Novel process for extracting L-malic acid

Abstract

The invention belongs to the technical field of production of amino acids, and relates to a process for extracting high-quality L-malic acid in biological fermentation liquor by acidolysis, neutralization, grading film filtration and ion exchange technologies. The process comprises the following steps: acidizing by using phosphoric acid, filtering with micro-filtration membranes and ultrafiltration membranes to remove bacterial protein, other macromolecule impurities, calcium phosphate and other solids; neutralizing fermentation liquor by using calcium hydroxide and calcium carbonate, acidizing by using phosphoric acid, filtering with micro-filtration membranes and ultrafiltration membranes to create a decisive condition for ion exchange and concentration crystallization of a cooling evaporator of the L-malic acid. According to the process, the purity of the L-malic acid extracted once is greater than 99%, the total yield is above 90%, the phosphoric acid is of moderate acidity, and membrane filtering equipment is high in automation degree, stable in operation and convenient for industrial popularization, so that the process has favorable economic benefit, environmental benefit and application prospect.

Description

[0001] technical field

[0002] The invention belongs to the technical field of amino acid production, and the invention relates to a new technology for downstream extraction of L-malic acid fermentation liquid, in particular to a new technology for extracting L-malic acid. Background technique

[0003] Malic acid, also known as 2-hydroxysuccinic acid, has three isomers of L-malic acid, D-malic acid and DL-malic acid due to an asymmetric carbon atom in the molecule. The naturally occurring malic acid is L-shaped, and it exists in almost all fruits, most of which are pome fruits. It can be extracted from the juice of hawthorn, apple and grape fruit, and can also be produced from fumaric acid through biological fermentation. It is an important intermediate product of the internal circulation of the human body and is easily absorbed by the human body. Therefore, it is widely used as a food additive and functional food with excellent performance in the fields of food, cosmetics...