阅读说明：本技术 一种丙酸锌的发酵生产工艺 (Fermentation production process of zinc propionate ) 是由 龚国利 王欣 田露 于 2020-06-12 设计创作，主要内容包括：一种丙酸锌的发酵生产工艺,将小麦粉和去离子水混合,pH调到3.8-4.3,加热到50～55℃,加入真菌α-淀粉酶,酶解,得到小麦酶解液；将产酸丙酸杆菌在种子培养基中培养,得到了种子液；将种子液接种到发酵培养基中,调节pH为5.2-5.5,发酵200-240h,得到发酵液,将发酵液离心,浓缩,冷冻干燥,得到丙酸锌。由于产酸丙酸杆菌在发酵过程中为产物抑制型,当发酵液中丙酸的产量过高会抑制菌体的增长,进而导致丙酸的产量降低,本发明在发酵过程中流加氧化锌水溶液,进而生成丙酸锌,提高了丙酸锌的产量,同时也提供了生产丙酸锌的新方法。(A fermentation production process of zinc propionate comprises mixing wheat flour and deionized water, adjusting pH to 3.8-4.3, heating to 50-55 deg.C, adding fungal alpha-amylase, and performing enzymolysis to obtain wheat enzymolysis solution; culturing acid-producing propionibacterium in a seed culture medium to obtain a seed solution; inoculating the seed liquid into a fermentation culture medium, adjusting the pH value to 5.2-5.5, fermenting for 200-240h to obtain fermentation liquid, centrifuging, concentrating, and freeze-drying the fermentation liquid to obtain the zinc propionate. The propionibacterium acidovorans is product-inhibited in the fermentation process, and the increase of thalli can be inhibited when the yield of propionic acid in fermentation liquor is too high, so that the yield of propionic acid is reduced.)

1. The fermentation production process of zinc propionate is characterized by comprising the following steps:

s1, mixing wheat flour and deionized water to obtain a mixed solution, adjusting the pH of the mixed solution to 3.8-4.3, heating to 50-55 ℃, adding fungal alpha-amylase, performing enzymolysis, and performing centrifugal filtration to obtain a wheat enzymolysis solution;

s2, culturing acid-producing propionibacterium in a seed culture medium to obtain a seed solution;

s3, preparing a fermentation medium by using the fermentation medium, inoculating the seed liquid into the fermentation medium, adjusting the pH to 5.2-5.5 by using ammonia water, fermenting for 200-240h to obtain fermentation liquid, centrifuging, concentrating, and freeze-drying the fermentation liquid to obtain the zinc propionate.

2. The fermentation production process of zinc propionate according to claim 1, wherein in step S1, the wheat flour is 100-200 mesh.

3. The fermentation production process of zinc propionate according to claim 1, wherein in step S1, the mass ratio of wheat flour to deionized water is 1 (3-5).

4. The process of claim 1, wherein the pH of the solution is adjusted to 3.8-4.3 with acetic acid in step S1.

5. The fermentation production process of zinc propionate according to claim 1, wherein in step S1, the amount of fungal alpha-amylase added is 1-3 g per liter of mixed liquor; the enzymolysis time is 20-24 h.

6. The fermentation production process of zinc propionate according to claim 1, wherein in step S2, the seed liquid culture medium comprises sodium lactate and yeast powder, wherein the concentration of sodium lactate is 10-15g/L, and the concentration of yeast powder is 7.5-15 g/L.

7. The process of claim 1, wherein the culturing temperature in step S2 is 30 ℃ and the culturing time is 20-24 h.

8. The process of claim 1, wherein in step S3, 100mL of seed solution is added per liter of fermentation medium.

9. The fermentation production process of zinc propionate according to claim 1, wherein in step S3, the mass concentration of ammonia water is 30-50%.

10. The fermentation production process of zinc propionate according to claim 1, wherein in step S3, the fermentation medium comprises wheat hydrolysate, yeast powder, corn steep liquor and zinc oxide, and the concentration of the wheat hydrolysate is: 600-800mL/L, the concentration of yeast powder is 10g/L, the concentration of corn steep liquor is 10g/L, and the concentration of zinc oxide is 50 g/L.

Technical Field

The invention relates to a method for producing zinc propionate, in particular to a fermentation production process of zinc propionate.

Background

With the shortage of petroleum resources and the more serious problem of environmental pollution, the traditional propionic acid synthesized by petrochemical industry cannot meet the requirement of people on green preservatives, and people utilize propionibacterium to produce propionic acid so as to synthesize zinc propionate. Because the propionibacterium has tenacious vitality, propionic acid can be produced by utilizing various substrates, and the propionibacterium is widely applied to industries such as food, pharmacy and the like nowadays.

With the rapid development of the food industry, people have higher and higher requirements on green and healthy food preservatives. Zinc propionate is widely used because Propionic Acid (Propionic Acid) has a preservative function, but Propionic Acid is poor in stability, is easy to lose in the storage process, and has a poor preservative effect, so that the Propionic Acid is generally in the form of propionate. Zinc is a trace element required by human life activity, and can accelerate growth and development, improve taste, prevent infection and promote wound healing. Zinc propionate is a food preservative, and zinc propionate is a green preservative, so that even if a large amount of zinc propionate is given to the body, propionic acid is discharged with urine and cannot be accumulated in the body, and zinc ions are absorbed and utilized by the body, so that the zinc propionate is nontoxic to the body. Zinc propionate is used as preservative in food such as cake and bread, and can be added into animal feed for sterilization and zinc supplementation. Therefore, the preparation of the zinc propionate with dual functions of zinc supplement and corrosion prevention has important significance. Therefore, there is a need to provide a new method for preparing zinc propionate.

Disclosure of Invention

The invention aims to solve the existing demand of people on green food preservatives, and provides a fermentation production process of zinc propionate.

In order to achieve the purpose, the invention adopts the following technical scheme:

a fermentation production process of zinc propionate comprises the following steps:

s1, mixing wheat flour and deionized water to obtain a mixed solution, adjusting the pH of the mixed solution to 3.8-4.3, heating to 50-55 ℃, adding fungal alpha-amylase, performing enzymolysis, and performing centrifugal filtration to obtain a wheat enzymolysis solution;

s2, culturing acid-producing propionibacterium in a seed culture medium to obtain a seed solution;

s3, preparing a fermentation medium by using the fermentation medium, inoculating the seed liquid into the fermentation medium, adjusting the pH to 5.2-5.5 by using ammonia water, fermenting for 200-240h to obtain fermentation liquid, centrifuging, concentrating, and freeze-drying the fermentation liquid to obtain the zinc propionate.

The present invention is further improved in that in step S1, the wheat flour is 100-200 mesh.

The invention is further improved in that in the step S1, the wheat flour and the deionized water are mixed according to the mass ratio of 1 (3-5).

In a further development of the invention, in step S1, the pH is adjusted to 3.8 to 4.3 with acetic acid.

The invention has the further improvement that in the step S1, the addition amount of the fungal alpha-amylase is 1-3 g per liter of mixed liquor; the enzymolysis time is 20-24 h.

The further improvement of the invention is that in step S2, the seed liquid culture medium comprises sodium lactate and yeast powder, wherein the concentration of the sodium lactate is 10-15g/L, and the concentration of the yeast powder is 7.5-15 g/L.

The invention is further improved in that in step S2, the culture temperature is 30 ℃, and the culture time is 20-24 h.

A further improvement of the present invention is that in step S3, 100mL of seed solution per liter of fermentation medium is added.

The invention is further improved in that in the step S3, the mass concentration of the ammonia water is 30-50%.

The invention has the further improvement that in the step S3, the fermentation medium comprises wheat hydrolysate, yeast powder, corn steep liquor and zinc oxide, and the concentration of the wheat hydrolysate is as follows: 600-800mL/L, the concentration of yeast powder is 10g/L, the concentration of corn steep liquor is 10g/L, and the concentration of zinc oxide is 50 g/L.

Compared with the prior art, the invention has the following beneficial technical effects: compared with the traditional chemical method for producing the zinc propionate, the method for producing the zinc propionate by the microbial fermentation method has the advantage that the green wheat enzymolysis liquid is selected as a carbon source in a fermentation culture medium in order to ensure that the product zinc propionate is safer as a preservative. The method adds zinc oxide aqueous solution in the fermentation process to generate zinc propionate, thereby improving the yield of the zinc propionate and simultaneously providing a new method for producing the zinc propionate.

Detailed Description

The technical solutions in the examples of the present invention will be fully and clearly described below with reference to the examples.

The invention provides a new idea for producing zinc propionate by adopting a healthy and green carbon source, namely wheat as a raw material and a method for producing the zinc propionate by microbial fermentation.

The invention relates to a production process method of zinc propionate, which comprises the following steps:

s1, crushing wheat into powder, sieving the powder by a sieve of 100-200 meshes, weighing the wheat powder, putting the wheat powder into a triangular flask, mixing wheat flour and deionized water according to the mass ratio of 1: 5-1: 3, adjusting the pH to 3.8-4.3 by using acetic acid, heating to 50-55 ℃, adding fungal alpha-amylase, performing enzymolysis for 20-24 hours, and performing centrifugal filtration to obtain wheat enzymolysis liquid, namely a carbon source.

S2. activation of Propionibacterium acidovorans: propionibacterium acidocaldarium (p. acidipropionici) as a fermentation strain. Preparing a seed culture medium, sterilizing at 121 ℃ for 20min, inoculating propionibacterium acidovorans (P. acidipropionici) into the seed culture medium, and culturing in a constant temperature incubator at 30 ℃ for 20-24h to obtain a seed solution.

S3, propionibacterium acidogenic (P. acidipropionici) inoculation and fermentation: preparing a fermentation culture medium, wherein the fermentation culture medium comprises wheat enzymolysis liquid. Sterilizing at 121 ℃ for 20min, cooling to 30-32 ℃, adding 100mL of seed liquid into each liter of culture medium, then inoculating the seed liquid of acid-producing propionibacterium (P.acidipropionicici) into a fermentation culture medium, adjusting the pH value to 5.2-5.5 with ammonia water at the beginning of fermentation, and obtaining fermentation liquid after the fermentation time is 200-240 h.

S4, centrifuging the fermentation liquor obtained in the step S3 to remove thalli and impurities, taking the supernatant, concentrating, and freeze-drying to obtain zinc propionate crystals.

Further, in step S1, the amount of the fungal alpha-amylase added to the mixed system of wheat flour and deionized water is 1-3 g/L.

Further, in step S2, propionibacterium acidogenic (p. acidipropionici) was stored in the laboratory, seed broth medium: sodium lactate: 10-15g/L, yeast powder: 7.5-15 g/L.

Further, in step S2, the mass concentration of the ammonia water is 30-50%.

Further, in step S3, the fermentation medium: carbon source: wheat hydrolysate: 600 + 800mL/L, yeast powder: 10g/L, 10g/L of corn steep liquor, zinc oxide: 50 g/L.

Further, the supernatant was evaporated and concentrated to 2/5 of the original volume in step S4.

The following are specific examples.