Preparation method of salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation

Abstract

The invention discloses a preparation method of salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation and control. The method comprises the following steps: grinding coffee beans and blending a grinding two kinds of coffee beans with different baking degrees and then blending; powder pressing and high-pressure extraction: adding the pyrazine flavor coffee extract microcapsules into the coffee base in the powder pressing process, and performing high-pressure extraction on the pressed coffee powder to release grease and dissolve out flavor substances; preparing a salted egg yolk milk cover: preparing the salted egg yolk milk cover through pre-cooling treatment, seasoning mixing and stirring; and layered assembly and finished product preparation of the salted egg yolk coffee: sequentially adding ice cubes, milk, coffee liquid and a salted egg yolk milk cover to complete the preparation of the salted egg yolk coffee. According to the method disclosed by the invention, the innovative drink with salty and fresh flavor and mellow taste of coffee can be prepared by regulating and controlling the molecular synergistic effect of the characteristic flavor substances of the coffee baking derived alkyl pyrazine and the salted egg yolk, and the method can be used for industrial production of functional coffee drinks, prefabricated coffee concentrated solutions and solid drinks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coffee beverage processing and flavor regulation, and particularly relates to a preparation method of salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation. BACKGROUND

[0002] Coffee is the most consumed beverage in the world and one of the most valuable commodities. With the change of people's eating habits and the influence of western culture, the number of people consuming coffee is also rising. According to a number of authoritative data and market research, China's coffee market has become one of the most dynamic markets in the world. Pyrazine compounds are key roasting carriers of roasted coffee, are a class of nitrogen-containing heterocyclic compounds, naturally exist in roasted foods, fermented foods and coffee, and have the characteristics of nut, caramel and roasting aroma.

[0003] There are two outstanding problems in the traditional regulation method: one is that the regulation is extensive, and the excessive dissolution of bitter taste, astringent taste or miscellaneous taste often accompanies the improvement of the target flavor; the second is that although the addition of essence or single flavor substance can make up for the deficiency, it is easy to lead to superficial and unnatural aroma, and lack of integration with coffee base. Especially in the emerging compound beverage of salted egg yolk coffee, the flavor coordination between the salty and fresh emulsified ingredients and the coffee base is more difficult. If the dynamic control of pyrazine substances is lacking, the problem of single or unstable flavor level often occurs.

[0004] The core value of the present application lies in that the key bridge flavor substance-pyrazine in salted egg yolk coffee can be dynamically and synergistically regulated from raw material processing, process extraction to finished product blending, so as to solve the bottleneck of the prior art and realize the stability, harmony and optimization of product flavor. SUMMARY

[0005] The present application aims at the deficiencies of the prior art, and provides a preparation method of salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation. The present application can prepare an innovative beverage with the integration of salty and fresh flavor and the rich taste of coffee by regulating the molecular synergy effect of alkyl pyrazine derived from coffee roasting and salted egg yolk characteristic flavor substances; the present application is mainly applied to the industrialized production of functional coffee beverage, pre-made coffee concentrate and solid beverage.

[0006] The purpose of the present application is achieved by the following technical scheme: a preparation method of salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation, comprising the following steps: Step one, grinding and base blending of coffee beans: grinding and blending two kinds of coffee beans with different roasting degrees; Step two, powder pressing and high-pressure extraction: adding pyrazine flavor coffee extract microcapsules to the coffee base during powder pressing, and performing high-pressure extraction on the pressed coffee powder to release oil and dissolve flavor substances; Step three, preparation of salty egg yolk milk cover: through the process of pre-cooling, mixing spices, stirring to prepare salty egg yolk milk cover; Step four, layered assembly of salty egg yolk coffee and finished product: add ice, milk, coffee liquid, salty egg yolk milk cover in turn, complete the preparation of salty egg yolk latte coffee, and obtain the finished product.

[0007] Further, in the step one, the step of base preparation specifically includes: through the proportioning of two different roasting degree coffee beans, the content of pyrazine substances and the sensory thickness are directionally adjusted to realize the directional regulation of pyrazine content and sensory flavor.

[0008] Further, in the step two, the preparation step of coffee extract microcapsule specifically includes: using water phase molecular embedding method to prepare coffee characteristic aroma nanocarrier material capsule, that is, under stirring and water bath, first disperse the nanocarrier into 120-210 mL water, then add coffee extract, react for 10 min, then ultrasonic extraction at 35℃ for 0-60 min, put the beaker into 4℃ refrigerator for 24 h, then filter to obtain the precipitate, and dry the precipitate in the oven at 55℃ for 4 h to obtain coffee extract microcapsule, and finally perform liquid phase determination to measure the content of various pyrazines.

[0009] Further, in the step two, the pressure and temperature of extraction are 20 bar and 92℃-96℃ respectively, and the dynamic release of pyrazine flavor substances is realized by adjusting the temperature gradient of extraction.

[0010] Further, in the step three, the preparation of salty egg yolk milk cover specifically includes: a. pre-cooling: refrigerate milk and light cream for 3-4 hours; b. mixing spices: mix 10-30 g of salty egg yolk milk cover powder, 80-100 mL of light cream, and 150-200 mL of pure milk according to the proportion, then add light cream and condensed milk, and refrigerate for 10 minutes; c. stirring: mix for 2-4 min until no particles, transfer to milk cover machine and whip until smooth, complete the preparation of salty egg yolk milk cover.

[0011] Further, the step four specifically includes: first add ice to the cup as the bottom, then add 10-20 mL of vanilla syrup, pour 100-200 mL of milk into the bottom of the cup, slowly pour coffee liquid along the wall of the cup to form a gradual layered, and finally cover the top with salty egg yolk milk cover, complete the preparation of a cup of salty egg yolk latte coffee, and obtain the finished product.

[0012] Compared with the prior art, the beneficial effects of the present application are: the present application realizes the precise control of the key flavor substance of pyrazine by establishing a four-fold dynamic regulation system of "raw material ratio-microcapsule release-temperature segmentation-direct addition", which not only significantly improves the nut, caramel and dark chocolate flavor levels of coffee, but also makes the aroma present progressive release and more lasting lingering effect through the synergistic effect of instantaneous and delayed release; the present application proves that the method described in the present application has scientific basis in improving the flavor coordination and stability through sensory evaluation and GC-MS spectrum data verification; at the same time, the stability and bioavailability of active ingredients such as tetramethylpyrazine are enhanced under nano-embedding, so that the beverage has both functionality and health value; the process link in the present application is clear and easy to industrialize, and can be applied to various product forms such as instant coffee, pre-concentrated liquid and solid beverage, providing differentiated technical support and market value for the coffee industry. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a technical process overview diagram of the salted egg yolk coffee preparation method based on pyrazine flavor synergy and dynamic regulation of the present application; Figure 2 is a content change diagram of different proportion coffee pyrazine flavor substances of the present application; Figure 3 is a change diagram of the embedding rate performance of coffee extract microcapsules under different ultrasonic times of the present application; Figure 4 is a radar chart of sensory evaluation of three coffee samples of the present application; Figure 5 is a change diagram of the embedding rate performance of coffee extract microcapsules under different wall-to-core ratios of the present application; Figure 6 is a change diagram of the content of characteristic aroma ingredients under different extraction temperatures of the present application; Figure 7 is a result diagram of the relative content of volatile components of different coffee samples of the present application; Figure 8 is a volatile substance content result diagram of different coffee samples of the present application. DETAILED DESCRIPTION

[0014] The exemplary embodiments will be described in detail herein with reference to the attached drawings. In the following description, the same numbers are used to indicate the same elements throughout the several views. The embodiments described in the following exemplary embodiments are not meant to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the present application as detailed in the appended claims. It is understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

[0015] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in this application and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or," as used herein, refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0016] It will be understood that, although the terms first, second, third, etc. can be used herein to describe various information, these terms are not intended to denote a temporal or chronological order. Rather, these terms are used solely to distinguish one from another only. For example, a first information can be termed a second information, and similarly, a second information can also be termed a first information, without departing from the scope of the present application. As used herein, the word "if' can be construed to mean "when" or "upon" or "in response to determining" depending on the context. Also, the term "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.

[0017] The application will be described in detail below with reference to the drawings. The features of the embodiments and examples described below can be combined with each other, without conflict.

[0018] Referring to Figure 1 The preparation method of the salted egg yolk coffee based on the synergistic and dynamic regulation of the pyrazine flavor of the present application selects a Brazilian coffee sample as the research object, and the preparation method specifically includes the following steps: Step one, grinding and base preparation of coffee beans: grind and prepare two coffee beans with different roasting degrees.

[0019] Further, the step of base preparation specifically includes: through the proportioning of two coffee beans with different roasting degrees, the content of pyrazine substances and the sensory thickness are directionally adjusted to realize the directional regulation of the content of pyrazine substances and the sensory flavor. Different roasting degrees refer to clearly different roasting degrees, such as light and medium roasting degrees, and the like.

[0020] Step two, powder pressing and high-pressure extraction: during the powder pressing process, pyrazine flavor coffee extract microcapsules are added to the coffee base, and high-pressure extraction is performed on the coffee powder after powder pressing to release oil and dissolve flavor substances.

[0021] The extraction pressure and temperature are 20 bar and 92-96℃, respectively, which can ensure sufficient extraction power, and the dynamic release of pyrazine flavor substances can be achieved by adjusting the temperature gradient of extraction (such as 92℃, 94℃, 96℃). At 92℃, the taste is bright, the sourness and original flavor are prominent, such as floral fragrance; at 94℃, the balance of sour and sweet flavors is highlighted, with prominent flavors of almond, hazelnut, etc.; at 96℃, the taste is mellow, with prominent flavors of dark chocolate, caramel and cocoa.

[0022] Further, the preparation steps of the coffee extract microcapsule specifically include: using a water phase molecular embedding method to prepare a coffee characteristic aroma (pyrazine flavor) nanocarrier material capsule, which includes five processes in sequence: mixing, refrigeration, filtration, drying, and measurement. Specifically, under stirring and water bath, first disperse the nanocarrier into 120-210 mL of water, then add a certain amount of coffee extract (pyrazine flavor substances), react for 10 min, then ultrasonically extract at 35℃ for 0-60 min, place the beaker in a 4℃ refrigerator for 24 h, then filter to obtain a precipitate, dry the precipitate in a 55℃ oven for 4 h to obtain coffee extract microcapsules, and finally perform liquid phase measurement to measure the content of various pyrazines, i.e., use high-performance liquid chromatography for quantitative analysis to measure the content of various pyrazines (unit: mg / L). By changing the embedding rate and release rate of the coffee extract microcapsule, the flavor hierarchy of pyrazine substances can be achieved. The pyrazine flavor coffee extract microcapsule is embedded in the press powder process, and the synergistic effect of instantaneous release and delayed release of the coffee extract microcapsule can enhance the nutty and caramel flavors.

[0023] Step three, preparation of salted egg yolk milk cover: through three processes of pre-cooling treatment, mixing of seasonings, and stirring preparation, the salted egg yolk milk cover is prepared.

[0024] Specifically, a. pre-cooling treatment: refrigerate the milk and light cream for 3-4 hours to ensure stable whipping stability through low temperature; b. mixing of seasonings: mix the salted egg yolk milk cover powder with pure milk in a certain proportion, then add light cream and condensed milk, and refrigerate for 10 minutes for shaping; c. stirring preparation: mix at low speed for 2-4 min until there are no particles, then transfer to a milk cover machine for whipping to a smooth and fluffy texture, and the preparation of the salted egg yolk milk cover is completed.

[0025] Step four, layered assembly and finished product of salted egg yolk coffee: add ice cubes, milk, coffee liquid, and salted egg yolk milk cover in sequence to complete the preparation of salted egg yolk latte coffee and obtain the finished product.

[0026] Specifically, ice cubes are first added to a cup as a base, 10-20 mL of vanilla syrup is then added, 100-200 mL of milk is poured into the bottom of the cup, coffee liquid is slowly injected along the cup wall to form a gradient layer, and finally a salty egg yolk milk cover is added on top to complete the preparation of a cup of salty egg yolk latte coffee, and the finished product is obtained. After adding the salty egg yolk milk cover, the relative abundance of various volatile flavor compounds can be more balanced, and the aroma profile is more stable.

[0027] In some other embodiments, step five, evaluation of the flavor quality of the coffee sample, is also included: flavor analysis is performed on different coffee samples to verify the influence of the synergistic effect of pyrazines on the overall flavor characteristics. The evaluation of the flavor quality includes sensory scoring and gas chromatography-mass spectrometry (GC-MS) spectrum analysis, which are used to verify the effect of dynamic regulation on the release of pyrazine substances and the overall aroma balance.

[0028] Further, sensory scoring invites 10 members who have long-term research on coffee to form an evaluation team to conduct sensory evaluation under room temperature conditions. The evaluation members perform sensory scoring on the coffee samples according to the standard in Table 1, with a full score of 10. The coffee samples include sample A, sample B, and sample C. Sample A is ordinary coffee, sample B is salty egg yolk coffee without the addition of coffee extract microcapsules, and sample C is salty egg yolk coffee with the addition of coffee extract microcapsules.

[0029] Table 1: Sensory evaluation scoring standard for salty egg yolk coffee

[0030] Further, GC-MS spectrum analysis is achieved by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) spectrum analysis. Specifically, coffee liquid (5-10 mL) is placed in a headspace bottle; DVB / CAR / PDMS fiber is pre-equilibrated at 60℃ for 10 min and extracted for 30-40 min; the GC injection port is 250℃, and the DB-WAX program is used for temperature rising; MS: EI 70eV, m / z 35-350. Qualitative analysis is performed using the NIST library + retention index, and statistics are compared. The chromatographic conditions for collecting GC-MS spectrum information of the coffee sample include: (1) a DB-WAX quartz capillary column with a size of 30m x 0.25mm x 0.25µm; (2) temperature rising program: initial temperature 40℃, holding for 2 min, rising to 120℃ at a rate of 4℃ / min, holding for 4 min, and finally rising to 240℃ at a rate of 10℃ / min, holding for 2 min; (3) He carrier gas flow rate is 0.8-1.0 mL / min. The mass spectrometry conditions for collecting GC-MS spectrum information of the coffee sample: EI ion source, electron energy 70eV, ion source temperature 230℃, quadrupole rod temperature 150℃, and mass range 35-550m / z.

[0031] The preparation method of salted egg yolk coffee based on the synergistic effect of pyrazine flavor and dynamic regulation will be described in detail below according to the embodiments, and the purposes and effects of the present application will become more apparent.

[0032] Example 1 This embodiment is mainly used to verify the preparation method of salted egg yolk coffee based on the synergistic effect of pyrazine flavor and dynamic regulation, which specifically includes the following steps: (1) 2-6 g of light to medium roasted coffee beans and 2-6 g of medium to dark roasted coffee beans are mixed to change the nutty aroma, caramel aroma and full-bodied feeling, and the results are shown in Table 2 and Figure 2

[0033] Table 2: Description of aroma substances of coffee in different proportions

[0034] (2) After the prepared coffee beans are crushed, the essence of the coffee beans is extracted at a certain temperature and high efficiency and uniformity to release oil.

[0035] (3) Pre-cooling treatment: milk and light cream need to be refrigerated for 3-4 hours (low temperature ensures the stability of whipping); mixed seasoning: 30 g of salted egg yolk topping powder, 100 mL of light cream, and 200 mL of pure milk, mix the salted egg yolk topping powder with milk according to a certain proportion, then add light cream and condensed milk, and refrigerate for 10 minutes; stirring production: mix at low speed for 2 min until there are no particles, transfer to a milk cover machine and whip to a smooth and smooth texture, to obtain the prepared salted egg yolk milk cover.

[0036] (4) First, add ice cubes to the cup as a base, then add 10 mL of vanilla syrup, pour 100 mL of milk into the bottom of the cup, slowly pour the coffee liquid along the wall of the cup to form a gradient layer, and finally cover the top with salted egg yolk milk cover.

[0037] (5) Evaluation of the flavor quality of the coffee sample: flavor analysis is performed on different coffee samples to verify the influence of pyrazine synergistic effect on the overall flavor characteristics.

[0038] Example 2 This embodiment mainly investigates the influence of different ultrasonic times on the embedding rate performance of coffee extract microcapsules, which specifically includes the following steps: (1) Add coffee extract microcapsules with different ultrasonic times to the coffee base, the times are 0 min, 20 min, 40 min, and 60 min, to regulate the compactness and embedding rate of the microcapsules, then put the microcapsules into 4℃ refrigerator for 24h. After filtration, the precipitate is dried in a 55℃ oven for 4h to obtain coffee extract microcapsules, and the results are shown in Figure 3

[0039] ​​(2) The prepared coffee powder is pressed into coffee beans, and the essence of the coffee beans is extracted at a high efficiency and uniformly at a temperature of 92°C to release oil.

[0040] (3) Pre-cooling treatment: milk and light cream need to be refrigerated for 3-4 hours (low temperature ensures stable whipping stability); mixed ingredients: 30 g of salted egg yolk topping powder, 100 mL of light cream, and 200 mL of pure milk. The salted egg yolk topping powder is mixed with milk at a certain ratio, heated, then light cream and condensed milk are added, and refrigerated for 10 minutes for shaping; stirring preparation: low-speed mixing for 2 min until no particles are formed, then transferred to a milk cover machine for whipping to a smooth and smooth texture, obtaining the prepared salted egg yolk milk cover.

[0041] (4) First, add ice cubes to the cup as a base, then add 10 mL of vanilla syrup, pour 100 mL of milk into the bottom of the cup, slowly inject coffee liquid along the cup wall to form a gradient layer, and finally cover the top with salted egg yolk milk cover.

[0042] (5) Sensory evaluation of two coffee samples, one ordinary coffee (sample A), one salted egg yolk coffee without adding coffee extract microcapsules (sample B), and one salted egg yolk coffee with coffee extract microcapsules (sample C), the results are shown in Table 3 and Figure 4 .

[0043] Table 3: Sensory evaluation index and score

[0044] Example 3 This example mainly investigates the influence of different wall-to-core ratios on the embedding rate performance of coffee extract microcapsules and the content change of aroma components at different extraction temperatures, which includes the following steps: (1) Add coffee extract microcapsules with different wall-to-core ratios to the coffee base, the ratios are 1:6, 1:8, 1:10, and 1:12 respectively, then put the microcapsules into a 4°C refrigerator for 24 hours. After filtration, the precipitate is dried in a 55°C oven for 4 hours to obtain coffee extract microcapsules, the results are shown in Figure 5 .

[0045] (2) After the coffee powder is prepared, the coffee beans are pressed, and three temperature settings of 92°C, 94°C, and 96°C are used for comparative experiments to achieve the directional release of different volatile flavor substances: 92°C: sour and floral active substances are preferentially released, with a fresh and bright taste; 94°C: the balance between sweet and sour is achieved, with sufficient presentation of pyrazine substances and nutty aroma; 96°C: caramel and dark chocolate flavors are significantly enhanced, with a full and rich overall flavor. The results of different aroma components are shown in Figure 6 .

[0046] (3) Pre-cooling treatment: milk, light cream needs to be refrigerated for 3-4 hours (low temperature to ensure the stability of whipping); mixed ingredients: 30g of salted egg yolk milk cover powder, 100ml of light cream, 200ml of pure milk, mix the salted egg yolk milk cover powder with milk according to a certain proportion, heat, then add light cream and condensed milk, and refrigerate for 10 minutes; stirring production: mix at low speed for 2 minutes until there is no granular substance, transfer to the milk cover machine to whip until the texture is smooth and dense, and obtain the prepared salted egg yolk milk cover.

[0047] (4) First, add ice cubes to the cup as a base, then add 10ml of vanilla syrup, pour 100ml of milk into the bottom of the cup, slowly inject coffee liquid along the cup wall to form a gradient layer, and finally cover the top with salted egg yolk milk cover.

[0048] (5) Evaluation of the flavor quality of the coffee sample: flavor analysis was performed on different coffee samples to verify the influence of pyrazine synergistic effect on the overall flavor characteristics.

[0049] Example 4 This example mainly investigates the relative content of volatile components of different coffee samples and the content of volatile substances of different coffee samples, which includes the following steps: (1) Select coffee with a light to medium roasting and medium to deep roasting ratio of 3:1, and add 5% of coffee extract microcapsules.

[0050] (2) After the coffee powder is prepared, the coffee beans are pressed and the essence of the coffee beans is extracted at 92°C to release the oil.

[0051] (3) Pre-cooling treatment: milk, light cream needs to be refrigerated for 3-4 hours (low temperature to ensure the stability of whipping); mixed ingredients: 30g of salted egg yolk milk cover powder, 100ml of light cream, 200ml of pure milk, mix the salted egg yolk milk cover powder with milk according to a certain proportion, heat, then add light cream and condensed milk, and refrigerate for 10 minutes; stirring production: mix at low speed for 2 minutes until there is no granular substance, transfer to the milk cover machine to whip until the texture is smooth and dense, and obtain the prepared salted egg yolk milk cover.

[0052] (4) First, add ice cubes to the cup as a base, then add 10ml of vanilla syrup, pour 100ml of milk into the bottom of the cup, slowly inject coffee liquid along the cup wall to form a gradient layer, and finally cover the top with salted egg yolk milk cover.

[0053] (5) GC-MS qualitative analysis was performed on different coffee samples, and the GC-MS analysis program was used to obtain volatile component spectrum data. The GC-MS spectrum information of all samples was analyzed, and the results were obtained. The characteristic aroma component results are shown in Table 4 and Figure 7 Table 5, and the volatile component content is shown in Figure 8 .

[0054] Table 4: Characteristic aroma ingredient results

[0055] The above embodiments are only preferred embodiments of the application, but the design and concept of the application are not limited thereto.

[0056] The product uses microcapsule molecular embedding means to realize the combination of the bioactive substance tetramethylpyrazine and coffee. The coffee product presents bright fruit acid and caramel aroma, gives chocolate tail notes, and enhances the mellow feeling, providing a theoretical basis and technical support for the industrialization of functional salty coffee products.

[0057] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation, characterized in that, Includes the following steps: Step 1: Grinding and blending coffee beans: Grind two different roasting levels of coffee beans and blend them. Step 2, tamping and high-pressure extraction: During the tamping process, pyrazine-flavored coffee extract microcapsules are added to the coffee base, and the tamped coffee powder is subjected to high-pressure extraction to release oils and dissolve flavor substances. Step 3: Preparation of Salted Egg Yolk Milk Foam: The salted egg yolk milk foam is prepared through three processes: pre-cooling, mixing seasonings, and stirring. Step 4: Layering and finishing the salted egg yolk coffee: Add ice cubes, milk, coffee liquid, and salted egg yolk milk foam in sequence to complete the preparation of the salted egg yolk latte and obtain the finished product.

2. The method for preparing salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation according to claim 1, characterized in that, In step one, the base blending step specifically includes: adjusting the ratio of two coffee beans with different roasting levels to directionally regulate the content of pyrazine substances and sensory body, thereby achieving targeted control of pyrazine substance content and sensory flavor.

3. The method for preparing salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation according to claim 1, characterized in that, In step two, the preparation of coffee extract microcapsules specifically includes: preparing coffee-characteristic aroma nanocarrier material capsules using an aqueous molecular encapsulation method. Specifically, under stirring and a water bath, the nanocarrier is first dispersed in 120-210 mL of water, then coffee extract is added. After reacting for 10 min, ultrasonic extraction is performed at 35°C for 0-60 min. The beaker is then placed in a 4°C refrigerator for 24 h, filtered to obtain a precipitate, and the precipitate is dried in a 55°C oven for 4 h to obtain coffee extract microcapsules. Finally, liquid chromatography is performed to measure the content of various pyrazines.

4. The method for preparing salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation according to claim 1, characterized in that, In step two, the extraction pressure and temperature are 20 bar and 92℃~96℃, respectively. The dynamic release of pyrazine flavor compounds is achieved by adjusting the extraction temperature gradient.

5. The method for preparing salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation according to claim 1, characterized in that, Step three, specifically the preparation of salted egg yolk milk foam, includes: a. Pre-cooling: refrigerate milk and light cream for 3-4 hours; b. Mixing ingredients: mix 10-30g of salted egg yolk milk foam powder, 80-100mL of light cream, and 150-200mL of pure milk in proportion, then add light cream and condensed milk, and refrigerate for 10 minutes to set; c. Stirring: mix with a mixer for 2-4 minutes until there are no lumps, transfer to a milk foam maker and whip until a smooth and creamy texture is achieved, thus completing the preparation of salted egg yolk milk foam.

6. The method for preparing salted egg yolk coffee based on pyrazine flavor synergy and dynamic regulation according to claim 1, characterized in that, Step four specifically includes: first, add ice cubes to the cup as a base, then add 10-20mL of vanilla syrup, pour 100-200mL of milk into the bottom of the cup, slowly pour coffee liquid along the cup wall to form a gradient layer, and finally cover the top with salted egg yolk milk foam to complete the preparation of a salted egg yolk latte and obtain the finished product.

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