A method for extracting grape flavor

Abstract

The invention discloses a method for extracting grape flavor, which comprises the following steps: raw material preparation: adding raisin slurry and immobilized cellulase into an enzymolyzer and letting them stand to obtain a lower layer liquid; enzymolysis preparation: slowly adding an organic solvent that is insoluble in water and has a density less than that of water into the enzymolyzer to obtain an upper layer liquid; enzymolysis: performing enzymolysis according to the cellulase activity temperature, during which the evaporated gas in the enzymolyzer is condensed and the water phase is removed, and the lower layer liquid is stirred regularly; purification: concentrating the upper layer liquid by reduced pressure evaporation to obtain grape flavor; the carrier of the immobilized cellulase is selected from one or more of chitosan, silicon dioxide, and metal organic framework, the boiling point of the organic solvent is higher than the activity temperature of the cellulase, and the organic solvent is at least used to dissolve the grape essence. The method for extracting grape flavor provided by the invention has the effects of improving enzymolysis efficiency and shortening enzymolysis time.

Description

Technical Field

[0001] The invention belongs to the technical field of spice preparation, and in particular relates to a method for extracting grape spice. Background Art

[0002] Raisin is a raw material that can be used to extract spices. The chemical composition of raisin is relatively stable and is not easily affected by external conditions and undergoes significant changes. This makes the extraction process more controllable and the extracted spice components are relatively consistent, ensuring the stability of product quality.

[0003] Enzyme-assisted extraction technology, as an important method in the grape flavor extraction industry, has been widely used and deeply studied in recent years. This technology mainly relies on the catalytic effect of enzymes on specific substrates, which increases the accessibility of intracellular components by destroying plant cell walls and cell membranes, thereby improving extraction efficiency. For example, cellulase and pectinase can decompose cellulose and pectin in grapes, thereby releasing more aroma components and polyphenols. Enzyme-assisted extraction technology plays an important role in the grape flavor extraction industry with its advantages of high efficiency, mildness and high selectivity.

[0004] As a biocatalyst, the activity of enzymes is affected by many factors, among which reaction time is a key parameter. Long reaction time may lead to reduced enzyme activity and affect extraction efficiency. Summary of the invention

[0005] In view of the deficiencies of the prior art, the object of the present invention is to provide a method for extracting grape flavor.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0007] A method for extracting grape flavors comprises the following steps:

[0008] Raw material preparation: add raisin slurry and immobilized cellulase into the enzymolyzer and let it stand to obtain the lower layer liquid;

[0009] Preparation for enzymatic hydrolysis: slowly add an organic solvent that is insoluble in water and has a density less than that of water into the enzymatic hydrolyzer to obtain a supernatant;

[0010] Enzymolysis: Enzymolysis is performed according to the cellulase activity temperature. During the enzymolysis process, the evaporated gas in the enzymolyzer is condensed and the water phase is removed, and the lower liquid is stirred regularly;

[0011] Purification: Concentrate the upper liquid by vacuum evaporation to obtain grape flavor;

[0012] The carrier of the immobilized cellulase is selected from one or more of chitosan, silicon dioxide, and metal organic framework. The boiling point of the organic solvent is higher than the active temperature of the cellulase. The organic solvent is at least used to dissolve grape essence.

[0013] In the present invention, the lower layer liquid is stirred regularly, which can play the role of mixing grape fibers and immobilized cellulase, and is conducive to the enzymolysis work; at the same time, the regular stirring will not damage the upper layer liquid for a long time, which is conducive to the upper layer liquid to cover and seal the lower layer liquid, thereby reducing the heat exchange rate between the liquid phase and the gas phase in the enzymolyzer, and is conducive to maintaining the temperature of the liquid phase.

[0014] Preferably, the immobilized cellulase is obtained by immobilizing the cellulase on a carrier of immobilized cellulase by adsorption or chemical connection.

[0015] Preferably, the cellulase in the immobilized cellulase is selected from one or more of endocellulase, exocellulase and β-glucosidase.

[0016] Preferably, the cellulase in the immobilized cellulase accounts for 1% to 4% of the mass of the lower layer liquid.

[0017] Preferably, the organic solvent is selected from one or more of ethyl acetate and petroleum ether.

[0018] In the present invention, the organic solvent is specifically selected from ethyl acetate.

[0019] Preferably, the enzymatic hydrolysis temperature is 40-55°C.

[0020] In the present invention, the enzymatic hydrolysis temperature does not exceed 55° C., which is beneficial to reducing the inactivation of cellulase due to high temperature denaturation, improving the efficiency of subsequent enzymatic hydrolysis, and facilitating the recovery and reuse of cellulase.

[0021] In the present invention, the enzymatic hydrolysis temperature is specifically 50°C.

[0022] Preferably, the enzymatic hydrolysis time is 6 to 8 hours.

[0023] Preferably, in the enzymatic hydrolysis step, during enzymatic hydrolysis, the thickness of the upper liquid is 0.1 to 2 cm.

[0024] In the present invention, after the water in the lower layer of liquid evaporates, it can pass through the upper layer of liquid with a thickness of 0.1 to 2 cm; when the thickness of the upper layer of liquid is less than 0.1 cm, the covering and sealing effect with the lower layer of liquid is not good, and the amount of the substance obtained by enzymatic hydrolysis absorbed by the organic solvent is limited; when the thickness of the upper layer of liquid is greater than 2 cm, it is not easy for the water in the lower layer of liquid to pass through the upper layer of liquid after evaporation, resulting in insufficient evaporation of water in the lower layer of liquid.

[0025] In the present invention, during enzymatic hydrolysis, the thickness of the upper liquid is specifically 1 cm.

[0026] Preferably, in the purification step, before the upper layer liquid is concentrated by evaporation under reduced pressure, an organic solvent is added to the upper layer liquid, and the upper layer liquid is allowed to stand for 1 to 2 hours before being evaporated under reduced pressure and concentrated.

[0027] In the present invention, the solution is allowed to stand for 1 hour and then evaporated under reduced pressure for concentration.

[0028] In the present invention, adding an organic solvent is beneficial to more fully separating the grape essence dissolved in water and improving the extraction rate.

[0029] The main raw materials of the present invention are introduced as follows:

[0030] Ethyl acetate: Ethyl acetate has a lower density than water and a boiling point of 77.2° C. It has good solubility and high volatility, which is beneficial to the extraction and purification work in the present invention.

[0031] Petroleum ether: Petroleum ether is insoluble in water, has a lower density than water, has good solubility, and has high volatility, which is beneficial to the extraction and purification work in the present invention. Different types of petroleum ether have various boiling points. It is understood that in the present invention, petroleum ether is selected to have a boiling point of 90 to 120°C.

[0032] Compared with the prior art, the advantages of the present invention include:

[0033] (1) The present invention provides a method for extracting grape flavor, wherein the carrier of the immobilized cellulase is chitosan or a metal organic framework, and both chitosan and the metal organic framework are not easily soluble in water, so that the immobilized cellulase is easy to separate, and the cellulase is easy to be recovered and reused;

[0034] (2) In the method for extracting grape flavor provided by the present invention, chitosan or metal organic framework is not easily soluble in water, so that the immobilized cellulase is mainly mixed with the precipitated grape fiber, which is beneficial to increase the probability of collision and contact between the cellulase and the ordinary fiber, thereby improving the enzymatic hydrolysis efficiency of the cellulase;

[0035] (3) The present invention provides a method for extracting grape flavors. The raisin slurry is in the form of fine particles. During the enzymatic hydrolysis process, the cold and hot water flows naturally swirl during the heating process, which is beneficial to increase the probability of collision and contact between cellulase and ordinary fibers, thereby improving the enzymatic hydrolysis efficiency of cellulase and shortening the enzymatic hydrolysis time.

[0036] (4) The present invention provides a method for extracting grape flavors. The product after enzymatic hydrolysis of grapes is dissolved in an organic solvent. The organic solvent is located in the upper layer, which can reduce the concentration of substances released by enzymatic hydrolysis of grapes in water, and is beneficial to reducing the probability of contact and collision between cellulase and substances other than grape fibers, thereby increasing the probability of contact and collision between cellulase and ordinary fibers, thereby improving the enzymatic hydrolysis efficiency of cellulase and shortening the enzymatic hydrolysis time.

[0037] (5) The present invention provides a method for extracting grape flavor. During the enzymatic hydrolysis process, the evaporated water phase is removed, so that the water content in the lower layer liquid is gradually reduced, so that the concentration of cellulase in the lower layer liquid gradually increases as the enzymatic hydrolysis proceeds, which is beneficial to compensate for the effect of the decrease in enzymatic hydrolysis rate caused by the decrease in the activity of some cellulases in the later stage of enzymatic hydrolysis, thereby helping to improve the enzymatic hydrolysis efficiency and shorten the enzymatic hydrolysis time. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 This is an internal schematic diagram of an enzymolyzer involved in the method for extracting grape flavors of the present invention;

[0040] Figure 2 for Figure 1 A partial enlarged view of .

[0041] Reference numerals:

[0042] 11. Tank body; 12. Feed inlet; 13. Stirring motor; 14. Stirring rod; 15. Stirring paddle; 16. Discharge port; 17. Heating water pipe; 18. Condensation needle; 19. Liquid receiving barrel; 21. Water guide pipe. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to understand the characteristics and effects of the present application, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the common meanings understood by those skilled in the art for the present application. In case of conflict, the definitions in this specification shall prevail.

[0044] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present application in any way, that is, the content of the present application can be implemented without being limited by any specific theory or mechanism.

[0045] As used herein, "this application" means "the present invention" or "the present disclosure".

[0046] The use of "one", "an", "a kind" or similar expressions to describe the components and technical features described in this application is merely for the convenience of expression and to provide a general meaning to the scope of this application. Therefore, such description should be understood to include one or at least one, and the singular also includes the plural, unless it is obvious that it refers to another meaning.

[0047] In this document, "or its combination" means "or any combination thereof", and "any one", "any one" means "any one", "any one" or "any one".

[0048] As used herein, the terms "comprises," "including," "having," "containing," or any other similar terms are open-ended transitional phrases that are intended to cover non-exclusive inclusions. For example, a composition or article containing multiple elements is not limited to the elements listed herein, but may also include other elements that are not explicitly listed but are generally inherent to the composition or article. In addition, unless otherwise expressly stated, the term "or" refers to an inclusive "or" rather than an exclusive "or." For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist). In addition, in this article, the terms "comprising", "including", "having", and "containing" should be interpreted as being specifically disclosed and simultaneously covering closed conjunctions such as "consisting of", "consisting of", and "the remainder is", as well as conjunctions such as "consisting essentially of", "mainly consisting of", "mainly consisting of", "basically containing", "essentially consisting of", "essentially consisting of", and "essentially containing".

[0049] In this article, all features or conditions such as numerical values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be deemed to have covered and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions), especially integer values. For example, the range description of "1.0 to 8.0" or "between 1.0 and 8.0" or "between 1.0 and 8.0" should be deemed to have specifically disclosed all sub-ranges such as 1.0 to 8.0, 1.0 to 7.0, 2.0 to 8.0, 2.0 to 6.0, 3.0 to 6.0, 4.0 to 8.0, 3.0 to 8.0, etc., and should be deemed to cover endpoint values, especially sub-ranges defined by integer values, and should be deemed to have specifically disclosed individual values ​​such as 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, etc. Unless otherwise indicated, the foregoing method of interpretation applies to all contents of the entire application, regardless of whether the scope is broad or not.

[0050] If the quantity, concentration or other numerical value or parameter is expressed as a range, a preferred range (or a better range) or a series of upper and lower limits, it should be understood that all ranges consisting of any pair of the upper limit or preferred value (or a better value) of the range and the lower limit or preferred value (or a better value) of the range have been specifically disclosed herein, regardless of whether these ranges are disclosed separately. In addition, if a numerical range is mentioned herein, unless otherwise specified, the range should include its endpoints and all integers and fractions within the range.

[0051] In this document, numerical values ​​should be understood to have the accuracy of the number of significant digits of the numerical value, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover the range of 39.50 to 40.49.

[0052] In this article, for the use of Markush groups or optional terms to describe the features or examples of the present application, those skilled in the art should understand that all subgroups or any individual elements in the Markush group or option list can also be used to describe the present application. For example, if X is described as "selected from the group consisting of X1, X2 and X3", it also means that the claim that X is X1 and the claim that X is X1 and / or X2 and / or X3 have been fully described. Furthermore, for the use of Markush groups or optional terms to describe the features or examples of the present application, those skilled in the art should understand that any combination of subgroups or individual members of all elements in the Markush group or option list can also be used to describe the present application. Accordingly, for example, if X is described as "selected from the group consisting of X1, X2 and X3", and Y is described as "selected from the group consisting of Y1, Y2 and Y3", it means that the claim that X is X1 and / or X2 and / or X3 and Y is Y1 and / or Y2 and / or Y3 has been fully described.

[0053] Unless otherwise specified, in this application, a compound refers to a chemical substance formed by two or more elements connected by chemical bonds, including small molecule compounds and polymer compounds, but not limited thereto. The interpretation of a compound in this article is not limited to a single chemical substance, but can also be interpreted as the same type of chemical substances with the same composition or the same properties.

[0054] If not otherwise specified, in this application, polymer refers to the product formed by monomer through polymerization reaction, often including many polymer aggregates, each polymer is formed by many simple structural units repeatedly connected by covalent bonds, and monomer is a compound of synthetic polymer. Polymer can include homopolymer, copolymer, prepolymer, etc., and is not limited to this. Homopolymer refers to a polymer polymerized by a monomer. Copolymer includes random copolymer (structure is such as -AABABBBAAABBA-), alternating copolymer (structure is such as -ABABABAB-), graft copolymer (structure is such as -AA(A-BBBB)AA(A-BBBB)AAA-) and block copolymer (structure is such as -AAA AA-BBBBBB-AAAAA-) etc. Prepolymer refers to a polymer with a lower molecular weight between the monomer and the final polymer, and the prepolymer contains reactive functional groups that can further undergo polymerization reaction to obtain a product with a higher molecular weight that is fully cross-linked or hardened. Polymer certainly includes oligomers, and is not limited to this. Oligomers, also known as low polymers, are polymers composed of 2 to 20 repeating units, usually 2 to 5 repeating units.

[0055] Unless otherwise specified, the "resin" in this application is a customary name for a synthetic polymer, which may include monomers, polymers thereof, combinations of monomers, combinations of polymers thereof, or combinations of monomers and polymers thereof, etc., and is not limited thereto.

[0056] If not otherwise specified, in the present application, modified products include products after modification of reactive functional groups of each resin, products after prepolymerization of each resin with other resins, products after crosslinking of each resin with other resins, products after copolymerization of each resin with other resins, and the like.

[0057] If not otherwise specified, the unsaturated bonds described in the present application refer to reactive unsaturated bonds, such as but not limited to unsaturated double bonds that can undergo cross-linking reactions with other functional groups, such as but not limited to unsaturated carbon-carbon double bonds that can undergo cross-linking reactions with other functional groups.

[0058] The unsaturated carbon-carbon double bonds described in the present application preferably include, but are not limited to, vinyl, vinylbenzyl, (meth)acryloyl, allyl or a combination thereof. Vinyl should be interpreted to include vinyl and vinylidene. (Meth)acryloyl should be interpreted to include acryloyl and methacryloyl.

[0059] Unless otherwise specified, the hydrocarbon groups described in this application include, but are not limited to, alkyl, alkenyl or alkynyl, and include their various isomers when interpreted. For example, a C1-C6 divalent hydrocarbon group is interpreted to include a C1-C6 divalent straight-chain hydrocarbon group, a C2-C6 divalent branched hydrocarbon group or a C3-C6 divalent cyclic hydrocarbon group. For another example, a propyl group should be interpreted to include n-propyl and isopropyl.

[0060] Unless otherwise specified, in this application, parts by weight represent relative parts by weight in a composition, which may be any weight unit, such as but not limited to kilograms, kilograms, grams, pounds, etc. For example, 100 parts by weight of polyphenylene ether resin may represent 100 kilograms of polyphenylene ether resin or 100 pounds of polyphenylene ether resin.

[0061] It should be understood that the features disclosed in the various embodiments herein may be arbitrarily combined to form the technical solution of the present application, as long as there is no contradiction in the combination of these features.

[0062] In the following descriptions:

[0063] Chitosan cross-linked SBA-15 mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c): enzyme loading per gram of carrier is 1.120 g;

[0064] Xinjiang green raisins: average sugar content 80.1%;

[0065] β-Glucosidase: content ≥99.9%.

[0066] Enzyme digester:

[0067] See also Figure 1 The enzymolyzer involved in the method for extracting grape flavor in the present invention includes a tank body 11, a feed port 12 and a stirring motor 13 are installed on the top of the tank body 11, a rotating shaft of the stirring motor 13 is connected to a stirring rod 14, the stirring rod 14 extends into the interior of the tank body 11, and a stirring paddle 15 is connected to the end of the stirring rod 14; the stirring paddle 15 can be driven to rotate by the stirring motor 13, so that the material in the tank body 11 can be stirred.

[0068] A discharge port 16 and a heating water pipe 17 are installed at the bottom of the tank body 11 . The heating water pipe 17 is distributed on the outer surface of the tank body 11 . The tank body 11 can be heated by passing hot liquid into the heating water pipe 17 .

[0069] See also Figure 1 and Figure 2 A liquid receiving bucket 19 and a vertical condensation needle 18 are installed inside the tank body 11. The liquid receiving bucket 19 is located below the condensation needle 18 and is used to receive the liquid dripping from the condensation needle 18. A water pipe 21 extending out of the tank body 11 is installed at the bottom of the liquid receiving bucket 19; the condensation needle 18 is cooled by an external cold source, so that the temperature of the condensation needle 18 is lower than the temperature inside the tank body 11 during enzymatic hydrolysis.

[0070] In the present invention, both the organic solvent and water will evaporate, and the evaporated organic solvent and water will liquefy when encountering the condensation needle 18, and finally drip into the liquid receiving bucket 19. During enzymolysis, as the organic solvent and water continue to liquefy, the liquid in the liquid receiving bucket 19 gradually increases, and the density of the organic solvent is smaller than that of water. In the liquid receiving bucket 19, the organic solvent is separated from the water, and the organic solvent floats on the water surface. During the enzymolysis process, the water phase at the lower layer of the liquid receiving bucket 19 can be guided out through the water guide pipe 21, and this process can reduce the amount of water in the tank body 11; when there is more organic solvent in the liquid receiving bucket 19, it is only necessary to wait for the organic solvent and water to continue to liquefy, and the liquefied water sinks, causing the organic solvent to float. As the liquefied water increases, the organic solvent eventually overflows from the mouth of the liquid receiving bucket 19 and falls back into the tank body 11.

[0071] In the above process, water can be discharged through the water pipe 21 and the organic solvent can be left in the tank body 11 .

[0072] Specifically, transparent observation windows may be provided on the tank body 11 and the liquid receiving bucket 19 , and liquid level sensors may also be installed to monitor the heights of the organic solvent and water.

[0073] The present application will be described below with specific implementations and examples. It should be understood that these specific implementations and examples are merely illustrative and are not intended to limit the scope of the present application and its use.

[0074] Unless otherwise stated, the methods, reagents and conditions used in the following preparation examples, comparative examples and examples are conventional methods, reagents and conditions in the art.

[0075] Preparation Example

[0076] Preparation Example 1

[0077] The raw materials used in this preparation example include: 1 kg of raisins.

[0078] The preparation method of this preparation example includes:

[0079] Z1. Soak raisins in 3 kg of deionized water at 15 °C for 12 h.

[0080] Z2. Beat the soaked raisins with a beater for 30 minutes to make a slurry to obtain a raisin slurry.

[0081] Comparative Example

[0082] Comparative Example 1

[0083] The raw materials used in this comparative example include: 500 g of raisin slurry obtained in Preparation Example 1 and 5 g of β-glucosidase.

[0084] The preparation method of this comparative example comprises:

[0085] D1, adding raisin slurry and β-glucosidase into an enzymolyzer and letting it stand to obtain a lower layer liquid;

[0086] D2. Slowly pour ethyl acetate onto the lower liquid. The thickness of ethyl acetate is 1 cm. After standing, the upper liquid is obtained.

[0087] D3, the temperature of the enzymolyzer was set to 50°C, the stirring speed was 1 rotation every 5 minutes, and the enzymolysis time was 6 hours; when the temperature of the lower layer liquid reached 50°C, ethyl acetate was added to the upper layer liquid to make the thickness of ethyl acetate 1 cm; during the enzymolysis process, the external cold source was turned on, and the height of the water phase in the receiving bucket was kept at half the height of the receiving bucket by controlling the switch of the water pipe;

[0088] D4. After the enzymatic hydrolysis is completed, ethyl acetate is added to the enzymatic hydrolyzer to make the thickness of ethyl acetate 5 cm. The temperature is naturally reduced and allowed to stand for 1 hour. The upper liquid is refluxed and extracted for 3 hours and then concentrated under reduced pressure in a rotary evaporator with a vacuum degree of 0.09 MPa and a temperature of 30°C. The reduced pressure concentration is completed when no more liquid flows out of the condenser to obtain grape flavor.

[0089] Comparative Example 2

[0090] The difference between this comparative example and comparative example 1 is that the amount of β-glucosidase used in the raw material of this comparative example is 20 g, and the enzymatic hydrolysis time in step D3 of the preparation method of this comparative example is 8 h.

[0091] Comparative Example 3

[0092] The difference between this comparative example and comparative example 1 is that: in the raw material used in this comparative example, 5g of β-glucosidase is replaced with 9.46g of chitosan cross-linked SBA-15 type mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c); in the preparation method of this comparative example, the enzymatic hydrolysis time in step D3 is 8h, the external cold source is turned off, and the water pipe is closed.

[0093] Comparative Example 4

[0094] The difference between this comparative example and comparative example 3 is that the amount of chitosan cross-linked SBA-15 type mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c) used in the raw materials used in this comparative example is 23.65 g, and the enzymatic hydrolysis time in step D3 of the preparation method of this comparative example is 7 hours.

[0095] Comparative Example 5

[0096] The difference between this comparative example and comparative example 3 is that the amount of chitosan cross-linked SBA-15 type mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c) used in the raw materials used in this comparative example is 47.3 g, and the enzymatic hydrolysis time in step D3 of the preparation method of this comparative example is 6 hours.

[0097] Example

[0098] Example 1

[0099] The raw materials used in this example include: 500 g of raisin slurry obtained in Preparation Example 1, and 9.46 g of chitosan-crosslinked SBA-15 mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c).

[0100] The preparation method of this embodiment includes:

[0101] S1, adding raisin slurry and chitosan cross-linked SBA-15 mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c) into an enzymolyzer and letting it stand to obtain a lower layer liquid;

[0102] S2, slowly pour ethyl acetate onto the lower liquid layer, the thickness of ethyl acetate is 1 cm, and after standing, obtain the upper liquid layer;

[0103] S3, the temperature of the enzymolyzer is set to 50°C, the stirring speed is 1 rotation every 5 minutes, and the enzymolysis time is 6 hours; after the temperature of the lower layer liquid reaches 50°C, ethyl acetate is added to the upper layer liquid to make the thickness of ethyl acetate 1 cm;

[0104] S4. After the enzymolysis is completed, ethyl acetate is added to the enzymolyzer to make the thickness of ethyl acetate 5 cm. The temperature is naturally reduced and allowed to stand for 1 hour. The upper liquid is refluxed and extracted for 3 hours and then concentrated under reduced pressure in a rotary evaporator with a vacuum degree of 0.09 MPa and a temperature of 30°C. The reduced pressure concentration is completed when no more liquid flows out of the condenser to obtain grape flavor.

[0105] Example 2

[0106] The difference between this embodiment and embodiment 1 is that the enzymatic hydrolysis time in step S3 of the preparation method of this embodiment is 7 hours.

[0107] Example 3

[0108] The difference between this embodiment and embodiment 1 is that the enzymatic hydrolysis time in step S3 of the preparation method of this embodiment is 8 hours.

[0109] Example 4

[0110] The difference between this example and Example 1 is that the amount of chitosan cross-linked SBA-15 type mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c) in the raw materials used in this example is 23.65 g.

[0111] Example 5

[0112] The difference between this embodiment and embodiment 4 is that the enzymatic hydrolysis time in step S3 of the preparation method of this embodiment is 7 hours.

[0113] Example 6

[0114] The difference between this embodiment and embodiment 4 is that the enzymatic hydrolysis time in step S3 of the preparation method of this embodiment is 8 hours.

[0115] Example 7

[0116] The difference between this example and Example 1 is that the amount of chitosan cross-linked SBA-15 type mesoporous silica (SBA-15) immobilized β-glucosidase (β-G1c) in the raw materials used in this example is 47.3 g.

[0117] Example 8

[0118] The difference between this embodiment and embodiment 7 is that the enzymatic hydrolysis time in step S3 of the preparation method of this embodiment is 7 hours.

[0119] Example 9

[0120] The difference between this embodiment and embodiment 7 is that the enzymatic hydrolysis time in step S3 of the preparation method of this embodiment is 8 hours.

[0121] Test Results

[0122] Table 1 Experimental data of Examples 1 to 9 and Comparative Examples 1 to 5

[0123]

[0124] According to Table 1 above, by comparing Example 1 with Comparative Example 1, it can be seen that under the same enzyme addition amount and the same enzymatic hydrolysis time, the amount of grape flavor obtained in Example 1 is higher than that in Comparative Example 1. The possible reason is that part of the enzyme in Comparative Example 1 is dissolved in ethyl acetate, and the enzyme content in the lower layer liquid is less than that in Example 1.

[0125] By comparing Example 1 and Comparative Example 3, it can be obviously found that the amount of grape flavor obtained after removing the liquefied water during the enzymatic hydrolysis process in Example 1 is higher than that in Comparative Example 3. This may be because in Example 1, the water content in the lower layer liquid gradually decreases, so that the concentration of cellulase in the lower layer liquid gradually increases with the progress of enzymatic hydrolysis, which is beneficial to compensate for the effect of the decrease in enzymatic hydrolysis rate caused by the decrease in the activity of some cellulases in the later stage of enzymatic hydrolysis, thereby helping to improve the enzymatic hydrolysis efficiency and shorten the enzymatic hydrolysis time.

[0126] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, some simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for extracting grape flavor, characterized in that: The following steps are involved: Raw material preparation: add raisin slurry and immobilized cellulase into the enzymolyzer and let it stand to obtain the lower layer liquid; Preparation for enzymatic hydrolysis: slowly add an organic solvent that is insoluble in water and has a density less than that of water into the enzymatic hydrolyzer to obtain a supernatant; Enzymolysis: Enzymolysis is performed according to the cellulase activity temperature. During the enzymolysis process, the evaporated gas in the enzymolyzer is condensed and the water phase is removed, and the lower liquid is stirred regularly; Purification: Concentrate the upper liquid by vacuum evaporation to obtain grape flavor; The carrier of the immobilized cellulase is selected from one or more of chitosan, silicon dioxide, and metal organic framework; the boiling point of the organic solvent is higher than the active temperature of the cellulase; and the organic solvent is used to dissolve grape essence at least; The enzymolyzer comprises a tank body (11), a liquid receiving bucket (19) and a vertical condensation needle (18) are installed inside the tank body (11), the liquid receiving bucket (19) is located below the condensation needle (18), and a water guide pipe (21) extending out of the tank body (11) is installed at the bottom of the liquid receiving bucket (19); The enzymolysis temperature is 40-55°C; The immobilized cellulase is obtained by immobilizing the cellulase on a carrier of the immobilized cellulase through adsorption or chemical connection.

2. A method for extracting grape flavor according to claim 1, characterized in that: The cellulase in the immobilized cellulase is selected from one or more of endocellulase, exocellulase and β-glucosidase.

3. A method for extracting grape flavor according to claim 1, characterized in that: The cellulase in the immobilized cellulase accounts for 1% to 4% of the mass of the lower layer liquid.

4. The method for extracting grape flavor according to claim 1, characterized in that: The organic solvent is selected from one or more of ethyl acetate and petroleum ether.

5. The method for extracting grape flavor according to claim 1, characterized in that: The enzymolysis time is 6 to 8 hours.

6. The method for extracting grape flavor according to claim 1, characterized in that: In the enzymatic hydrolysis step, during enzymatic hydrolysis, the thickness of the upper layer liquid is 0.1 to 2 cm.

7. The method for extracting grape flavor according to claim 1, characterized in that: In the purification step, before the upper layer liquid is concentrated by evaporation under reduced pressure, an organic solvent is added to the upper layer liquid, and the upper layer liquid is allowed to stand for 1 to 2 hours before being evaporated under reduced pressure and concentrated.

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