CN115039865A - A kind of method for preparing diacetyl type natural milk-flavor base material by enzymolysis - Google Patents

Abstract

The invention discloses a method for preparing diacetyl natural milk flavor base material by enzymolysis, which comprises the following steps: (1) weighing a substrate, an auxiliary substrate and water, uniformly mixing, heating for sterilization, adding a complex enzyme, performing enzymolysis for 8-12 hours at 40-45 ℃, and performing enzyme deactivation treatment to obtain an enzymolysis liquid; the substrate is non-dairy creamer; the auxiliary substrate is whey powder; the compound enzyme comprises Lipase AY and protease MSD, and the mass ratio of the Lipase AY to the protease MSD is (2-4): 1; (2) cooling the enzymolysis liquid, and subpackaging to obtain the diacetyl natural milk flavor base material. According to the method, specific base material selection is matched with a complex enzyme enzymolysis preparation process, under the condition of specific parameters, the diacetyl content of the obtained diacetyl type natural milk flavor base material is high, the milk flavor of the product is pure and has high stability, the fragrance-retaining time is long, the flavor is coordinated, and no pungent smell exists.

Description

A kind of method for preparing diacetyl type natural milk-flavor base material by enzymolysis

technical field

The invention relates to a preparation method of a milk-flavor base material, in particular to a method for preparing a diacetyl type natural milk-flavor base material by enzymatic hydrolysis.

Background technique

Milk flavor is one of the most widely used flavors in the food industry. Generally, the flavor components of milk flavor are lactones, medium and short-chain fatty acids, esters, thiazoles, ethyl vanillin, acetoin, bisulfite, etc. Acetyl, delta-decalactone and other compounds, but due to the complex composition of flavor substances in milk flavor essence, and the content is very small, how to increase the content of flavor components has become a key factor in the production and processing of milk flavor essence.

At present, the main processing methods of milk flavor base materials are divided into three categories: chemical synthesis method, microbial fermentation method and enzymatic hydrolysis method. However, although these three methods have obvious advantages, their disadvantages cannot be ignored either. The chemical synthesis method has simple technological process, low production cost and high production stability, but the obtained product has a single and unnatural flavor. If the concentration is too high, it will have a certain discordant flavor; although the microbial fermentation method and the enzymatic hydrolysis method can obtain a more flavorful flavor High-level products, but their own production efficiency is not high, and the aroma is difficult to control, not only for the selection of raw materials, but also for the control of more production parameters. If the enzymatic hydrolysis or fermentation is excessive, it is extremely easy to cause product flavor. of dissonance.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing diacetyl-type natural milk-flavored base material by enzymatic hydrolysis. Under specific parameter conditions, the obtained diacetyl-type natural milk-flavor base material has high diacetyl content, pure product aroma and high stability, long-lasting fragrance retention time and harmonious flavor.

To achieve the above object, the technical scheme adopted in the present invention is:

A method for preparing diacetyl-type natural milk-flavor base material by enzymolysis, comprising the following steps:

(1) Weigh the substrate, co-substrate and water and mix them evenly. After heating and sterilizing, add the compound enzyme and enzymolysis at 40-45°C for 8-12 hours, then inactivate the enzyme to obtain the enzymatic hydrolysis solution; the substrate It is non-dairy creamer; the co-substrate is whey powder; the composite enzyme includes lipase Lipase AY and protease MSD, and the mass ratio of the two is (2-4): 1;

(2) The enzymolysis solution is cooled and packaged to obtain the diacetyl-type natural milk-flavored base material.

In the technical scheme of the present invention, non-dairy creamer with various flavors and rich fat content (up to 80%) is used as the raw material substrate (this component is also called creamer, which has a richer flavor and more stable properties than milk powder), Supplemented with whey powder, a high protein-rich dairy product processing by-product, as a co-substrate, after the two substrates are compounded and hydrolyzed by lipase and protease respectively, the aroma layer is diversified and rich and lasting. The natural milk-flavored base material of the product, the content of the aroma component diacetyl in the product is relatively high, so that when the product is applied in the field of processed food and other fields, only a small amount of content can be introduced to achieve high-efficiency food flavor imparting or improvement.

After repeated experiments and researches by the inventor, when the enzymatic hydrolysis of protein and fat in the raw material needs to be carried out simultaneously, Lipase AY, which can make the product have a rich and soft milky aroma, and the enzymatic hydrolysis product have a milky aroma, is selected. The combination effect of alcohol positive and strong protease MSD is better than that of other common enzymes. However, not any combination of enzymes can achieve good results. If the ratio is improper, it may not only inhibit the content of diacetyl in the product, but also cause the aroma of the product to decrease, and even produce a discordant odor.

The action time and hydrolysis temperature of the enzyme have a certain influence on the flavor quality of the milky base material formed, but when both lipase and protease are hydrolyzed simultaneously, the selection of these two parameters is different from that when a single enzyme is used for hydrolysis. The selection situation is not the same, and the composite effect of simultaneous enzymatic hydrolysis needs to be comprehensively considered. If the action time is too short or the enzymatic hydrolysis temperature is too low, the enzymatic hydrolysis degree will be insufficient, and the flavor product diacetyl cannot be fully formed. However, if the enzymatic hydrolysis time is too long, too much enzymatic hydrolysate will inhibit the subsequent reaction of the enzyme, so that the final enzymatic hydrolysis efficiency will be lower; too high temperature will easily lead to the inactivation of the enzyme or the low enzymatic hydrolysis efficiency, which will affect the flavor of the product. , and it takes too much time and wastes costs, so it is necessary to control the appropriate enzymatic hydrolysis time and enzymatic hydrolysis temperature.

Preferably, in the step (1), the mass ratio of lipase Lipase AY and protease MSD is 2:1, the temperature during enzymatic hydrolysis by the compound enzyme is 40° C., and the time is 8h.

After careful screening by the inventor, the diacetyl-type natural milk-flavor base material prepared under the above conditions has the highest content of diacetyl, and at the same time, the milk aroma is the most mellow and rich, sweet and attractive, and the flavor is synergistic and lasting, and the evaluation is the highest.

Preferably, the added amount of the composite enzyme is 0.24-0.36% by weight of the substrate.

More preferably, the added amount of the composite enzyme is 0.24-0.3% by weight of the substrate.

More preferably, the added amount of the composite enzyme is 0.24% by weight of the substrate.

The compound enzyme contains lipase and protease, which can effectively enzymatically hydrolyze the fat and protein in the substrate and co-substrate respectively and convert them into aroma substances such as diacetyl. When the ratio with protease remains unchanged, the overall addition is too little, and the obtained product, whether it is the yield of diacetyl or the aroma, is difficult to achieve the ideal standard, but if the overall addition is too much, it may also be due to the reverse inhibition of the enzyme product or other factors. The product is further enzymatically hydrolyzed, so that the content of diacetyl decreases, and the aroma decreases sharply.

Preferably, the addition amount of the auxiliary substrate is 40-120% by weight of the substrate.

More preferably, the addition amount of the auxiliary substrate is 40-80% by weight of the substrate.

Preferably, the addition amount of the auxiliary substrate is 80% by weight of the substrate.

The co-substrate mainly provides the raw material protein for the enzymatic hydrolysis of protease MSD, and participates in the generation of the aroma components of the final product. The inventors have found through research that the addition of the co-substrate is properly matched with the substrate, which can make the aroma components in the product. The content multiplier is increased, and the aroma evaluation is higher.

Preferably, the pH of the mixture obtained by uniformly mixing the substrate, the auxiliary substrate and the water in the step (1) is 6.5-7.5.

More preferably, the pH of the mixture obtained by uniformly mixing the substrate, the auxiliary substrate and the water in the step (1) is 7.

The pH of the enzymatic hydrolysis raw material has a great influence on the enzymatic hydrolysis activity of the compound enzyme, and a suitable acid-base environment can make the enzymatic hydrolysis efficiency of the compound enzyme higher and the content of the product diacetyl higher.

The present invention also provides a diacetyl-type natural milk-flavor base material prepared by adopting the above-mentioned method for preparing a diacetyl-type natural milk-flavor base material by enzymatic hydrolysis.

The diacetyl-type natural milk-flavor base material prepared by the method of the present invention has a high proportion of diacetyl, and in practical application, only a small amount of addition can be used to obtain an ideal fragrance, and at the same time, the fragrance is mellow, natural and sweet without greasy feeling. , the aroma is harmonious and stable and lasting, and at the same time, the production process of the product is simple, the production cost is low, and the commercial cost performance is high.

The beneficial effects of the present invention are as follows: the present invention provides a method for preparing a diacetyl type natural milk-flavored base material by enzymatic hydrolysis. The method selects a specific substrate and cooperates with a compound enzyme enzymatic hydrolysis preparation process, and under specific parameter conditions The obtained diacetyl-type natural milk-flavor base material has high diacetyl content, the product has pure milk aroma and high stability, long-lasting fragrance retention time, coordinated flavor and no irritating odor.

Description of drawings

Fig. 1 is the test result diagram of the co-substrate species selection and exploration in Effect Example 1 of the present invention;

Fig. 2 is the test result diagram of selecting and exploring the addition amount of auxiliary substrate in Effect Example 2 of the present invention;

Fig. 3 is the test result diagram of the pH selection of enzymolysis raw material in the effect example 3 of the present invention;

Fig. 4 is the test result diagram of lipase and protease ratio selection in composite enzyme in effect example 4 of the present invention;

Fig. 5 is the test result graph that the compound enzyme addition amount is selected and explored in the effect example 5 of the present invention;

Fig. 6 is the test result diagram of lipase species selection and exploration in Effect Example 6 of the present invention;

Fig. 7 is the test result diagram of enzymolysis temperature selection inquiry in effect example 7 of the present invention;

FIG. 8 is a graph of the test results of the enzymatic hydrolysis time selection exploration in Effect Example 7 of the present invention.

Detailed ways

The main experimental equipment used in the present invention is shown in Table 1.

Table 1 Main experimental equipment

The standard of diacetyl content determination and aroma assessment in the present invention is as follows:

(1) Determination of diacetyl content

Take 20 mL of sample and add equal volume of 8% trichloroacetic acid to mix, centrifuge in a high-speed refrigerated centrifuge at 4°C and 10000 r/min for 10 min, take the supernatant and filter it again with filter paper, respectively take 10 mL of the clarified solution and add it to two test tubes. Add 0.5mL of 1% o-phenylenediamine to one test tube, and leave the second test tube as blank control. After mixing, react in the dark for 30 min, add 2 mL of 4 mol/L hydrochloric acid to the first test tube, and add 2.5 mL of 4 mol/L hydrochloric acid to the second tube. After mixing, measure the absorbance at 335 nm.

(2) Aroma assessment

Select 15 professionally trained personnel to form a sensory evaluation and appraisal team for the aroma of milk-flavored base materials, and score the milk-flavored base material's milky aroma intensity, sweet aroma intensity, aroma coordination and fragrance retention time respectively, and the scoring results are among 4. And, the total score is 10.

The detailed scoring criteria are shown in Table 2.

Table 2

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below with reference to specific embodiments.

The raw materials used in the embodiments of the present invention/comparative examples are as follows:

Whole milk powder, skimmed milk powder, New Zealand Fonterra Co., Ltd.;

Non-dairy creamer, whey powder, Guangdong Mingkang Flavors and Fragrances Co., Ltd.;

Lipase G50, MER, A12, 20000L, AY, R, TL, TG; Protease MSD, Japan Amano Enzyme Products Co., Ltd. Shanghai Representative Office;

O-phenylenediamine, trichloroacetic acid, HCl, etc., commercially available analytical grades.

Example 1

The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to the present invention comprises the following steps:

(1) Weigh 10g of substrate vegetable fat powder, 8g of co-substrate whey powder and 32mL of water in a conical flask and mix them evenly (pH=7), heat in a constant temperature water bath at 75°C for sterilization for 20min and add 0.24% bottom After enzymatic hydrolysis at 40 °C for 8 hours in a constant temperature shaker, the enzyme hydrolysis solution was obtained by inactivating the enzyme at 90 °C for 10 minutes; the composite enzyme includes lipase Lipase AY and protease MSD, and the mass ratio of the two is 2:1;

(2) The enzymatic hydrolyzate is subjected to cooling treatment and then packaged to obtain the diacetyl-type natural milk-flavored base material.

Example 2

The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to the present invention comprises the following steps:

(1) Weigh 10g of substrate vegetable fat powder, 4g of co-substrate whey powder and 32mL of water in a triangular flask and mix them evenly (pH=7), heat in a constant temperature water bath at 75°C for sterilization for 20min and add 0.24% bottom After enzymatic hydrolysis at 45 °C for 8 h in a constant temperature shaker, the enzyme inactivation solution was obtained at 90 °C for 10 min to obtain an enzymatic hydrolysis solution; the composite enzyme includes lipase Lipase AY and protease MSD, and the mass ratio of the two is 4:1;

(2) The enzymatic hydrolyzate is subjected to cooling treatment and then packaged to obtain the diacetyl-type natural milk-flavored base material.

Comparative Example 1

The only difference between this comparative example and Example 2 is that the whey powder was replaced with whole milk powder.

Comparative Example 2

The only difference between this comparative example and Example 2 is that the whey powder was replaced with skim milk powder.

Comparative Example 3

The only difference between this comparative example and Example 2 is that no co-substrate is added in the preparation step.

Example 3

The only difference between this example and Example 2 is that the addition amount of the co-substrate is 8 g.

Example 4

The only difference between this example and Example 2 is that the added amount of the co-substrate is 12 g.

Comparative Example 4

The only difference between this comparative example and Example 3 is that the pH of the mixture obtained by uniformly mixing the substrate, co-substrate and water in the step (1) is 5.

Comparative Example 5

The only difference between this comparative example and Example 3 is that the pH of the mixture obtained by uniformly mixing the substrate, co-substrate and water in the step (1) is 6.

Comparative Example 6

The only difference between this comparative example and Example 3 is that the pH of the mixture obtained by uniformly mixing the substrate, co-substrate and water in the step (1) is 8.

Comparative Example 7

The only difference between this comparative example and Example 3 is that the pH of the mixture obtained by uniformly mixing the substrate, co-substrate and water in the step (1) is 9.

Example 5

The only difference between this example and Example 3 is that the mass ratio of lipase Lipase AY and protease MSD is 3:1.

Example 6

The only difference between this example and Example 3 is that the mass ratio of the lipase Lipase AY and the protease MSD is 2:1.

Comparative Example 8

The only difference between this comparative example and Example 3 is that the mass ratio of lipase Lipase AY and protease MSD is 1:1.

Comparative Example 9

The only difference between this comparative example and Example 3 is that the mass ratio of the lipase Lipase AY and the protease MSD is 5:1.

Example 7

The only difference between this example and Example 6 is that the addition amount of the composite enzyme in the step (1) is 0.3% by weight of the substrate.

Example 8

The only difference between this example and Example 6 is that the addition amount of the composite enzyme in the step (1) is 0.36% by weight of the substrate.

Comparative Example 10

The only difference between this comparative example and Example 6 is that the addition amount of the composite enzyme in the step (1) is 0.12% by weight of the substrate.

Comparative Example 11

The only difference between this comparative example and Example 6 is that the addition amount of the composite enzyme in the step (1) is 0.18% by weight of the substrate.

Comparative Example 12

The only difference between this comparative example and Example 6 is that the lipase Lipase AY is replaced by lipase G50.

Comparative Example 13

The only difference between this comparative example and Example 6 is that the lipase Lipase AY is replaced by the lipase MER.

Comparative Example 14

The only difference between this comparative example and Example 6 is that the lipase Lipase AY is replaced with lipase 20000L.

Comparative Example 15

The only difference between this comparative example and Example 6 is that the lipase Lipase AY is replaced with lipase R.

Comparative Example 16

The only difference between this comparative example and Example 6 is that the lipase Lipase AY is replaced by the lipase TL.

Comparative Example 17

The only difference between this comparative example and Example 6 is that the lipase Lipase AY is replaced by the lipase TG.

Comparative Example 18

The only difference between this comparative example and Example 6 is that the lipase Lipase AY is replaced by lipase A12.

Example 9

The only difference between this example and Example 1 is that the temperature during enzymatic hydrolysis in the step (1) is 45°C.

Comparative Example 19

The only difference between this comparative example and Example 1 is that the temperature during enzymatic hydrolysis in the step (1) is 35°C.

Comparative Example 20

The only difference between this comparative example and Example 1 is that the temperature during enzymatic hydrolysis in the step (1) is 50°C.

Comparative Example 21

The only difference between this comparative example and Example 1 is that the temperature during enzymatic hydrolysis in the step (1) is 55°C.

Example 10

The only difference between this example and Example 1 is that the time for enzymatic hydrolysis in the step (1) is 12h.

Comparative Example 22

The only difference between this comparative example and Example 1 is that the time during enzymatic hydrolysis in the step (1) is 0h.

Comparative Example 23

The only difference between this comparative example and Example 1 is that the enzymatic hydrolysis time in the step (1) is 4h.

Comparative Example 24

The only difference between this comparative example and Example 1 is that the enzymatic hydrolysis time in the step (1) is 16h.

Effect example 1

In order to verify the preference for the selection of co-substrate species in the method of the present invention, the products of Example 2 and Comparative Examples 1 to 3 were subjected to performance tests, and the results are shown in Figure 1 .

As can be seen from Figure 1, when other conditions remain unchanged, the type of co-substrate has a greater impact on the content of diacetyl in the product and the aroma score. The natural milk aroma prepared when whey powder and skimmed milk powder are used as co-substrates The diacetyl content of the base material reached 10mg/mL, and the aroma score of the product prepared with whey powder was higher. In general, the preparation of diacetyl type natural milk-flavor base material with whey powder as the auxiliary substrate had the best effect. .

Effect example 2

In order to verify the preference of the amount of co-substrate added in the method of the present invention, the products of Examples 2 to 4 and Comparative Example 3 were tested for performance, and the results are shown in Figure 2 .

It can be seen from Figure 2 that when other conditions remain unchanged, the addition amount of the co-substrate has no linear relationship with the increase in the content of diacetyl in the product. When the co-substrate is whey powder, the added content can be obtained at 8 g. The highest diacetyl yield and aroma score, and further increase of the added content led to a decrease in the diacetyl content, and the aroma score was less than 5 points.

Effect example 3

In order to verify the preference of the pH of the enzymatic hydrolysis raw materials in the method of the present invention, the products of Example 3 and Comparative Examples 4-7 were tested for performance, and the results are shown in Figure 3.

It can be seen that when the pH of the enzymatic hydrolysis raw material mixture changes from 5 to 9, the diacetyl content and aroma evaluation of the product fluctuate little. In general, the aroma score is the highest when pH=7, which can reach more than 8 points.

Effect example 4

In order to verify the optimal ratio of lipase and protease in the composite enzyme in the method of the present invention, the products of Example 3, Examples 5-6 and Comparative Examples 8-9 were tested for performance, and the results are shown in Figure 4.

As can be seen from Figure 4, when the quality of lipase and protease in the compound enzyme is the same, although the output of diacetyl content is high, the aroma score of the product is not high, less than 7.5 points, indicating that the aroma of the product is related to milk Fragrance, sweet fragrance, harmony and persistence are not directly related to the diacetyl concentration; however, as the proportion of lipase increases, the aroma score of the product also increases gradually. When the ratio of the two enzymes reaches 2:1 When the aroma score of the product reaches 8 points or more, and the diacetyl content is also as high as 22 mg/L or more; as the proportion of lipase further increases, the aroma score of the product decreases, indicating that excessive lipase hydrolysis in the raw material may cause the product to produce Discordant smell.

Effect example 5

After determining the ratio between the enzymes of the composite enzyme in the preparation process of the product, it is necessary to further study the preference of the added amount of the composite enzyme of the present invention. The performance tests of the products of Examples 6-8 and Comparative Examples 10-11 are carried out, and the results are shown in Figure 5 shown.

As can be seen from Figure 5, when the addition amount of the compound enzyme is 0.12% of the substrate content, the substrate and co-substrate are not fully enzymatically hydrolyzed, the production of diacetyl is insufficient, and the aroma of the product is insufficient; The amount of diacetyl in the product increases, the concentration of diacetyl in the product increases, and the aroma score also increases, and reaches a peak when the addition amount reaches 0.24; however, with the further increase in the addition amount, the aroma score of the product decreases significantly, the product begins to produce an uncoordinated flavor, and excessive enzymes The product of the solution also begins to inhibit the activity of the enzyme.

Effect example 6

Since the substrate is a fat-rich non-dairy creamer, the type of lipase has a decisive effect on the quality of the milk-flavored base material obtained by enzymatic hydrolysis of the raw material. The products of Example 6 and Comparative Examples 12 to 18 were tested for performance, and the results were as follows shown in Figure 6. It can be seen that the preferred lipase Lipase AY of the present invention has the highest diacetyl content in the diacetyl-type natural milk-flavor base material obtained under the same enzymatic hydrolysis environment, and the aroma score is the highest, and if some other enzymes are used for compound enzymatic hydrolysis , it is likely to lead to insufficient aroma of the product, or even a discordant pungent odor. As shown by lipase TG, the aroma score of the milk-flavored base product prepared with this enzyme is only 4.5 points, which is obviously impossible to use or Sales.

Effect example 7

After the type of complex enzyme and the enzymatic hydrolysis environment are determined, in order to further confirm the preference of the method of the present invention in the selection of temperature and time during enzymatic hydrolysis, Example 1, Examples 9-10 and Comparative Examples 19- 24 products were tested for performance, and the results are shown in Figures 7 and 8. It can be seen that when the temperature of enzymatic hydrolysis is low, the content of diacetyl produced by enzymatic hydrolysis is high, but the aroma of the obtained product is insufficient; When the temperature was raised to 40-45°C, the content of diacetyl also increased slightly, and the aroma score increased from the original 7 points to about 8 points; when the temperature rose to 50°C or even 60°C, due to the inhibition of enzyme activity, not only output The diacetyl content of the product was reduced, the aroma score was reduced to below 6 points, and the product odor harmony and persistence decreased significantly.

On the other hand, as the enzymatic hydrolysis time increases, the content of diacetyl in the product also increases gradually, and the aroma quality also improves. However, after the enzymatic hydrolysis time is too long, some by-products may be produced, which reduces the odor of the product and appears Unnatural smell, the lowest aroma score is only 4 points.

After screening, the best enzymatic hydrolysis temperature of the composite enzyme of the present invention is 40-45°C, and the best time is 8-12h.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that, The technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims (9)

1. a method for preparing diacetyl type natural milk-flavor base material by enzymolysis, is characterized in that, comprises the following steps: (1) Weigh the substrate, co-substrate and water and mix them evenly. After heating and sterilizing, add the compound enzyme and enzymolysis at 40-45°C for 8-12 hours, then inactivate the enzyme to obtain the enzymatic hydrolysis solution; the substrate It is non-dairy creamer; the co-substrate is whey powder; the composite enzyme includes lipase Lipase AY and protease MSD, and the mass ratio of the two is (2-4): 1; (2) The enzymolysis solution is cooled and packaged to obtain the diacetyl-type natural milk-flavored base material. 2. the method for preparing diacetyl type natural milk-flavor base material by enzymolysis as claimed in claim 1, is characterized in that, in described step (1), the mass ratio of lipase Lipase AY and protease MSD is 2:1, compound The temperature of enzymatic hydrolysis was 40°C and the time was 8h. 3 . The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to claim 1 , wherein the addition amount of the composite enzyme is 0.24-0.36% of the weight percentage of the substrate. 4 . 4 . The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to claim 3 , wherein the added amount of the composite enzyme is 0.24-0.3% of the weight percentage of the substrate. 5 . 5 . The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to claim 1 , wherein the addition amount of the auxiliary substrate is 40-120% of the weight percentage of the substrate. 6 . 6 . The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to claim 5 , wherein the addition amount of the auxiliary substrate is 40-80% of the weight percentage of the substrate. 7 . 7. The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to claim 1, characterized in that, in the step (1), the pH of the mixture obtained by uniformly mixing the substrate, the auxiliary substrate and the water is 6.5～ 7.5. 8 . The method for preparing diacetyl-type natural milk-flavored base material by enzymolysis according to claim 7 , wherein the pH of the mixture obtained by uniformly mixing the substrate, the auxiliary substrate and the water in the step (1) is 7. 9 . 9. A diacetyl-type natural milk-flavor base material prepared by the method for preparing a diacetyl-type natural milk-flavor base material by enzymatic hydrolysis according to any one of claims 1 to 8.

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