CN112970517A - Corn steep liquor treatment product and application thereof in biological fermentation - Google Patents

Abstract

The invention belongs to the technical field of biology, and discloses a preparation process of a corn steep liquor treatment substance, which is characterized by comprising the following steps: 1) preheating, 2) neutralizing and settling, 3) hydrolyzing, 4) adding nutrient salt, 5) inactivating enzyme, and 6) filtering. The invention can increase the economic benefit of corn processing enterprises and effectively relieve the problem of relative shortage of protein resources.

Description

Corn steep liquor treatment product and application thereof in biological fermentation

Technical Field

The invention belongs to the technical field of biology, and particularly relates to a corn steep liquor treatment substance and application thereof in biological fermentation.

Background

In the production process of corn starch, corn kernels need to be soaked in sulfurous acid water, 0.8m3 of soaking water is generated when 1 ton of corn is soaked, the liquid obtained after the soaking water is concentrated is corn steep liquor, and the yield of the corn steep liquor is about 13% of the corn processing amount.

At present, corn steep liquor is mainly used as a culture medium nitrogen source in the fermentation industry. However, with the rapid increase of the processing capacity of the corn in recent years, the supply of the corn steep liquor is larger than the demand, and no other large-dosage use outlet is found. The corn steep liquor contains rich protein, but the Maillard reaction is serious in the processing and concentrating process, so that the corn steep liquor has more complex components, high acidity, high viscosity and dark color. The disposal of corn steep liquor has become the most problematic by-product of corn starch processing enterprises at present.

At present, corn processing enterprises spray corn steep liquor into corn husks (spray corn husks), and the spray corn husks are dark in color, easy to absorb water, absorb moisture and mildew due to serious Maillard reaction. A significant portion of corn processing plants also burn corn steep liquor, using 60 yuan coal for every 1 ton of corn steep liquor burned. Corn starch processing enterprises are also actively looking for new uses for corn steep liquor.

The dry matter of corn steep liquor contains about 45% protein, mainly high-quality albumin and globulin. At present, the deep processing of the corn steep liquor protein on an industrial scale utilizes key technologies to research and develop new technologies, and the demands are urgent. In the production of corn processing 'penta-acid-sugar', corn starch is produced firstly, then amino acid, organic acid and starch sugar are produced by taking starch as raw material, corn steep liquor which is a byproduct is produced in the production process of the corn starch, and the processing amount of the corn steep liquor is about 13% when 1 ton of corn is processed. At present, corn steep liquor is mainly used as a culture medium nitrogen source in the fermentation industry. However, with the rapid expansion of corn processing capacity, the amount of corn steep liquor is not rapidly increased, which results in unreasonable treatment in corn processing enterprises.

The domestic edible fungus industry has large scale, and the thalli nitrogen source raw materials compete with the breeding industry for soybean meal and bran, so the price is higher. In the culture medium of edible fungi, a large amount of nitrogen source nutrients and growth promoters are required according to the difference of fungi. Currently, the nitrogen source nutrients of the fungus package are commonly bean pulp and bran. The fermented corn steep liquor is used as an edible fungus growth promoter, so that the protein in the corn steep liquor can be effectively utilized, and the problem of higher price of the edible fungus industrial fungi can be relieved to a certain extent.

Disclosure of Invention

The invention aims to solve the technical problem of providing a corn steep liquor treatment substance and application thereof in biological fermentation, aiming at increasing the economic benefit of corn processing enterprises and effectively relieving the problem of relative shortage of protein resources.

The invention is realized by the following technical scheme.

A preparation process of a corn steep liquor treatment product comprises the following steps: 1) preheating, 2) neutralizing and settling, 3) hydrolyzing, 4) adding nutrient salt, 5) inactivating enzyme, and 6) filtering.

Specifically, the preparation process comprises the following steps:

1) preheating: adding 5-10 tons of corn steep liquor into a fermentation tank, heating to 90 deg.C, inactivating for 30min under heat preservation condition, and cooling to above 30 deg.C;

2) neutralization and sedimentation: adding 100-300kg NaOH into a fermentation tank, reacting for 20 min, adding 10-30kg Ca (OH)2, reacting for 20-40min, pH 6.0-7.0, and temperature 40-50 deg.C;

3) hydrolysis: adding 5-10kg of neutral protease, hydrolyzing at 40-50 deg.C for 2-4 hr;

4) adding nutrient salt, and then adding 300kg of water into the tank;

5) enzyme deactivation: stopping heating when the enzyme deactivation temperature reaches 90 ℃, and keeping the temperature for 10 minutes;

6) and (3) filtering: and (5) filtering by using a plate frame.

Preferably, the first and second electrodes are formed of a metal,

the nutrient salt comprises the following components:

3kg of sodium benzoate, 500g of monopotassium phosphate, 500g of magnesium sulfate and 500g of ammonium sulfate.

Preferably, the first and second electrodes are formed of a metal,

the enzyme activity of the neutral protease is 10 ten thousand u/g.

The invention also claims the product obtained by the preparation process.

The invention also claims the application of the product in biological fermentation.

Compared with the prior art, the invention has the advantages of improvement and achievement:

aiming at the problem that the corn steep liquor is not recycled, the invention adopts the fermentation engineering technology to treat the corn steep liquor. According to the nitrogen source requirement of the edible fungus matrix, the corn steep liquor is used for partially replacing raw materials such as bran, bean flour and the like, and the cost of the raw materials is obviously reduced on the premise of ensuring the yield. On one hand, the problem that the corn steep liquor is difficult to treat in the industry is solved. On the other hand, the method provides a short-culture-time and medium-long-acting nitrogen source for the edible fungus industry, and assists the healthy development of the edible fungus industry.

Aiming at the problems existing at present, the invention processes the corn steep liquor into the edible fungus growth promoting liquid, can effectively improve the use value of corn soaking water protein, increases the economic benefit of corn processing enterprises, and effectively relieves the problem of relative shortage of protein resources. The promotion of the sustainable development of agricultural production and the healthy development of the corn processing industry in China has important significance for the diversification of corn products. The corn steep liquor is applied to the production of the black fungus, the social and ecological benefits are obvious, and the requirement of the conservation-oriented edible fungus industry in China is realized at an accelerated speed.

The invention carries out pretreatment such as normal pressure sterilization, mechanical stirring and the like on the corn steep liquor, and adjusts the acidity and viscosity of the corn steep liquor to be in a state suitable for hydrolysis. Preparing hydrolysate by adopting a protease hydrolysis method, adjusting technical parameters such as pH, fermentation time and the like, accurately controlling fermentation, separating, removing sediment and purifying corn steep liquor hydrolysate by adopting a plate-and-frame filter press, and measuring molecular weight distribution and nutritional indexes after enzyme deactivation treatment of the corn steep liquor hydrolysate. The obtained corn steep liquor growth promoter can be used for growth of edible fungi.

The corn steep liquor is used as a raw material, the key technology and the production system for producing the biological growth promoting base material by industrial scale microbial fermentation are researched, and a series of biological growth promoting agent products are researched and developed.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the present application will be clearly and completely described below with reference to specific embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. 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.

Example 1

The industrial scale edible fungus growth promoting liquid process flow comprises the following steps:

1 preheating

Adding 7 tons of corn steep liquor into a fermentation tank, heating to 90 ℃, inactivating for 30min under the condition of heat preservation, and cooling to more than 30 ℃.

2 neutralization and sedimentation

187kg NaOH was added to the fermenter and reacted for 20 min, 20kg Ca (OH)2 was added and reacted for 40min, pH 6.6. The temperature was 47 ℃.

3 hydrolysis of

Adding 6kg neutral protease (10 ten thousand u/g), hydrolyzing at 47 deg.C, and maintaining the temperature for 3 h.

4 adding nutrient salt

3kg of sodium benzoate, 500g of monopotassium phosphate, 500g of magnesium sulfate and 500g of ammonium sulfate.

300kg of water is added into the tank before enzyme deactivation.

5 inactivating enzyme

Stopping heating when the enzyme deactivation temperature reaches 90 ℃, and preserving the heat for 10 minutes.

6 filtration

The corn steep liquor is pumped into the tank body for 80m²And (5) filtering by using a plate frame. The filtration pressure was 8kg/cm²The compaction pressure is 20MPa, the back pressure is 30 MPa, and the number of matched plates is 49.

And (3) detecting a product:

detecting pH6.57, and the soluble salt-free solid content is 35.9g/100 mL; total nitrogen 2.24g/100 mL; 1.04g/100mL of amino acid nitrogen; coliform group bacteria 30 MPN/mL.

Example 2

The industrial scale edible fungus growth promoting liquid process flow comprises the following steps:

1 preheating

Adding 7 tons of corn steep liquor into a fermentation tank, heating to 90 ℃, inactivating for 30min under the condition of heat preservation, and cooling to more than 30 ℃.

2 neutralization and sedimentation

275kg NaOH was added to the fermentor and the reaction time was 20 min, 20kg Ca (OH)2 was added and the reaction was 40min, pH 7.0. The temperature was 50 ℃.

3 hydrolysis of

Adding 6kg neutral protease (10 ten thousand u/g), hydrolyzing at 50 deg.C, and maintaining the temperature for 3 h.

4 adding nutrient salt

3kg of sodium benzoate, 500g of monopotassium phosphate, 500g of magnesium sulfate and 500g of ammonium sulfate.

300kg of water is added into the tank before enzyme deactivation.

5 inactivating enzyme

Stopping heating when the enzyme deactivation temperature reaches 90 ℃, and preserving the heat for 10 minutes.

6 filtration

The corn steep liquor is pumped into the tank body for 80m²And (5) filtering by using a plate frame. The filtration pressure was 8kg/cm²The compaction pressure is 20MPa, the back pressure is 30 MPa, and the number of matched plates is 49.

And (3) detecting a product:

detecting pH6.87, wherein the soluble salt-free solid is 36.3g/100 mL; total nitrogen 2.29g/100 mL; 1.07g/100mL of amino acid nitrogen; coliform group 31 MPN/mL.

Example 3

The industrial scale edible fungus growth promoting liquid process flow comprises the following steps:

1 preheating

Adding 7 tons of corn steep liquor into a fermentation tank, heating to 90 ℃, inactivating for 30min under the condition of heat preservation, and cooling to more than 30 ℃.

2 neutralization and sedimentation

300kg NaOH was added to the fermenter for 20 min, and 20kg Ca (OH)2 was added for 40min, pH 7.0. The temperature was 50 ℃.

3 hydrolysis of

Adding 5kg neutral protease (10 ten thousand u/g), hydrolyzing at 50 deg.C, and maintaining the temperature for 4 h.

4 adding nutrient salt

3kg of sodium benzoate, 500g of monopotassium phosphate, 500g of magnesium sulfate and 500g of ammonium sulfate.

350 kg of water is added into the tank before enzyme deactivation.

5 inactivating enzyme

Stopping heating when the enzyme deactivation temperature reaches 90 ℃, and keeping the temperature for 15 minutes.

6 filtration

The corn steep liquor is pumped into the tank body for 80m²And (5) filtering by using a plate frame. The filtration pressure was 8kg/cm²The compaction pressure is 20MPa, the back pressure is 30 MPa, and the number of matched plates is 49.

And (3) detecting a product:

detecting pH6.71, and the soluble salt-free solid content is 35.4g/100 mL; total nitrogen 2.21g/100 mL; 1.02g/100mL of amino acid nitrogen; coliform group 31 MPN/mL.

The foregoing list is only illustrative of the preferred embodiments of the present invention. It is obvious that the invention is not limited to the above embodiments, but that many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.

Claims (6)

1. A preparation process of a corn steep liquor treatment product is characterized by comprising the following steps: 1) preheating, 2) neutralizing and settling, 3) hydrolyzing, 4) adding nutrient salt, 5) inactivating enzyme, and 6) filtering.

2. The process according to claim 1, characterized in that it comprises the following steps:

1) preheating: adding 5-10 tons of corn steep liquor into a fermentation tank, heating to 90 deg.C, inactivating for 30min under heat preservation condition, and cooling to above 30 deg.C;

2) neutralization and sedimentation: adding 100-300kg NaOH into a fermentation tank, reacting for 20 min, adding 10-30kg Ca (OH)2, reacting for 20-40min, pH 6.0-7.0, and temperature 40-50 deg.C;

3) hydrolysis: adding 5-10kg of neutral protease, hydrolyzing at 40-50 deg.C for 2-4 hr;

4) adding nutrient salt, and then adding 300kg of water into the tank;

5) enzyme deactivation: stopping heating when the enzyme deactivation temperature reaches 90 ℃, and keeping the temperature for 10 minutes;

6) and (3) filtering: and (5) filtering by using a plate frame.

3. The process according to claim 2, characterized in that the nutrient salt has the composition:

3kg of sodium benzoate, 500g of monopotassium phosphate, 500g of magnesium sulfate and 500g of ammonium sulfate.

4. The process according to claim 2, wherein the neutral protease has an enzymatic activity of 10 wu/g.

5. The product obtained by the process according to claims 1-4.

6. Use of the product of claim 5 in biological fermentation.