1 Squeeze method
The pressing method for Maize Oil is mainly to use external mechanical pressure to squeeze and separate the oil from the oil material. The oil production method used for oil crops is the pressing method. Compared with other oil extraction methods, corn germ oil production process, equipment and operation technology are roughly the same. The oil production process includes cleaning, drying, softening, flaking, steaming, oil extraction and refining. series process. During this process, the cleaning is mainly to separate the endosperm and hulls in the corn, so as to avoid the impact of such substances on the oil yield and oil quality. The softening moisture is usually 10%~12%, the temperature is controlled at about 60°C, and the softening time is controlled at 15~20min. When going through the process of flaking, the thickness of the flakes should be controlled after flaking, and for billets of different purity, the requirements for moisture and steaming temperature should also be differentiated. Usually, the temperature of steaming and frying should follow the The purity of the billet is improved, but the pressed moisture needs to be reduced accordingly.
2 Leaching method
The leaching method mainly adopts the extraction principle. In the process of oil extraction, the solvent is mainly used to separate the relevant components in the solid material. The main process of the extraction method is to immerse the pre-pressed cake in a selected solvent, so that the oil can be dissolved in the solvent to form a mixed oil. After the mixed oil is made, it can separate the mixed oil and solid residue, and then according to different boiling points
The mixed oil is subjected to operations such as evaporation and stripping, so that the solvent can be evaporated into vapor to the maximum extent, and separated from the oil, and finally oil is obtained. The solvent vapor can continue to be used after being condensed and cooled and recovered. Since the meal contains a certain solvent, the dry meal can be obtained after desolventization and drying. The solvent vapor volatilized during desolventization and drying is condensed and It can still be used after cooling and recycling.
3 Supercritical CO2 extraction method
The supercritical CO2 fluid extraction method mainly refers to that in the supercritical state, the CO2 fluid lacks an obvious gas-liquid interface, so that the gas density is close to the liquid density, and finally it is in a gas-liquid critical state. This property is between gas and liquid. At this time, when the supercritical fluid is contacted with the substance to be separated, the components with polarity, low boiling point and different molecular weight can be selectively extracted sequentially. In addition, in the process of using supercritical CO2 fluid extraction, the oil extraction method is a combination of extraction and separation processes, which effectively utilizes the free diffusion between CO2 gas and liquid, so that it can be extracted in a supercritical state. Extracts the oil from corn germ, which effectively separates the oil.
4 Water enzymatic method
In recent years, the extraction process of Maize Oil has adopted a new oil recovery method of hydroenzyme method. The extraction process is mainly to crush the oil to a certain particle size and then add the corresponding hydrolytic enzyme to decompose the hemicellulose, lignin and cellulose of the germ cell wall by enzymolysis, so that the oil can be effectively released. In the process of extracting corn oil by aqueous enzymatic method, the raw material is corn germ, and in the process of extracting oil by enzymatic method, the pH value of corn, germination rate, enzyme dosage, water treatment time and enzyme type and other factors affect the oil extraction rate. After a certain analysis.