Compound enzyme preparation for preservation and preparation method thereof

Abstract

The invention relates to the technical field of food preservation, in particular to a compound enzyme preparation for preservation and a preparation method thereof, and the compound enzyme preparation is prepared from the following raw materials in parts by mass: 5-10 parts of compound enzyme particles, 4-8 parts of an enzyme composition, 2-5 parts of sodium carboxymethyl cellulose, 3-5 parts of vitamin E, 6-7 parts of a coalescing agent and 5-10 parts of glycerol. The compound enzyme particles are prepared from chitosan, an enzyme composition and glycerol, and can be dissolved and form a film after meeting water; the enzyme composition is obtained by mixing maltogenic amylase, lysozyme, glucose oxidase, alpha-amylase, xylanase, lipase and protease; the coalescing agent is prepared from starch and alpha-amylase, the starch is subjected to freezing ball milling, then enzyme treatment is performed, and then freezing ball milling is performed, so that the obtained coalescing agent has relatively high water absorption and water retention; therefore, the prepared compound enzyme preparation for preservation has higher preservation stability and a wider application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of food preservation, and in particular to a composite enzyme preparation for preservation and a preparation method thereof. Background Art

[0002] Food preservatives are indispensable additives in the process of food processing, storage and transportation. They are required to be non-toxic, have little residue and be highly effective. Foodborne diseases caused by pathogenic microorganisms of food corruption are an important aspect of food safety issues. In the transportation of vegetables, fruits, fish, etc., in order to maintain their freshness and prevent food corruption and deterioration, methods such as drying, refrigeration, freezing, and sealed vacuum storage are generally used. However, each method has its limitations. For example, vacuum preservation and low-temperature preservation will cause problems such as water loss, poor taste, and high energy consumption. Although the addition of chemical preservatives such as sodium benzoate and potassium sorbate can inhibit the growth and reproduction of microorganisms to achieve the preservation effect, their long-term consumption may have potential hazards to human health, such as causing allergic reactions and affecting the balance of intestinal flora.

[0003] As a new type of biological preservation technology, compound enzyme preparations can effectively delay the food spoilage process and improve the preservation effect through the synergistic effect between different enzymes. For example, the patent technology document CN112616889A discloses a compound enzyme preparation for bread preservation, which includes the following components by mass percentage: 25%-35% maltogenic amylase, 15%-25% lysozyme, 8%-12% glucose oxidase, 8%-12% xylanase, 4%-6% lipase, 2%-8% stabilizer, and 12%-28% carrier. The invention extends the shelf life of bread through the synergistic effect of various enzymes, and realizes the preservation, mildew prevention and quality improvement of bread without affecting the original bread processing process, effectively avoiding the problem of bread being thrown away and wasted due to bread mold, deterioration, drying and hardening.

[0004] The patent document CN113367172A discloses a bread improver of a compound emulsifying enzyme preparation, which includes the following raw materials: compound enzyme preparation, compound emulsifier, yeast activator, antioxidant, vitamin, curing agent, water retention agent and flour gluten enhancer; the invention can significantly adjust the dough performance, increase the volume of bread, significantly increase the stiffness of bread, and improve the softness of bread by using the compound enzyme preparation in the improvement of flour quality; through the synergistic effect of various enzymes in the compound enzyme preparation, the aging of fermented baked flour products can be effectively delayed, and the shelf life of processed toast bread can be extended; lipase can hydrolyze fat into unsaturated fatty acids and monoglycerides, wherein unsaturated fatty acids are essential fatty acids for the human body and improve the nutritional value of bread. However, these existing compound enzyme preparations rely more on empirical ratios in formula design, and still have problems such as poor fresh-keeping stability and uneven fresh-keeping effect.

[0005] Therefore, according to the above-mentioned related technologies, it is urgent to develop a compound enzyme preparation for preservation and a preparation method thereof. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a compound enzyme preparation for preservation and a preparation method thereof, so as to solve the problem that the compound enzyme preparation for food preservation prepared in the prior art has poor preservation stability.

[0007] Based on the above purpose, the present invention provides a composite enzyme preparation for preservation and a preparation method thereof.

[0008] A composite enzyme preparation for preservation, comprising the following raw materials in parts by weight: 5-10 parts of composite enzyme microparticles, 4-8 parts of enzyme composition, 2-5 parts of sodium carboxymethyl cellulose, 3-5 parts of vitamin E, 6-7 parts of film-forming aid, and 5-10 parts of glycerol;

[0009] The composite enzyme particles are prepared from chitosan, enzyme composition and glycerol;

[0010] The enzyme composition is obtained by mixing maltogenic amylase, lysozyme, glucose oxidase, α-amylase, xylanase, lipase and protease;

[0011] The film-forming aid is prepared from starch and alpha-amylase.

[0012] Preferably, the mass ratio of the maltogenic amylase, lysozyme, glucose oxidase, α-amylase, xylanase, lipase and protease is 0.1-0.3:1.5-2:0.2-0.4:0.1-0.3:0.3-0.5:0.3-0.5:0.5-1.

[0013] Preferably, the preparation method of the composite enzyme microparticles is as follows:

[0014] Step A1. Add carboxymethyl chitosan to distilled water, stir at 35-40°C for 1-1.5h, then add the enzyme composition and glycerol, stir well and then ultrasonically defoam to obtain an enzyme dispersion;

[0015] Step A2. Pour the enzyme dispersion onto a film-forming plate, and then dry it in a vacuum drying oven at 28-30°C. Take the solidified film, crush it, and sieve it to obtain composite enzyme particles.

[0016] Preferably, the mass ratio of distilled water, carboxymethyl chitosan, enzyme composition and glycerol in step A1 is 100-120:2-3:0.5-2:1-2.

[0017] Preferably, the amount of the enzyme dispersion in step A2 is 50-60 g.

[0018] Preferably, the aperture of the sieve during sieving in step A2 is 500-700 mesh.

[0019] Preferably, the preparation method of the film-forming aid is as follows:

[0020] Step B1. Dry-milling the starch at 500-600 r / min for 30-40 min at -15--10°C, then adding α-amylase at 25-30°C and mixing evenly, reacting for 25-30 hours to obtain pre-modified starch;

[0021] Step B2. dry-mill the pre-modified starch at 500-600 r / min for 20-30 min at -15--10°C to obtain a film-forming aid.

[0022] Preferably, the starch in step B1 is any one of mung bean starch, corn starch, potato starch and wheat starch.

[0023] Preferably, the mass ratio of starch to α-amylase in step B1 is 6-7:0.2-0.5.

[0024] A method for preparing a composite enzyme preparation for preservation comprises the following steps:

[0025] The composite enzyme particles, enzyme composition, sodium carboxymethyl cellulose, vitamin E and film-forming aid are added into glycerol and stirred evenly to obtain a composite enzyme preparation.

[0026] Beneficial effects of the present invention:

[0027] The invention provides a composite enzyme preparation for preservation and a preparation method thereof. The invention prepares composite enzyme microparticles which can be stably stored, dissolve in water and form a film by treating an enzyme composition, and prepares a film-forming aid with good water absorption and water retention by treating starch. At the same time, the composite enzyme preparation prepared by the invention further adds an enzyme composition which can quickly take effect, sodium carboxymethyl cellulose which can interact with dissolved composite starch microparticles to improve the film-forming rate, vitamin E which improves antioxidant capacity and glycerol which maintains the stability of the composite enzyme preparation. Therefore, compared with the prior art, the composite enzyme preparation for preservation prepared by the invention has higher freshness-preserving stability and wider application prospects. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0029] The sources and properties of some of the raw materials used in the present invention are as follows:

[0030] Maltogenic amylase was purchased from Jiangxi Huayuyuan Biotechnology Co., Ltd., CAS: 9001-64-3, activity is 5000-20000U / g, lysozyme was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 12650-88-3, activity is 20000-50000U / g, glucose oxidase was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 9001-37-0, activity is 5000-20000U / g, α -Amylase was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 9000-90-2, activity is 5000-10000U / g, xylanase was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 9012-54-8, activity is 5000-10000U / g, lipase was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 9001-62-1, activity is 1000-20000U / g, protease was purchased The activity was 5000-10000U / g from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 9068-59-1, carboxymethyl chitosan was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 83512-85-0, glycerol was purchased from Nanjing Zunde Technology Co., Ltd., CACS: 56-81-5, mung bean starch was purchased from Zhengzhou Jiuting Chemical Products Co., Ltd., CAS: 74-79-3, corn starch was purchased from Wuhan Xingzhongcheng Technology Co., Ltd., CAS: 2567-51-3, potato starch was purchased from Hebei Yaxin Biotechnology Co., Ltd., CAS: 9005-25-8, wheat starch was purchased from Wuhan Xingzhongcheng Technology Co., Ltd., CAS: 68412-29-3, sodium carboxymethyl cellulose was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 9002-32-4, and vitamin E was purchased from Hebei Qiansheng Biotechnology Co., Ltd., CAS: 59-02-9.

[0031] Example 1: A method for preparing a composite enzyme preparation for preservation is as follows:

[0032] S1. 0.1 g of maltogenic amylase, 1.5 g of lysozyme, 0.2 g of glucose oxidase, 0.1 g of α-amylase, 0.3 g of xylanase, 0.3 g of lipase and 0.5 g of protease were mixed to obtain an enzyme composition;

[0033] S2. 2g of carboxymethyl chitosan was added to 100g of distilled water, stirred at 35°C for 1h, then 0.5g of the enzyme composition and 1g of glycerol were added, stirred and then ultrasonically defoamed to obtain an enzyme dispersion;

[0034] S3. Pour 50 g of the enzyme dispersion onto the film-forming plate, and then dry it in a vacuum oven at 28 ° C. Take the solidified film and crush it, sieve it through a sieve with a pore size of 500 mesh to obtain composite enzyme particles;

[0035] S4. At -15°C, 6 g of mung bean starch was dry-milled at 500 r / min for 30 min, and then 0.2 g of α-amylase was added at 25°C and mixed evenly. After reacting for 25 h, pre-modified starch was obtained;

[0036] S5. dry-milling the pre-modified starch at 500 r / min for 20 min at -15°C to obtain a film-forming aid;

[0037] S6. 5g of composite enzyme particles, 4g of enzyme composition, 2g of sodium carboxymethyl cellulose, 3g of vitamin E and 6g of film-forming aid were added to 5g of glycerol and stirred to obtain a composite enzyme preparation;

[0038] Example 2: A method for preparing a composite enzyme preparation for preservation is as follows:

[0039] S1. 0.2 g of maltogenic amylase, 1.7 g of lysozyme, 0.3 g of glucose oxidase, 0.2 g of α-amylase, 0.4 g of xylanase, 0.4 g of lipase and 0.7 g of protease were mixed to obtain an enzyme composition;

[0040] S2. Add 2.3g of carboxymethyl chitosan to 105g of distilled water, stir at 37°C for 1.2h, then add 1g of the enzyme composition and 1.3g of glycerol, stir well and then ultrasonically defoam to obtain an enzyme dispersion;

[0041] S3. Pour 53 g of the enzyme dispersion onto the film-forming plate, and then dry it in a vacuum oven at 29 ° C. Take the solidified film and crush it, sieve it through a 600-mesh sieve to obtain composite enzyme particles;

[0042] S4. At -12°C, 6.3 g of corn starch was dry-milled at 530 r / min for 33 min, and then 0.3 g of α-amylase was added at 27°C and mixed evenly. After reacting for 27 h, pre-modified starch was obtained;

[0043] S5. dry-milling the pre-modified starch at 530 r / min for 23 min at -12°C to obtain a film-forming aid;

[0044] S6. 7g of composite enzyme particles, 5g of enzyme composition, 3g of sodium carboxymethyl cellulose, 3.4g of vitamin E and 6.3g of film-forming aid were added to 7g of glycerol and stirred to obtain a composite enzyme preparation;

[0045] Example 3: A method for preparing a composite enzyme preparation for preservation is as follows:

[0046] S1. 0.2 g of maltogenic amylase, 1.9 g of lysozyme, 0.3 g of glucose oxidase, 0.2 g of α-amylase, 0.4 g of xylanase, 0.4 g of lipase and 0.9 g of protease were mixed to obtain an enzyme composition;

[0047] S2. Add 2.7 g of carboxymethyl chitosan to 110 g of distilled water, stir at 39 ° C for 1.4 h, then add 1.5 g of the enzyme composition and 1.7 g of glycerol, stir and then ultrasonic defoam to obtain an enzyme dispersion;

[0048] S3. Pour 57 g of the enzyme dispersion onto the film-forming plate, and then dry it in a vacuum oven at 29 ° C. Take the solidified film and crush it, sieve it through a 6700 mesh sieve to obtain composite enzyme particles;

[0049] S4. At -11 ° C, 6.7 g of potato starch was dry-milled at 570 r / min for 37 min, and then 0.4 g of α-amylase was added at 29 ° C and mixed evenly. After reacting for 29 h, a pre-modified starch was obtained;

[0050] S5. dry-milling the pre-modified starch at 570 r / min for 27 min at -11°C to obtain a film-forming aid;

[0051] S6. 9 g of the composite enzyme particles, 7 g of the enzyme composition, 4 g of sodium carboxymethyl cellulose, 4 g of vitamin E and 6.7 g of a film-forming aid were added to 9 g of glycerol and stirred to obtain a composite enzyme preparation;

[0052] Example 4: A method for preparing a composite enzyme preparation for preservation is as follows:

[0053] S1. 0.3 g of maltogenic amylase, 2 g of lysozyme, 0.4 g of glucose oxidase, 0.3 g of α-amylase, 0.5 g of xylanase, 0.5 g of lipase and 1 g of protease were mixed to obtain an enzyme composition;

[0054] S2. 3g of carboxymethyl chitosan was added to 120g of distilled water, stirred at 40°C for 1.5h, then 2g of the enzyme composition and 2g of glycerol were added, stirred and then ultrasonically defoamed to obtain an enzyme dispersion;

[0055] S3. Pour 60 g of the enzyme dispersion onto the film-forming plate, and then dry it in a vacuum oven at 30 ° C. Take the solidified film and crush it, sieve it through a sieve with a pore size of 700 mesh to obtain composite enzyme particles;

[0056] S4. At -10°C, 7 g of wheat starch was dry-milled at 600 r / min for 40 min, and then 0.5 g of α-amylase was added at 30°C and mixed evenly. After reacting for 30 h, a pre-modified starch was obtained;

[0057] S5. dry-milling the pre-modified starch at 600 r / min for 30 min at -10°C to obtain a film-forming aid;

[0058] S6. Add 10 g of composite enzyme microparticles, 8 g of enzyme composition, 5 g of sodium carboxymethyl cellulose, 5 g of vitamin E and 7 g of film-forming aid to 10 g of glycerol, stir evenly to obtain a composite enzyme preparation.

[0059] Comparative Example 1:

[0060] Compared with Example 1, this comparative example only replaces the "complex enzyme particles" added in the preparation process of the compound enzyme preparation with "enzyme composition", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a compound enzyme preparation is obtained.

[0061] Comparative Example 2:

[0062] Compared with Example 1, this comparative example only replaces the "film-forming aid" added in the preparation process of the compound enzyme preparation with "mung bean starch", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a compound enzyme preparation is obtained.

[0063] Comparative Example 3:

[0064] Compared with Example 1, this comparative example only replaces the "film-forming aid" added in the preparation process of the compound enzyme preparation with "pre-modified starch", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a compound enzyme preparation is obtained.

[0065] Comparative Example 4:

[0066] Compared with Example 1, this comparative example did not add a film-forming aid during the preparation of the compound enzyme preparation, and the remaining steps and parameters were the same, which will not be repeated in this comparative example. Finally, a compound enzyme preparation was obtained.

[0067] Comparative Example 5:

[0068] Compared with Example 1, vitamin E was not added during the preparation of the compound enzyme preparation in this comparative example, and the remaining steps and parameters were the same, which will not be repeated in this comparative example, and finally a compound enzyme preparation was obtained.

[0069] Comparative Example 6:

[0070] Compared with Example 1, sodium carboxymethyl cellulose was not added during the preparation of the compound enzyme preparation in this comparative example, and the remaining steps and parameters were the same, which will not be repeated in this comparative example, and finally a compound enzyme preparation was obtained.

[0071] Performance Testing:

[0072] Take 5 g of the composite enzyme preparation prepared in Example 1 to Example 4 and Comparative Example to Comparative Example 6, add it to 5 g of water, stir evenly, and obtain a preservative;

[0073] Determination of chronic toxicity:

[0074] According to the determination standard of GB / T15193.17-2003 "Chronic Toxicity and Carcinogenicity Test", 100 healthy weaned mice of almost the same age and weight were selected, half of which were female and half were male, and the female mice were non-pregnant, as a test group. A test group can be divided into 4 groups, the first group is the high-dose group; the second group is the low-dose group; the third group is the normal-dose group; and the fourth group is the control group. The first group was fed with 100g of bread sprayed with 10g of the preservative prepared by Example 1-Example 4 and Comparative Example 1-Example 6; the second group was fed with 100g of bread sprayed with 0.1g of the preservative prepared by Example 1-Example 4 and Comparative Example 1-Example 6; the third group was fed with 100g of feed sprayed with 1g of the preservative prepared by Example 1-Example 4 and Comparative Example 1-Example 6; the fourth group was fed with 100g of bread sprayed with 0g of the preservative prepared by Example 1-Example 4 and Comparative Example 1-Example 6. Except for the different amounts of preservative used, all other factors were the same. After 18 months of feeding, the organs and tissues of all mice were examined under a biological microscope. Those that died during the experiment were also examined. The mice were weighed and recorded every week for the first three months of feeding, and once a month after three months. Blood tests were performed in the third and sixth months of the experiment and every six months thereafter. The data were recorded and analyzed based on the data to see if the mice in each group had symptoms of poisoning, carcinogenesis, and anorexia.

[0075] Determination of freshness stability:

[0076] Take four groups of bread, 20 breads in each group, of which the pH of the first group of bread is 7, the pH of the second group of bread is 7, the pH of the third group of bread is 5, and the pH of the fourth group of bread is 9. After spraying 100g of each bread with 1g of preservative, take 10g of bread sample under sterile environment and add it to 90mL of normal saline. Place it in a homogenizer and process it at a speed of 10000r / min for 1min to make a 1:10 dilution. Take 1mL of the 1:10 dilution and slowly inject it into 9mL of normal saline along the wall of the tube, put it on a micro mixer, mix it for 30s, mix it evenly, and make a 1:100 dilution. Pipette 1mL of the dilution into a sterile plate, and then immediately inject the culture medium cooled to 46℃±1℃ into the plate, and carefully rotate the plate to mix the sample and the culture medium thoroughly. Make two plates for each dilution. After the agar solidifies, invert the plates and culture the first, third and fourth groups in a constant temperature incubator at 25°C for 72h±3h before taking them out; culture the second group in a constant temperature incubator at 5°C for 72h±3h before taking them out. Calculate the total number of bacteria in the plate, and multiply the total number of bacteria by the dilution factor to get the total number of bacteria per gram of sample. After calculating the total number of bacteria on each plate, find the average value of the colonies on the two plates with the same dilution, and then randomly select 3 breads from each group of 20 breads for testing and take the average value as the colony count (CFU). This method was used to measure the bread sprayed with freshness-preserving spray prepared using Examples 1 to 4 and Comparative Examples 1 to 6; the measurement results are shown in Table 1;

[0077] Table 1

[0078]

[0079] Data Analysis:

[0080] As can be seen from Table 1, the composite enzyme preparation prepared by the present invention is not only healthy and non-toxic, but also has better resistance to low temperature and acid and alkali, and can exert relatively good preservation ability in various environments;

[0081] This may be because the present invention processes the enzyme composition to prepare composite enzyme microparticles that can be stably stored and dissolve and form a film when in contact with water, and processes the starch to prepare a film-forming aid with good water absorption and water retention; at the same time, the composite enzyme preparation prepared by the present invention also adds an enzyme composition that can quickly take effect, sodium carboxymethyl cellulose that can interact with the dissolved composite starch microparticles to improve the film-forming rate, vitamin E that improves the antioxidant capacity, and glycerol that maintains the stability of the composite enzyme preparation; therefore, after the composite enzyme preparation prepared by the present invention is sprayed on the surface of bread, the enzyme composition therein can quickly play a role in preserving, and after spraying for a period of time, the composite enzyme microparticles, glycerol, sodium carboxymethyl cellulose, vitamin E, film-forming aid and glycerol therein will interact with each other, which will not affect the quality of the bread and can also relatively quickly produce a fresh-keeping film layer with high fresh-keeping stability, thereby inhibiting the respiratory metabolism and water loss of the bread, thereby extending the shelf life of the bread.

[0082] As for Comparative Example 1, since the "compound enzyme microparticles" added in the preparation process of the compound enzyme preparation are replaced by "enzyme composition", it can be seen from Table 1 that its preservation ability, low temperature resistance, and acid and alkali resistance are relatively poor compared with those of Example 1. This may be because after the compound enzyme preparation prepared by the present invention is sprayed on the surface of bread for a period of time, the compound enzyme microparticles therein will interact with other ingredients, which will not affect the quality of the bread and can also relatively quickly produce a fresh-keeping film layer with high fresh-keeping stability, thereby inhibiting the respiratory metabolism and water loss of the bread, thereby extending the shelf life of the bread.

[0083] In Comparative Example 2, since the "film-forming aid" added in the preparation process of the compound enzyme preparation is replaced with "mung bean starch", it can be seen from Table 1 that its preservation ability, low temperature resistance, and acid and alkali resistance are relatively poor compared with Example 1. This may be because the film-forming aid prepared by the present invention will interact with other ingredients after being sprayed on the surface of bread for a period of time, which will not affect the quality of the bread and can also relatively quickly produce a fresh-keeping film layer with high preservation stability, thereby inhibiting the respiratory metabolism and water loss of the bread, thereby extending the shelf life of the bread. The film-forming aid prepared by layer-by-layer treatment of starch has better water retention and water absorption capacity than starch, which can accelerate the film formation speed, and its absorption of water can also reduce the influence of small pH fluctuations on the preservation ability of the compound enzyme preparation.

[0084] In Comparative Example 3, since the "film-forming aid" added in the preparation process of the compound enzyme preparation is replaced by "pre-modified starch", it can be seen from Table 1 that its preservation ability, low temperature resistance, and acid and alkali resistance are relatively poor compared with Example 1. This may be because the film-forming aid prepared by the present invention will interact with other ingredients after being sprayed on the surface of bread for a period of time, which will not affect the quality of the bread and can also relatively quickly produce a fresh-keeping film layer with high preservation stability, thereby inhibiting the respiratory metabolism and water loss of the bread, thereby extending the shelf life of the bread. The film-forming aid prepared by layer-by-layer treatment of starch has better water retention and water absorption capacity than those within the pre-modification point range. While it can accelerate the film formation speed, its absorption of water can also reduce the influence of small pH fluctuations on the preservation ability of the compound enzyme preparation.

[0085] Since no film-forming aid was added during the preparation of the compound enzyme preparation in Comparative Example 4, it can be seen from Table 1 that its fresh-keeping ability, low-temperature resistance, and acid and alkali resistance are relatively poor compared with Example 1. This may be because the film-forming aid in the compound enzyme preparation prepared by the present invention will interact with other ingredients after being sprayed on the surface of bread for a period of time, which will not affect the quality of the bread and can also relatively quickly produce a fresh-keeping film layer with high fresh-keeping stability, thereby inhibiting the respiratory metabolism and water loss of the bread, thereby extending the shelf life of the bread.

[0086] Since vitamin E was not added during the preparation of the compound enzyme preparation in Comparative Example 5, it can be seen from Table 1 that its preservation ability, low temperature resistance, and acid and alkali resistance are relatively poor compared with Example 1. This may be because the vitamin E in the compound enzyme preparation prepared by the present invention will interact with other ingredients after being sprayed on the surface of bread for a period of time, which will not affect the quality of the bread and can also relatively quickly produce a fresh-keeping film layer with high preservation stability, thereby inhibiting the respiratory metabolism and water loss of the bread, and thus extending the shelf life of the bread; and the antioxidant ability of vitamin E can ensure the stability of the film layer, so that the compound enzyme preparation can exert a better preservation ability under various environments.

[0087] Since sodium carboxymethyl cellulose was not added during the preparation of the compound enzyme preparation in Comparative Example 6, it can be seen from Table 1 that its fresh-keeping ability, low-temperature resistance, and acid and alkali resistance are relatively poor compared with Example 1. This may be because the sodium carboxymethyl cellulose in the compound enzyme preparation prepared by the present invention will interact with other ingredients after being sprayed on the surface of bread for a period of time, which will not affect the quality of the bread and can also relatively quickly produce a fresh-keeping film layer with high fresh-keeping stability, thereby inhibiting the respiratory metabolism and water loss of the bread, thereby extending the shelf life of the bread.

[0088] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0089] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite enzyme preparation for preservation, characterized in that: The method comprises the following raw materials in parts by weight: 5-10 parts of composite enzyme microparticles, 4-8 parts of enzyme composition, 2-5 parts of sodium carboxymethyl cellulose, 3-5 parts of vitamin E, 6-7 parts of film-forming aid, and 5-10 parts of glycerol; The composite enzyme particles are prepared from chitosan, enzyme composition and glycerol; The enzyme composition is obtained by mixing maltogenic amylase, lysozyme, glucose oxidase, α-amylase, xylanase, lipase and protease; The film-forming aid is prepared from starch and alpha-amylase.

2. The composite enzyme preparation for preservation according to claim 1, characterized in that: The mass ratio of the maltogenic amylase, lysozyme, glucose oxidase, α-amylase, xylanase, lipase and protease is 0.1-0.3:1.5-2:0.2-0.4:0.1-0.3:0.3-0.5:0.3-0.5:0.5-1.

3. The composite enzyme preparation for preservation according to claim 1, characterized in that: The preparation method of the composite enzyme microparticles is as follows: Step A1. Add carboxymethyl chitosan to distilled water, stir at 35-40°C for 1-1.5h, then add the enzyme composition and glycerol, stir well and then ultrasonically defoam to obtain an enzyme dispersion; Step A2. Pour the enzyme dispersion onto a film-forming plate, and then dry it in a vacuum drying oven at 28-30°C. Take the solidified film, crush it, and sieve it to obtain composite enzyme particles.

4. The composite enzyme preparation for preservation according to claim 3, characterized in that: The mass ratio of distilled water, carboxymethyl chitosan, enzyme composition and glycerol in step A1 is 100-120:2-3:0.5-2:1-2.

5. The composite enzyme preparation for preservation according to claim 3, characterized in that: The amount of the enzyme dispersion used in step A2 is 50-60 g.

6. The composite enzyme preparation for preservation according to claim 3, characterized in that: The aperture of the sieve during sieving in step A2 is 500-700 mesh.

7. The composite enzyme preparation for preservation according to claim 1, characterized in that: The preparation method of the film-forming aid is as follows: Step B1. Dry-milling the starch at 500-600 r / min for 30-40 min at -15--10°C, then adding α-amylase at 25-30°C and mixing evenly, reacting for 25-30 hours to obtain pre-modified starch; Step B2. dry-mill the pre-modified starch at 500-600 r / min for 20-30 min at -15--10°C to obtain a film-forming aid.

8. The composite enzyme preparation for preservation according to claim 7, characterized in that: The starch in step B1 is any one of mung bean starch, corn starch, potato starch and wheat starch.

9. The composite enzyme preparation for preservation according to claim 7, characterized in that: The mass ratio of starch to α-amylase in step B1 is 6-7:0.2-0.

5.

10. A method for preparing a composite enzyme preparation for preservation according to any one of claims 1 to 9, characterized in that: The following steps are involved: The composite enzyme particles, enzyme composition, sodium carboxymethyl cellulose, vitamin E and film-forming aid are added into glycerol and stirred evenly to obtain a composite enzyme preparation.

Images