Views: 5 Author: Site Editor Publish Time: 2022-09-02 Origin: Site
Excessive benzopyrene content in camellia oil may occur in the planting, harvesting, and processing.
In the planting process, if the industrial "three wastes" pollute the air, water and soil, if they contain polycyclic aromatic hydrocarbons, if the camellia tree grows in these environments, it will be polluted to a certain extent. Heavy industrial enterprises produce carbon black, oil refining, coking, synthetic rubber and other industries, which contain a large amount of benzopyrene in waste water, waste gas and waste residue. These wastes are discharged into rivers or into soil, and benzopyrene in them gradually accumulates in aquatic products or crops. .
In the production process, there are three reasons for benzopyrene exceeding the standard: one is that the tea seeds are mixed with oil as a lubricant; the other is that the tea farmers are drying the tea seeds on the asphalt road, and the molten asphalt is mixed into the tea seeds at high temperature; The tea seed raw material has undergone mildew, which will also produce excessive benzopyrene.
In the processing stage, it is understood that due to factors such as relatively low prices, the main solvent currently used in my country is No. 6 extraction solvent, commonly known as leaching light gasoline. This is a leaching solvent produced by petrochemical plants. Its main components are six-carbon alkanes and naphthenes, with a boiling point of 60-90 °C. Generally speaking, the longer the boiling range, the more complex the components, and the more likely they contain impurities that are harmful to the human body, such as benzene, toluene and polycyclic aromatic hydrocarbons. In addition, in the oil pretreatment stage, especially for the oil with high oil content, in order to improve the oil production effect, a certain amount of cellulose, hemicellulose and lignin are generally introduced into the kernel due to the high oil content. shell to achieve the best pressing process parameters. During the oil steaming and frying stage, due to high humidity and high temperature, it is easy to cause local high temperature, especially for cellulose-based shells, incomplete combustion, carbonization or scorch will occur, resulting in pollutants.
At present, there are several methods for the control and elimination of benzopyrene: controlling the pollution of raw materials, improving the production process, using adsorbents to remove benzopyrene, and screening and separating bacteria that can degrade benzopyrene. In the refining process of benzopyrene in oil, the alkali refining process, decolorization and deodorization process can reduce the content of benzopyrene in oil to a certain extent. At present, the most studied method for removing benzopyrene is the use of adsorbents, among which activated carbon is the most reported. Activated carbon has a very large surface area, contains phenolic functional groups, and its surface is non-polar and hydrophobic, so it can adsorb a large amount of benzopyrene. A large number of experiments show that in the process of oil refining, the use of activated carbon as an adsorbent has a significant effect on the removal of benzopyrene in oil.