Preparation method of aldose hexose-zinc complex

Abstract

The invention discloses a preparation method of a hexacaraban-zinc complex, which comprises the following steps: adding a zinc salt solution into a hexacaraban solution to obtain a mixed solution; adjusting the pH value of the mixed solution by using a NaOH solution; raising the temperature and continuously stirring; and after the reaction is finished, cooling the mixed solution to room temperature, filtering, adding absolute ethyl alcohol into the filtrate, stirring and mixing, standing, separating the lower-layer precipitate, washing the precipitate, and drying to obtain the hexacaraban-zinc complex. The aldose hexose-zinc complex is applied as an additive of animal feed and used for supplementing zinc elements in animal bodies, and aldose hexose serving as an animal energy source can be efficiently absorbed by animals and is basically free of residues in animal excreta, so that the aldose hexose-zinc complex is safe and environment-friendly. Therefore, the aldose-zinc complex obtained by complexing aldose with Zn < 2 + > can effectively improve the absorption and uptake rate of animals to Zn < 2 + >, reduce the excretion amount of zinc elements in the external environment of the animals, and avoid pollution to the environment while adding trace zinc elements in animal bodies.

Description

Technical Field

[0001] This invention belongs to the field of animal feed preparation technology containing trace elements, and more specifically, this invention relates to a method for preparing a hexacarbon aldose-zinc complex. Background Technology

[0002] Zinc, an essential mineral element, though comprising only 20-30 parts per million in animals, participates in almost all life processes, from gene expression regulation to immune defense, earning it the title of "the indispensable spark plug of life." Its central role in animal growth and development has become a focus of attention in animal nutrition, physiology, and modern animal husbandry. Zinc's biological functions are primarily manifested in its role as a structural component and activation center of enzymes. The activity of over 300 enzymes depends on the presence of zinc, and these enzymes are widely involved in key biochemical pathways such as nucleic acid replication and transcription, protein synthesis, and carbohydrate and energy metabolism. For example, DNA and RNA polymerases are fundamental to cell division and differentiation, and zinc deficiency directly inhibits the activity of these enzymes, leading to impaired cell proliferation and stunted animal growth. This mechanism lays the core molecular basis for zinc's influence on growth and development. Zinc is crucial for the normal development and functional maintenance of the immune system. As an "immune mineral," zinc ensures the development of central immune organs such as the thymus and spleen, and regulates the activity and function of T lymphocytes, natural killer cells (NK cells), and macrophages. Zinc deficiency can lead to lymphoid tissue atrophy and reduced antibody production, significantly increasing an animal's susceptibility to pathogen infections, thereby indirectly restricting growth potential. In terms of tissue structure and repair, zinc is crucial for the health of epithelial cells, connective tissue, and bones. It maintains the integrity of skin, coat, hooves, and intestinal mucosa by regulating collagen and keratin synthesis. Typical zinc deficiency symptoms, such as incomplete keratinization of the skin, rough fur, and hoof cracks, directly reflect zinc's key role in maintaining structural barrier function. Simultaneously, zinc promotes bone calcification by activating alkaline phosphatase, directly affecting bone development and strength. Zinc also deeply participates in endocrine regulation. It affects the secretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1), and the synthesis of sex hormones, thereby regulating animal growth rate, puberty initiation, and reproductive performance at the systemic level. Furthermore, zinc maintains taste bud function by constituting gustin; its deficiency can lead to decreased appetite, creating a vicious cycle of reduced feed intake and nutritional deficiencies.

[0003] It is worth noting that zinc bioavailability is often influenced by dietary factors. For example, excessive calcium and phosphorus in the diet (especially in the form of phytate phosphorus) can form insoluble complexes with zinc, severely hindering its absorption and thus inducing secondary zinc deficiency. This characteristic means that the actual zinc requirement often varies depending on the dietary composition. Furthermore, most of the high zinc content (especially zinc oxide) is excreted into the environment in feces, not only failing to achieve efficient zinc utilization but also causing environmental pollution. A hexose aldose is a monosaccharide containing six carbon atoms and having an aldehyde group (-CHO) at one end of its molecule. Its general formula is C6H ... 12 O, hexoses mainly include D-galactose, D-glucose, D-mannose, and L-sorbose. Hexoses are direct energy sources for organisms, undergoing complete oxidation through glycolysis and the tricarboxylic acid cycle. They are also the basic unit of cellulose, a major component of plant cell walls, and chitin, the shell material of insects, shrimp, and crabs. As components of glycoproteins and glycolipids, hexoses play the role of "recognition tags" in cell recognition, immune responses, and signal transduction. Organic zinc, especially amino acid chelated zinc, such as zinc methionine, combines essential trace elements for animal growth with amino acids to synthesize chelated compounds with cyclic structures, making it a trace element supplement close to the natural form found in animals. Compared to inorganic zinc, it is highly efficient, low in toxicity, low in pollution, and easily absorbed. Furthermore, since different tissues and enzyme systems in animals require different proportions and amounts of certain amino acids, chelating zinc with specific amino acids or peptides can increase the transport of zinc to specific tissues. Opportunities in tissue and enzyme systems. Organic zinc, especially amino acid chelated zinc, such as zinc methionine, reacts with amino acids to synthesize chelated compounds with cyclic structures, making it a trace element supplement that closely resembles the natural form found in animals. Compared to inorganic zinc, it is highly efficient, low in toxicity, low in pollution, and easily absorbed. Furthermore, because different tissues and enzyme systems in animals require different proportions and amounts of certain amino acids, chelating zinc with specific amino acids or peptides increases the chances of transporting the corresponding zinc element to specific tissues and enzyme systems. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0005] To achieve these and other advantages according to the present invention, the present invention provides a method for preparing a hexose aldose-zinc complex, comprising the following steps; Step 1: Weigh out a hexose and dissolve it in hot deionized water to obtain a hexose solution; weigh out a zinc salt and dissolve it in deionized water to obtain a zinc salt solution. Step 2: Under vigorous stirring, slowly add the zinc salt solution to the hexose aldose solution to obtain a mixed solution; adjust the pH of the mixed solution to 7.5~9.0 with NaOH solution; raise the temperature to 60~80℃ and continue stirring for 2~12 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add anhydrous ethanol to the filtrate, stir and mix, let it stand for 3-12 hours, separate the lower precipitate, wash the precipitate and spray dry it to obtain the hexose aldose-zinc complex.

[0006] Preferably, in step one, the aldose includes one or more of D-galactose, D-glucose, D-mannose, D-mannose, and L-sorbose; and the ratio of the aldose to hot deionized water is 1~3 mol: 400~600 mL.

[0007] Preferably, in step one, the zinc salt is ZnSO4·7H2O, the molar ratio of ZnSO4·7H2O to hexose aldose is 1:1~3, and the volume ratio of ZnSO4·7H2O to deionized water is 1mol:300~500mL.

[0008] Preferably, in step two, the concentration of the NaOH solution is 0.1~2 mol / L.

[0009] Preferably, in step three, during spray drying, the inlet temperature is 180~200℃ and the outlet temperature is 80~90℃.

[0010] Preferably, in step one, a modified aldose is used to replace the original aldose, and the method for preparing the modified aldose includes: S11. Dissolve hexose in deionized water, add NaOH solution to adjust the pH of the solution to 10-11, and obtain an alkaline solution of hexose; S12. Heat the alkaline solution of hexacarbon aldehyde to 60~70℃, start stirring, add H2O2 solution dropwise, continue stirring for 2~4 hours after the addition is complete, and cool to room temperature to obtain an alkaline solution of hexacarbon aldehyde oxidized by H2O2. S13. Dissolve chitosan in acetic acid solution to obtain chitosan solution. Mix chitosan solution with alkaline solution of hexacarbon aldehyde oxidized by H2O2, add crosslinking agent, stir and heat to 60~80℃, keep warm for 2~4h, and cool to obtain pre-crosslinked solution. S14. Pour the pre-crosslinking solution onto the substrate surface, allow it to dry initially to form a gel film, then heat it to cure and complete the crosslinking process to obtain a crosslinked film. Crush the crosslinked film, wash it with deionized water until neutral, and dry it to obtain modified hexose.

[0011] Preferably, in S12, the mass fraction of the H2O2 solution is 10%~30%, and the H2O2 in the H2O2 solution accounts for 5%~8% of the mass of the hexacarbon aldose.

[0012] Preferably, in step S13, the concentration of the acetic acid solution is 0.5~5wt%; the ratio of chitosan, acetic acid solution, and alkaline solution of hexacarbonaldehyde oxidized by H2O2 is 1~5g:100~500mL:50~100mL.

[0013] Preferably, in step S13, the crosslinking agent is citric acid or genipin, and the amount of the crosslinking agent is 10% to 20% of the mass of chitosan.

[0014] Preferably, in step S14, the initial drying temperature is 80~90℃, the heating curing temperature is 120~130℃, and the heating curing time is 30~60min.

[0015] This invention includes at least the following beneficial effects: This invention uses hexose aldose as a complexing Zn 2+ A carrier was used to prepare a hexose-zinc complex. This hexose-zinc complex is used as an additive in animal feed to supplement zinc levels in animals. Hexoses, as an energy source for animals, are efficiently absorbed and leave virtually no residue in animal excrement. Therefore, the use of hexose-zinc complexes is beneficial. 2+ The obtained aldose-zinc complex can effectively improve the animal's absorption of Zn. 2+ The absorption and uptake rate is improved, reducing the amount of zinc excreted by animals in the external environment. While adding trace amounts of zinc to the animal body, it does not cause pollution to the environment. Therefore, the hexacarbon aldose-zinc complex obtained by this invention is a green, safe, and environmentally friendly animal feed additive.

[0016] In another embodiment, this invention uses hydrogen peroxide (H₂O₂) to oxidize hexose aldoses under alkaline conditions. The oxidation process converts the aldehyde and / or primary hydroxyl groups of the hexose aldoses into carboxyl groups (-COOH). The carboxyl groups have a much stronger complexing ability with zinc ions than the original hydroxyl and aldehyde groups. By introducing natural high-molecular-weight chitosan, a large number of amino groups (-NH₂) are introduced into the system. Amino groups have a strong coordination ability with zinc ions.

[0017] The resulting modified hexose possesses both carboxyl and amino groups, two strong coordinating groups, enabling it to form more stable chelates with higher coordination numbers with zinc ions, thus significantly improving the complexing capacity of zinc and the stability of the complex. Using citric acid or genipin as cross-linking agents, the oxidized hexose is cross-linked with chitosan to form a three-dimensional network hydrogel. After cross-linking and curing, the modified hexose acquires a three-dimensional network structure with amino and carboxyl groups, further enhancing its complexing ability with zinc ions and improving the stability of the hexose-zinc complex. Simultaneously, the three-dimensional network encapsulates zinc ions, effectively preventing unnecessary reactions with other substances in the acidic environment of the animal's stomach, ensuring its smooth arrival in the intestines for absorption. This network structure can serve as a sustained-release carrier for zinc ions, prolonging its duration of action and improving bioavailability.

[0018] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0019] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0020] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof. Example 1 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of ZnSO4·7H2O and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0021] Example 2 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of modified D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of ZnSO4·7H2O and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. The preparation methods for modified D-glucose include: S11. Dissolve 100g in 500mL of deionized water, add NaOH solution to adjust the pH of the solution to 11, and obtain D-glucose alkaline solution; S12. Heat the D-glucose alkaline solution to 65℃, start stirring, and add 40mL of 20wt% H2O2 solution dropwise. After the addition is complete, continue stirring for 3h. After cooling to room temperature, the D-glucose alkaline solution oxidized by H2O2 is obtained. S13. Dissolve 5g of chitosan in 300mL of 2wt% acetic acid solution to obtain chitosan solution. Mix the chitosan solution with 50mL of D-glucose alkaline solution oxidized by H2O2, add 0.5g of citric acid powder, stir and heat to 80℃, keep warm for 3h, and cool to obtain pre-crosslinked solution. S14. Pour the pre-crosslinking solution onto a clean glass plate surface, dry it at 80°C to form a gel film, then heat it to 120°C to solidify it, keep it at that temperature for 30 minutes to complete the crosslinking and obtain a crosslinked film; pulverize the crosslinked film, wash it with deionized water until neutral, and dry it to obtain modified D-glucose.

[0022] Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0023] Example 3 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of modified D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of ZnSO4·7H2O and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. The preparation methods for modified D-glucose include: S11. Dissolve 100g in 500mL of deionized water, add NaOH solution to adjust the pH of the solution to 11, and obtain D-glucose alkaline solution; S12. Heat the D-glucose alkaline solution to 65℃, start stirring, and add 30mL of 20wt% H2O2 solution dropwise. After the addition is complete, continue stirring for 3h. After cooling to room temperature, the D-glucose alkaline solution oxidized by H2O2 is obtained. S13. Dissolve 5g of chitosan in 300mL of 2wt% acetic acid solution to obtain chitosan solution. Mix the chitosan solution with 60mL of D-glucose alkaline solution oxidized by H2O2, add 0.8g of citric acid powder, stir and heat to 80℃, keep warm for 3h, and cool to obtain pre-crosslinked solution. S14. Pour the pre-crosslinking solution onto a clean glass plate surface, dry it at 80°C to form a gel film, then heat it to 120°C to solidify it, keep it at that temperature for 30 minutes to complete the crosslinking and obtain a crosslinked film; pulverize the crosslinked film, wash it with deionized water until neutral, and dry it to obtain modified D-glucose.

[0024] Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0025] Example 4 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of modified D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of ZnSO4·7H2O and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. The preparation methods for modified D-glucose include: S11. Dissolve 100g in 500mL of deionized water, add NaOH solution to adjust the pH of the solution to 11, and obtain D-glucose alkaline solution; S12. Heat the D-glucose alkaline solution to 65℃, start stirring, and add 25mL of 20wt% H2O2 solution dropwise. After the addition is complete, continue stirring for 3h. After cooling to room temperature, the D-glucose alkaline solution oxidized by H2O2 is obtained. S13. Dissolve 5g of chitosan in 300mL of 2wt% acetic acid solution to obtain chitosan solution. Mix the chitosan solution with 80mL of D-glucose alkaline solution oxidized by H2O2, add 1g of citric acid powder, stir and heat to 80℃, keep warm for 3h, and cool to obtain pre-crosslinked solution. S14. Pour the pre-crosslinking solution onto a clean glass plate surface, dry it at 80°C to form a gel film, then heat it to 120°C to solidify it, keep it at that temperature for 30 minutes to complete the crosslinking and obtain a crosslinked film; pulverize the crosslinked film, wash it with deionized water until neutral, and dry it to obtain modified D-glucose.

[0026] Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0027] Example 5 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of modified D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of ZnSO4·7H2O and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. The preparation methods for modified D-glucose include: S11. Dissolve 100g in 500mL of deionized water, add NaOH solution to adjust the pH of the solution to 11, and obtain D-glucose alkaline solution; S12. Heat the D-glucose alkaline solution to 65℃, start stirring, and add 25mL of 20wt% H2O2 solution dropwise. After the addition is complete, continue stirring for 3h. After cooling to room temperature, the D-glucose alkaline solution oxidized by H2O2 is obtained. S13. Dissolve 5g of chitosan in 300mL of 2wt% acetic acid solution to obtain chitosan solution. Mix the chitosan solution with 50mL of D-glucose alkaline solution oxidized by H2O2, add 0.5g of genipin, stir and heat to 80℃, keep warm for 3h, and cool to obtain pre-crosslinked solution. S14. Pour the pre-crosslinking solution onto a clean glass plate surface, dry it at 80°C to form a gel film, then heat it to 120°C to solidify it, keep it at that temperature for 30 minutes to complete the crosslinking and obtain a crosslinked film; pulverize the crosslinked film, wash it with deionized water until neutral, and dry it to obtain modified D-glucose.

[0028] Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0029] Comparative Example 1 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of oxidized modified D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of ZnSO4·7H2O and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. The preparation methods for oxidatively modified D-glucose include: S11. Dissolve 100g in 500mL of deionized water, add NaOH solution to adjust the pH of the solution to 11, and obtain D-glucose alkaline solution; S12. Heat the D-glucose alkaline solution to 65℃, start stirring, and add 25mL of 20wt% H2O2 solution dropwise. After the addition is complete, continue stirring for 3h. After cooling to room temperature, the D-glucose alkaline solution oxidized by H2O2 is obtained. S13. Add 0.5g of citric acid powder to 50mL of D-glucose alkaline solution oxidized by H2O2, stir and heat to 80℃, keep warm for 3h, and then cool to obtain the membrane solution. S14. Pour the film solution onto a clean glass plate surface, dry it initially at 80°C, then heat it to 120°C to solidify it, keep it at that temperature for 30 minutes, wash the solid powder with deionized water until it is neutral, and dry it to obtain oxidized modified D-glucose.

[0030] Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0031] Comparative Example 2 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of oxidized modified D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of zinc salt and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. The preparation methods for oxidatively modified D-glucose include: S11. Dissolve 100g in 500mL of deionized water, add NaOH solution to adjust the pH of the solution to 11, and obtain D-glucose alkaline solution; S12. Heat the D-glucose alkaline solution to 65℃, start stirring, and add 25mL of 20wt% H2O2 solution dropwise. After the addition is complete, continue stirring for 3h. After cooling to room temperature, the D-glucose alkaline solution oxidized by H2O2 is obtained. S13. Add 0.5g genipin to 50mL of D-glucose alkaline solution oxidized by H2O2, stir and heat to 80℃, keep warm for 3h, and then cool to obtain the membrane solution. S14. Pour the film solution onto a clean glass plate surface, dry it initially at 80°C, then heat it to 120°C to solidify it, keep it at that temperature for 30 minutes, wash the solid powder with deionized water until it is neutral, and dry it to obtain oxidized modified D-glucose.

[0032] Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0033] Comparative Example 3 A method for preparing a D-glucose-zinc complex includes the following steps: Step 1: Weigh 1 mol of modified D-glucose and dissolve it in 500 mL of hot deionized water at 60℃ to obtain a D-glucose solution; weigh 0.5 mol of ZnSO4·7H2O and dissolve it in 300 mL of deionized water to obtain a zinc salt solution. The preparation methods for modified D-glucose include: S11. Dissolve 100g in 500mL of deionized water, add NaOH solution to adjust the pH of the solution to 11, and obtain D-glucose alkaline solution; S12. Dissolve 5g of chitosan in 300mL of 2wt% acetic acid solution to obtain chitosan solution. Mix the chitosan solution with 50mL of D-glucose alkaline solution, add 0.5g of genipin, stir and heat to 80℃, keep warm for 3h, and cool to obtain pre-crosslinked solution. S13. Pour the pre-crosslinking solution onto a clean glass plate surface, dry it at 80°C to form a gel film, then heat it to 120°C to solidify it, keep it at that temperature for 30 minutes to complete the crosslinking and obtain a crosslinked film; pulverize the crosslinked film, wash it with deionized water until neutral, and dry it to obtain modified D-glucose.

[0034] Step 2: Under vigorous stirring, slowly add the zinc salt solution to the D-glucose solution to obtain a mixed solution; adjust the pH of the mixed solution to 8.5 with 1 mol / L NaOH solution; raise the temperature to 70℃ and stir continuously for 6 hours. Step 3: After the reaction is complete, cool the mixed solution to room temperature, filter it, add 500 mL of anhydrous ethanol to the filtrate, stir and mix, let it stand for 12 h, separate the lower precipitate, wash the precipitate, and spray dry it (inlet temperature 180℃, outlet temperature 80℃) to obtain D-glucose-zinc complex.

[0035] The zinc complexation rate (the ratio of zinc ion content in the D-glucose-zinc complex to the total zinc ion content) of the D-glucose-zinc complex in steps two of Examples 1-5 was determined respectively. The determination method is based on the sucrose zinc section of the "New Feed and New Feed Additive Product Standard NYSL-1003-2024", replacing sucrose in the standard with D-glucose. Since fructose determination is not involved here, the zinc complexation rate of the D-glucose-zinc complex can be directly referenced from that standard. The particle size of the D-glucose-zinc complex (passing rate using an 850 μm pore size test sieve) and the particle size of the D-glucose-zinc complex were also determined. The results are shown in the table below. Table 1. Complexation rate and particle size data for each sample As can be seen from Table 1, the zinc complexation rates of Examples 2-5 are significantly higher than those of Examples 1 and Comparative Examples 1-3, all exceeding 95.0%. Furthermore, the D-glucose-zinc complexes obtained in Examples 2-5 all exhibited a passing rate of over 95% on an 850 μm sieve. This indicates that the D-glucose-zinc complexes and particle sizes obtained in the above examples meet the requirements of the standard "New Feed and New Feed Additive Product Standard NYSL-1003-2024". Example 5, using genipin as a crosslinking agent, showed the highest zinc complexation rate and 850 μm particle size passing rate.

[0036] The D-glucose-zinc complexes prepared in Examples 1-5 and Comparative Examples 1-3 were used as feed additives and added to the feed of AA broiler chickens. The feed for AA broiler chickens consisted of 59% corn flour, 30% soybean meal, 5.5% corn gluten meal, 2.6% soybean oil, 1% dicalcium phosphate, 1.2% limestone powder, 0.3% L-lysine, 0.1% DL-methionine, and 0.3% salt by weight. The addition amount of D-glucose-zinc complex was 100 mg / kg (i.e., 100 mg added to 1 kg of AA broiler chicken feed). (D-glucose-zinc complex); 450 one-day-old AA broiler chickens were fed a diet supplemented with D-glucose-zinc complex. The 450 chickens were divided into 8 groups, each fed with a diet supplemented with D-glucose-zinc complex as described in Examples 1-5 and Comparative Examples 1-3, respectively. A control group without D-glucose-zinc complex was used. The feeding period was 21 days. Each AA broiler chicken in each group was weighed daily on an empty stomach, and feed intake was recorded. The average daily weight gain, average daily feed intake, and feed conversion ratio were calculated for each group, as shown in the table below: Table 2 Feeding data for each group of AA broiler chickens As can be seen from Table 2, feeding AA broiler chickens with the D-glucose-zinc complex obtained in Examples 4 and 5 can significantly improve the nutrient conversion rate of feed and promote the growth and development of AA broiler chickens.

[0037] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0038] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A process for the preparation of a six-carbon aldosugar-zinc complex, characterized in that, Comprising the following steps; Step one, weigh the six-carbon aldehyde sugar and dissolve it in hot deionized water to obtain a six-carbon aldehyde sugar solution; weigh the zinc salt and dissolve it in deionized water to obtain a zinc salt solution; Step two, slowly add the zinc salt solution to the six-carbon aldehyde sugar solution under vigorous stirring to obtain a mixed solution; adjust the pH value of the mixed solution to 7.5-9.0 with NaOH solution; heat to 60-80℃ and continue stirring for 2-12h; Step three, after the reaction is completed, cool the mixed solution to room temperature, filter, add anhydrous ethanol to the filtrate, stir and mix, then stand for 3-12h, separate the lower layer precipitate, wash and spray dry the precipitate to obtain a six-carbon aldehyde sugar-zinc complex.

2. The method of preparing a six-carbon aldosugar-zinc complex according to claim 1, wherein the aldosugar is glucose. In the step one, the six-carbon aldehyde sugar includes one or more of D-galactose, D-glucose, D-mannose, D-mannose, L-sorbose; the use amount ratio of the six-carbon aldehyde sugar to the hot deionized water is 1-3mol:400-600mL.

3. The method for preparing the hexose aldose-zinc complex as described in claim 1, characterized in that, In the step one, the zinc salt is ZnSO4·7H2O, the molar ratio of ZnSO4·7H2O to the six-carbon aldehyde sugar is 1:1-3; the use amount ratio of ZnSO4·7H2O to the deionized water is 1mol:300-500mL.

4. The method for preparing the hexose aldose-zinc complex as described in claim 1, characterized in that, In the step two, the concentration of the NaOH solution is 0.1-2mol / L.

5. The method for preparing the hexacarbon aldose-zinc complex as described in claim 1, characterized in that, In the step three, when spray drying, the inlet temperature is 180-200℃ and the outlet temperature is 80-90℃.

6. The method for preparing the hexose aldose-zinc complex as described in claim 1, characterized in that, In the step one, a modified six-carbon aldehyde sugar is used to replace the six-carbon aldehyde sugar, and the preparation method of the modified six-carbon aldehyde sugar includes: S11, dissolve the six-carbon aldehyde sugar in deionized water, add NaOH solution to adjust the pH of the solution to 10-11 to obtain a six-carbon aldehyde sugar alkaline solution; S12, heat the six-carbon aldehyde sugar alkaline solution to 60-70℃, start stirring, and add H2O2 solution dropwise, continue stirring for 2-4h after the dropwise addition is completed, and cool to room temperature to obtain an H2O2 oxidized six-carbon aldehyde sugar alkaline solution; S13, dissolve chitosan in acetic acid solution to obtain a chitosan solution, mix the chitosan solution with the H2O2 oxidized six-carbon aldehyde sugar alkaline solution, add a crosslinking agent, stir and heat to 60-80℃, keep warm for 2-4h, and cool to obtain a pre-crosslinking solution; S14, pour the pre-crosslinking solution on the surface of the substrate, form a gel film after preliminary drying, then heat and solidify to complete crosslinking, and obtain a crosslinked film; crush the crosslinked film, wash with deionized water until neutral, and dry to obtain a modified six-carbon aldehyde sugar.

7. The method for preparing the hexacarbon aldose-zinc complex as described in claim 6, characterized in that, In the S12, the mass fraction of the H2O2 solution is 10%-30%, and the H2O2 in the H2O2 solution accounts for 5%-8% of the mass of the six-carbon aldehyde sugar.

8. The method for preparing the hexacarbon aldose-zinc complex as described in claim 6, characterized in that, In the S13, the concentration of the acetic acid solution is 0.5-5wt%; the use amount ratio of chitosan, acetic acid solution, and H2O2 oxidized six-carbon aldehyde sugar alkaline solution is 1-5g:100-500mL:50-100mL.

9. The method for preparing the hexacarbon aldose-zinc complex as described in claim 6, characterized in that, In the S13, the crosslinking agent is citric acid or genipin, and the amount of the crosslinking agent is 10%-20% of the mass of the chitosan.

10. The method for preparing the hexacarbon aldose-zinc complex as described in claim 6, characterized in that, In the S14, the preliminary drying temperature is 80-90℃, the heating and curing temperature is 120-130℃, and the heating and curing time is 30-60min.

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