Preparation method of calcium propionate

Abstract

The invention discloses a preparation method of calcium propionate, which comprises the following steps: S1, preparation of an organic wheat carbon source: putting organic wheat flour into a fermentation tank, diluting until the concentration is 20-25%, adjusting the pH value to 5.5-6, adding protease and amylase which account for 0.1-0.2% of the mass of the organic wheat flour, and liquefying at 90-110 DEG C for 1 hour; adding saccharifying enzyme and saccharifying for 8-15 hours to prepare an organic wheat carbon source; s2, expanding culture of strains: in a sterile environment, inoculating an original strain of propionibacterium into an LB culture medium for culture to obtain well-grown seeds; s3, inoculating grown seeds into a seed tank for culturing, wherein the seed tank comprises an organic wheat carbon source; the seed tank is connected into the fermentation tank; s4, deslagging, decolorizing, concentrating and finely filtering to obtain calcium propionate liquid; the method has the characteristics of simple process, simple fermentation formula, high strain metabolism expression and no residue; and the fermentation period is effectively shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of calcium propionate preparation, and in particular to a method for preparing calcium propionate. Background Art

[0002] Calcium propionate, also known as calcium propionate salt or calcium oleate, has a chemical formula of (CH₃CH₂COO)₂Ca. Calcium propionate is recognized as a safe additive by the US FDA and can be absorbed by humans and animals through metabolism, providing essential calcium, a level of performance unmatched by other antifungal agents.

[0003] Currently, there are two main methods for producing calcium propionate. The first is chemical synthesis (neutralization reaction), which uses propionic acid and calcium hydroxide or calcium carbonate as raw materials to neutralize and produce calcium propionate. This process is then dehydrated, crystallized, and dried. This process is mature, low-cost, and high-purity, but the initial preparation of propionic acid and the disposal of its byproducts place high environmental demands.

[0004] The second method is biological fermentation: Propionibacterium (such as Propionibacterium) ferments glucose or glycerol to produce propionic acid, which is then neutralized with calcium hydroxide to produce calcium propionate. This method is naturally safe and meets cleanliness standards, making it suitable for use in food, feed, and other fields.

[0005] The prior art, such as patent number CN115678925A, discloses a method for preparing calcium propionate, which comprises the following steps: S1: slant culturing the activated propionibacterium and preparing an initial bacterial suspension; S2: preparing an initial culture medium, wherein the culture medium comprises 2% glucose, 1% sucrose, 2.5% peptone, 5.15% yeast extract, and 89.35% drinking water, and the pH value of the culture medium is 7.0-8.0; S3: placing the initial bacterial suspension in the initial culture medium for culturing to obtain a propionibacterium suspension; S4: placing the propionibacterium suspension in a fermentation tank and adding a fermentation medium for fermentation to obtain propionic acid produced by fermentation, wherein the fermentation medium comprises 10% glucose, 1% peptone, 2% yeast extract, 0.1% Na2HPO4, and 0.1% MgSO4 7H2O, 0.05% Tween 80, and 86.75% drinking water or purified water, wherein the pH of the fermentation medium is 7.0-8.0; S5: filtering the propionic acid produced by fermentation through an anion permeable membrane to remove propionate, and reacting the anion with calcium hydroxide to obtain a calcium propionate solution; S6: evaporating and crystallizing the calcium propionate solution to obtain calcium propionate crystals. The carbon sources used are glucose and sucrose, which are processed raw materials and may contain residues. Summary of the Invention

[0006] The purpose of the invention is to provide a preparation method of calcium propionate, which solves the problem in the prior art that the carbon sources are glucose and sucrose, which are processed raw materials and may contain residues, and how to meet the requirements of being natural and organic.

[0007] The present invention is achieved by providing a method for preparing calcium propionate, which comprises the following steps:

[0008] S1. Preparation of organic wheat carbon source: organic wheat flour is added to a fermentation tank and diluted to a concentration of 20%-25% organic wheat flour, the pH is adjusted to 5.5-6, and 1‰-2‰ of protease and amylase are added to the organic wheat flour, and the mixture is liquefied at a temperature of 90°C-110°C for 1 hour; then 1‰-2‰ of saccharifying enzyme is added to the organic wheat flour and saccharified for 8-15 hours to prepare the organic wheat carbon source;

[0009] S2. Strain expansion: In a sterile environment, the original strain of Propionibacterium (freeze-dried tube, about 2 ml) was inoculated into an LB medium shake flask at a rate of 1-5‰ to obtain well-grown shake flask seeds;

[0010] S3, inoculating the shake flask seeds grown in S2 into a seed tank for cultivation, wherein the seed tank contains the organic wheat carbon source of S1; and the seed tank is connected to a fermentation tank;

[0011] S4, removing slag, decolorizing, concentrating and fine filtering to obtain calcium propionate liquid.

[0012] The raw material of the present invention is organic wheat flour, rather than a processed carbon source such as ready-made glucose or sucrose. The present invention uses organic wheat flour as the raw material to prepare the carbon source. Specifically, the organic wheat flour is put into a fermentation tank, and after dilution, the wheat flour is sheared and broken by the dual action of protease and amylase to facilitate saccharification and ensure the uniformity of dispersion of the organic wheat flour. Then, saccharifying enzyme is added for saccharification to obtain the organic wheat carbon source in the fermentation tank. The organic wheat flour is used as the main raw material, supplemented by organic yeast powder, and the carbon source is obtained by fermentation and culture with propionibacterium, which completely meets the requirements of foreign customers for high-standard biological fermentation of calcium propionate, and has the characteristics of simple process, simple fermentation formula, high metabolic expression of the strain, and no residue. Moreover, the fermentation cycle of the present invention can be effectively shortened compared with the existing technology.

[0013] A further technical solution of the present invention is: in step S1, water is added to dilute the organic wheat flour, and dilute sulfuric acid is added to adjust the pH.

[0014] A further technical solution of the present invention is: in step S2, the volume of the LB culture medium shake flask is 150 mL / 500 mL, the culture temperature is 35° C.-37° C., and the culture time is 18 h-20 h.

[0015] A further technical solution of the present invention is: the culture medium formula of the seed tank in step S3 includes 5-10% organic wheat carbon source, 0.1-0.5% peptone, 1-2% organic yeast powder, 0.1-0.2% dipotassium hydrogen phosphate, 0.1-0.2% potassium dihydrogen phosphate, 0.01-0.05% MgSO4.7H2O, and the rest is drinking water or purified water.

[0016] A further technical solution of the present invention is that the seed tank is inoculated with grown shake flask seeds at an inoculation rate of 0.5%-1%, the culture temperature is 35-37°C, and the culture time is 18h-20h.

[0017] A further technical solution of the present invention is: the culture medium of the fermentation tank in step S3 includes 5-10% organic wheat carbon source, 0.1-0.3% peptone, 0.5-1% organic yeast powder, 0.1-0.2% dipotassium hydrogen phosphate, 0.1-0.2% potassium dihydrogen phosphate, 0.01-0.05% MgSO4.7H2O, and the rest is drinking water or purified water; the seed tank is connected to the sterilized fermentation tank, and the amount of the seed tank connected to the fermentation tank is 5-10%.

[0018] A further technical solution of the present invention is: in the fermentation process in the fermentation tank in step S3, 25% sodium hydroxide solution is added to adjust the pH value to 7-8, a carbon source is supplemented, and an organic wheat carbon source is added.

[0019] Organic wheat flour carbon source is used as a supplementary carbon source to promote rapid bacterial growth and product metabolism;

[0020] The amount of seed tank connected to the fermentation tank is 5-10%. Through fermentation control, the formula is reasonably adjusted to reduce the use of inorganic salts and other substances; the carbon source is supplemented in time to meet the expansion needs of the strain; and by adding organic wheat carbon source, the rapid expansion of the strain and the concentrated metabolism of the product during the calcium propionate fermentation process are achieved.

[0021] A further technical solution of the present invention is: in step S4, the deslagging and decolorization is carried out by using a ceramic membrane: filtering is performed by a membrane system, the pore size of the ceramic membrane is 50nm, the operating pressure is 20-30kg, and the flux is 20m 2 / h; remove impurities and bacteria to purify materials; concentrate to high-efficiency concentration: use a high-efficiency concentrator to quickly concentrate the liquid 2-4 times, the vacuum degree reaches 0.995bar, and the temperature is 60℃; the concentrate is filtered through a large plate and frame to remove calcium sulfate precipitate and collect the clear liquid.

[0022] Ceramic membrane deslagging and decolorization can effectively intercept various solids, large pigments, proteins, and bacteria with a retention rate of 100% and a flux of 20m 2 / h, good stability, ensuring product purity and content. High-efficiency concentration effectively guarantees product yield. The concentrate is concentrated according to 200 units of propionic acid content, requiring fast speed and completion in the shortest time.

[0023] A further technical solution of the present invention is: the preparation method further comprises:

[0024] S5. High-pressure spray drying granulation: The calcium propionate liquid obtained by fine filtration is atomized at a pressure of 20MPa-30MPa, an air inlet temperature of 180°C-200°C, and an air outlet temperature of 90°C-105°C to obtain an atomized particle size: 80-mesh particles account for 30-50%, and particles below 200 mesh account for less than 2%;

[0025] S6, fully automatic aseptic packaging. Use a fully automatic packaging machine for packaging to ensure packaging under aseptic conditions and ensure product quality.

[0026] The high-pressure spray drying granulation of the present invention has good product fluidity. Compared with traditional centrifugal spray drying, the product has good particle size, good fluidity and outstanding physical properties.

[0027] Through this process, high-content and high-purity calcium propionate is finally obtained.

[0028] The present invention has the following beneficial effects: The fermentation cycle is controlled within 182 hours, nearly 70 hours shorter than the conventional fermentation cycle of 252.5 hours. The fermentation unit reaches 65-75g / L, compared to the current average of 55g / L, increasing yield by over 20%-30%, and the product content reaches 42%. This effectively solves the technical difficulties in the fermentation process for producing calcium propionate products, fully addressing customer needs and representing a breakthrough.

[0029] To address the shortcomings of existing technologies, the present invention provides a method for producing organic calcium propionate using an organic wheat flour fermentation process. Using organic wheat flour as the primary raw material, supplemented with organic yeast powder, and produced through fermentation with Propionibacterium acnes, this method fully addresses the high-standard biological fermentation calcium propionate requirements of international customers. Furthermore, it features a simple process, a simple fermentation formula, high bacterial metabolic expression, and no residual residue. DETAILED DESCRIPTION

[0030] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0031] Example 1:

[0032] A method for preparing calcium propionate, comprising the following steps:

[0033] S1. Preparation of organic wheat carbon source: organic wheat flour was added to a fermentation tank, diluted by 20%, adjusted to a pH of 5.5, and 1‰ of protease and amylase were added. The mixture was liquefied at 90°C for 1 hour. 1‰ of saccharifying enzyme was then added and saccharified for 8 hours to prepare the organic wheat carbon source.

[0034] S2. Strain expansion: In a sterile environment, the original strain of Propionibacterium is inoculated into an LB medium shake flask for cultivation to obtain well-grown shake flask seeds;

[0035] S3, inoculating the grown shake flask seeds into a seed tank for cultivation, wherein the seed tank contains an organic wheat carbon source; and the seed tank is connected to a fermentation tank;

[0036] S4, removing slag, decolorizing, concentrating, and fine filtering to obtain calcium propionate liquid;

[0037] S5. High-pressure spray drying granulation: The calcium propionate liquid obtained by fine filtration is atomized at a pressure of 20 MPa, an air inlet temperature of 180°C, and an air outlet temperature of 90°C to obtain an atomized particle size: 80-mesh particles account for 45%, and particles below 200 mesh account for less than 2%;

[0038] S6, fully automatic aseptic packaging.

[0039] In this embodiment, in step S1, water is added to dilute the organic wheat flour, and dilute sulfuric acid is added to adjust the pH.

[0040] In this embodiment, in step S2, the volume of the LB culture medium shake flask is 150 mL / 500 mL, the culture temperature is 35° C., and the culture time is 18 h.

[0041] In this embodiment, the formula of the seed tank in step S3 includes 5% organic wheat carbon source, 0.1% peptone, 1% organic yeast powder, 0.2% dipotassium hydrogen phosphate, 0.15% potassium dihydrogen phosphate, and 0.04% MgSO4.7H2O.

[0042] In this embodiment, the seed tank is inoculated with grown shake flask seeds at an inoculation rate of 0.5%, the culture temperature is 35° C., and the culture time is 48 h.

[0043] In this embodiment, the fermentation tank in step S3 includes 5% organic wheat carbon source, 0.1% peptone, 0.5% organic yeast powder, 0.2% dipotassium hydrogen phosphate, 0.15% potassium dihydrogen phosphate, and 0.04% MgSO4.7H2O; the seed tank is connected to the sterilized fermentation tank, and the amount of the seed tank connected to the fermentation tank is 5%.

[0044] In this embodiment, during the fermentation process in the fermentation tank in step S3, 25% sodium hydroxide solution is added to adjust the pH value to 7-8, a carbon source is supplemented, and an organic wheat carbon source (liquid) is added.

[0045] In this embodiment, the deslagging and decolorization in step S4 is carried out by using a ceramic membrane: filtering is performed through a membrane system, the pore size of the ceramic membrane is 50 nm, the operating pressure is 20 kg, and the flux is 20 m 2 / h; remove impurities and bacteria to purify materials; concentrate to high-efficiency concentration: use a high-efficiency concentrator to quickly concentrate the liquid 2-4 times, the vacuum degree reaches 0.995bar, and the temperature is 60℃; the concentrate is filtered through a large plate and frame to remove calcium sulfate precipitate and collect the clear liquid.

[0046] In this example, the formulation employed was optimized and innovated, ultimately achieving a fermentation cycle of 182 hours, nearly 70 hours shorter than the conventional fermentation cycle of 252.5 hours. The fermentation unit reached 65g / L, compared to the current average of 55g / L, resulting in an 18% increase in yield and a product content of 42%. This effectively addresses the technical challenges inherent in the production of calcium propionate using fermentation processes, fully addressing customer needs and demonstrating breakthrough results.

[0047] Example 2:

[0048] In this embodiment, the organic wheat flour carbon source was prepared as follows: the organic wheat flour was added to a fermentation tank, diluted with water at 25% to liquefy, the pH was adjusted to 6.0, and 2‰ of protease and amylase were added; the liquefaction time was 1 hour at a temperature of 110°C; then 2‰ of saccharifying enzyme was added, and the mixture was saccharified at 60°C for 15 hours to prepare the organic wheat carbon source, which was sterilized for use in fermentation culture.

[0049] In this example, the strain was expanded as follows: in a sterile environment, the original strain of Propionibacterium acidophilum was inoculated into an LB medium shake flask with a filling volume of 150 ml / 500 ml, a culture temperature of 37° C., and a culture time of 46 h to obtain well-grown shake flask seeds.

[0050] In this example, seed tank culture was performed using a formulation consisting of 10% organic wheat carbon source, 0.5% peptone, 2% organic yeast powder, 0.2% dipotassium hydrogen phosphate, 0.15% potassium dihydrogen phosphate, and 0.04% MgSO₄. The shake flasks were inoculated with -1% of the grown seeds, incubated at 37°C for 42 hours.

[0051] In this example, the fermentation tank culture was prepared with the following ingredients: 10% organic wheat carbon source, 0.3% peptone, 1% organic yeast powder, 0.2% dipotassium hydrogen phosphate, 0.15% potassium dihydrogen phosphate, and 0.04% MgSO4.7H2O. After sterilization, the mixture was introduced into the seed tank and the fermentation cycle was 182 hours.

[0052] In this embodiment, the fermentation process in the fermenter culture is fed with the following materials: 25% sodium hydroxide solution is used to adjust the pH value to 7-8; organic wheat flour carbon source is used as a supplementary carbon source; rapid bacterial growth and product metabolism are promoted; fermentation control: the amount of seed tank connected to the fermenter is 10%, and through fermentation control, the formula is reasonably adjusted to reduce the use of inorganic salts and other substances; the carbon source is supplemented in time to meet the expansion needs of the strain; and by feeding the organic wheat flour liquid, rapid expansion of the strain and concentrated metabolism of the product during the calcium propionate fermentation process are achieved.

[0053] In this embodiment, ceramic membrane deslagging and decolorization: filtration is performed through a membrane system, the pore size of the ceramic membrane is 50nm, the operating pressure is 30kg, and various solids, large pigments, proteins, and bacteria are effectively intercepted, with a retention rate of 100% and a flux of 20m 2 / h, good stability, ensuring product purity and content. Remove impurities and bacteria; pure materials.

[0054] In this example, high-efficiency concentration is performed using a high-efficiency concentrator to rapidly concentrate the liquid by 2-4 times, with a vacuum of 0.995 bar and a temperature of 60°C. This effectively ensures product yield, and the concentrate is concentrated to a propionic acid content of 200 units. This process is required to be completed quickly and in the shortest possible time.

[0055] In this embodiment, large plate and frame fine filtration: the concentrated liquid is filtered through a large plate and frame to remove calcium sulfate precipitation, and the clear liquid is collected (there is a lot of precipitation, so top water is needed).

[0056] In this embodiment, high-pressure spray drying granulation is used to obtain a solid powder containing only propionic acid and acetic acid (the propionic acid content is about 65%) at a pressure of 30 MPa, an air inlet temperature of 200°C, an air outlet temperature of 105°C, and an atomized particle size: 80 mesh particle size accounts for 50%, and less than 200 mesh and below; the product has good fluidity, and compared with traditional centrifugal spray drying: good particle size, good fluidity, and outstanding physical properties.

[0057] Fully automatic aseptic packaging:

[0058] We use fully automatic packaging machines for packaging to ensure packaging under sterile conditions and ensure product quality.

[0059] Through this process, high-content and high-purity calcium propionate is finally obtained.

[0060] In this embodiment, a stable production strain was formed by optimizing and subculturing a high-yield strain. The formulation employed was optimized and innovated, ultimately achieving a fermentation cycle of 182 hours, nearly 70 hours shorter than the conventional fermentation cycle of 252.5 hours. The fermentation unit reached 75g / L, a more than 30% increase in yield compared to the current average of 55g / L, and the product content reached 42%. This effectively addresses the technical difficulties encountered in the production of calcium propionate products using fermentation processes, fully addressing customer needs and demonstrating breakthrough results.

[0061] Example 3:

[0062] A method for preparing calcium propionate, comprising the following steps:

[0063] S1. Preparation of organic wheat carbon source: organic wheat flour was added to a fermentation tank, diluted by 22%, adjusted to a pH of 5.5, and 1‰ of protease and amylase were added. The mixture was liquefied at 100°C for 1 hour. 1‰ of saccharifying enzyme was then added and saccharified for 12 hours to prepare the organic wheat carbon source.

[0064] S2. Strain expansion: In a sterile environment, the original strain of Propionibacterium is inoculated into an LB medium shake flask for cultivation to obtain well-grown shake flask seeds;

[0065] S3, placing grown shake flask seeds in a seed tank for cultivation, wherein the seed tank contains an organic wheat carbon source; and placing the seed tank in a fermentation tank;

[0066] S4, removing slag, decolorizing, concentrating, and fine filtering to obtain calcium propionate liquid;

[0067] S5. High-pressure spray drying granulation: The calcium propionate liquid obtained by fine filtration is atomized at a pressure of 25 MPa, an air inlet temperature of 190°C, and an air outlet temperature of 100°C to obtain an atomized particle size: 80-mesh particles account for 42%, and particles below 200 mesh account for less than 2%;

[0068] S6, fully automatic aseptic packaging.

[0069] In this embodiment, in step S1, water is added to dilute the organic wheat flour, and dilute sulfuric acid is added to adjust the pH.

[0070] In this embodiment, in step S2, the volume of the LB culture medium shake flask is 150 mL / 500 mL, the culture temperature is 36° C., and the culture time is 19 h.

[0071] In this embodiment, the formula of the seed tank in step S3 includes 8% organic wheat carbon source, 0.5% peptone, 1% organic yeast powder, 0.1% dipotassium hydrogen phosphate, 0.1% potassium dihydrogen phosphate, and 0.04% MgSO4.7H2O.

[0072] In this embodiment, the seed tank was inoculated with grown shake flask seeds at an inoculation rate of 0.5%, the culture temperature was 35° C., and the culture time was 47 h.

[0073] In this embodiment, the fermentation tank in step S3 contains 5% organic wheat carbon source, 0.1% peptone, 0.5% organic yeast powder, 0.1% dipotassium hydrogen phosphate, 0.1% potassium dihydrogen phosphate, and 0.04% MgSO4.7H2O; the seed tank is connected to the sterilized fermentation tank, and the amount of seed tank connected to the fermentation tank is 8%. The fermentation cycle is 180 hours.

[0074] In this embodiment, during the fermentation process in the fermentation tank in step S3, 25% sodium hydroxide solution is added to adjust the pH value to 7-8, a carbon source is supplemented, and an organic wheat carbon source (liquid) is added.

[0075] In this embodiment, the deslagging and decolorization in step S4 is carried out by using a ceramic membrane: filtering is performed through a membrane system, the pore size of the ceramic membrane is 50 nm, the operating pressure is 20 kg, and the flux is 20 m 2 / h; remove impurities and bacteria to purify materials; concentrate to high-efficiency concentration: use a high-efficiency concentrator to quickly concentrate the liquid 2-4 times, the vacuum degree reaches 0.995bar, and the temperature is 60℃; the concentrate is filtered through a large plate and frame to remove calcium sulfate precipitate and collect the clear liquid.

[0076] In this embodiment, the formulation employed has been optimized and innovated, ultimately achieving a fermentation cycle of less than 180 hours, nearly 70 hours shorter than the conventional fermentation cycle of 252.5 hours. The fermentation unit reached 70g / L, compared to the current average of 55g / L, resulting in a 27% increase in yield and a product content of 40%. This effectively addresses the technical challenges associated with the production of calcium propionate products through fermentation, fully addressing customer needs and achieving a breakthrough.

[0077] Comparative Example 1:

[0078] A preparation method of calcium propionate comprises the following steps:

[0079] S1. Strain expansion: In a sterile environment, the original strain of Propionibacterium is inoculated into an LB medium shake flask for cultivation to obtain well-grown shake flask seeds;

[0080] S2. Inoculate the grown shake flask seeds in a seed tank for cultivation. The seed tank contains 2% glucose, 1% sucrose, 0.1-0.5% peptone, 1-2% organic yeast powder, 0.25% dipotassium hydrogen phosphate, 0.15% potassium dihydrogen phosphate, 0.04% MgSO4.7H2O, and the remainder is drinking water. Inoculate the seed tank in a fermentation tank. The fermentation tank contains 10% glucose, 0.1-0.3% peptone, 0.5-1% organic yeast powder, 0.25% dipotassium hydrogen phosphate, 0.15% potassium dihydrogen phosphate, 0.04% MgSO4.7H2O, and the remainder is drinking water or purified water.

[0081] S3, deslagging, decolorization, concentration and fine filtration are carried out using the same parameters and methods as in Example 1 to obtain calcium propionate liquid.

[0082] The carbon sources in Comparative Example 1 are glucose and sucrose, which not only cannot meet the requirement of no organic residue, but also have a fermentation cycle of 248 hours and an average fermentation unit of 58 g / L.

[0083] Comparative Example 2:

[0084] A method for preparing calcium propionate comprises the following steps:

[0085] S1. Strain expansion: In a sterile environment, the original strain of Propionibacterium is inoculated into an LB medium shake flask for cultivation to obtain well-grown shake flask seeds;

[0086] S2. Grown shake flask seeds are inoculated into a seed tank for cultivation, wherein the culture medium in the seed tank comprises 12% of the organic wheat carbon source in Example 1, 0.08% of peptone, 5% of organic yeast powder, 0.5% of dipotassium hydrogen phosphate, 0.3% of potassium dihydrogen phosphate, and 0.08% of MgSO4.7H2O, and the remainder is drinking water; the seed tank is inoculated into a fermentation tank, wherein the fermentation tank comprises 12% of the organic wheat carbon source in Example 1, 0.08% of peptone, 5% of organic yeast powder, 0.5% of dipotassium hydrogen phosphate, 0.3% of potassium dihydrogen phosphate, and 0.08% of MgSO4.7H2O, and the remainder is drinking water or purified water; the seed tank is inoculated into a sterilized fermentation tank, and the amount of the seed tank inoculated into the fermentation tank is 5%.

[0087] S3, deslagging, decolorization, concentration, and fine filtration are performed using the same parameters and methods as in Example 1 to obtain calcium propionate liquid.

[0088] The proportions of the culture medium in Comparative Example 2 were different from those in Examples 1 to 3. The fermentation period was 252.5 hours, and the average fermentation unit was 55 g / L.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing calcium propionate, characterized in that: The method comprises the following steps: S1. Preparation of organic wheat carbon source: organic wheat flour is added to a fermentation tank and diluted to a concentration of 20%-25% organic wheat flour, the pH is adjusted to 5.5-6, and 1‰-2‰ of protease and amylase are added to the organic wheat flour, and the mixture is liquefied at a temperature of 90°C-110°C; then, 1‰-2‰ of saccharifying enzyme is added to the organic wheat flour and saccharified for 8-15 hours to prepare the organic wheat carbon source; S2. Strain expansion: In a sterile environment, the original strain of Propionibacterium is inoculated into LB medium for cultivation to obtain well-grown seeds; S3, seeding the grown seeds of S2 into a seed tank for cultivation, wherein the seed tank contains the organic wheat carbon source of S1; and the seed tank is connected to a fermentation tank; S4, removing slag, decolorizing, concentrating and fine filtering to obtain calcium propionate liquid.

2. A method for preparing calcium propionate according to claim 1, characterized in that: In step S1, water is added to dilute the organic wheat flour, and dilute sulfuric acid is added to adjust the pH.

3. A method for preparing calcium propionate according to claim 1, characterized in that: In step S2, the LB culture medium is placed in a shake flask with a filling volume of 150 mL / 500 mL, the culture temperature is 35° C.-37° C., and the culture time is 18 h-20 h.

4. The method for preparing calcium propionate according to claim 1, wherein: The seed tank in step S3 comprises the following culture medium by mass fraction: 5-10% organic wheat carbon source, 0.1-0.5% peptone, 1-2% organic yeast powder, 0.1-0.2% dipotassium hydrogen phosphate, 0.1-0.2% potassium dihydrogen phosphate, 0.01-0.05% MgSO4.7H2O, and the rest is drinking water.

5. A method for preparing calcium propionate according to claim 4, characterized in that: The inoculation amount of the grown seeds in the S3 seed tank is 0.5%-1%, the culture temperature is 35°C-37°C, and the culture time is 36h-48h.

6. The method for preparing calcium propionate according to claim 1, wherein: The fermentation tank in step S3 includes the following culture medium by mass fraction: 5-10% organic wheat carbon source, 0.1-0.3% peptone, 0.5-1% organic yeast powder, 0.1-0.2% dipotassium hydrogen phosphate, 0.1-0.2% potassium dihydrogen phosphate, 0.01-0.05% MgSO4.7H2O, and the remainder is drinking water or purified water; the seed tank is connected to the sterilized fermentation tank, and the amount of the seed tank connected to the fermentation tank is 5-10%.

7. A method for preparing calcium propionate according to claim 6, characterized in that: In step S3, during the fermentation process in the fermentation tank, 25% sodium hydroxide solution is added to adjust the pH value to 6-7, a carbon source is supplemented, and an organic wheat carbon source is added.

8. The method for preparing calcium propionate according to claim 1, wherein: In step S4, a ceramic membrane is first used for deslagging and decolorization, specifically filtering through a membrane system, the pore size of the ceramic membrane is 50nm, the operating pressure is 20-30kg, and the flux is 20m 2 / h; remove impurities and bacteria to purify the material; then use a concentrator to concentrate the liquid 2-4 times, the vacuum degree reaches 0.995bar, and the temperature is 60℃; concentrate it into a concentrate containing propionic acid: finally, the concentrate is filtered through a plate and frame to remove other precipitates, and the clear liquid is collected to obtain.

9. The method for preparing calcium propionate according to claim 1, wherein: The preparation method further comprises: S5. High-pressure spray drying granulation: The calcium propionate liquid obtained by fine filtration is atomized at a pressure of 20MPa-30MPa, an air inlet temperature of 180°C-200°C, and an air outlet temperature of 90°C-105°C to obtain an atomized particle size: 80-mesh particles account for 30-50%, and particles below 200 mesh account for less than 2%; S6, fully automatic aseptic packaging.