Features of removal of coloring substances during bleaching vegetable oils

Abstract

In modern conditions of vegetable oil processing, the issues of improving the quality and safety of refined oils remain relevant. It has been noted that the most effective one is complex or complete refining of vegetable oils, which ensures the removal of the main groups of related substances by traditional and improved methods. The complexity of the organization of refining technology is associated with the accompanying oxidation of oils at certain stages and a decrease in their resistance to oxidation during storage. Moreover, this is most characteristic of the time-consuming operation of adsorption bleaching when using acidactivated mineral adsorbents containing active metals that contribute to the activation of oxidative processes. A new approach to the organization of the technology of removing coloring substances during bleaching involves the use of a «wet» method of clarification of hydrated wet oil. This technology helps to reduce the oxidation of bleached oil at a high level of clarification. The effectiveness of the method is increased due to the use of a mixture of mineral and vegetable adsorbents, the bleaching ability of which is enhanced by the use of mechanochemical activation (MHA). It has been noted that a plant adsorbent obtained from dried crushed pea leaves containing pectin and hemicellulose is effective. MHA contributes to the complex effect on the treated system due to local pressures and shear deformations, which activate the adsorption properties of the modified mineral-vegetable adsorbent and increases its selective effect. The proposed technology using a mixture of sorbents and MHA increases the resistance of oil to oxidation and reduces the accumulation of oxidation products in it during storage, it improves the quality of bleached oil, which should provide a high effect of the final stage of complete refining – deodorization.