Production process of tea seed essence

Abstract

The invention belongs to the technical field of biomass extraction. The invention relates to a tea seed extract, in particular to a production process of tea seed extract. The production method comprises the following steps: mixing camellia oleifera seed meal with water, and carrying out ultrasonic impregnation to obtain an impregnation liquid; starch and water are mixed and then gelatinized, and gelatinized starch liquid is obtained; adding gelatinized starch liquid into the impregnation liquid, uniformly mixing, and freezing into a solid mixture; freezing and grinding the solid mixture to obtain a ground material; completely unfreezing the ground material to obtain ground slurry; adding a gelatin solution into the grinding slurry, and uniformly stirring and mixing to obtain mixed slurry; adjusting the pH value of the mixed slurry to obtain acidified mixed slurry; adding the compound enzyme liquid into the acidified mixed slurry, carrying out enzymolysis reaction, then adding amylase liquid, continuously carrying out heat-preservation enzymolysis reaction, carrying out enzyme deactivation and separation, and taking supernate; and purifying and drying the supernate to obtain the tea seed extract.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass extraction, and more specifically, relates to a production process of tea seed essence. Background Art

[0002] Tea saponin, also known as camellia saponin, is a mixture of saponins found in tea seeds and tea leaves. At the same time, tea saponin is also a small molecule substance with excellent performance and a green natural surfactant. The waste product after tea seed oil is squeezed out is tea seed meal.

[0003] There are many common methods for extracting tea saponin from camellia seed meal: Traditional solvent extraction method, such as ethanol extraction method: using ethanol as solvent, tea saponin is extracted by heating reflux or soaking, and the tea saponin yield can reach 17.43%-26.36%.

[0004] Bio-enzyme method: Use bio-enzymes (such as cellulase, protease, lipase, etc.) to decompose impurities in tea seed meal to improve the extraction rate and purity of tea saponin. The enzymatic extraction rate can reach 86.86%, but the reaction time is relatively long.

[0005] The bioenzymatic extraction of tea saponin usually requires the synergistic action of multiple enzymes, such as cellulase, protease and lipase. However, the optimal action conditions of different enzymes (such as temperature, pH value, enzyme dosage, etc.) are different, and precise optimization combination is required to achieve the best extraction effect. In addition, the specificity of the enzyme may lead to poor removal of certain impurities, affecting the purity of tea saponin.

[0006] In addition, although the bio-enzyme method can improve the extraction rate of tea saponin, its extraction efficiency is relatively low and the reaction time is long. For example, the enzymatic hydrolysis time for extracting tea saponin by enzymatic hydrolysis usually takes more than 60 minutes.

[0007] Based on this, the production process of extracting tea saponin from camellia oleifera seed cake by bio-enzymatic method still needs to be optimized. Summary of the invention

[0008] The technical problem to be solved by the present invention is that when tea saponin is extracted from camellia oleifera seed meal using biological enzymes as raw materials, the presence of various impurities in the camellia oleifera seed meal affects the contact between the biological enzymes and the target components during the enzymatic hydrolysis reaction, thereby affecting the extraction of tea saponin. Based on the above problem, the present invention provides a production process for tea seed essence.

[0009] The purpose of the invention is to provide a production process of tea seed essence.

[0010] The above-mentioned purpose of the present invention is achieved through the following technical solutions: A production process of tea seed essence, the specific production steps comprising: Frozen grinding of camellia oleifera meal: After mixing camellia oleifera seed meal and water in a mass ratio of 1:5-10, ultrasonically impregnating for more than 30 minutes to obtain an impregnation liquid; Mix starch and water in a mass ratio of 1:10-12 and gelatinize to obtain a gelatinized starch solution; Adding 10-12% of the mass of the impregnated liquid gelatinized starch solution to the impregnated liquid, mixing evenly, and freezing into a solid mixture; The solid mixture is freeze-ground to obtain a grind; Biological enzyme hydrolysis: After the ground material is completely thawed, a ground slurry is obtained; Adding a gelatin solution with a mass fraction of 3-5% to the grinding slurry, and stirring and mixing evenly to obtain a mixed slurry; wherein the amount of the gelatin solution is 8-10% of the mass of the grinding slurry, and the isoelectric point of the gelatin is 7.0; Adjusting the pH value of the mixed slurry to 4.8-5.5 to obtain an acidified mixed slurry; Add the complex enzyme solution to the acidified mixed slurry, keep the enzymatic hydrolysis reaction at 50-55°C for 30-35 minutes, then add the amylase solution, keep the enzymatic hydrolysis reaction at 30-35 minutes, inactivate the enzyme, and then centrifuge to obtain the supernatant; The complex enzyme solution includes the following raw materials in parts by weight: 30-31 parts of lipase, 28-30 parts of papain, 3-5 parts of trypsin, 32-33 parts of cellulase, 300-320 parts of water; The dosage of the composite enzyme solution is 3-5% of the mass of the acidified mixed slurry; The amylase solution is an α-amylase solution with a mass fraction of 3-5%, and the amount of the amylase solution is 2-4% of the mass of the acidified mixed slurry; The supernatant is purified and dried to obtain tea seed essence.

[0011] Beneficial effects of the above technical solution: The above technical solution first freezes and grinds the tea seed meal before using the bio-enzyme hydrolysis, and in the process of freeze-grinding, a starch paste solution is mixed in. The advantage of doing so is that during the gelatinization process, the hydrogen bonds between starch molecules are broken, so that the starch molecules are gradually dissociated and dispersed into the water. In this process, the particles absorb a large amount of water and swell to form a uniform dispersion. After mixing with the tea seed meal, it can be firmly adsorbed and fixed on the surface of the tea seed meal particles, thereby forming a gelatinized starch film, which can significantly improve the water absorption of the tea saponin particles. Absorption effect, in this way, during the freezing process, a gelatinized starch ice crystal layer can be formed on the surface of the camellia oleifera meal particles. In the subsequent freezing and grinding process, the gelatinized starch ice crystal layer will be broken under the grinding pressure, thereby causing the rapid refinement of the camellia oleifera meal particles. Thanks to the uniform adsorption of the gelatinized starch ice crystal layer, the refinement process is more uniform, and the morphology and particle size of the particles after fragmentation are also more uniform, thereby avoiding the disadvantage that the bioenzymatic hydrolysis process, especially for large particles, takes a long time due to the uneven size of the camellia oleifera meal particles after refinement; It should be noted that if gelatinized starch is missing, it is difficult for the tea seed oil residue on the surface of the camellia meal particles to form a good interface with water. Therefore, the ice crystals formed by freezing water are difficult to assist in the refinement of the camellia meal particles during the freezing and grinding process. More importantly, gelatinized starch can adsorb and evenly disperse the crushed camellia meal particles due to the exposure of active polar functional groups, reducing the sedimentation of the camellia meal particles and, to a certain extent, facilitating the subsequent stable and effective direct contact with the biological enzyme. The inventors further found that the process of bioenzymatic hydrolysis also needs to be considered. This is mainly because the general bioenzymatic hydrolysis process needs to adjust the pH to a certain condition. In the process of adjusting the pH, the biomass components of protein, fat and sugar in the camellia oleifera meal will cause some substances to precipitate due to the broken charge balance. In the process of precipitation, some components such as the bioenzyme will be precipitated together, thereby affecting the hydrolysis efficiency of the bioenzyme. In the above technical solution, adding a certain amount of gelatin with an isoelectric point of 7.0 can solve this technical problem. In the process of adjusting the system pH to the range of the above solution, the amino group in the gelatin molecular structure is protonated and positively charged. Due to the principle of like charges repelling each other, the gelatin molecular chain is stretched, and under the synergistic effect of the gelatinized starch molecular chain, the components can be evenly dispersed. In addition, in the process of bioenzymatic hydrolysis, even if substances such as protein are continuously released from the inside of the camellia oleifera meal particles, once they are captured by the gelatin molecules, they can also assist in their uniform dispersion, avoiding premature precipitation and affecting the hydrolysis reaction. Gelatin and gelatinized starch will also be gradually hydrolyzed by biological enzymes in the later stage of the hydrolysis process, and their hydrolysis products will not have an adverse effect on the final purity of the product.

[0012] Furthermore, the ultrasonic immersion includes: maintaining the temperature at 35-45° C. and ultrasonic frequency at 60-80 kHz for more than 30 minutes.

[0013] Furthermore, the gelatinization includes: mixing starch and water in a mass ratio of 1:10-12, and then stirring and gelatinizing for 45-60 minutes at a temperature of 90-95°C and a stirring speed of 300-400 r / min.

[0014] Further, the cryogenic grinding comprises: In a cryo-grinder, freeze-grind for 40-60 min at a temperature of -20--50°C.

[0015] Further, the purification comprises: Add acetone (10-12% of the mass of the supernatant) to the supernatant, stir and mix evenly, let stand for 4-6 hours, filter and collect the precipitate.

[0016] Furthermore, the freezing and grinding of the camellia oleifera seed meal further comprises: The camellia seed meal is subjected to microwave treatment for 30-45 minutes under a microwave power of 300-400 W to obtain pretreated camellia seed meal; The pretreated camellia oleifera seed meal and water are mixed in a mass ratio of 1:5-10, and ultrasonically immersed for more than 30 minutes to obtain an immersion liquid; Mix starch and water in a mass ratio of 1:10-12 and gelatinize to obtain a gelatinized starch solution; Adding 10-12% of the mass of the impregnated liquid gelatinized starch solution to the impregnated liquid, mixing evenly, and freezing into a solid mixture; The solid mixture is cryogenically ground to obtain a grind.

[0017] By utilizing microwave treatment, the volatile matter in the camellia oleifera seed meal can be volatilized during the treatment process. During the volatilization process, the permeability of the plant cells of the camellia oleifera seed meal can be increased, thereby facilitating the rapid hydrolysis reaction in the subsequent treatment process.

[0018] Furthermore, the moisture content of the camellia oleifera seed meal is 8-10%.

[0019] The moisture content refers to the weight of the raw material before and after drying, which is obtained by continuously drying the raw material in an oven at a temperature of 90°C until constant weight is achieved. DETAILED DESCRIPTION

[0020] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0021] Unless otherwise specified, the reagents and materials used in the following examples are commercially available. Example 1

[0022] Frozen grinding of camellia oleifera meal: The camellia oleifera seed meal with a moisture content of 8% was subjected to microwave treatment for 30 minutes at a microwave power of 300 W to obtain pretreated camellia oleifera seed meal; The pretreated camellia oleifera seed meal and water were mixed in a mass ratio of 1:5, and then ultrasonically immersed for 30 minutes at a temperature of 35°C and an ultrasonic frequency of 60kHz to obtain an immersion liquid; Starch and water were mixed in a mass ratio of 1:10, and the mixture was stirred at 90°C and 300 r / min for 45 minutes to obtain a gelatinized starch solution; Adding gelatinized starch solution of 10% of the mass of the impregnation liquid to the impregnation liquid, stirring and mixing for 3 hours at a stirring speed of 300 r / min, and then freezing to a solid mixture at a temperature of -30°C; The solid mixture was transferred to a freezer grinder, and the mixture was freeze-ground for 40 min at -20°C, and the material was discharged to obtain a grind; Biological enzyme hydrolysis: The ground material is left to stand at room temperature until it is completely thawed to obtain a ground slurry; Adding a gelatin solution with a mass fraction of 3% to the grinding slurry, and stirring and mixing with a stirrer at a speed of 300 r / min for 40 minutes to obtain a mixed slurry; wherein the amount of the gelatin solution is 8% of the mass of the grinding slurry, and the isoelectric point of the gelatin is 7.0; The pH value of the mixed slurry is adjusted to 4.8 to obtain an acidified mixed slurry; Add the complex enzyme solution to the acidified mixed slurry, keep the enzymatic hydrolysis reaction at 80r / min and 50℃ for 30min, then add the amylase solution, keep the enzymatic hydrolysis reaction at 30min, heat to 75℃, keep the enzyme inactivated for 10min, centrifuge and take the supernatant; The complex enzyme solution includes the following raw materials in parts by weight: 30 parts lipase, 28 parts papain, 3 parts trypsin, 32 parts cellulase, 300 parts water; The dosage of the composite enzyme solution is 3% of the mass of the acidified mixed slurry; The amylase solution is an α-amylase solution with a mass fraction of 3%, and the amount of the amylase solution is 2% of the mass of the acidified mixed slurry; Add acetone in an amount of 10% of the mass of the supernatant to the supernatant, stir and mix with a stirrer at a speed of 200 r / min for 10 minutes, let it stand at room temperature for 4 hours, filter, collect the precipitate, and dry it to obtain tea seed essence. Example 2

[0023] Frozen grinding of camellia oleifera meal: The camellia oleifera seed meal with a moisture content of 9% was subjected to microwave treatment for 35 minutes at a microwave power of 360 W to obtain pretreated camellia oleifera seed meal; The pretreated camellia oleifera seed meal and water were mixed in a mass ratio of 1:8, and then ultrasonically immersed for 35 minutes at a temperature of 40°C and an ultrasonic frequency of 70kHz to obtain an immersion liquid; Starch and water were mixed in a mass ratio of 1:11, and the mixture was stirred at 92°C and 350 r / min for 50 min to obtain a gelatinized starch solution. Add 11% gelatinized starch solution by weight of the impregnation liquid to the impregnation liquid, stir and mix for 4 hours at a stirring speed of 350 r / min, and then freeze to form a solid mixture at a temperature of -35°C; The solid mixture was transferred to a freezer grinder, and the mixture was freeze-ground for 50 min at -30°C, and the material was discharged to obtain a grind; Biological enzyme hydrolysis: The ground material is left to stand at room temperature until it is completely thawed to obtain a ground slurry; Adding a gelatin solution with a mass fraction of 4% to the grinding slurry, and stirring and mixing with a stirrer at a speed of 350r / min for 50min to obtain a mixed slurry; wherein the amount of the gelatin solution is 9% of the mass of the grinding slurry, and the isoelectric point of the gelatin is 7.0; The pH value of the mixed slurry was adjusted to 5.2 to obtain an acidified mixed slurry; Add the complex enzyme solution to the acidified mixed slurry, keep the enzymatic hydrolysis reaction at 90r / min and 52℃ for 32min, then add the amylase solution, keep the enzymatic hydrolysis reaction at 32min, heat to 75℃, keep the enzyme inactivation for 10min, centrifuge and take the supernatant; The complex enzyme solution includes the following raw materials in parts by weight: 30 parts lipase, 29 parts papain, 4 parts trypsin, 32 parts cellulase, 310 parts water; The dosage of the composite enzyme solution is 4% of the mass of the acidified mixed slurry; The amylase solution is an α-amylase solution with a mass fraction of 4%, and the amount of the amylase solution is 3% of the mass of the acidified mixed slurry; Add acetone (11% of the mass of the supernatant) to the supernatant, stir with a stirrer at 200 r / min for 10 min, let stand at room temperature for 5 h, filter, collect the precipitate, and dry to obtain tea seed essence. Example 3

[0024] Frozen grinding of camellia oleifera meal: The camellia oleifera seed meal with a moisture content of 10% was subjected to microwave treatment for 45 minutes at a microwave power of 400 W to obtain pretreated camellia oleifera seed meal; The pretreated camellia oleifera seed meal and water were mixed in a mass ratio of 1:10, and then ultrasonically immersed for 50 minutes at a temperature of 45°C and an ultrasonic frequency of 80kHz to obtain an immersion liquid; Starch and water were mixed in a mass ratio of 1:12, and the mixture was stirred at 95°C and 400 r / min for 60 min to obtain a gelatinized starch solution; Adding 12% of the mass of the impregnated liquid with gelatinized starch solution to the impregnated liquid, stirring and mixing for 5 hours at a stirring speed of 400 r / min, and then freezing to a solid mixture at a temperature of -45°C; The solid mixture was transferred to a freezer grinder, and the mixture was freeze-ground for 60 min at -50°C, and the material was discharged to obtain a grind; Biological enzyme hydrolysis: The ground material is left to stand at room temperature until it is completely thawed to obtain a ground slurry; Adding a gelatin solution with a mass fraction of 5% to the grinding slurry, and stirring and mixing with a stirrer at a speed of 400 r / min for 60 minutes to obtain a mixed slurry; wherein the amount of the gelatin solution is 10% of the mass of the grinding slurry, and the isoelectric point of the gelatin is 7.0; The pH value of the mixed slurry is adjusted to 5.5 to obtain an acidified mixed slurry; Add the complex enzyme solution to the acidified mixed slurry, keep the enzymatic hydrolysis reaction at 55°C for 35 minutes under the conditions of stirring speed of 120r / min, and then add the amylase solution, keep the enzymatic hydrolysis reaction at 75°C for 10 minutes, and then centrifuge to take the supernatant; The complex enzyme solution includes the following raw materials in parts by weight: 31 parts lipase, 30 parts papain, 5 parts trypsin, 33 parts cellulase, 320 parts water; The dosage of the composite enzyme solution is 5% of the mass of the acidified mixed slurry; The amylase solution is an α-amylase solution with a mass fraction of 5%, and the amount of the amylase solution is 4% of the mass of the acidified mixed slurry; Add 12% acetone by mass of the supernatant to the supernatant, stir and mix with a stirrer at 200 r / min for 10 min, let stand at room temperature for 6 h, filter, collect the precipitate, and dry to obtain tea seed essence. Example 4

[0025] The present embodiment differs from the embodiment 1 in that no microwave treatment is performed and other conditions remain unchanged.

[0026] Comparative Example 1 The difference between this comparative example and Example 1 is that no gelatinized starch solution is added, and other conditions remain unchanged.

[0027] Comparative Example 2 Compared with Example 1, this comparative example differs in that: frozen grinding is not used, specifically: The camellia oleifera seed meal with a moisture content of 8% was subjected to microwave treatment for 30 minutes at a microwave power of 300 W to obtain pretreated camellia oleifera seed meal; The pretreated camellia oleifera seed meal and water were mixed in a mass ratio of 1:5, and then ultrasonically immersed for 30 minutes at a temperature of 35°C and an ultrasonic frequency of 60kHz to obtain an immersion liquid; Starch and water were mixed in a mass ratio of 1:10, and the mixture was stirred at 90°C and 300 r / min for 45 minutes to obtain a gelatinized starch solution; Add 10% gelatinized starch solution by weight of the impregnation liquid to the impregnation liquid, stir and mix for 3 h at a stirring speed of 300 r / min, grind for 40 min at room temperature in a grinder, and discharge to obtain a grind; The rest of the conditions remain unchanged.

[0028] Comparative Example 3 The difference between this comparative example and Example 1 is that no gelatin solution is added, and the other conditions remain unchanged.

[0029] The performance tests were performed on the products obtained in the above embodiments and comparative examples. The specific test methods and test results are as follows: The purity of tea saponin in the products obtained in each embodiment and comparative example was tested by high performance liquid chromatography. The specific test conditions were: C18 column, methanol-water (volume ratio of 9:1) as the mobile phase, and the detection wavelength of 280 nm. The specific test results are shown in Table 1. ; It can be seen from the test results in Table 1 that the bio-enzyme hydrolysis method adopted in the present invention can obtain a product of relatively high purity, and it was found during the hydrolysis process that no obvious flocculent precipitate appeared in Examples 1-4 during the extraction process, especially in the hydrolysis stage, while the comparative examples all showed a certain degree of sedimentation, which affected the progress of the hydrolysis reaction.

[0030] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A production process of tea seed essence, characterized in that: The specific production steps include: Frozen grinding of camellia oleifera meal: After mixing camellia oleifera seed meal and water in a mass ratio of 1:5-10, ultrasonically impregnating for more than 30 minutes to obtain an impregnation liquid; Mix starch and water in a mass ratio of 1:10-12 and gelatinize to obtain a gelatinized starch solution; Adding 10-12% of the mass of the impregnated liquid gelatinized starch solution to the impregnated liquid, mixing evenly, and freezing into a solid mixture; The solid mixture is freeze-ground to obtain a grind; Biological enzyme hydrolysis: After the ground material is completely thawed, a ground slurry is obtained; Adding a gelatin solution with a mass fraction of 3-5% to the grinding slurry, and stirring and mixing evenly to obtain a mixed slurry; wherein the amount of the gelatin solution is 8-10% of the mass of the grinding slurry, and the isoelectric point of the gelatin is 7.0; Adjusting the pH value of the mixed slurry to 4.8-5.5 to obtain an acidified mixed slurry; Add the complex enzyme solution to the acidified mixed slurry, keep the enzymatic hydrolysis reaction at 50-55°C for 30-35 minutes, then add the amylase solution, keep the enzymatic hydrolysis reaction at 30-35 minutes, inactivate the enzyme, and then centrifuge to obtain the supernatant; The complex enzyme solution includes the following raw materials in parts by weight: 30-31 parts of lipase, 28-30 parts of papain, 3-5 parts of trypsin, 32-33 parts of cellulase, 300-320 parts of water; The dosage of the composite enzyme solution is 3-5% of the mass of the acidified mixed slurry; The amylase solution is an α-amylase solution with a mass fraction of 3-5%, and the amount of the amylase solution is 2-4% of the mass of the acidified mixed slurry; The supernatant is purified and dried to obtain tea seed essence.

2. The production process of tea seed essence according to claim 1, characterized in that: The ultrasonic immersion comprises: continuously immersing the mixture at a temperature of 35-45° C. and an ultrasonic frequency of 60-80 kHz for more than 30 minutes.

3. The production process of tea seed essence according to claim 1, characterized in that: The gelatinization comprises: mixing starch and water in a mass ratio of 1:10-12, and then stirring and gelatinizing for 45-60 minutes at a temperature of 90-95° C. and a stirring speed of 300-400 r / min.

4. The production process of tea seed essence according to claim 1, characterized in that: The cryo-grinding comprises: In a cryo-grinder, freeze-grind for 40-60 min at a temperature of -20--50°C.

5. The production process of tea seed essence according to claim 1, characterized in that: The purification comprises: Add 10-12% acetone to the supernatant, stir and mix evenly, let stand for 4-6 hours, filter and collect the precipitate.

6. The production process of tea seed essence according to claim 1, characterized in that: The freezing and grinding of the camellia oleifera seed meal also includes: The camellia seed meal is subjected to microwave treatment for 30-45 minutes under a microwave power of 300-400 W to obtain pretreated camellia seed meal; The pretreated camellia oleifera seed meal and water are mixed in a mass ratio of 1:5-10, and ultrasonically immersed for more than 30 minutes to obtain an immersion liquid; Mix starch and water in a mass ratio of 1:10-12 and gelatinize to obtain a gelatinized starch solution; Adding 10-12% of the mass of the impregnated liquid gelatinized starch solution to the impregnated liquid, mixing evenly, and freezing into a solid mixture; The solid mixture is cryogenically ground to obtain a grind.

7. The production process of tea seed essence according to claim 6, characterized in that: The moisture content of the camellia oleifera seed meal is 8-10%.