Method for removing free fatty acid in grease by enzyme catalysis

Abstract

The invention discloses a method for removing free fatty acid in grease by enzyme catalysis, which comprises the following steps of mixing a natural deep-eutectic solvent with crude vegetable oil, adding lipase, stirring for reaction, and after the reaction is finished, performing centrifugal separation to obtain an upper oil phase, namely the crude vegetable oil without the free fatty acid. The multifunctional natural deep-eutectic solvent system constructed by the invention can realize synchronous deacidification and dehydration of lipase catalysis, the acyl acceptor type natural deep-eutectic solvent is a reaction substrate and a reaction medium, and is esterified with free fatty acid as a substrate into glyceride, so that the conversion of the free fatty acid into the glyceride is realized, the raw material loss is reduced, and the grease yield is improved. Quick separation from an oil phase can be achieved, the deacidification process is accelerated, the reaction time can be shortened to be within 3h, the product is easy to separate and purify, and a catalytic reaction system can be recycled in multiple batches.

Description

technical field [0001] The invention relates to a processing technology for oil refining and deacidification, in particular to a method for using a multifunctional natural deep eutectic solvent to catalyze the removal of free fatty acids in oil by lipase. Background technique [0002] Unprocessed natural animal and vegetable oils usually contain nutrient-rich glycerides, active components and proteins, as well as substances such as easily oxidized free fatty acids. The existence of such substances will accelerate the oxidation of oils and even threaten human health, thereby It is necessary to process and remove free fatty acids to make edible oil meet the national food safety standards. Therefore, processing and deacidification is an essential process in the oil refining process. [0003] The current deacidification processes for oil mainly include chemical alkali refining deacidification, physical deacidification, and biological enzymatic deacidification. Among them, chemi...

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Problems solved by technology

Among them, chemical alkali refining deacidification is the most commonly used method because of its low cost, simple process flow and high deacidification efficiency, but the disadvantage of this process is that it will form a large amount of saponins, especially the high acid value crude oil leads to neutral oil The loss is large, and the active ingredients in the oil are also lost due to the saponin, which reduces the quality of the oil, and a large amount of industrial wastewater will be generated in the subsequent process of chemical deacidification, which will aggravate the environmental pressure

The physical deacidification method also has a certain application prospect. Its main characteristics are simple process flow and no waste water pollution, but the energy consumption demand is large, the process temperature is high, and it is easy to cause the occurrence of oil side reactions. Deep color increases the cost of subsequent decolorization treatment

In comparison, the enzymatic deacidification of biological lipase has attracted more and more attention, mainly due to the advantages of green, safe, and specificity of the enzymatic deacidification process, although the enzymatic deacidification process has relatively high Good application potential, its traditional process is still insufficient, usually enzymatic catalytic deacidification needs to add strong polar acyl acceptors (polar alcohols) to react with free fatty acids, catalyze the formation of product glyceride and water, and the reaction It is reversible. In order to speed up the forward reaction, the strategy is to maintain a vacuum to reduce the accumulation of product moisture, but this process undoubtedly limits the batch addition of volatile acyl acceptors, and the "one-pot" process is directly affected by the high concentration of polar alcohols. Reduce enzyme catalytic activity and stability, it is difficult to meet the requirements of actual industrial production

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