阅读说明：本技术 一种利用甘薯制备味精的发酵方法及装置 (Fermentation method and device for preparing monosodium glutamate by utilizing sweet potatoes ) 是由 来凤堂 李树标 郑世涛 薄文文 高翠娟 王婷 于 2020-07-16 设计创作，主要内容包括：本发明公开了一种利用甘薯制备味精的发酵方法及装置,它包括步骤1)制备发酵培养基,步骤2)发酵培养,步骤3)过滤浓缩,步骤4)结晶,步骤5)制备味精,本发明结构合理,转化效率和纯度高,并对发酵和曝气结构都进行了优化,有效的解决了现有技术所存在的技术问题。(The invention discloses a fermentation method and a device for preparing monosodium glutamate by sweet potatoes, which comprise the steps of 1) preparing a fermentation culture medium, 2) fermenting and culturing, 3) filtering and concentrating, 4) crystallizing and 5) preparing monosodium glutamate.)

1. A fermentation method for preparing monosodium glutamate by utilizing sweet potatoes is characterized by comprising the following steps:

step 1) preparing a fermentation culture medium, step 2) fermenting and culturing, step 3) filtering and concentrating, step 4) crystallizing, and step 5) preparing monosodium glutamate.

2. The fermentation method for preparing monosodium glutamate from sweet potatoes according to claim 1, wherein the fermentation method comprises the steps of 1) preparing a fermentation medium, wherein the fermentation medium comprises a fermentation medium A, a fermentation medium B and a fermentation medium C which are used separately;

the fermentation medium A comprises (by mass): 15% of sweet potato glucose, 2.5% of sweet potato galactose, 0.2% of urea, 0.02% of ferrous sulfate, 0.01% of magnesium sulfate, 0.02% of potassium sulfate, 0.02% of polyether modified silicone oil, 0.15% of potassium dihydrogen phosphate, 0.05% of ammonium dihydrogen phosphate, 0.05% of biotin, 0.5% of sodium bicarbonate and the balance of water;

the fermentation medium B comprises (by mass): 11.5 percent of urea, 0.5 percent of phenylalanine and 0.2 percent of defoaming agent;

the fermentation medium C comprises (by mass): 25% of sweet potato glucose, 4.5% of sweet potato galactose, 0.15% of biotin and 1.5% of sodium bicarbonate;

step 2) fermentation culture, sterilizing the fermentation medium A, placing the fermentation medium A in a fermentation tank, adjusting the pH value to 6.9-7.0 by sulfuric acid and sodium hydroxide, uniformly stirring, controlling the temperature to be 32-33 ℃, inoculating corynebacterium glutamicum seed liquid, starting a stirring device and an aeration device, and fermenting for 8-12 hours; then heating to 33-35 ℃, feeding the fermentation medium B and the fermentation medium C, keeping the pH value at 7.0-7.2 and the sugar content not less than 0.65%, fermenting for 24-28h, stopping feeding, and continuing to ferment for 0.5-2h to obtain fermentation liquor;

step 3) filtering and concentrating, namely centrifuging and filtering the fermentation liquor, taking supernatant, filtering the supernatant by using a microfiltration membrane, decoloring the filtrate by using a decoloring tank, and evaporating and concentrating the filtrate to 1/3-2/3 of the volume of the original solution;

step 4) crystallizing, namely placing the concentrated solution into an isoelectric point tank, cooling to 25 ℃, continuously stirring, and adding sulfuric acid in a flowing manner until the pH value is 4.8; slowly adding sulfuric acid, adding seed crystal when the pH value is less than 4.5, reducing the stirring speed to 30 r/min, crystallizing for 2-3 hours, then continuously slowly adding sulfuric acid until the pH value is 3.2, cooling to 8-10 ℃, and growing crystals for 6-10 hours; stopping stirring, precipitating for 2-4 hours, and filtering supernatant to obtain wet sodium glutamate crystals;

and 5) preparing monosodium glutamate, namely adding 5%, 10%, 15% or 20% of sodium glutamate, or adding sodium chloride and selenide, or adding sodium chloride and iodide, decoloring again through a decoloring film, and drying to obtain monosodium glutamate.

3. The fermentation method and apparatus for preparing monosodium glutamate from sweet potatoes according to claim 1, wherein the fermentation method for preparing monosodium glutamate from sweet potatoes comprises:

step 1) preparing a fermentation medium, wherein the fermentation medium comprises a fermentation medium A, a fermentation medium B and a fermentation medium C which are used separately;

the fermentation medium A comprises (by mass): 12% of sweet potato glucose, 5% of sweet potato galactose, 0.2% of urea, 0.02% of ferrous sulfate, 0.01% of magnesium sulfate, 0.02% of potassium sulfate, 0.02% of glycerol, 0.15% of potassium dihydrogen phosphate, 0.05% of ammonium dihydrogen phosphate, 0.05% of biotin, 0.5% of sodium carbonate and the balance of water;

the fermentation medium B comprises (by mass): 30% of ammonia water, 0.5% of phenylalanine and 0.2% of defoaming agent;

the fermentation medium C comprises (by mass): sweet potato glucose 20%, sweet potato galactose 8%, biotin 0.15%, and sodium bicarbonate 1.5%;

step 2) fermentation culture, sterilizing a fermentation medium A, placing the fermentation medium A in a fermentation tank, adjusting the pH value to 6.9-7.0 by sulfuric acid and sodium hydroxide, uniformly stirring, controlling the temperature to be 32-33 ℃, inoculating corynebacterium glutamicum seed liquid with the inoculation amount of 5-10%, starting a stirring device and an aeration device, and fermenting for 8-12 hours at the stirring speed of 60-220 r/min; then heating to 34-36 ℃, feeding the fermentation medium B and the fermentation medium C, keeping the pH value at 7.0-7.2 and the content not less than 0.65%, stirring at the speed of 180-;

step 3) filtering and concentrating, namely centrifuging and filtering the fermentation liquor, taking supernatant, filtering the supernatant through a microfiltration membrane, decoloring the filtrate through a decoloring tank, and evaporating and concentrating the filtrate to 1/3 of the volume of the original solution;

step 4) crystallizing, namely placing the concentrated solution into an isoelectric point tank, cooling to 25 ℃, continuously stirring, and adding sulfuric acid in a flowing manner until the pH value is 4.8; slowly adding sulfuric acid, adding seed crystal when the pH value is less than 4.5, reducing the stirring speed to 30 r/min, crystallizing for 2-3 hours, then continuously slowly adding sulfuric acid until the pH value is 3.2, cooling to 4-8 ℃, and growing crystals for 6-10 hours; stopping stirring, precipitating for 2-4 hours, and filtering supernatant to obtain wet sodium glutamate crystals;

and 5) preparing monosodium glutamate, namely adding 5% of sodium chloride and selenide into sodium glutamate, decoloring again through a decoloring film, and drying to obtain monosodium glutamate.

4. The fermentation method for preparing monosodium glutamate from sweet potatoes according to claim 2 or 3, wherein the filtration is centrifugal filtration, supernatant is obtained, then the supernatant is subjected to filter pressing by a half-frame filter, activated carbon powder is adopted for adsorption in a decoloring tank, then the supernatant is subjected to microfiltration membrane filtration, and then the supernatant is subjected to secondary decoloring by a resin column until the crystallization light transmittance is more than 80%.

5. The fermentation method for preparing monosodium glutamate by using sweet potatoes according to claim 1, wherein a stirring shaft and upper stirring blades are arranged in the fermentation tank, and an interlayer for circulating media is arranged in the side wall of the fermentation tank; the top of the fermentation tank is respectively connected with a stirring tank I and a stirring tank II through pipelines; the bottom of the fermentation tank is a conical bottom, and an aeration pipe close to or attached to the conical bottom is arranged at the bottom of the fermentation tank; and vertical battens are arranged on the inner side wall of the fermentation tank.

6. The fermentation device for preparing monosodium glutamate from sweet potatoes according to claim 5, wherein a stirring device and a temperature control device are arranged in the stirring tank I and the stirring tank II; be equipped with the solenoid valve on agitator tank I and agitator tank II's the pipeline, be equipped with atomizer behind the pipeline stretches into the fermentation cylinder, be equipped with the atmospheric pressure storehouse on agitator tank I and the agitator tank II.

7. The fermentation device for preparing monosodium glutamate from sweet potatoes as claimed in claim 5, wherein the aeration pipe is spiral or has a plurality of groups of gradually narrowed circles, and the aeration pipe is provided with rubber membrane micropores with a diameter of 150-800 μm.

8. The fermentation device for preparing monosodium glutamate by using sweet potatoes according to claim 5, wherein a lower stirring blade is arranged at the bottom end of the stirring shaft; the lower stirring blade extends into the conical bottom, and the bottom edge of the lower stirring blade is an inclined edge and is close to the upper surface of the aeration pipe.

Technical Field

The invention belongs to the technical field of biological fermentation and equipment, and particularly relates to a fermentation method and a fermentation device for preparing monosodium glutamate by utilizing sweet potatoes.

Background

Monosodium glutamate is one of seasonings, mainly has the effect of enhancing the delicate flavor of food, is mostly used in Chinese dishes, can also be used for soup and sauce, and mainly contains sodium glutamate.

The monosodium glutamate is sodium glutamate crystal prepared by fermenting and purifying grains as raw materials. Since 1965, China has completely adopted sugar or starch raw materials to produce glutamic acid, then the glutamic acid is extracted by isoelectric point crystallization precipitation, ion exchange or zinc salt refining and the like, and sodium glutamate crystals are prepared by processes of decolorization, deferrization, evaporation, crystallization and the like.

Application publication No.: CN109797176A discloses an environment-friendly process for preparing monosodium glutamate, which comprises the following steps: step 1) preparing glutamic acid fermentation liquor, step 2) reusing the strains, and step 3) preparing monosodium glutamate. Inoculating Corynebacterium glutamicum seed solution (1 × 108 cfu/ml) in a fermentation tank containing fermentation medium according to an inoculation amount of 8% for fermentation, wherein the culture temperature is 35 deg.C, the dissolved oxygen level is kept at 20 by adjusting stirring speed and ventilation, and the pH value is kept at 6.8(0-24 h) and 6.5(24-48 h) by automatically feeding ammonia water; controlling the residual sugar to be not less than 1.0 by feeding glucose solution with the concentration of 100g/L, and stopping fermentation for 48 hours to obtain glutamic acid fermentation liquor; wherein the fermentation medium comprises the following components in percentage by mass: 9 percent of glucose, 2 percent of molasses, 3 percent of corn steep liquor, 0.5 percent of urea, 0.01 percent of ferrous sulfate, 0.01 percent of magnesium sulfate, 0.01 percent of monopotassium phosphate and pH6.8. The invention increases the yield of monosodium glutamate by producing acid again from the waste thalli.

Application publication No.: CN105124518A, discloses a process for preparing monosodium glutamate from potato starch: adding medium-temperature alpha amylase, xylanase, 0.2% beta-glucanase and saccharifying enzyme to prepare enzymatic hydrolysate; preparing a fermentation culture medium, sterilizing and cooling to 33 ℃; selecting corynebacterium crenatum B9, inoculating strains for fermentation, wherein the inoculation amount is 1%, the fermentation temperature is 38 ℃, and the culture time is 29-31 hours; and extracting and refining after fermentation to prepare the monosodium glutamate. The purity of the monosodium glutamate prepared by the invention reaches more than 99.2 percent, and completely meets the national requirements on salt-free monosodium glutamate. The process can be directly inoculated with strains for fermentation, and has the advantages of high fermentation efficiency, short fermentation time and cost saving.

The current monosodium glutamate production process flow is as follows: glutamic acid fermentation liquor obtained by microbial fermentation is extracted by adopting a continuous isoelectric process to obtain monosodium glutamate precursor glutamic acid in the fermentation liquor, and then alkali is added for neutralization and crystallization to obtain monosodium glutamate. But the fermentation liquor has incomplete reaction and contains a large amount of thalli, proteins, pigments, various salts, ions and the like, thereby seriously restricting the quality of the finished product of the glutamic acid.

Disclosure of Invention

The invention aims to solve the technical problems of low efficiency and poor effect of a monosodium glutamate fermentation method in the prior art, and provides a fermentation method and a fermentation device for preparing monosodium glutamate by using sweet potatoes, so as to solve the defects in the prior art.

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

a fermentation method for preparing monosodium glutamate by utilizing sweet potatoes comprises the following steps:

step 1) preparing a fermentation culture medium, step 2) fermenting and culturing, step 3) filtering and concentrating, step 4) crystallizing, and step 5) preparing monosodium glutamate.

Specifically, the step 1) of preparing a fermentation medium, wherein the fermentation medium comprises a fermentation medium A, a fermentation medium B and a fermentation medium C which are used separately;

the fermentation medium A comprises (by mass): 15% of sweet potato glucose, 2.5% of sweet potato galactose, 0.2% of urea, 0.02% of ferrous sulfate, 0.01% of magnesium sulfate, 0.02% of potassium sulfate, 0.02% of polyether modified silicone oil, 0.15% of potassium dihydrogen phosphate, 0.05% of ammonium dihydrogen phosphate, 0.05% of biotin, 0.5% of sodium bicarbonate and the balance of water;

the fermentation medium B comprises (by mass): 11.5 percent of urea, 0.5 percent of phenylalanine and 0.2 percent of defoaming agent;

the fermentation medium C comprises (by mass): 25% of sweet potato glucose, 4.5% of sweet potato galactose, 0.15% of biotin and 1.5% of sodium bicarbonate.

Step 2) fermentation culture, sterilizing the fermentation medium A, placing the fermentation medium A in a fermentation tank, adjusting the pH value to 6.9-7.0 by sulfuric acid and sodium hydroxide, uniformly stirring, controlling the temperature to be 32-33 ℃, inoculating corynebacterium glutamicum seed liquid, starting a stirring device and an aeration device, and fermenting for 8-12 hours; then heating to 33-35 ℃, feeding the fermentation medium B and the fermentation medium C, keeping the pH value at 7.0-7.2 and the sugar content not less than 0.65%, fermenting for 24-28h, stopping feeding, and continuing fermenting for 0.5-2h to obtain the fermentation liquid.

And 3) filtering and concentrating, namely centrifuging and filtering the fermentation liquor, taking supernatant, filtering the supernatant by using a microfiltration membrane, decoloring the filtrate by using a decoloring tank, and evaporating and concentrating the filtrate to 1/3-2/3 of the volume of the original solution.

Step 4) crystallizing, namely placing the concentrated solution into an isoelectric point tank, cooling to 25 ℃, continuously stirring, and adding sulfuric acid in a flowing manner until the pH value is 4.8; slowly adding sulfuric acid, adding seed crystal when the pH value is less than 4.5, reducing the stirring speed to 30 r/min, crystallizing for 2-3 hours, then continuously slowly adding sulfuric acid until the pH value is 3.2, cooling to 8-10 ℃, and growing crystals for 6-10 hours; stopping stirring, precipitating for 2-4 hr, and filtering to remove supernatant to obtain wet sodium glutamate crystal.

And 5) preparing monosodium glutamate, namely adding 5%, 10%, 15% or 20% of sodium glutamate, or adding sodium chloride and selenide, or adding sodium chloride and iodide, decoloring again through a decoloring film, and drying to obtain monosodium glutamate.

Further, a fermentation device for preparing monosodium glutamate by utilizing sweet potatoes comprises fermentation equipment, filtering equipment and crystallization equipment, wherein the fermentation equipment comprises a fermentation tank; a stirring shaft and an upper stirring blade are arranged in the fermentation tank, and an interlayer for circulating media is arranged in the side wall of the fermentation tank; the top is respectively connected with the stirring tank I and the stirring tank II through pipelines; the bottom of the fermentation tank is a conical bottom, and an aeration pipe close to or attached to the conical bottom is arranged at the bottom of the fermentation tank; and vertical battens are arranged on the inner side wall of the fermentation tank.

Stirring devices and temperature control devices are arranged in the stirring tank I and the stirring tank II; be equipped with the solenoid valve on agitator tank I and agitator tank II's the pipeline, be equipped with atomizer behind the pipeline stretches into the fermentation cylinder, be equipped with the atmospheric pressure storehouse on agitator tank I and the agitator tank II.

The aeration pipe adopts a spiral shape or a plurality of groups of gradually narrowed circles, rubber membrane micropores are arranged on the aeration pipe, and the diameter of each micropore is 150-800 mu m.

The bottom end of the stirring shaft is provided with a lower stirring blade; the lower stirring blade extends into the conical bottom, and the bottom edge of the lower stirring blade is an inclined edge and is close to the upper surface of the aeration pipe.

The invention has reasonable structure, high conversion efficiency and purity, optimizes fermentation and aeration structures and effectively solves the technical problems in the prior art.

Drawings

FIG. 1 is a schematic flow diagram of the present invention;

FIG. 2 is a schematic view of the fermentation structure of the present invention;

fig. 3 is a schematic view of the structure of the aeration pipe of the invention.

In the figure, 1, a fermentation tank 2, a stirring tank I3, a stirring tank II 4, an electromagnetic valve 5, an air pressure bin 6, an upper stirring blade 7, a stirring shaft 8, an upper stirring blade 9, a batten 10, an interlayer 11, a lower stirring blade 12, a conical bottom 13, an aeration pipe 14 and an air inlet pipe.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is apparent that the embodiments described below are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.