Calcium propionate preservative and preparation method thereof

Abstract

The invention relates to a calcium propionate preservative and a preparation method thereof, and relates to the technical field of food additives. The calcium propionate preservative disclosed by the invention is granular, the molar ratio of Mg to Ca is 0.03-0.20 in terms of metal ions, the particle size range is 50-1500 [mu] m, the most frequent particle size D is 900 [mu] m or more, and the most frequent particle size D refers to the diameter of the particle with the highest occurrence frequency in the calcium propionate particles. According to the calcium propionate preservative, the storage stability is improved, and a preferable scheme has a controllable slow-release effect and is beneficial to exerting long-acting anti-corrosion and mildew-proof effects. According to the preparation method of the calcium propionate preservative, calcium propionate particles with the characteristics and advantages can be obtained, and the yield is relatively higher.

Description

Technical Field

[0001] The present invention relates to the technical field of food additives, and more specifically, to a calcium propionate preservative and a preparation method thereof. Background Art

[0002] Calcium propionate is a new type of food additive approved for use by the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO). It can provide antiseptic and mildew-proof effects. Calcium propionate has a slightly special odor, is easily deliquescent in humid air, is easily soluble in water, is sensitive to light and heat, and decomposes into calcium carbonate at 330-340°C. Calcium propionate has a special effect on enzymes and bacteria, but has limited effect on bacteria and no effect on yeast. It can be absorbed by the human body through metabolism and provides a macronutrient element, calcium, and is almost non-toxic to the human body.

[0003] Existing studies have shown that the antiseptic properties of calcium propionate are comparable to those of sodium propionate. The principle is that it forms propionic acid in an acidic medium and exerts an antibacterial effect. Calcium propionate used in cakes, bread and cheese can not only inhibit the reproduction of bacteria, but also supplement calcium in the diet. Calcium propionate is used as a preservative for bread and cakes. It has an inhibitory effect on mold and aerobic Bacillus that can cause bread to produce sticky substances, but has no inhibitory effect on yeast. While preserving and extending the shelf life, it can provide calcium necessary for the human body, playing the role of strengthening food. In addition, it is effective against mold, aerobic spore-producing bacteria, Gram-negative bacteria, aflatoxin, etc. in starch, protein-containing and oily substances, and has unique anti-mold and antiseptic properties.

[0004] Calcium propionate needs to be stored in a dry and cool warehouse and protected from rain and moisture. Due to its strong hygroscopicity, it will decompose in a humid environment, which will affect its performance. Calcium propionate is usually prepared by reacting calcium oxide and propionic acid, filtering, concentrating, crystallizing, and drying. The yield of granular calcium propionate needs to be improved. Summary of the invention

[0005] In order to solve the above technical problems existing in the prior art, the object of the present invention is to provide a calcium propionate preservative with higher stability and a preparation method thereof.

[0006] The first aspect of the present invention relates to a calcium propionate preservative, characterized in that the calcium propionate is granular, and its particle size range is 50μm to 1500μm, and its most frequent particle size D is above 900μm, and the most frequent particle size D refers to the particle diameter with the highest frequency in the calcium propionate particles.

[0007] The mode particle size is greater than 900 μm, and preferably greater than 950 μm.

[0008] The calcium propionate preservative contains Mg, and the molar ratio of Mg / Ca is 0.01 to 0.20 in terms of metal ions.

[0009] The molar ratio of Mg / Ca is preferably 0.03 to 0.10, and more preferably 0.03 to 0.08.

[0010] The outer surface of the calcium propionate particles has a gelatin coating layer, and the gelatin coating layer contains 10 to 75 wt % of calcium propionate.

[0011] Wherein, the thickness of the gelatin coating layer is 5 μm to 20 μm.

[0012] The second aspect of the present invention also relates to a method for preparing a calcium propionate preservative, the preparation method comprising the following steps:

[0013] (1) adding CaO and MgO powders into distilled water to obtain a mixed slurry, slowly adding food-grade propionic acid, and reacting in a constant temperature water bath to obtain a clear solution;

[0014] (2) filtering the obtained clear solution, collecting the mother liquor, crystallizing in a flash evaporator, and drying to obtain calcium propionate crystals.

[0015] Wherein, the temperature of the constant temperature water bath is 30-40°C.

[0016] Wherein, the preparation method further comprises:

[0017] (3) preparing a mixed aqueous solution of gelatin and calcium propionate;

[0018] (4) spraying the fluidized calcium propionate crystals with the mixed aqueous solution in a fluidized bed;

[0019] (5) Drying the sprayed calcium propionate crystals.

[0020] Compared with the prior art, the calcium propionate preservative and the preparation method thereof of the present invention have the following beneficial effects:

[0021] The particle size distribution of the calcium propionate preservative of the present invention is relatively concentrated and uniform, which improves the stability of the calcium propionate preservative. When used as a food additive, it can also supplement the nutrients Ca and Mg necessary for the human body and help maintain the Ca-Mg balance of the human body. The preferred embodiment has a controllable sustained release effect, which is conducive to exerting a long-term antiseptic and mildew-proof effect. The preparation method of the calcium propionate preservative can not only obtain calcium propionate particles with the above-mentioned characteristics and advantages, but also has a relatively higher yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of particle size distribution. DETAILED DESCRIPTION

[0023] The calcium propionate preservative and the preparation method thereof of the present invention will be further described below in conjunction with specific embodiments to help those skilled in the art to have a more complete, accurate and in-depth understanding of the technical solution of the present invention.

[0024] In view of the problem that the calcium propionate particles prepared by conventional processes in the prior art have poor stability, moisture absorption leads to their decomposition and affects their anti-corrosion and mildew-proofing effects, the present invention provides a calcium propionate preservative and a preparation method thereof. The present invention adds an appropriate amount of magnesium source (which can be added in the form of MgO, Mg(OH)2, etc.) to the calcium source for preparing calcium propionate, and can prepare crystalline particles with relatively concentrated and uniform particle size distribution. The calcium propionate preservative with the distribution of crystalline particles and material characteristics has significantly improved storage stability compared with the calcium propionate particles prepared by the conventional method, and exhibits lower water absorption under ambient humidity. The added Mg element is a necessary nutrient element for the human body, which is beneficial to the human body to supplement Ca and Mg, and helps to maintain the Ca-Mg balance of the human body. The present invention further controls the decomposition rate of the calcium propionate crystal particles by coating the calcium propionate particles in the fluidized state and changing the content of calcium propionate in the coating layer, which is beneficial to the long-term exertion of its anti-corrosion and mildew-proofing effects.

[0025] In the present invention, the calcium propionate particles are sieved after preparation to obtain particles with a particle size range of 50 μm to 1500 μm, and the weight of the remaining part / total weight is the sieve retention rate. For the calcium propionate particles with a particle size range of 50 μm to 1500 μm obtained by sieving, the particle size distribution is measured by a laser particle size distribution instrument, and the following is obtained: Figure 1 The illustrated particle size-frequency distribution curve, wherein the particle diameter with the highest frequency in the calcium propionate particles is the most frequent particle size D, and its most frequent particle size D is above 900 μm, preferably above 950 μm. The calcium propionate particles having the above-mentioned particle size distribution characteristics can be obtained by adding Mg to the calcium propionate preservative to replace part of the Ca. Specifically, the calcium propionate preservative contains Mg, and the molar ratio of Mg / Ca is 0.01 to 0.20, preferably 0.03 to 0.10, and more preferably 0.03 to 0.08, calculated as metal ions. The calcium propionate particles having the material characteristics and particle size characteristics of the present invention not only have good flow operability and are easy to use and operate, but also unexpectedly, can significantly improve the storage stability of the particles.

[0026] In addition, in order to obtain a controlled sustained release effect and extend the antiseptic and antifungal effect of calcium propionate, the outer surface of the calcium propionate particles has a gelatin coating layer, the gelatin coating layer contains 10 to 75 wt% of calcium propionate, the remainder is gelatin, and the thickness of the gelatin coating layer is 1 μm to 20 μm.

[0027] The preparation method of the calcium propionate preservative of the present invention can be obtained by the following preparation method:

[0028] First, CaO and MgO powders are added to distilled water to obtain a mixed slurry, and food-grade propionic acid is slowly added under stirring conditions, and the mixture is reacted in a constant temperature water bath at 30 to 40° C. to make the reaction solution clear, and the mixture is continued to react under heating conditions in the constant temperature water bath for 10 minutes;

[0029] Second, the obtained clarified solution is filtered and the calcium propionate mother liquor is collected; the collected calcium propionate mother liquor is poured into a flash evaporator for crystallization, and then the collected calcium propionate crystals are placed in a drying oven at a temperature of 120° C. for drying to obtain calcium propionate crystals.

[0030] In order to obtain the gelatin coating layer, the preparation method further comprises the following steps:

[0031] Third, weighing and preparing a mixed aqueous solution containing gelatin and calcium propionate according to the ratio;

[0032] Fourth, spraying the fluidized calcium propionate crystals with the mixed aqueous solution in a fluidized bed;

[0033] Fifth, the sprayed calcium propionate crystals are dried. The sprayed calcium propionate crystals can be dried using flowing high-temperature gas. The drying gas can be air, nitrogen, etc. The drying temperature is preferably 80-150°C, more preferably 100-130°C.

[0034] Example 1

[0035] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.03, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0036] Example 2

[0037] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.03, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 30°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0038] Example 3

[0039] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.05, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution is clarified; filter the obtained clarified solution to collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0040] Example 4

[0041] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.05, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 30°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0042] Example 5

[0043] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.08, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution to collect a calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0044] Example 6

[0045] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.08, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 30°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0046] Example 7

[0047] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.12, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0048] Example 8

[0049] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.12, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 30°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, dry the collected calcium propionate crystals in a drying oven at a temperature of 120°C, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0050] Example 9

[0051] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.15, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 100°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0052] Example 10

[0053] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.15, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 30°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 130°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this embodiment.

[0054] Embodiment 11

[0055] The calcium propionate preservative obtained according to the method of Example 5 is sent into a fluidized bed and sprayed with a mixed aqueous solution containing gelatin and calcium propionate (the weight ratio of calcium propionate to gelatin is 1:4). After spraying, it is dried with flowing air at a temperature of 120°C to obtain a surface-coated calcium propionate preservative. The thickness of the gelatin coating layer is controlled to be 2 μm by the spraying time.

[0056] Example 12

[0057] The calcium propionate preservative obtained according to the method of Example 6 is sent into a fluidized bed and sprayed with a mixed aqueous solution containing gelatin and calcium propionate (the weight ratio of calcium propionate to gelatin is 1:3). After spraying, it is dried with flowing air at a temperature of 120°C to obtain a surface-coated calcium propionate preservative. The thickness of the gelatin coating layer is controlled to be 2 μm by the spraying time.

[0058] Comparative Example 1

[0059] Prepare 50g of CaO powder with a purity of more than 99.9%, put it in a beaker, add 1000g of distilled water and stir to obtain a slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution is clarified; filter the obtained clarified solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500 μm, thereby obtaining the calcium propionate preservative of this comparative example.

[0060] Comparative Example 2

[0061] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.01, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution is clarified; filter the obtained clarified solution to collect a calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this comparative example.

[0062] Comparative Example 3

[0063] Prepare CaO powder with a purity of more than 99.9% and MgO powder with a purity of more than 99.9%, add 50g of CaO and MgO powder in a Ca / Mg molar ratio of 1:0.25, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 40°C, and continue to react for 10 minutes after the reaction solution is clarified; filter the obtained clarified solution to collect a calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, put the collected calcium propionate crystals into a drying oven at a temperature of 120°C for drying, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this comparative example.

[0064] Comparative Example 4

[0065] Prepare CaO powder with a purity of more than 99.9% and TiO2 powder with a purity of more than 99.9%, add 50g of CaO and TiO2 powder in a Ca / Ti molar ratio of 1:0.08, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 30°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, dry the collected calcium propionate crystals in a drying oven at a temperature of 120°C, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this comparative example.

[0066] Comparative Example 5

[0067] Prepare CaO powder with a purity of more than 99.9% and SiO2 powder with a purity of more than 99.9%, add 50g of CaO and SiO2 powder in a Ca / Si molar ratio of 1:0.08, stir and mix to obtain a composite powder, place the composite powder in a beaker, add 1000g of distilled water and stir to obtain a mixed slurry, and slowly add food-grade propionic acid under stirring, react in a constant temperature water bath at 30°C, and continue to react for 10 minutes after the reaction solution becomes clear; filter the obtained clear solution and collect the calcium propionate mother liquor; pour the collected calcium propionate mother liquor into a flash evaporator for crystallization to obtain calcium propionate crystals, dry the collected calcium propionate crystals in a drying oven at a temperature of 120°C, and then sieve to obtain particles with a particle size range of 50 to 1500μm, thereby obtaining the calcium propionate preservative of this comparative example.

[0068] The particle size distribution curve and the most frequent particle size D of the calcium propionate preservative prepared in Examples 1-10 and Comparative Examples 1-5 were measured by a laser particle size distribution instrument. 5g samples of the calcium propionate preservative prepared in Examples 1-10 and Comparative Examples 1-5 were respectively placed in plastic cups with a volume of 50ml (the plastic cups were numbered 1, 2, 3 ... 15, 16, 17 in sequence), and the plastic cups were placed in a thermostat with a relative humidity RH of 75% and a temperature of 35°C for 48 hours. After being taken out, the appearance of each sample in each plastic cup was visually inspected. In addition, 5g samples of the calcium propionate preservative prepared in Examples 1-12 and Comparative Examples 1-5 were respectively placed in plastic cups with a volume of 50ml (the plastic cups were numbered 1, 2, 3 ... 15, 16, 17 in sequence), and the plastic cups were placed in a thermostat with a relative humidity RH of 70% and a temperature of 20°C for 10 days, and the weight changes of each sample were measured and calculated. The results are shown in Table 1.

[0069] Table 1

[0070] serial number Most frequent particle size D(μm) Screening rate (%) Appearance Weight change (%) 1 Example 1 923 92 No change +10.4 2 Example 2 927 90 No change +10.2 3 Example 3 964 93 No change +9.3 4 Example 4 959 91 No change +9.3 5 Example 5 973 95 No change +8.1 6 Example 6 978 97 No change +8.0 7 Example 7 991 87 No change +8.7 8 Example 8 993 86 No change +8.9 9 Example 9 1023 83 Basically no change +15.6 10 Example 10 1028 85 Basically no change +15.4 11 Embodiment 11 - - No change +6.2 12 Example 12 - - No change +6.5 13 Comparative Example 1 781 81 deliquescence +32.2 14 Comparative Example 2 803 83 deliquescence +25.4 15 Comparative Example 3 1031 73 Deliquescence, agglomeration +40.1 16 Comparative Example 4 923 78 deliquescence +31.1 17 Comparative Example 5 813 72 deliquescence +35.6

[0071] For ordinary technicians in this field, the specific embodiments are only illustrative descriptions of the present invention. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A calcium propionate preservative, characterized in that: The calcium propionate is in granular form, with a particle size range of 50 μm to 1500 μm, and a most frequent particle size D of more than 900 μm. The most frequent particle size D refers to the particle diameter with the highest frequency in the calcium propionate particles.

2. The calcium propionate preservative according to claim 1, characterized in that: The mode particle size is greater than 900 μm.

3. The calcium propionate preservative according to claim 1 or 2, characterized in that: The mode particle size is greater than 950 μm.

4. The calcium propionate preservative according to any one of claims 1 to 3, characterized in that: The calcium propionate preservative contains Mg element, and the molar ratio of Mg / Ca is 0.03-0.20 in terms of metal ions.

5. The calcium propionate preservative according to claim 4, characterized in that: The molar ratio of Mg / Ca is preferably 0.03 to 0.10, more preferably 0.03 to 0.

08.

6. The calcium propionate preservative according to any one of claims 1 to 5, characterized in that: The outer surface of the calcium propionate particles is provided with a gelatin coating layer, and the gelatin coating layer contains 10 to 75 wt % of calcium propionate.

7. The calcium propionate preservative according to claim 6, characterized in that: The thickness of the gelatin coating layer is 5 μm to 20 μm.

8. A method for preparing a calcium propionate preservative, characterized in that The preparation method comprises the following steps: (1) adding CaO and MgO powders into distilled water to obtain a mixed slurry, slowly adding food-grade propionic acid, and reacting in a constant temperature water bath to obtain a clear solution; (2) filtering the obtained clear solution, collecting the mother liquor, crystallizing in a flash evaporator, and drying to obtain calcium propionate crystals.

9. The method for preparing the calcium propionate preservative according to claim 8, characterized in that: The temperature of the constant temperature water bath is 30-40°C.

10. The method for preparing the calcium propionate preservative according to claim 8 or 9, characterized in that: The preparation method further comprises: (3) preparing a mixed aqueous solution of gelatin and calcium propionate; (4) spraying the fluidized calcium propionate crystals with the mixed aqueous solution in a fluidized bed; (5) Drying the sprayed calcium propionate crystals.

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