Difference Between Hot Pressing And Cold Pressing Of Walnut Oil

There are two main methods for extracting walnut oil: cold pressing and hot pressing. In cold pressing, fresh walnut kernels are peeled, crushed, and then pressed to obtain crude oil. The crude oil is then filtered and refined to obtain the finished walnut oil. In this process, the temperature of the crushed walnut kernels remains relatively low, which helps preserve the nutritional properties of the oil. The resulting walnut oil is lighter in color, has fewer impurities, and higher nutritional value.

In hot pressing, after fresh walnut kernels are peeled, they are dried and then pressed to obtain crude oil. The crude oil is then filtered and refined to obtain the finished walnut oil. Hot pressing involves higher temperatures during the pressing process, which may cause some proteins to undergo changes. However, hot pressing can increase the oil yield and result in walnut oil with a more aromatic flavor.

To ensure the extraction of high-quality walnut oil, the walnut oil production equipment needs to pay attention to several factors, such as cleaning and crushing, shelling, controlling moisture and temperature, pressing, refining, and other steps. First, the walnuts need to be pre-processed by cleaning them thoroughly and then crushing them into small pieces or particles. Next, the shelling process is carried out to obtain the walnut kernels. Then, the moisture and temperature of the walnut kernels are controlled through roasting, which facilitates better oil pressing. After that, an oil press machine is used to extract the crude oil, which is further refined using refining equipment to remove impurities, acids, colors, odors, and wax, ensuring that the walnut oil is of good quality and safe for consumption.