CN107836691B

CN107836691B - Natural milk-flavor essence base material and preparation method thereof

Info

Publication number: CN107836691B
Application number: CN201711249047.1A
Authority: CN
Inventors: 王蓓; 冯钰琳; 裴海闰; 王绒雪; 曹雁平
Original assignee: Beijing Technology and Business University
Current assignee: Beijing Technology and Business University
Priority date: 2017-11-30
Filing date: 2017-11-30
Publication date: 2021-04-20
Anticipated expiration: 2037-11-30
Also published as: CN107836691A

Abstract

The invention discloses a preparation method of a natural milk flavor essence base material, which comprises the following steps: (1) hydrolyzing the mature milk curd for 20-60 min by using compound protease at 45-55 ℃, and after the hydrolysis is finished, inactivating the enzyme, homogenizing and cooling to obtain a compound protease hydrolysate; the compound protease comprises protease Flavourzyme and protease Neutrase; in the milk bean curd, the addition amount of protease Flavourzyme is 1000-1500U/g protein, and the addition amount of protease Neutrase is 800-1200U/g protein; (2) adding 20,000L of lipase Platase into the composite protease hydrolysate at the temperature of 30-40 ℃, stirring for lipolysis reaction until the lipolysis rate is 15-20%, and after the reaction is finished, inactivating enzyme, homogenizing and drying to obtain the natural milk flavor essence base material. The preparation method is simple to operate, and the compound protease and the lipase are adopted to carry out step-by-step hydrolysis on the mature milk tofu to obtain the dairy product essence base material which not only has more volatile flavor components, but also has more flavor components.

Description

Natural milk-flavor essence base material and preparation method thereof

Technical Field

The invention relates to the technical field of dairy product processing, in particular to a natural milk flavor essence base material for increasing volatile flavor substances of dairy products and a preparation method thereof.

Background

The milk flavor essence is one of the most widely applied essences in the food industry, and is mainly used for enhancing the flavor of cold foods, candies, beverages and the like. Therefore, the development of the milk flavor essence series products has wide market prospect.

Milk-flavored aroma is mainly composed of lower fatty acids, carbonyl compounds and trace amounts of volatile components. The medium-short chain fatty acid has a large direct contribution to the milk flavor and is a direct factor for forming the milk flavor. The milk fragrance components generally comprise alcohols, aldehydes, acids, ketones, esters, lactones, sulfides and the like, and fragrance sources of the milk fragrance components comprise natural fragrance components in fresh milk and fragrance components formed in the process of processing dairy products, and mainly comprise diacetyl (2, 3-butanedione), acetoin, delta lactones, delta decalactone, delta dodecalactone, lactonic and the like.

Currently, there are several methods for preparing various dairy essence bases on the market: manually blending monomer incense raw materials; the natural extract is used for preparing the color essence, and the enzyme hydrolyzed cream is used for preparing various milk essence base materials through modification and blending.

The flavor and the components of the essence base materials obtained by different preparation methods are greatly different. Wherein the essence base material prepared by enzymatic hydrolysis can endow the product with natural milk flavor. The preparation of the milk flavor essence by enzymatic hydrolysis takes cream (or dilute cream) as a raw material, and the cream is hydrolyzed under certain conditions by utilizing an enzymatic hydrolysis technology to enhance the flavor by 150 to 250 times to generate a compound with the milk flavor characteristic. The flavoring agent is a natural food additive, has natural and soft fragrance, obviously improves and enhances the inherent quality of the flavoring product, and endows the flavoring product with natural milk flavor taste, which cannot be achieved by the similar milk flavor essence prepared by monomer spices.

The production method of the enzymatic milk flavor is based on selecting proper cream varieties, and performing enzymolysis on triglyceride of fatty acid (saturated and unsaturated) triglyceride, ketoacid and hydroxy acid in cream to obtain saturated and unsaturated fatty acid, ketoacid and hydroxy acid. The fragrance contribution of even-numbered carbon in the fatty acid is large, and the hydroxy acid is further dehydrated and cyclized to generate C-butyrolactone and D-lactone with different carbon numbers, particularly C-butyrolactone with even-numbered carbon, although the content is small, the fragrance contribution is large. The ketonic acid is further decarbonized to generate methyl ketone compounds, thereby playing a role in enhancing the fragrance.

However, the basic materials of the dairy essence by enzymolysis mainly take enzymolysis products obtained by hydrolyzing milk fat by using specific lipase as main materials, wherein the basic materials have more volatile flavor components, most of the components are medium-short carbon-chain fatty acids, and the volatility is strong; but the taste components are relatively few.

Disclosure of Invention

The invention provides a preparation method of a natural milk-flavor essence base material, and the prepared natural milk-flavor essence base material has better taste and smell.

The invention provides the following technical scheme:

a preparation method of a natural milk flavor base stock comprises the following steps:

(1) hydrolyzing the mature milk curd for 20-60 min by using compound protease at 45-55 ℃, and after the hydrolysis is finished, inactivating the enzyme, homogenizing and cooling to obtain a compound protease hydrolysate;

the compound protease comprises protease Flavourzyme and protease Neutrase;

in the milk bean curd, the addition amount of protease Flavourzyme is 1000-1500U/g protein, and the addition amount of protease Neutrase is 800-1200U/g protein;

(2) adding 20,000L of lipase Platase into the composite protease hydrolysate at the temperature of 30-40 ℃, stirring for lipolysis reaction until the lipolysis rate is 15-20%, and after the reaction is finished, inactivating enzyme, homogenizing and drying to obtain the natural milk flavor essence base material.

According to the preparation method, the milk curd is hydrolyzed step by adopting the compound protease and the lipase to obtain the essence base material of the dairy product, the essence base material is softer and more delicate in flavor, the milk taste is more mellow, and the quality of the essence base material is greatly improved. The preparation method is simple to operate, the prepared natural milk flavor essence base material not only has more volatile flavor components, but also has more flavor development components, the comprehensive taste is mainly thick milk flavor, the delicate flavor is prominent, other tastes are moderate, the caramel flavor and the flower flavor are larger, and the whole taste is richer.

The mature milk curd refers to fermented milk curd and can be prepared by a traditional method. Preferably, in the step (1), the preparation method of the milk curd comprises the following steps:

(1-1) preparing raw milk into a mass ratio of protein to fat of 0.4-0.45% by using cream; most preferably, the mass ratio of the protein to the fat is adjusted to 0.42%;

(1-2) sterilizing and fermenting the prepared raw milk, wherein the fermentation temperature is 35-40 ℃, and the fermentation time is 5-9 hours;

the purpose of sterilization is to kill pathogenic bacteria and harmful bacteria in raw milk and destroy harmful enzymes, so that the quality of the milk curd is stable and the shelf life can be prolonged. The sterilization process directly affects the quality of the milk curd, and if the temperature is too high and the time is too long, the curd is soft, the contraction action is weakened, the moisture is increased, the lactose contained in the curd is increased, and the curd time is prolonged.

Preferably, the sterilization temperature is 60-65 ℃, and the sterilization time is 20-40 min.

The lactobacillus leavening agent has the following functions in the maturation of the milk curd: firstly, lactose is fermented to produce lactic acid, which has a significant effect on the texture of the clot; secondly, the lactobacillus has stronger protease and peptidase activities, and has obvious influence on the improvement of the flavor of the milk bean curd in the subsequent after-ripening process.

Preferably, the adopted leavening agents are leavening agent R-704 and a strain with the preservation number of CGMCC No.10995, and the ratio of the strain with the preservation number of CGMCC No.10995 to the leavening agent R-704 in the leavening agents is 1-2: 1.

The strain with the preservation number of CGMCC No.10995 is Pedicoccus aciditictici, the Latin chemical name is Pedicoccus aciditictici, and the strain is named as PAXM22 strain. The strain is preserved in the general microbiological culture collection center of China Committee for culture Collection of microorganisms at 19 th 6 th 2015, and the preservation address is No. 3 Xilu No.1 Beijing Zhongyang district of China.

The strain with the preservation number of CGMCC No.10995 has stronger peptidase activity (2479U/g), the peptidase can hydrolyze casein to obtain more flavor peptides and amino acid components, and the components have important effect on the good taste of the milk bean curd.

Starter R-704 was purchased from hansen.

More preferably, the amount of the fermentation agent added is 10⁸cfu/100ml。

And (1-3) discharging whey after fermentation, squeezing and forming, and after-ripening to obtain the milk tofu.

And squeezing for 16h under the pressure of 7-8Pa, then carrying out vacuum packaging, and carrying out cold storage at 4 ℃ for 3 days, and then carrying out aging to obtain the mature milk tofu.

When the hydrolysis temperature is too high or too low, the activity of the protease is reduced, and the hydrolysis result is influenced. Preferably, in the step (1), the compound protease is adopted to hydrolyze the mature milk curd at the temperature of 49-51 ℃ for 30-35 min.

When the protease is added in an excessive amount, the degree of hydrolysis is not easily controlled, and excessive hydrolysis results in bitterness, while when the protease is added in an excessive amount, the hydrolysis time is long, and the hydrolysis efficiency is low. Preferably, in the step (1), the protease Flavourzyme is protease Flavourzyme500MG, and the addition amount is 1200-1300U/g protein;

the addition amount of the protease Neutrase is 900-1000U/g protein.

Preferably, in the step (2), the temperature of the lipolysis reaction is 35-40 ℃, the time of the lipolysis reaction is 30-35 min, and the stirring speed is 100-200 rpm.

Similarly, too high a lipase addition can result in excessive hydrolysis, resulting in too large release of short chain fatty acids and poor flavor; when the amount is too small, the hydrolysis time is long and the hydrolysis efficiency is low. More preferably, in the step (2), the amount of 20,000L lipase is 950 to 1100U/g fat.

Preferably, in the step (2), the reaction end point of the lipolysis reaction is 8-12% of the lipolysis rate.

When the lipolysis rate is 8-12%, the obtained product has the best sensory evaluation result.

The invention also discloses the natural milk flavor essence base material prepared by the preparation method.

Compared with the prior art, the invention has the beneficial effects that:

(1) the preparation method is simple to operate, and the compound protease and the lipase are adopted to carry out step-by-step hydrolysis on the mature milk tofu to obtain the dairy product essence base material which not only has more volatile flavor components, but also has more flavor components;

(2) in the aspect of taste, the molecular weight distribution of the prepared natural milk flavor base material is mainly concentrated below 1000Da, most of the natural milk flavor base material is small molecular weight polypeptide and free amino acid, the molecular weight is nearly 60 percent of the whole body, most of the taste peptides are small peptides with the molecular weight within 1000, and the molecular weight of the traditional milk tofu is concentrated above 7000. The sensory evaluation result of the natural milk flavor essence base material obviously increases the delicate flavor and the thick taste, although the bitter taste is also enhanced, the strength is not large, so the influence of protease enzymolysis on the taste sensory quality of the milk curd has an important role;

(3) in the aspect of smell, compared with the traditional milk bean curd, the content of fatty acid, ester compounds and pyrazine compounds in the natural milk flavor base material obtained by enzymolysis is obviously increased; the fatty acid is a characteristic flavor component in the mature cheese and has relatively strong milk flavor; the added ester compound enables the flower fragrance of the natural milk flavor base material to be obviously higher than that of the traditional milk bean curd sample; the pyrazine compounds can obviously enhance the scorched flavor of the natural milk flavor base material and have better contribution to the sensory quality of the natural milk flavor base material.

Drawings

FIG. 1 is a schematic flow chart of the preparation of the natural milk flavor base of the embodiment;

FIG. 2 is a comparison of the flavor profile of natural milk flavor base and traditional milk tofu.

Detailed Description

Examples

The preparation method of the natural milk-flavor essence base material comprises the following steps as shown in figure 1:

1. a milk bean curd making process;

raw milk standardization → sterilization → addition of leavening agent → natural fermentation → acid curd block → cutting → heating and stirring → whey discharge → press molding → product

(1) Standardization of raw milk: preparing the raw material milk into the cream with the mass ratio of protein to fat of 0.8;

(2) sterilization of raw milk: the purpose of sterilization is to kill pathogenic bacteria and harmful bacteria in raw milk and destroy harmful enzymes, so that the quality of the milk curd is stable and the shelf life can be prolonged. The sterilization process directly affects the quality of the milk curd, and if the temperature is too high and the time is too long, the curd is soft, the contraction action is weakened, the moisture is increased, the lactose contained in the curd is increased, and the curd time is prolonged. The milk curd is generally sterilized at 63 ℃ for 30min, and the conventional pasteurization condition for cheese products can ensure that most harmful microorganisms are inhibited.

(3) Addition of a starter: and (3) when the temperature of the sterilized milk is cooled to 30-32 ℃, adding a leavening agent, and uniformly stirring. The lactobacillus leavening agent has the following functions in the maturation of the milk curd: firstly, lactose is fermented to generate lactic acid, so that the pH value is reduced to reach the isoelectric point of casein to generate curd, and meanwhile, the growth of pathogenic bacteria and putrefying bacteria can be inhibited by low pH value; secondly, the strain with the preservation number of CGMCC No.10995 has certain peptidase activity, the peptidase can hydrolyze casein to obtain more flavor peptides and amino acid components, and the components play an important role in the good taste of the milk curd.

(4) Acid curdled milk block: the sour curd produced by the leaven is utilized to form a milk block after the milk reaches a certain acidity.

(5) Cutting and discharging whey: the fermented sour curd is cut under aseptic conditions into soybean-sized particles, and whey can be effectively discharged. And then, carrying out whey discharging after wrapping by 3-4 layers of gauze, and then putting the gauze into a mould to carry out squeezing forming under certain pressure, wherein the whey discharging temperature is controlled to be about 25 ℃.

(6) Heating and stirring: after the milk blocks are cut, heating and stirring are started, wherein the heating and stirring temperature is 50-80 ℃, and whey is discharged by heating and stirring at a higher temperature.

(7) Whey discharging: standing to room temperature, wrapping all the contents by 3-4 layers of gauze, discharging whey, then putting the gauze into a mould for squeezing and forming at a certain pressure, squeezing for 16 hours at a pressure of 7-8Pa, and obtaining a finished product.

2. Enzyme-treated milk curd

(1) Under the condition that the pH value of the system is naturally reduced, the cooked self-made milk curd is used as a raw material, two different proteases are used for compositely hydrolyzing the self-made milk curd taste enhancing product, the reaction condition is 50 ℃, the reaction time is 34min, the addition amount of Flavourzyme500MG enzyme is 1250U/g protein, and the addition amount of Neutrase enzyme is 950U/g protein. After the reaction is finished, inactivating enzyme of the enzymolysis product for 5 minutes at 95 ℃, homogenizing, and naturally cooling.

(2) And further adding 20,000L of lipase Platase into the composite protease hydrolysate to simulate the action effect of the lipase in the cheese maturation process so as to improve the aroma quality of the milk curd, wherein the specific enzymolysis conditions are as follows: under the reaction conditions of 38 ℃ and a stirring speed of 150rpm, 20,000L of lipase Platase was added to the reaction mixture in an amount of 1000U/g of fat, followed by reaction for 30 minutes until the rate of lipolysis reached 10% (the rate of lipolysis (%) (amount of change in acid value before and after the reaction/saponification value. times.100). And (3) inactivating enzyme of the enzymolysis product for 15 minutes at 95 ℃, homogenizing, freeze-drying, vacuumizing and packaging to obtain the essence base material.

Secondly, comparing the essence base material prepared by the method with the milk curd before enzymolysis

The taste of the enzymolysis milk tofu (the prepared natural milk flavor essence base material) is mainly represented by fresh taste and strong taste which are obviously increased, in addition, the milk taste and the bitter taste are also slightly increased, the smell is represented by caramel taste and flower fragrance which are obviously increased, but the milk odor is also obviously increased, so the comprehensive taste of the enzymolysis milk tofu is mainly the milk taste, the fresh taste is prominent, other tastes are moderate, and the enzymolysis milk tofu has larger caramel taste and flower fragrance, and the whole taste is richer; the traditional milk tofu is not prominent enough in fresh taste, thick taste and the like, and the taste and the smell are relatively flat.

The flavor profile of the enzymatic milk curd is compared with that of the conventional milk curd as shown in FIG. 2.

1. And (3) flavor development: amino acid analysis

The results of comparing the molecular weights of the enzymatic fermented milk curd with those of the conventional fermented milk curd are shown in Table 1.

TABLE 1 comparison of molecular weight distribution of the enzyme-hydrolyzed milk curd with that of the conventional milk curd

As can be seen from Table 1, the molecular weight distribution of the enzymatic milk-curd is mainly concentrated below 1000Da, and is mostly small molecular weight polypeptide and free amino acid, and studies have shown that the flavor-developing peptide is mostly small peptide with molecular weight of 1000 or more, the content of the small peptide with molecular weight of 1000 or less and the amino acid in the enzymatic milk-curd accounts for nearly 60% of the whole, while the molecular weight of the traditional milk-curd is mostly concentrated above 7000, and in addition, the sensory evaluation result of the enzymatic milk-curd is that the delicate flavor and the thick taste are significantly increased, although the bitter taste is also enhanced, but the intensity is not strong, so the influence of protease enzymolysis on the sensory quality of the taste of the milk-curd is important.

In addition, the comparison results of the amino acid content of the finally prepared enzymatic milk curds with those of the milk curds prepared by the conventional method are shown in table 2.

TABLE 2 analysis and comparison of amino acids in natural milk flavor base and conventional milk tofu

As can be seen from Table 2, the total amino acid content and the free amino acid content of the conventional milk curd are much smaller than those of the enzyme-hydrolyzed milk curd. The lactobacillus protease and peptidase used in the method have higher activity, and can obviously increase the content of flavor components in the milk curd in the cheese curd and the subsequent after-ripening process. The content of flavor-developing amino acid in the milk bean curd prepared by the traditional method is far less than that of flavor-developing components in the enzymolysis milk bean curd.

The contents of free amino acids in different types of flavors in the enzymatic fermented milk curd and the traditional fermented milk curd are different from those in table 3.

TABLE 3 comparative analysis of the content of free amino acids in different types of flavors

As can be seen from table 3, the content of the bitter amino acids in the enzyme-hydrolyzed milk curd sample was relatively high, but the bitter intensity was slightly enhanced in sensory evaluation compared to that before the enzyme hydrolysis, but the unpleasant bitter taste was not exhibited, and thus the increase in the content of the bitter amino acids had less influence on the sensory quality of the enzyme-hydrolyzed cheese. In addition, the enzymolysis milk curd contains more components with thick taste, and the amino acids can interact with sweet amino acids and fresh amino acids in free amino acids, so that the overall sensory quality of the enzymolysis milk curd is improved.

2. In the aspect of smell: GC-MS analysis

The analysis results of the volatile flavor components in the milk-made bean curd before and after the enzymatic hydrolysis are shown in Table 4.

Table 4 analysis results of volatile flavor components of milk curd before and after enzymolysis

It can also be seen from table 4 that the contents of fatty acids, esters and pyrazines in the fermented milk curd are significantly increased, especially even-numbered fatty acids with short carbon chains such as butyric acid, caproic acid, caprylic acid and capric acid.

First, the fatty acids are characteristic flavor components in the ripened cheese, have a strong milk flavor at low concentrations, can impart a milk odor peculiar to the cheese at medium concentrations, and if the concentration is high, the sour taste and the milk odor are excessive, thereby adversely affecting the sensory quality of the cheese. In addition, the compounds are precursor substances of other flavor substances in the cheese, such as ketone, alcohol, ester, lactone and the like, and are important characteristic flavor components in the cheese. According to the preparation method, the medium-concentration fatty acid with medium and short carbon chains is obtained by hydrolyzing the fat in the cheese by using the microbial lipase in the process of simulating cheese ripening by using the lipase, so that the milk odor intensity in the volatile flavor characteristic of the cheese after enzymolysis is remarkably increased, but the milk odor intensity after dilution is reduced and the milk odor intensity is increased because the enzymolysis product is used as an essence base material and is properly diluted before use, so that the quality of the flavored product is greatly improved.

And secondly, an ester compound is derived from an esterification reaction of an alcohol compound and a fatty acid compound generated in the cheese fermentation process, more alcohol components can be generated in the milk curd fermentation process in the previous stage, and the alcohol compounds can generate an esterification reaction with fatty acid generated in the subsequent fat enzymolysis reaction, so that the content of the ester component in the enzymolysis milk curd is increased, particularly the content of fatty acid ethyl ester with medium and short carbon chains is increased, the ester is called butter ester, most of the ester has obvious flower and fruit fragrance, and the flower fragrance of the enzymolysis milk curd is obviously higher than that of a traditional milk curd sample. In addition, the ester compounds can alleviate unpleasant tastes (rancidity and bitterness) caused by too high concentrations of the fatty acid or amine compounds, so that the cheese is endowed with softer flavor, and the compounds have better influence on the sensory quality of the enzymatic fermented milk curd.

The content of pyrazine compounds in the volatile flavor components is also increased, the compounds mainly come from Maillard reaction between reducing sugar and amino acid in the milk bean curd, most of the compounds have caramel taste, nut taste and the like, and can obviously enhance the scorched flavor in the enzymatic hydrolysis milk bean curd, so that the compounds also have good contribution to the sensory quality of enzymatic hydrolysis products.

Therefore, the milk odor, the flower fragrance and the burnt odor of the milk bean curd sample are all greatly increased after the enzymolysis, and the sensory quality of the milk bean curd sample is greatly improved.

The above-mentioned embodiments are intended to illustrate the technical solutions and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, additions, equivalents, etc. made within the scope of the principles of the present invention should be included in the scope of the present invention.

Claims

1. The preparation method of the natural milk flavor base stock is characterized by comprising the following steps:

the compound protease comprises protease Flavourzyme and protease Neutrase;

the preparation method of the milk curd comprises the following steps:

(1-1) preparing raw milk into a mass ratio of protein to fat of 0.4-0.45% by using cream;

(1-2) sterilizing and fermenting the prepared raw milk, wherein the fermentation temperature is 35-40 ℃, and the fermentation time is 5-9 hours; the adopted leavening agents are leavening agent R-704 and bacterial strain with the preservation number of CGMCC No. 10995; in the leavening agent, the ratio of the strain with the preservation number of CGMCC No.10995 to the leavening agent R-704 is 1-2: 1;

(1-3) discharging whey after fermentation, squeezing and forming, and after-ripening to obtain a milk bean curd;

2. The preparation method of the natural milk flavor base material according to claim 1, wherein in the step (1), the hydrolysis temperature is 49-51 ℃, and the hydrolysis time is 30-35 min.

3. The preparation method of the natural milk flavor base material according to claim 2, characterized in that in the step (1), the protease Flavourzyme is protease Flavourzyme500MG, and the addition amount is 1200-1300U/g protein;

the addition amount of the protease Neutrase is 900-1000U/g protein.

4. The preparation method of the natural milk flavor base material according to claim 1, wherein in the step (2), the temperature of the lipolysis reaction is 35-40 ℃, the time of the lipolysis reaction is 30-35 min, and the stirring speed is 100-200 rpm.

5. The preparation method of the natural milk flavor base stock according to claim 4, wherein in the step (2), the addition amount of 20,000L lipase is 950-1100U/g fat.

6. The preparation method of the natural milk flavor base material according to claim 1, wherein in the step (2), the reaction endpoint of the lipolysis reaction is that the lipolysis rate is 8-12%.

7. The method for preparing the natural milk flavor base material according to claim 1, wherein in the step (1-2), the addition amount of the leavening agent is 10⁸cfu/100ml。

8. A natural milk-flavor essence base material, which is characterized by being prepared by the preparation method according to any one of claims 1 to 7.