Comparison of different pressing methods
There are many different ways to get vegetable oil. For example physical screw press method,hydraulic press method,solvent extraction method and so on. Physical screw press method contain with one time press and double press, hot press and cold press. Do you know what are the differences between physical screw press methods?
І. Difference of One time press and double press：
1.The residual oil in the cake: both one time press and double press is about 6-8%, depending on the different model oil press.
2.The equipment used in the first press is less than that in the second press, which saves the cost; the crude oil in the second press is easier to filter and has less residue oil.
Ⅱ. Difference of hot press and cold press:
1.Cold pressing is to press the oil without heating or low temperature before pressing, and under the environment of lower than 60 ℃, the oil is squeezed with low temperature and acid value. Generally, it does not need to be refined. After precipitation and filtration, the product oil is obtained. The color of the oil is good, but the flavor of the oil is not fragrant and the oil yield is low. It is generally suitable for the pressing of high-end quality oil.
2. Hot pressing is to clean and crush the oil and then heat it at high temperature, which causes a series of changes inside the oil plant, such as destroying the oil cell, promoting the protein denaturation, reducing the oil viscosity, etc., so as to be suitable for pressing oil and increasing the oil yield. Hot pressing technology is generally used for large-scale production and processing of edible oil, with fragrant smell, dark color and high oil yield, but it is easy to cause the loss of nutrients in raw materials.
