Modified activated carbon for removing polycyclic aromatic hydrocarbon in vegetable oil as well as preparation method and application of modified activated carbon

Abstract

The invention discloses modified activated carbon for removing polycyclic aromatic hydrocarbon in vegetable oil. The modified activated carbon is prepared by the following steps: pretreating wooden activated carbon to remove impurities; then preparing a surfactant into a solution, and mixing and stirring the solution with the wood activated carbon subjected to impurity removal in proportion; and after the reaction is finished, filtering and washing to obtain the surfactant modified activated carbon adsorbent. The adsorbent prepared by the invention has the advantages of easily available raw materials, simple process and low cost, the modified activated carbon prepared by modifying the surfactant is large in specific surface area and small in pore size, can simultaneously adsorb pigments, benzo [a] pyrene, polycyclic aromatic hydrocarbon and other substances in grease, and has the adsorption rate of 99.8%. Micronutrients (VE and sterol) in the vegetable oil are efficiently retained while adsorption detoxification is performed, and the retention rates of the VE and the sterol are 77.8% and 97.2% or above respectively.

Description

technical field [0001] The invention belongs to the technical field of food processing, and in particular relates to the preparation of modified activated carbon and its method for removing polycyclic aromatic hydrocarbons in vegetable oil. Background technique [0002] Polycyclic aromatic hydrocarbons (PAHs) are a class of condensed aromatic compounds containing two or more benzene rings arranged in angular, linear or clustered forms. They are composed of coal, petroleum, wood, natural gas, gasoline, tobacco A class of persistent organic pollutants produced by incomplete combustion or thermal decomposition of other organic substances. According to the number of benzene rings, PAHs can be divided into heavy PAHs (referred to as HPAHs, the number of benzene rings > 5) and light PAHs (referred to as LPAHs, 2 ≤ benzene ring number ≤ 4). Each benzene ring in the PAHs molecule has a conjugated large π bond with closed electron clouds, the solution is fluorescent, and the elec...

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Problems solved by technology

In my country's GB 2762-2017 "National Food Safety Standard Limits of Contaminants in Food", only the content of BaP is stipulated not to exceed 10 µg / kg, and there is no limit for total PAHs, which is far from the international limit, which affects The reputation of my country's edible oil market and the confidence of consumers also restrict the sustainable development of the oil industry to varying degrees

[0004] The source of polycyclic aromatic hydrocarbons in edible oil is mainly: the oil is dried on the coal tar road surface, and the molten asphalt at high temperature can adhere to the oil seeds, causing oil pollution in the harvesting process. During the process, it is easy to transfer to the oil, causing pollution in the oil; in the process of production and processing, the drying, steaming, frying and uneven coking of the oil will produce polycyclic aromatic hydrocarbons, which will eventually dissolve in the oil; all kinds of carbon black and coal, petroleum, etc. Combustion produces incomplete combustion flue gas or pyrolysis gas often produces a large amount of PAHs, which may increase the PAHs content in oil as a heating medium; the presence of polycyclic aromatic hydrocarbons in the vegetable oil extraction solvent used in the leaching production process will also cause leaching process oil pollution in

[0005] At present, the content of polycyclic aromatic hydrocarbons in edible oil is reduced by protecting the oil from drying environment and low-temperature production and processing, but the loss is high, which makes the cost unacceptable; or in the process of oil processing, a certain amount of polycyclic aromatic hydrocarbons is removed through adsorption and decolorization. Aromatics and oils are added with a certain amount of activated carbon at high temperature, mixed and stirred, and finally filtered, but the operation is relatively cumbersome, and the filtered residue is easy to pollute the environment, and the purified oil obtained after filtration will affect its quality and natural flavor during the high temperature and high pressure process

Chinese patent application CN110760385A A method for removing benzo[a]pyrene from camellia oil (patent application number 201911117997.8), preparing montmorillonite hydrothermal carbon composite material and adding it to tea oil to remove benzo[a]pyrene, which separates benzo[a] The process of ]pyrene is complicated and not easy to operate in practice; and water participates in the removal process of benzo[a]pyrene, which easily causes oxidative rancidity of oil

Chinese patent application CN102260591A A method for removing benzopyrene from edible oil (patent application number 201110183678.4), using TiO 2 -Composite nanomaterial film of ZnO, the degradation degree of cooking oil is not high (80%) when treated with ultraviolet radiation, and ultraviolet radiation may lead to the generation of peroxides, thereby affecting the quality of oil

At present, activated carbon is generally used in oil processing plants to remove aflatoxins from vegetable oils. However, from the current application, it is found that activated carbon can easily adsorb micronutrient components in oil (such as V E , sterols, oryzanol, etc.) and flavor substances, affect the nutritional value of edible oil

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