CN112080540A

CN112080540A - Yeast hydrolysate with high nucleotide content and preparation method thereof

Info

Publication number: CN112080540A
Application number: CN202010938259.6A
Authority: CN
Inventors: 游杭柳; 潘良康
Original assignee: Guangxi Puleyi Biotechnology Co ltd
Current assignee: Guangxi Puleyi Biotechnology Co ltd
Priority date: 2020-09-09
Filing date: 2020-09-09
Publication date: 2020-12-15

Abstract

The invention discloses a yeast hydrolysate with high nucleotide content and a preparation method thereof, and the preparation method comprises the following steps: preparing yeast milk, heating the yeast milk to 55-59 ℃, adding papain and YC enzyme into the yeast milk for hydrolysis for 8-14h, and stirring intermittently during hydrolysis; heating the hydrolyzed product to 65-70 deg.C, adjusting pH to 5.0-6.0, adding nuclease for enzymolysis for 10-14h, inactivating enzyme, concentrating, and spray drying to obtain yeast hydrolysate. The hydrolysate prepared by the method has high nucleotide content, and the problem of low nucleotide content in the hydrolysate existing in the existing method can be effectively solved.

Description

Yeast hydrolysate with high nucleotide content and preparation method thereof

Technical Field

The invention relates to the technical field of yeast nucleotide production, in particular to a yeast hydrolysate with high nucleotide content and a preparation method thereof.

Background

Nucleotides are the basic unit of genetic material in organisms, are precursors of DNA and RNA, and are also the basic unit of intermediates necessary for protein synthesis. The nucleotide is used as an essential substance for cell synthesis, and has physiological functions of protecting intestinal mucosa, enhancing immunity of organisms and the like. Under normal circumstances, an adult animal can meet its own needs by endogenous nucleotides without deliberate supplementation. However, when animals are under immune stress, liver damage, hunger and grow rapidly, endogenous nucleotides often cannot meet the needs of various tissues and cells with vigorous metabolism, and the supplement of exogenous nucleotides is particularly important. Nucleotides are therefore also referred to as "conditionally essential nutrients".

The nucleotide and nucleoside in the feed can accelerate the growth of animals, improve the production performance of animals, increase the nucleic acid and protein content of intestinal mucosa and the nucleic acid content of liver, promote the growth of intestinal villus, increase the thickness of intestinal wall, enhance the phagocytosis of macrophage and strengthen the activity of natural killer cells. In a large-scale and intensive breeding environment or when the animals are in a sub-health state, the adaptation and the resistance of the animals to stress conditions can be improved by supplementing exogenous nucleotides in animal feed, and the method has important significance for maintaining the healthy production of the animals. The nucleotide is also an important phagostimulant in aquatic animals, mainly stimulates the taste of the aquatic animals and has strong delicate flavor. The feed for young animals such as broiler chicken, meat duck, weaned pig, etc. in the rapid growth period should be ensured to contain enough nucleotide

Yeast is the most widely used microorganism at the earliest time, and is rich in nucleic acid. The nucleotide produced by the yeast RNA enzymolysis method can obtain four kinds of nucleotides at one time, toxic and harmful substances are not added in the production process, the nucleotide has the characteristics of comprehensive nucleic acid types and high product safety, is most suitable for being used as a feed additive, shows obvious effects of growing, enhancing immunity and maintaining intestinal health on pigs, chickens and aquatic products, and has great application prospects in livestock, poultry and aquaculture. However, the yield of the conventional nucleotide production is low.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the yeast hydrolysate with high nucleotide content and the preparation method thereof, the content of the nucleotide in the yeast hydrolysate extracted by the method is higher, and the method can effectively solve the problem of low nucleotide content in the hydrolysate in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows:

a method for preparing yeast hydrolysate with high nucleotide content comprises the following steps:

(1) preparing wine brewing yeast milk, heating the yeast milk to 55-59 ℃, adding papain and YC enzyme into the yeast milk for hydrolysis for 8-14h, stirring discontinuously during the hydrolysis, and heating to 90-95 ℃ for treatment for 5-7 h;

(2) and (2) cooling the product subjected to heat treatment in the step (1) to 65-70 ℃, then adjusting the pH value to 5.0-6.0, adding nuclease into the product for enzymolysis for 10-14h, finally, inactivating the enzyme, concentrating and spraying the enzyme to dry to obtain the yeast hydrolysate.

In the scheme, papain and YC enzyme are added into yeast milk, the two enzymes are utilized to hydrolyze yeast milk cell protein, the structure of a yeast cell wall is damaged, contents such as nucleotide and the like in the yeast cell flow out, then the temperature is raised, the protein in the yeast cell is denatured, the flowing nucleotide is separated from the protein, and the subsequent enzymolysis of the nucleotide is facilitated;

adding nucleotidase into the heat-treated product, and carrying out enzymolysis on nucleotide dissolved out of the yeast cells by using the nucleotidase so as to improve the amount of nucleotide hydrolysate.

Further, the yeast milk in the step (1) is brewing yeast milk produced by molasses fermentation.

Further, the mass concentration of the yeast milk in the step (1) is 10-15%.

Further, the mass concentration of the yeast milk in the step (1) is 13%.

In the above scheme, the concentration of yeast milk is too high or low, and all can influence the enzymolysis reaction effect, and then influence the yeast content outflow effect, and yeast milk mass concentration is when 10-15%, and the broken wall effect is best among the enzymolysis process, and the yeast content outflow is the most.

In the above scheme, the concentration of the yeast milk is too high, the contact area of the yeast surface and the enzyme is small, the reaction space is small, the enzymolysis speed is reduced, the concentration of the yeast milk is too low, the preparation efficiency is reduced, and the preparation cost is increased.

Further, when the temperature of the yeast milk is raised to 58 ℃ in the step (1), papain and YC enzyme are added into the yeast milk for hydrolysis for 14 h.

In the scheme, the wall breaking effect of the papain and the YC enzyme on yeast cells is the best at the temperature.

Further, after papain and YC enzyme are added into the yeast milk in the step (1), the mass concentrations of the papain and the YC enzyme are 0.05-0.15% and 0.1-0.25% respectively.

Further, the YC enzyme in the step (1) is formed by mixing papain, alkaline enzyme, neutral enzyme and flavor enzyme, and the mass ratio of the papain to the alkaline enzyme to the neutral enzyme to the flavor enzyme is 18-22:38-42:18-22: 18-22.

Further, the YC enzyme in the step (1) is formed by mixing papain, alkaline enzyme, neutral enzyme and flavor enzyme, and the mass ratio of the papain to the alkaline enzyme to the neutral enzyme to the flavor enzyme is 20:40:20: 20.

In the scheme, the mixed enzyme is adopted for enzymolysis, so that the enzymolysis effect can be fully improved, and the hydrolysis amount of the nucleotide is further improved.

Further, the discontinuous stirring process in the step (1) is as follows: standing for 20min after stirring for 10 min.

In the above scheme, the stirring process can fully improve the action area of enzyme and yeast, improve the effect of enzyme, and intermittent stirring can make enzyme and yeast cell have abundant contact time, also can improve the enzymolysis effect.

Further, after the temperature in step (2) was raised to 68 ℃, the pH was adjusted to 5.5.

In the scheme, the temperature and the pH value are the optimal enzymolysis temperature of nuclease, so that the enzymolysis effect on nucleotide can be fully improved.

Further, the concentration of the nuclease in the step (2) is 0.05-0.15%.

Further, the enzymolysis time in the step (2) is 12 hours.

The beneficial effects produced by the invention are as follows: according to the method, the yeast nucleic acid is subjected to full enzymolysis through heat treatment and an additional enzymolysis technology, the prepared yeast hydrolysate has high nucleotide content which can reach 2.1 percent at most, and the adopted thermal enzymolysis technology can kill the mixed bacteria in the environment in the heating process, so that the threat of mixed bacteria pollution in the enzymolysis process is reduced, and the enzymolysis effect is improved; moreover, the preparation method is simple and has high production efficiency.

Detailed Description

Example 1

A yeast hydrolysate with high nucleotide content is prepared by the following steps:

(1) preparing yeast milk, adjusting the mass concentration of the yeast milk to 10%, heating the yeast milk to 55 ℃, adding papain and YC enzyme to make the concentrations reach 0.05% and 0.1% respectively, hydrolyzing for 8h, stirring for 10min in the hydrolysis process, standing for 20min, heating to 95 ℃ for processing for 5h, wherein the YC enzyme is prepared by mixing papain, alkaline enzyme, neutral enzyme and flavor enzyme, and the mass ratio of the papain, the alkaline enzyme, the neutral enzyme and the flavor enzyme is 18:38:18: 18;

(2) heating the product hydrolyzed in the step (1) to 65 ℃, then adjusting the pH value to 5.0, then adding nuclease into the product to enable the concentration to reach 0.05%, carrying out enzymolysis for 10 hours, heating to 95 ℃ after the enzymolysis is finished, inactivating the enzyme for 15min, concentrating the product at 55 ℃ until the mass concentration is 30%, and then spraying the product at 100 ℃ under the condition of 0KPa to obtain the yeast hydrolysate.

Example 2

(1) preparing yeast milk, adjusting the mass concentration of the yeast milk to 15%, heating the yeast milk to 59 ℃, adding papain and YC enzyme to make the concentrations reach 0.15% and 0.25% respectively, hydrolyzing for 14h, stirring for 10min in the hydrolysis process, standing for 20min, and heating to 90 ℃ for treatment, wherein the YC enzyme is prepared by mixing papain, alkaline enzyme, neutral enzyme and flavor enzyme, and the mass ratio of the papain, the alkaline enzyme, the neutral enzyme and the flavor enzyme is 22:42:22: 22;

(2) heating the product hydrolyzed in the step (1) to 70 ℃, then adjusting the pH value to 6.0, then adding nuclease into the product to enable the concentration to reach 0.15%, carrying out enzymolysis for 14h, heating to 95 ℃ after the enzymolysis is finished, inactivating the enzyme for 15min, concentrating the product at 60 ℃ until the mass concentration is 30%, and then carrying out spray drying at 110 ℃ under the condition of 0.05KPa to obtain the yeast hydrolysate.

Example 3

(1) preparing yeast milk, adjusting the mass concentration of the yeast milk to 13%, heating the yeast milk to 58 ℃, adding papain and YC enzyme to make the concentrations reach 0.1% and 0.2% respectively, hydrolyzing for 14h, stirring for 10min in the hydrolysis process, standing for 20min, and heating to 93 ℃ for treatment for 7h, wherein the YC enzyme is prepared by mixing papain, alkaline enzyme, neutral enzyme and flavor enzyme, and the mass ratio of the papain, the alkaline enzyme, the neutral enzyme and the flavor enzyme is 20:40:20: 20;

(2) heating the product hydrolyzed in the step (1) to 68 ℃, then adjusting the pH value to 5.5, then adding nuclease into the product to enable the concentration to reach 0.1%, carrying out enzymolysis for 12 hours, heating to 95 ℃ after the enzymolysis is finished, inactivating the enzyme for 15min, concentrating the product at 58 ℃ until the mass concentration is 30%, and then carrying out spray drying at 105 ℃ under the condition of 0.02KPa to obtain the yeast hydrolysate.

Example 4

(1) preparing yeast milk, adjusting the mass concentration of the yeast milk to 12%, heating the yeast milk to 56 ℃, adding papain and YC enzyme to make the concentrations reach 0.08% and 0.25% respectively, hydrolyzing for 10h, stirring for 10min in the hydrolysis process, standing for 20min, heating to 90 ℃, and treating for 6h, wherein the YC enzyme is prepared by mixing papain, alkaline enzyme, neutral enzyme and flavor enzyme, and the mass ratio of the papain, the alkaline enzyme, the neutral enzyme and the flavor enzyme is 22:40:18: 22;

(2) heating the product hydrolyzed in the step (1) to 65 ℃, then adjusting the pH value to 6.0, then adding nuclease into the product to enable the concentration to reach 0.13%, carrying out enzymolysis for 13h, heating to 95 ℃ after the enzymolysis is finished, inactivating the enzyme for 15min, concentrating the product at 60 ℃ until the mass concentration is 30%, and then carrying out spray drying at 110 ℃ under the condition of 0.05KPa to obtain the yeast hydrolysate.

Comparative example 1

(1) preparing yeast milk, adjusting the mass concentration of the yeast milk to 18%, heating the yeast milk to 58 ℃, adding papain to make the concentration reach 0.1%, respectively, hydrolyzing for 14h, stirring for 10min every time during the hydrolysis process, and standing for 20 min;

Test examples

The extract content in the yeast hydrolysates prepared in examples 1-4 and comparative example 1 was determined according to the method of 6.13 in GB/T23530-2009, and the specific results are shown in Table 1.

Table 1: nucleotide content detecting meter

	Nucleotide (%)
		Example 1	2.0
Example 2	2.0
		Example 3	2.1
Example 4	2.0
		Comparative example 1	1.2

As can be seen from the data in the table, the products obtained by the hydrolysis methods of examples 1 to 4 in this application had a higher nucleotide content, and the products of examples 1 to 4 had a higher nucleotide content than that of comparative example 1.

Claims

1. A method for preparing yeast hydrolysate with high nucleotide content is characterized by comprising the following steps:

(1) preparing brewing yeast milk, heating the yeast milk to 55-59 ℃, adding papain and YC enzyme into the yeast milk for hydrolysis for 8-14h, stirring discontinuously during the hydrolysis, and heating to 90-95 ℃ for treatment for 5-7 h;

2. The method for preparing yeast hydrolysate with high nucleotide content according to claim 1, wherein the yeast milk in step (1) has a mass concentration of 10-15%.

3. The method for preparing yeast hydrolysate with high nucleotide content according to claim 1, wherein in the step (1), when the yeast milk is heated to 58 ℃, papain and YC enzymes are added for hydrolysis for 14 h.

4. The method for preparing yeast hydrolysate with high nucleotide content as claimed in claim 1 or 3, wherein the mass concentrations of papain and YC enzyme are 0.05-0.15% and 0.1-0.25%, respectively, after papain and YC enzyme are added to the yeast milk in step (1).

5. The method for preparing yeast hydrolysate with high nucleotide content as claimed in claim 1, wherein the YC enzyme in step (1) is prepared by mixing papain, alkaline enzyme, neutral enzyme and flavor enzyme, and the mass ratio of the papain, the alkaline enzyme, the neutral enzyme and the flavor enzyme is 18-22:38-42:18-22: 18-22.

6. The method for preparing yeast hydrolysate having a high nucleotide content according to claim 1, wherein the intermittent stirring process in the step (1) comprises: standing for 20min after stirring for 10 min.

7. The method for producing a yeast hydrolysate with a high nucleotide content according to claim 1, wherein the pH is adjusted to 5.5 after the temperature is raised to 68 ℃ in the step (2).

8. The method for producing a yeast hydrolysate with a high nucleotide content as claimed in claim 1, wherein the mass concentration of nuclease after the nuclease is added in the step (2) is 0.05 to 0.15%.

9. The method for preparing yeast hydrolysate having a high nucleotide content according to claim 1, wherein the enzymatic hydrolysis time in the step (2) is 12 hours.

10. A high nucleotide content yeast hydrolysate prepared by the method of any one of claims 1 to 9.