Method for effectively preparing zeaxanthin from marigold oleoresin

Abstract

The invention discloses a method for effectively preparing zeaxanthin from marigold oleoresin; marigold oleoresin is used as the reaction raw material; zeaxanthin is obtained by utilizing isomerization reaction; marigold oleoresin is dissolved under ultrasonic conditions; and isomerization reaction is carried out under the action of microwave. According to the invention, conversion is carried out in an assisted manner by adopting an ultrasonic-microwave combined technology; the reaction conditions are mild; the product unit content is high; the conversion rate is high; the method is applied to industrially producing high-content edible zeaxanthin; found from experiments, because the ultrasonic-microwave combined technology is used in the reaction, the reaction time is easily shortened; the reaction temperature is reduced; the reaction conversion rate is increased; and the method disclosed by the invention is simple in process, low in energy consumption, little in harmful organic solvent, high in product unit content and high in conversion rate, and is applied to industrially producing edible zeaxanthin in a large scale.

Description

technical field [0001] The invention relates to a method for preparing zeaxanthin, in particular to a method for efficiently preparing zeaxanthin from a lutein extract. Background technique [0002] Zeaxanthin (zeaxanthin, 3,3-dihydroxy-β-carotene) is a carotenoid that exists widely in nature, and is isomers with lutein, and is the main carotenoid in human blood and tissues one. The zeaxanthin molecule contains 11 conjugated double bonds and the tail group has a hydroxyl group. This structure makes it have a strong antioxidant capacity, which can effectively remove active oxygen free radicals in the human body and improve physiological functions. Function, anti-aging effect. Medical research shows that zeaxanthin can delay and inhibit age-related macular degeneration, cataract, cancer, cardiovascular disease and other chronic diseases, especially in protecting eyes. As a physiologically active substance, zeaxanthin has broad research and development prospects in the field...

AI Technical Summary

Problems solved by technology

[0003] At present, there are four ways to obtain zeaxanthin. One is direct extraction from plants, but the content of zeaxanthin in plants is very low, the extraction steps are cumbersome, and a large amount of organic solvents are used, which has no economic value; the second is microbial fermentation. Because most microbial fermentation units are relatively low, resulting in low zeaxanthin content in the fermented liquid, the subsequent extraction is loaded down with trivial details, and is not suitable for industrial production; the third is the total chemical synthesis method, which has many reaction steps, many harmful chemical reagents, and low product yield. The obtained zeaxanthin is not conducive to human body absorption; the fourth is to use the chemical transformation method to prepare zeaxanthin, that is, to prepare zeaxanthin through lutein epimerization. At present, some patents and documents relate to the separation of zeaxanthin from marigolds. Method for preparing zeaxanthin from lutein crystals through epimerization

[0004] Chinese patent publication CN1915970A discloses a method for converting lutein into zeaxanthin, which uses lutein oleoresin extracted from marigold flowers as a raw material to prepare zeaxanthin by alkali-catalyzed reaction, but the obtained zeaxanthin conversion rate is only 30% %, and the product content is only 50%

[0005] Chinese patent announcement CN1082507C discloses a method for transforming lutein, which provides a method for producing zeaxanthin by chemical translocation from lutein, which mainly uses dimethyl sulfoxide and saturated alkanes A mixture of organic solvents such as aromatic hydrocarbons is used as a solvent, and alkali metal hydroxide is used as a catalyst to transposition lutein to produce zeaxanthin; but in this process, the amount of alkali is quite large, and it needs to be reacted at high temperature for dozens of hours. , causing a considerable part of lutein and the generated zeaxanthin to be degraded or carbonized, resulting in a rather low yield of less than 30%, which is not suitable for industrial production

[0006] Chinese patent publication CN 102399178A discloses a method for converting lutein esters into zeaxanthin in one pot, which realizes saponification and isomerization reactions under high temperature and strong alkali conditions simultaneously. Higher and longer time, resulting in higher energy consumption and cost, which is not conducive to industrial production

[0007] Chinese Patent Publication CN 101830841A discloses a method for preparing high-content zeaxanthin from lutein extract, which uses lutein extract as the initial raw material to obtain lutein crystals by saponification by controlling the temperature, and then raises the temperature of the system Carry out high-temperature conversion reaction, and the obtained zeaxanthin crystals are crystallized and washed with a mixed solvent (methanol / petroleum ether / water); this method consumes a large amount of harmful organic solvents, and the recovery and treatment of waste liquid is cumbersome, and large-scale production is easy to cause environmental damage Pollution