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Oil quality difference between cold press and hot press
Apr 17, 2018

In recent years, with the continuous improvement of people's living standard, people are more and more fond of cold pressed oil in edible oil.


The cold pressed oil is sent to the press before the oil is pressed without heating or low temperature. Oil from the low temperature, the acid value is low, generally do not need refining, after sedimentation and filtration after oil. Most of the vegetable oils used in our daily life are hot pressed oil. The rate of hot pressing oil is high and the operation is simple. Most of our oil shops are hot pressed.


Before the oil is pressed, the oil is cleaned and broken at high temperature to make a series of changes in the oil, which can destroy the oil cells, promote the protein denaturation, reduce the viscosity of the oil and so on, so as to squeeze oil and increase the oil production rate.


However, after high temperature treatment, the crude oil extracted from the oil is deep and the acid value is increased. Therefore, wool oil must be refined before it can be eaten. At the same time, high temperature oil extraction causes the bioactive substances (vitamin E, sterol, carotene and so on) in oil plants to be greatly lost during the pressing process, resulting in waste of resources.


The cold press has natural characteristics and avoids the adverse effects produced by traditional high temperature oil extraction. The natural flavor and color of the oil are preserved in the cold pressed oil, and the physiological active substances in the oil are preserved completely. (vitamin E has anti aging function, sterol has the function of healthy skin and the metabolism of human body is enhanced). The original flavor of cold pressed oil is the choice of healthy life.


But most of the oil is not suitable for cold press. For example, soybean, high mustard seed, cottonseed, peanut, sesame, soybean oil contains the smell of soybean, the spicy taste in high mustard seed oil, gossypol toxin in cottonseed oil and aflatoxin in the metamorphic oil, so it must be refined to remove it. The smell of sesame oil and Luzhou flavor peanut oil must be processed by hot pressing technology.


The raw material of the cold press must be selected, otherwise the quality of the cold pressed oil will be seriously affected by the influence of the maturity of the raw material and the harmful substances in the raw material, such as the aflatoxin and the gossypol toxin in the cottonseed. Generally speaking, cold pressing has low smoking point and unstable water content, which is not conducive to long-term storage.


Cold pressing usually needs to be crushed, and then the oil output can go up. Sometimes there are two presses and three presses. Hot press can be pressed again and again, that is the first time to extract oil. Cold pressed oil color, pale, but the smell of oil is not fragrant, do not get angry. Cold pressed oil will not froth when it is frying, and it will not be silted. Hot pressed (pressed) is oil after frying and frying, and then pressed. The oil is pure and fragrant, especially sesame and peanut. The drawback is that when it is not processed, the pot will start to foam when it is frying, but it can solve this problem after a simple treatment. This press is cold and hot food security can be both.


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