Datetime: 2022-05-10 01:45:16 Visit: 0
Hot pressing, also known as cooked pressing in some areas, is a common method of oil pressing in which the oil material is subjected to high-temperature heating before pressing. This treatment induces a series of changes within the oil crops, such as the destruction of oil material cells, protein denaturation, and reduced oil viscosity, which make it more suitable for oil pressing and improve oil extraction rate.
The oil obtained using this method has a pure taste and an intense aroma, particularly oils from materials with high oil content such as sesame and peanuts. However, the oil produced using this method has a dark color, high acid value, which tends to make the pan greasy when frying. Moreover, some of the nutrients in the oil (such as vitamin E, phytosterols, carotenoids, etc.) may be lost due to the high temperature used in the hot-pressing process.
Hot Pressing Process:
Cold pressing, also known as raw pressing, is an oil pressing method in which the oil material is pressed without being heated or after being slightly heated, at a low temperature, generally below 60℃. To improve the quality of the oil obtained by cold pressing, the raw materials for pressing are usually selected. Cold pressed oil is obtained at a low temperature and has a lower acid value, making it of higher quality.
Cold pressed oil retains the natural flavor and color of the oil material and preserves the nutrients in the oil, with a lower degree of protein denaturation, facilitating comprehensive use of the protein. Generally, cold pressed oil has a lower smoke point, which makes it less greasy when frying, and a clearer color and better appearance than hot pressed oil. However, since cold pressed oil is not subjected to heating, it may have unstable moisture content and is not suitable for long-term storage. In addition, cold pressed oil has a less intense fragrance than hot pressed oil. While hot pressed oil is known for its strong flavor, cold pressed oil is light flavor.
Cold Pressing Process:
Although cold pressed oil is nutritious and a healthy choice, different oil materials have unique characteristics that determine their suitability for each pressing method. For instance, cold pressed soybean oil may have a fishy smell that is not acceptable to everyone. Similarly, cold pressed sesame oil may have a less intense aroma, which may compromise its quality compared to hot pressed oil. Therefore, while choosing a pressing method, it is important to take into account the characteristics of the raw materials and the preferences of local consumers.
