce the contact time with air. The camellia oil should be sealed well, and the lid must be tightened hard to make it tightly sealed. Moreover, the number of times of opening the lid should be reduced as much as possible, so as to avoid the camellia oil from being exposed to air too much and being oxidized.