A preparation method of food-grade manganese glycinate

Abstract

The invention discloses a preparation method related to a food-grade manganese glycinate, and relates to the technical field of preparation of manganese glycinate. It comprises the following steps: by weight, 385-490 parts of manganese sulfate solution, 2-4 parts of antioxidants and 55-65 parts of carbonate are mixed and reacted; the mixed solution after the reaction is filtered to obtain crystals, and then the crystals are mixed and reacted with 370-480 parts of glycine solution, and then the reaction solution after the reaction is filtered, and the filtrate is taken and concentrated, cooled, and crystallized in sequence. The method can greatly reduce the sulfate residues in manganese glycinate, and the purity of the product manganese glycinate is high, the manganese content is high, the impurity ions are few, and it is easy for the human body to absorb.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of manganese glycinate, and in particular to a method for preparing food-grade manganese glycinate. Background Art

[0002] Manganese often exists in the form of inorganic salts such as manganese sulfate and manganese oxide. Manganese sulfate has high solubility, but it is easy to absorb moisture, which is not conducive to processing. Although manganese oxide has the advantages of low cost and high manganese content, it has poor solubility and low utilization rate. The chelate of manganese and amino acids has the advantages of good chemical stability, high bioavailability, and good palatability. Among them, manganese glycine is often used as a nutritional enhancer, such as a feed additive.

[0003] The molecular formula of manganese glycinate is Mn(C2H4NO2)2·H2O, molecular weight: 220.99, manganese content is 18%. It is light pink powder or crystal, easily soluble in water, and difficult to dissolve in ethanol.

[0004] At present, the preparation methods of glycine manganese are all prepared by reacting glycine and manganese sulfate. The obtained product is a complex and belongs to the category of feed-grade additives. There are a lot of sulfate residues in the product, which is not conducive to human absorption and utilization. For example, Wang Xiuru et al. disclosed a method for preparing feed-grade glycine manganese, which is prepared by glycine and manganese sulfate monohydrate at a molar ratio of 1.6:1 and 85°C. Wu Lunfu et al. disclosed a method for preparing a glycine manganese complex, which is prepared by reacting glycine and manganese sulfate and adding methanol to promote precipitation.

[0005] Therefore, it is particularly necessary to provide a method for preparing food-grade manganese glycinate.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing food-grade manganese glycinate, which can significantly reduce sulfate residues in manganese glycinate, and the product manganese glycinate has high purity, high manganese content, few impurity ions, and is easy for human body to absorb. Manganese glycinate belongs to the category of food-grade manganese nutritional enhancer.

[0008] The present invention is achieved in that:

[0009] The present invention provides a method for preparing food-grade manganese glycinate, which comprises the following steps:

[0010] By weight, 385-490 parts of manganese sulfate solution, 2-4 parts of antioxidant and 55-65 parts of carbonate are mixed for reaction; the mixed solution after the reaction is filtered to obtain crystals, and then the crystals are mixed with 370-480 parts of glycine solution for reaction, and then the reaction solution after the reaction is filtered, and the filtrate is concentrated, cooled and crystallized in sequence.

[0011] The carbonate is selected from sodium carbonate, sodium bicarbonate, sodium carbonate decahydrate or sodium carbonate heptahydrate.

[0012] The inventors found that manganese carbonate is first prepared by mixing manganese sulfate with carbonate, and the manganese carbonate prepared on the spot is active and can be directly reacted with glycine to synthesize glycine manganese. Since manganese carbonate is mixed with glycine solution in the form of crystals, the residual sulfate and other substances in the glycine manganese product are greatly reduced. After concentration and precipitation and crystallization, the purity of the product is further improved and the content of impurity ions is reduced.

[0013] The antioxidant is added to prevent manganese from being oxidized to a high-valent state during the preparation of manganese carbonate, which causes the intermediate product to be unable to continue the subsequent reaction with the glycine solution.

[0014] The manganese sulfate solution is, for example, a mixture of 85-90 parts of manganese sulfate monohydrate and 300-400 parts of water. The weight percentage of manganese sulfate monohydrate can be any one of 85 parts, 86 parts, 87 parts, 88 parts, 89 parts, 90 parts, or a range between any two of them.

[0015] In the above mixture, the weight proportion of water can be any one of 300 parts, 310 parts, 320 parts, 330 parts, 340 parts, 350 parts, 360 parts, 370 parts, 380 parts, 390 parts, and 400 parts, or a range between any two of them.

[0016] The weight proportion of carbonate can be any one of 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, or a range between any two of them.

[0017] The increase in the amount of manganese sulfate and carbonate added helps to increase the manganese content in the product glycine manganese. This is because the more manganese carbonate synthesized, the more fully it reacts with glycine, and the higher the manganese content.

[0018] The weight proportion of the added antioxidant (ie, reducing agent) may be any one of 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, or a range between any two of them.

[0019] The higher the amount of the above antioxidant added, the better the quality of the synthesized manganese carbonate, the less likely it is to be oxidized, and the higher the manganese content in the manganese glycinate product.

[0020] The 370-480 parts of glycine solution is a mixture of 70-80 parts of glycine and 300-400 parts of water. The weight proportion of glycine added to the mixture can be any one of 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts or a range between any two of them.

[0021] In a preferred embodiment of the present invention, the antioxidant is selected from at least two of sodium thiosulfate, sodium bisulfite, cysteine, VC, tea polyphenols, bamboo leaf extract, fatty acid ascorbic acid ester, VE and butylated hydroxyanisole.

[0022] The fatty acid ascorbate is selected from, for example, highly unsaturated fatty acid ascorbate, which refers to fatty acids generally having 18 to 22 carbon atoms and a degree of unsaturation of 2 to 6. Specifically, it includes linoleic acid (carbon number 18; unsaturation degree 2) to docosahexaenoic acid (DHA) (carbon number 22; unsaturation degree 6).

[0023] Highly unsaturated fatty acids include docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), α- or γ-linolenic acid, dihomo-γ-linolenic acid (DGLA), arachidonic acid, and the like.

[0024] The fatty acid ascorbic acid ester is for example selected from vitamin C palmitate.

[0025] In other embodiments, the antioxidant is selected from the group consisting of free radical scavengers, singlet oxygen scavengers, and combinations thereof.

[0026] In the present invention, the use of a specific antioxidant is advantageous for the yield and purity of manganese glycinate.

[0027] In a preferred embodiment of the present invention, there are two kinds of antioxidants, which has a better reducing effect than a single kind and can reduce the amount of antioxidants used.

[0028] The combination of the two antioxidants can ensure that manganese sulfate and carbonate can fully react and the product is not oxidized, the product purity is high, and the yield can reach 85-90%.

[0029] In a preferred embodiment of the present invention, the antioxidant is selected from sodium bisulfite and VC.

[0030] In a preferred embodiment of the present invention, the mass ratio of the sodium bisulfite to VC is 1:2-2.5.

[0031] If a ratio outside the limited range is used, it will lead to poor reduction effect, a large amount of antioxidant, poor quality of synthesized manganese carbonate, low manganese content, etc. Optionally, the mass ratio can be any one of 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4 and 1:2.5, or a range between any two of them.

[0032] In a preferred embodiment of the present invention, the antioxidant is added during the mixing reaction of the manganese sulfate solution and the carbonate.

[0033] In a preferred embodiment of the present invention, the temperature of the mixed reaction of the manganese sulfate solution, antioxidant and carbonate is 60-65°C.

[0034] If the reaction temperature is too high, for example 80-90°C, the synthesized manganese carbonate will turn yellow. This is because the higher the temperature, the easier it is for divalent manganese to be oxidized to high-valent manganese.

[0035] In an optional embodiment, the time for the mixed reaction of manganese sulfate solution, antioxidant and carbonate is 20-30 minutes. Manganese carbonate is very easy to be oxidized, and if the reaction time is too long, the antioxidant is easily consumed, thereby causing manganese carbonate to be oxidized to a high-valent manganese salt. Under the above reaction time, manganese sulfate and carbonate can be fully reacted.

[0036] In a preferred embodiment of the present invention, the temperature for the mixed reaction of the crystals and the glycine solution is 70-80°C, for example 71-75°C, or 75-80°C.

[0037] In an optional embodiment, the reaction time of the mixed reaction of the crystals and the glycine solution is 10-15 minutes.

[0038] In a preferred embodiment of the present invention, the concentration is concentrated by increasing the temperature.

[0039] The invention also provides a method for preparing food-grade manganese glycinate and use of the food-grade manganese glycinate prepared in preparing a nutrition enhancer.

[0040] For example, it can be used as a food metal ion chelating agent, trace element additive, etc. For example, it can be used for removing fishy smell, etc. The food-grade manganese glycinate product has high purity, few impurity ions, and is easy for human body to absorb.

[0041] The present invention has the following beneficial effects:

[0042] The invention provides a method for preparing food-grade manganese glycinate, wherein manganese carbonate is prepared by mixing manganese sulfate with carbonate, and then mixed with glycine. The manganese carbonate prepared on the spot is active and can be directly reacted with glycine to synthesize manganese glycinate. Since manganese carbonate is mixed with a glycine solution in the form of crystals, the residue of substances such as sulfate in the manganese glycinate product is greatly reduced, and the purity of the product is further improved and the content of impurity ions is reduced by concentration, precipitation and crystallization.

[0043] The antioxidant is added to prevent manganese from being oxidized to a high-valent state during the preparation of manganese carbonate, which causes the intermediate product to be unable to continue the subsequent reaction with the glycine solution.

[0044] The product manganese glycinate provided by the invention has high purity, high manganese content, few impurity ions, and is easy to be absorbed by human body, and belongs to the category of food-grade manganese nutrition enhancer. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0046] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0047] Example 1

[0048] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0049] In terms of weight, 65 parts of soda ash (sodium carbonate, the same below) were added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture was reacted at 60°C for 30 minutes. During the reaction, 4 parts of an antioxidant were added, and the antioxidant consisted of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0050] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0051] Example 2

[0052] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0053] In parts by weight, 60 parts of soda ash are added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0054] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0055] Example 3

[0056] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0057] In terms of weight, 55 parts of soda ash were added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture was reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant were added, and the antioxidant consisted of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0058] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0059] Example 4

[0060] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0061] In terms of weight, 65 parts of soda ash are added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 2 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0062] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0063] Example 5

[0064] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0065] In parts by weight, 65 parts of soda ash are added to a mixture of 85 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0066] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0067] Example 6

[0068] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0069] In parts by weight, 65 parts of soda ash are added to a mixture of 85 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0070] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0071] Example 7

[0072] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0073] In parts by weight, 65 parts of soda ash are added to a mixture of 85 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 3 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0074] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0075] Example 8

[0076] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0077] In parts by weight, 65 parts of soda ash are added to a mixture of 85 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0078] After the product is filtered, crystals are taken out and added to a mixture of 75 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken out, the temperature is raised and concentrated until a large amount of product is precipitated, and the temperature is cooled and crystallized to obtain glycine manganese product.

[0079] Example 9

[0080] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0081] In parts by weight, 65 parts of soda ash are added to a mixture of 85 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0082] After the product is filtered, crystals are taken out and added to a mixture of 70 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken out, and the temperature is raised and concentrated until a large amount of product is precipitated, and the temperature is cooled and crystallized to obtain glycine manganese product.

[0083] Example 10

[0084] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0085] In terms of weight, 65 parts of soda ash were added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture was reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant were added, and the antioxidant consisted of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0086] After the product is filtered, crystals are taken out and added to a mixture of 70 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken out, and the temperature is raised and concentrated until a large amount of product is precipitated, and the temperature is cooled and crystallized to obtain glycine manganese product.

[0087] Embodiment 11

[0088] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0089] In parts by weight, 65 parts of soda ash are added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 2 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.

[0090] After the product is filtered, crystals are taken out and added to a mixture of 75 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken out, the temperature is raised and concentrated until a large amount of product is precipitated, and the temperature is cooled and crystallized to obtain glycine manganese product.

[0091] Example 12

[0092] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0093] In terms of weight, 55 parts of soda ash were added to a mixture of 85 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture was reacted at 60° C. for 30 minutes. During the reaction, 2 parts of an antioxidant were added, and the antioxidant consisted of sodium bisulfite and VC in a mass ratio of 1:2.5.

[0094] After the product is filtered, crystals are taken out and added to a mixture of 70 parts of glycine and 400 parts of water, and reacted at 80°C for 10 minutes until it is clarified. After clarification, the filtrate is taken out, the temperature is raised and concentrated until a large amount of product is precipitated, and the temperature is cooled and crystallized to obtain glycine manganese product.

[0095] Comparative Example 1

[0096] A food-grade manganese glycinate, the preparation method of which is substantially the same as that of Example 1, the difference being only in the parameters, and specifically comprising the following steps:

[0097] In terms of weight, 65 parts of soda ash were added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture was reacted at 80° C. for 30 minutes. During the reaction, 4 parts of an antioxidant were added, and the antioxidant consisted of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0098] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0099] Comparative Example 2

[0100] This embodiment provides a method for preparing food-grade manganese glycinate, which specifically comprises the following steps:

[0101] In parts by weight, 65 parts of soda ash are added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 90° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0102] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0103] Comparative Example 3

[0104] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0105] In terms of weight, 45 parts of soda ash are added to a mixture of 60 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0106] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0107] Comparative Example 4

[0108] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0109] In terms of weight, 85 parts of soda ash are added to a mixture of 100 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0110] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0111] Comparative Example 5

[0112] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0113] In terms of weight, 65 parts of soda ash are added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 1 part of an antioxidant is added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0114] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0115] Comparative Example 6

[0116] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0117] In parts by weight, 65 parts of soda ash are added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:1.

[0118] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0119] Comparative Example 7

[0120] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0121] In parts by weight, 65 parts of soda ash are added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture is reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant are added, and the antioxidant is composed of sodium bisulfite and VC in a mass ratio of 1:3.

[0122] After the product is filtered, crystals are taken and added to a mixture of 80 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken and concentrated by heating until a large amount of product is precipitated, and then cooled and crystallized to obtain glycine manganese product.

[0123] Comparative Example 8

[0124] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0125] In parts by weight, 60 parts of manganese carbonate were added to a mixture of 80 parts of glycine and 400 parts of water, and the mixture was reacted at 80°C for 1 hour. The mixture was reacted until it was clear, and then filtered after clarification. The filtrate was taken, heated and concentrated until a large amount of product was precipitated, and cooled and crystallized to obtain glycine manganese product.

[0126] Comparative Example 9

[0127] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0128] In terms of weight, 65 parts of soda ash were added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture was reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant were added, and the antioxidant consisted of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0129] After the product is filtered, crystals are taken out and added to a mixture of 60 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken out, the temperature is raised and concentrated until a large amount of product is precipitated, and the temperature is cooled and crystallized to obtain glycine manganese product.

[0130] Comparative Example 10

[0131] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0132] In terms of weight, 65 parts of soda ash were added to a mixture of 90 parts of manganese sulfate monohydrate and 400 parts of water, and the mixture was reacted at 60° C. for 30 minutes. During the reaction, 4 parts of an antioxidant were added, and the antioxidant consisted of sodium bisulfite and VC in a mass ratio of 1:2.3.

[0133] After the product is filtered, crystals are taken out and added to a mixture of 90 parts of glycine and 400 parts of water, and reacted at 80°C for 15 minutes until it is clarified. After clarification, the filtrate is taken out, the temperature is raised and concentrated until a large amount of product is precipitated, and the temperature is cooled and crystallized to obtain glycine manganese product.

[0134] Comparative Example 11

[0135] This embodiment provides a method for preparing manganese glycinate, which specifically comprises the following steps:

[0136] In a mixture of 80 parts of glycine and 400 parts of water, 90 parts of manganese sulfate monohydrate are added by weight, and the mixture is reacted at 80°C for 15 minutes until the mixture is clarified. After clarification, the mixture is filtered, and the filtrate is taken, heated and concentrated until a large amount of product is precipitated, and cooled and crystallized to obtain glycine manganese product.

[0137] Experimental Example 1

[0138] The effects of different reaction temperatures on the quality of manganese carbonate synthesis are shown in Table 1.

[0139] As shown in Table 1, as the reaction temperature increases, the synthesized manganese carbonate turns yellow, because the higher the temperature, the easier it is for divalent manganese to be oxidized to high-valent manganese, resulting in a decrease in quality. Therefore, within the reaction temperature range provided by the present invention, it is helpful to improve the quality of manganese carbonate and increase the manganese content.

[0140] Table 1 Effect of different reaction temperatures on the quality of manganese carbonate synthesis.

[0141] serial number Example 1 Comparative Example 2 Comparative Example 3 Reaction temperature 60℃ 80℃ 90℃ Manganese carbonate color White Brown Slightly brown Brown and black Manganese content 20.15 15.17 15.06

[0142] Experimental Example 2

[0143] This experimental example verifies the effect of different weights of manganese sulfate monohydrate and soda ash on the manganese content.

[0144] The results are shown in Table 2. By comparison with Table 2, it can be seen that as the weight of manganese sulfate monohydrate and soda ash increases, the manganese content of the product increases. This is because the more manganese carbonate synthesized, the more fully it reacts with glycine, and the higher the manganese content.

[0145] Table 2 Statistical table of the effects of different weights of manganese sulfate monohydrate and soda ash on manganese content.

[0146]

[0147] Experimental Example 3

[0148] This experimental example verifies the effect of the amount of antioxidant added on the quality of manganese carbonate synthesis.

[0149] The results are shown in Table 3. By comparison with Table 3, it can be seen that as the amount of antioxidant added increases, the quality of the synthesized manganese carbonate is better, it is less likely to be oxidized, and the manganese content is higher.

[0150] Table 3 Statistical results of the effect of antioxidant addition on the synthetic quality of manganese carbonate.

[0151] serial number Example 1 Comparative Example 5 Antioxidant dosage 4 servings 1 serving Manganese carbonate color White Brown Slightly brown Manganese content 20.15 17.28

[0152] Experimental Example 4

[0153] This experimental example verifies the effect of different ratios of two antioxidants on the quality of manganese carbonate synthesis.

[0154] The results are shown in Table 4. By comparison with Table 4, it can be seen that the antioxidant ratio is within the required range, the synthesized manganese carbonate is of high quality and has a high manganese content.

[0155] Table 4 Statistical results of the effects of two antioxidants in different proportions on the synthetic quality of manganese carbonate.

[0156] serial number Example 1 Comparative Example 6 Comparative Example 7 Antioxidant ratio 1:2.3 1:1 1:3 Manganese carbonate color White Brown Slightly brown Brown Manganese content 20.15 17.23 18.86

[0157] Experimental Example 5

[0158] The reaction conditions of the synthesized manganese carbonate and the finished product manganese carbonate with glycine are shown in Table 5.

[0159] From Table 5, it can be seen that the currently prepared manganese carbonate can maintain its activity and can directly react with glycine, while the finished manganese carbonate has lost its activity and cannot react with glycine.

[0160] Table 5 Statistical table of the reaction results of different types of manganese carbonate and glycine.

[0161] serial number Example 1 Comparative Example 8 Is manganese carbonate synthesized now? yes no Reaction with glycine Bubbles are generated No phenomenon Filtered product color Light pink brown Manganese content 20.15 41.21

[0162] Experimental Example 6

[0163] The effect of different weights of glycine on manganese content is shown in Table 6.

[0164] From Table 6, it can be seen that the less glycine is added, the higher the manganese content of the product.

[0165] Table 6 Statistical results of the effect of different weights of glycine on manganese content.

[0166] serial number Example 1 Comparative Example 9 Comparative Example 10 Glycine weight 80 60 90 Manganese content 20.15 22.25 19.02

[0167] Experimental Example 7

[0168] The sulfate content in the products prepared by the manganese carbonate method and the manganese sulfate method is shown in Table 7.

[0169] From Table 7, it can be seen that the sulfate content in the product prepared by the manganese carbonate method is less than 1%, and the product purity is high, while the sulfate content of the product prepared by the direct reaction of manganese sulfate with glycine is greater than 20%, which is much more than that of the manganese carbonate method. Therefore, it is analyzed that the product prepared by this method is a mixture of glycine and manganese sulfate, rather than pure manganese glycine, so the manganese sulfate method is not advisable.

[0170] Table 7 Sulfate content in products prepared by manganese carbonate method and manganese sulfate method

[0171] serial number Example 1 Comparative Example 11 method Manganese carbonate method Manganese sulfate method Sulfate content ＜1％ ＞20％

[0172] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing food-grade manganese glycinate, characterized in that: It includes the following steps: By weight, 385-490 parts of manganese sulfate solution, 2-4 parts of antioxidant and 55-65 parts of carbonate are mixed for reaction; the mixed solution after the reaction is filtered to obtain crystals, and then the crystals are mixed with 370-480 parts of glycine solution for reaction, and then the reaction solution after the reaction is filtered, and the filtrate is concentrated, cooled and crystallized in sequence; The carbonate is selected from sodium carbonate, sodium bicarbonate, sodium carbonate decahydrate or sodium carbonate heptahydrate; the temperature of the mixed reaction of the manganese sulfate solution, antioxidant and carbonate is 60-65°C; the time of the mixed reaction of the manganese sulfate solution, antioxidant and carbonate is 20-30 minutes; the antioxidant is selected from sodium bisulfite and VC, and the mass ratio of sodium bisulfite to VC is 1:2-2.

5.

2. The method for preparing food-grade manganese glycinate according to claim 1, characterized in that: The antioxidant is added during the mixing reaction of the manganese sulfate solution and the carbonate.

3. The method for preparing food-grade manganese glycinate according to claim 1, characterized in that: The temperature for the mixed reaction of the crystals and the glycine solution is 70-80°C.

4. The method for preparing food-grade manganese glycinate according to claim 3, characterized in that: The reaction time of the mixed reaction of the crystals and the glycine solution is 10-15 minutes.

5. The method for preparing food-grade manganese glycinate according to claim 1, characterized in that: The concentration is temperature-increasing concentration.

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