Preparation method of L-fructose

Abstract

The invention discloses a preparation method of L-fructose. The preparation method comprises the following steps: S1, preparing a solid base catalyst KF / Fe-O-GN; s2, preparing a graphene / carbon nanotube / styrene sulfonated resin filler; s3, in the presence of a solid base catalyst KF / Fe-O-GN, preparing the L-fructose; s4, converting the resin filler prepared in the step S2 into a calcium type, adding the calcium type resin filler into a separation column, enabling the filtrate obtained in the step S3 to pass through the separation column, and collecting the separation liquid of the L-fructose section.The KF / Fe-O-GN solid alkali is added in the process of producing the L-fructose through the aldehyde-ketone reaction, the catalytic rate is increased to 96.4%, and the yield of the L-fructose is increased to 96.4%. Compared with the existing liquid base catalyst, solid base catalyst and the like, the catalytic rate is improved by 20-30%; the product is separated and purified through graphene / carbon nanotube / styrene sulfonated resin, the advantages of graphene and carbon nanotubes are combined, it is guaranteed that a good supporting network is formed in the resin, selective adsorption of the resin to L-fructose is remarkably improved, and the purity can reach 99.3%.

Description

technical field [0001] The invention belongs to the technical field of biological sugar, in particular to a preparation method of L-fructose. Background technique [0002] L-fructose has not yet been found in nature. It has the same degree of sweetness as D-fructose and cannot be metabolized in the human body. It is an ideal sweetener for diabetics, and it is not as unpleasant as artificial sweeteners. post-bitterness. At the same time, L-fructose is low-calorie, a low-energy sweetener and an inhibitor of various glycosidases. In addition, L-fructose has potential applications in the synthesis of biologically active compounds. [0003] In the preparation process of L-fructose, its purity is an important indicator for evaluating the final product. During processing, it is necessary to separate L-fructose from impurities by an acidic calcium chelating resin. 2+ Fructose resin can form a stable complex with fructose, and the adsorbent (Ca2+ type resin) in the adsorption colu...

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Problems solved by technology

[0003] In the preparation process of L-fructose, its purity is an important indicator for evaluating the final product. During processing, it is necessary to separate L-fructose from impurities by acidic calcium-type chelating resins. Due to Ca 2+ Type resin can form a stable complex with fructose, and the adsorbent (Ca2+ type resin) in the adsorption column can adsorb fructose, while impurities will not form such complexes and will not be adsorbed (or the adsorption force is small) Thus, under the action of the desorbent, the retention time of fructose through the resin is long, while the impurity is short, and the impurity is first sucked out from the resin, and the fructose and the impurity can be continuously separated. However, existing resins include styrene-based resins due to Its specific surface area is small, so that there are few active groups that can be loaded on it, and the contact area with the solution to be treated is small, the ion adsorption capacity is low, and the adsorption equilibrium time is long; in addition, the final yield of the product is another important factor for evaluating the product. Catalyst is an important additive to increase the yield of bio-sugar. In the existing bio-sugar preparation process, most of the commonly used catalysts are liquid acid catalysts or liquid base catalysts. The catalytic rate of these catalysts is low, and the separation procedure after the reaction is complicated. In addition, solid base catalysts or solid base catalysts are also used. At present, the problems of this kind are: the specific surface area of ​​the catalyst is small, which reduces the catalytic activity; or the sulfur-containing groups are easy to lose, and the activity fails quickly.

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