Method for prolonging shelf life of cooked cereal flour by adding lipase system
By adding mixed enzyme systems to the cereal cooked powder and using roller drying process, the problem of unsatisfactory extension of the shelf life of the cereal cooked powder in the prior art was solved, and a significant extension of the shelf life and improvement of product quality were achieved.
Patent Information
- Application Number
- CN202411762868.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-02-28
AI Technical Summary
The prior art has not been ideal for extending the shelf life of cereal cooked flour, and common methods such as steam enzyme depletion and the addition of antioxidants have problems such as time-consuming, energy-consuming and harsh sanitary conditions.
By adding mixed enzyme systems, including lipase, phospholipase and esterase, the enzyme treatment is performed, and combined with the roller drying process, cereal cooked powder with extended shelf life is prepared.
The shelf life of cereal cooked flour has been extended from 4 months to 12 months, reducing the generation of halo odor and improving the taste and nutritional value of the product.
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Figure CN119522975A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of enzyme treatment, and in particular to a method for extending the shelf life of cooked cereal flour by adding a lipase system. Background Art
[0002] Cereals, especially whole grain flour, usually develop a rancid smell during the shelf life. The reason is that the fat in the cereals and their processed products is degraded. Under the action of catalytic factors such as metal ions and light, the enzyme system carried by the cereals themselves is activated and enzymatic and non-enzymatic reactions occur, which promotes fat degradation to hydrolysis and oxidation reactions, or a combination of the two reactions, such as fat hydrolysis reactions to produce free fatty acids (FFA), which serve as substrates for subsequent oxidation reactions. The results of fat hydrolysis reactions (hydrolysis odor) and reactions with oxygen (oxidation odor) both produce rancid odors. As a result, cereal foods are very easy to oxidize and become rancid during processing and storage, resulting in the generation of unpleasant odors and bitterness, poor taste, and reduced nutritional value. Therefore, most people believe that inhibiting the activity of lipase in cereals is the key to preventing and delaying the rancidity of cereal foods.
[0003] At present, the methods widely used in the food industry are steam enzyme inactivation or high temperature enzyme inactivation or exogenous addition of antioxidants. The first method is that after using superheated steam or microwaves, the enzyme cannot be completely inactivated, and there are still residual enzymes that continue to react, because the nature of lipase has a "lid theory" phenomenon ("lid theory": most lipases also have a movable structure-"lid". This "lid" will cover the active catalytic site in the "ring" when the lipase is not activated. After the lipase molecule is activated, this "lid" will open, allowing the substrate of the enzyme to bind to the "substrate binding position" of the enzyme molecule). The "lid" not only puts the enzyme system itself in a semi-dormant state, but also protects the enzyme from being destroyed, thereby making the enzyme inactivation effect poor; the second method is that the fat content contained in the background of grains is relatively low, and adding too little antioxidants will not achieve the antioxidant effect. Although adding too much has a certain effect, it is easy to cause the addition amount to exceed the provisions of GB 2760. In summary, these methods are not only time-consuming and energy-consuming, but also have poor working and sanitary conditions. Therefore, it is urgent to develop a new method that can extend the shelf life of cooked grain flour. Summary of the invention
[0004] The present invention aims to provide a method for extending the shelf life of cooked cereal flour by adding lipase, so as to solve the problem that the shelf life extension effect of cooked cereal flour in the prior art is not ideal.
[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for extending the shelf life of cooked cereal powder by adding a lipase system, wherein the cereal system after crushing and pulping is treated with an enzyme mixture, and then dried and floured; the mixed enzyme is lipase 1, lipase 2, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase mixed in a mass ratio of 3-7: 0.1-3: 0.1-3: 0.1-1: 0.1-1: 0.1-1, and the added amount of the mixed enzyme is 0.1-0.3% of the mass of the cereal system.
[0006] Preferably, as an improvement, the mixed enzyme is a mixture of lipase 1, lipoxygenase, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase in a mass ratio of 4.5:1:0.85:1:1:1.
[0007] Preferably, as an improvement, the drying method is roller drying.
[0008] Preferably, as an improved condition for roller drying, the steam pressure is 0.2-0.5 MPa, the temperature is 140-180° C., the drum speed is 28-32 rpm, and the feed frequency is 10-50 Hz.
[0009] Preferably, as an improvement, in the pulverizing step, the grain size after pulverization is 60 to 100 meshes.
[0010] Preferably, as an improvement, the pulping process uses hot water at 65-75° C. to adjust the pulp according to a solid-liquid ratio of 1:0 to 1.8, and then grinds it with a colloid mill.
[0011] Preferably, as an improvement, a homogenization treatment is performed before the drying step, and mono- and di-glycerides of fatty acids are added to the system before homogenization, and the amount of mono- and di-glycerides added is 0.05-3%.
[0012] Preferably, as an improvement, the homogenization treatment conditions are a homogenization temperature of 45 to 75° C. and a homogenization time of 45 to 90 min.
[0013] The principle and advantage of this solution are: in actual application, the application of lipase in food is already relatively common at home and abroad, but most of them are used in the field of flavor improvement, such as: improving the flavor of oils and fats and improving and maintaining the elasticity of baked goods, improving the yield rate, and improving the dough. In this technical solution, during the research and development of cereal flour technology, the original intention of the inventor was to use enzymatic hydrolysis technology to improve the flavor and sensory quality of cereal flour products, but during the research and development stage, when investigating the indicators of the shelf life of cereal flour with lipase added, it was unexpectedly found that the shelf life of the enzyme-treated group was significantly extended. By conducting a reverse principle analysis of the above reasons, it was found that the addition of lipase system can accelerate the lipid substances in the grains through various reactions such as enzymatic hydrolysis to form volatilized substances. When the material is heated by roller drying and ripening process, it may undergo ester-oxygen reaction to form relatively smaller molecular substances with rancid smell, which evaporate with water vapor and escape from the cooked grain powder, or form more stable components with other substances such as protein, thereby reducing the fat content in the grains that is easily oxidized, fundamentally reducing the generation of rancid odor in the cooked grain powder during storage, thereby achieving the purpose of extending the shelf life.
[0014] During the technical research and development period, the optimization of the mixed enzyme system and the guarantee of the powder making effect are the difficulties of this technical solution. In this technical solution, the enzyme system meets the enzyme system requirements in GB2760. Lipase 1 is derived from Rhizopus chinensis, lipase 2 is derived from Aspergillus niger, phospholipase A1 is derived from Aspergillus oryzae, phospholipase C is derived from Bacillus licheniformis, phosphoinositide phospholipase C is derived from Bacillus licheniformis, and esterase is derived from Trichoderma reesei. In the process of exploring the best combination of complex enzyme systems, the inventors have tried different enzyme systems and different enzyme addition methods. The results showed that after adding a single enzyme system, some unpleasant odors may be easily produced due to the complexity of lipid substances in the grains. In order to ensure the effect of flour making, the inventors found that the early crushing particle size, pulping conditions and drying methods have a key influence on the flour making effect. The crushing particle size has a key influence on the release of grain enzyme activity, and too high pulping temperature will cause the grain flour to gelatinize and the viscosity of the system to increase, affecting the difficulty of later drying and the yield of flour making. The drying method directly affects the formation of cooked flour of grains with different flavor substances, and the crushing particle size, pulping conditions, and drying methods and conditions influence and restrict each other. Through repeated research and verification, a solution was finally obtained that not only ensures the product flavor and shelf life but also takes into account the flour making effect and the yield of grain flour.
[0015] In summary, the beneficial effects of the present technical solution are as follows: the present technical solution treats the grain flour with a mixed enzyme and combines it with a roller drying process, so that the obtained cooked grain flour not only has the wheat flavor of grains, but also optimizes the process parameters of the roller drying process to make the treated grain flour easy to prepare and have a delicate taste without being rough. Moreover, the shelf life of the cooked grain flour stored at room temperature is extended from 4 months to 12 months on the premise that the packaging is intact, which fully meets the requirements of food processing and is of great significance in the industry. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a comparison chart of fatty acid values of highland barley flour treated in different ways during storage in an embodiment of the present invention.
[0017] Figure 2 This is a comparison chart of the peroxide value of highland barley flour treated in different ways during storage in the embodiments of the present invention.
[0018] Figure 3 This is a comparison chart of the malondialdehyde content of highland barley flour treated in different ways during storage in the embodiments of the present invention.
[0019] Figure 4 This is the fat composition map of Example 1 of the present invention.
[0020] Figure 5 This is the fat composition map of Example 2 of the present invention.
[0021] Figure 6 This is the fat composition map of Example 3 of the present invention.
[0022] Figure 7 This is the fat composition spectrum of Comparative Example 1 of the present invention.
[0023] Figure 8 This is the fat composition profile of Comparative Example 2 of the present invention.
[0024] Fig. 9 This is the fat composition spectrum of Comparative Example 3 of the present invention. DETAILED DESCRIPTION
[0025] The following is further described in detail through specific implementations, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following implementations are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents, etc. used can all be obtained from commercial channels.
[0026] Program Overview:
[0027] A method for extending the shelf life of cooked cereal flour by adding lipase, comprising the following steps:
[0028] Step 1: Whole grain grinding and flour making: The particle size of the flour making is 60-100 mesh, which fully releases the enzyme activity of the grain kernels;
[0029] Step 2, pulping: slurrying is performed with hot water at 65-75°C according to a solid-liquid ratio of 1:1-1.8, and then grinding with a colloid mill to obtain system I;
[0030] Step 3, enzyme treatment: adding enzymes to system I for enzyme treatment, wherein the added enzymes are lipase 1, lipase 2, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase mixed in a mass ratio of 3-7: 0.1-3: 0.1-3: 0.1-1: 0.1-1: 0.1-1, and the amount of the mixed enzyme added is 0.1-0.3% of the mass of system I, and stirring is performed during the addition of the enzymes;
[0031] Among them, the enzyme systems all meet the requirements of enzyme systems in GB2760, lipase 1 is derived from Rhizopus chinensis, lipase 2 is derived from Aspergillus niger, phospholipase A1 is derived from Aspergillus oryzae, and phospholipase C is derived from Bacillus licheniformis;
[0032] Step 4: Homogenization: The homogenization time is 45 to 90 minutes, during which the temperature of the enzymatic hydrolysis tank is controlled at 50°C;
[0033] Step 5, drying: the drying method is roller drying, and the conditions are: steam pressure 0.5MPA, roller speed 30rpm, feeding frequency 28Hz;
[0034] Step 6: Flour making and packaging.
[0035] Example 1
[0036] A method for extending the shelf life of cooked cereal flour by adding lipase, comprising the following steps:
[0037] Step 1: crushing highland barley grains into powder: the particle size of the powder is 100 mesh, which can fully release the enzyme activity of the grain kernels;
[0038] Step 2, pulping: slurrying with hot water at 75°C according to a solid-liquid ratio of 1:1.5, and then grinding with a colloid mill to obtain system I;
[0039] Step 3, enzyme treatment: adding enzymes to system I for enzyme treatment, wherein the added enzymes are prepared by mixing lipase 1, lipoxygenase, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase in a mass ratio of 4.5:1:0.85:1:1:1, and the amount of the mixed enzyme added is 0.1% of the mass of system I, and stirring is performed during the addition of the enzymes;
[0040] Step 4: Homogenization: The homogenization time is 45 minutes, during which the temperature of the enzymatic hydrolysis tank is controlled at 50°C;
[0041] Step 5, drying: the drying method is roller drying, and the conditions are: steam pressure 0.5MPA, roller speed 30rpm, feeding frequency 28Hz;
[0042] Step 6: Flour making and packaging.
[0043] Example 2
[0044] A method for extending the shelf life of cooked cereal flour by adding lipase, comprising the following steps:
[0045] Step 1: crushing and milling highland barley: the particle size of the milled highland barley is 60 meshes, which fully releases the enzyme activity of the grains;
[0046] Step 2, pulping: slurrying is performed with hot water at 60°C according to a solid-liquid ratio of 1:1, and then grinding with a colloid mill to obtain system I;
[0047] Step 3, enzyme treatment: adding enzymes to system I for enzyme treatment, wherein the added enzymes are prepared by mixing lipase 1, lipoxygenase, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase in a mass ratio of 3:0.1:0.1:0.1:0.1:0.1, and the amount of the mixed enzyme added is 0.3% of the mass of system I, and stirring is performed during the addition of the enzymes;
[0048] Step 4: Homogenization: The homogenization time is 90 minutes, during which the temperature of the enzymatic hydrolysis tank is controlled at 50°C;
[0049] Step 5, drying: the drying method is roller drying; the roller drying conditions are: steam pressure 0.5MPA, roller speed 30, feeding frequency 28;
[0050] Step 6: Flour making and packaging.
[0051] Example 3
[0052] The difference between this embodiment and embodiment 1 is that: in this embodiment, in step 2, hot water is used for slurry adjustment according to a solid-liquid ratio of 1:1.8; the mixed enzyme in step 3 is lipase 1, lipoxygenase, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase mixed in a mass ratio of 7:3:3:1:1:1.
[0053] Comparative Example 1
[0054] The difference between this comparative example and Example 1 is that in this comparative example, the mixed enzyme in step 3 is a mixture of lipase 1 and phospholipase A1 in a mass ratio of 4.5:1.
[0055] Comparative Example 2
[0056] The difference between this comparative example and Example 1 is that in this comparative example, the mixed enzyme in step three is lipase 1, lipase 2, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase mixed in a mass ratio of 1:1:1:1:1:1:1.
[0057] Comparative Example 3
[0058] The difference between this comparative example and Example 1 is that in this comparative example, the enzyme in step 3 is a lipase from Mucor circinelloides (also known as Mucor javanica).
[0059] Experimental Example 1 Detection of fat content in highland barley cereals
[0060] Detection method: The fat content in the highland barley cereals of the above embodiments and comparative examples was detected according to GB5009.168. The test results are shown in Table 1 and Figure 4-9 The results show that the total fatty acids will decrease, and the various fatty acids will decrease to varying degrees. "ND" in Table 1 means not detected.
[0061] Table 1
[0062]
[0063]
[0064] Experimental Example 2: Detection of fatty acid values during storage
[0065] The fat content in highland barley grains was tested using the GB / T 5510-2024 Grain and Oil Inspection Grains and Products Fatty Acid Value Determination. The test conditions were: placed in a constant temperature and humidity chamber at 27°C and 75RH%, and stability was observed under accelerated conditions. The test results are shown in Table 2 and Figure 1 As shown: The results show that the fatty acid value of the cooked highland barley powder obtained by the methods of Examples 1-2 of the present invention is significantly lower than that of raw highland barley powder and cooked powder dried by conventional rollers.
[0066] Table 2
[0067] Storage time (month) Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 0 39.37 37.29 39.78 45.28 33.83 40.38 3 57.46 60.48 60.48 83.27 42.33 53.56 6 89.31 90.38 90.49 126.49 59.68 67.89 9 98.58 100.67 108.72 143.84 72.21 67.77 11 108.58 110.56 129.65 163.03 79.99 76.93 13 121.67 119.88 133.09 170.05 81.28 78.59 15 139.63 156.39 153.68 165.87 89.65 90.12
[0068] Experimental Example 3: Peroxide value detection during storage
[0069] The fat content in highland barley grains was tested using the GB / T 5510-2024 Grain and Oil Inspection Grains and Products Peroxide Value Determination. The test conditions were: placed in a constant temperature and humidity chamber at 27°C and 75RH%, and stability was observed under accelerated conditions. The test results are shown in Table 3 and Figure 2 As shown: The results show that the oxidation value of the cooked highland barley powder obtained by the method of Examples 1-2 of the present invention is significantly lower than that of raw highland barley powder and cooked powder dried by conventional rollers after storage for 9 days.
[0070] Table 3
[0071] Storage time (month) Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 0 2.73 2.88 1.79 1.94 1.98 2.45 3 3.83 4.43 4.26 3.79 3.73 3.48 6 6.44 6.28 8.12 7.59 7.97 5.58 9 8.34 9.14 10.34 11.22 7.88 6.51 11 7.25 7.21 9.75 10.27 7.92 4.44 13 6.37 6.07 7.44 8.39 6.39 3.86 15 4.27 5.15 5.28 6.32 3.94 3.54
[0072] Experimental Example 4: Detection of malondialdehyde content during storage
[0073] The fat content in highland barley grains was tested using the GB / T 5510-2024 Grain and Oil Inspection Grains and Products Malondialdehyde Content (mg / kg) test conditions: placed in a constant temperature and humidity chamber at 27°C and 75RH%, and stability was observed under accelerated conditions. The test results are shown in Table 4 and Figure 3 As shown: The results show that the malondialdehyde content of the cooked highland barley powder obtained by the methods of Examples 1-2 of the present invention is significantly lower than that of raw highland barley powder and cooked powder dried by conventional rollers during the entire storage period.
[0074] Table 4
[0075] Storage time (month) Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 0 0.38 0.32 0.48 0.53 0.32 0.27 3 0.58 0.61 0.81 0.89 0.67 0.34 6 0.87 0.75 1.14 0.95 1.03 0.42 9 0.99 1.01 1.27 1.31 1.01 0.58 11 1.23 1.11 1.32 1.39 0.95 0.60 13 1.37 1.32 1.43 1.55 1.07 0.75 15 1.40 1.58 1.54 1.74 1.12 0.81
[0076] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.
Claims
1. A method for extending the shelf life of cooked cereal flour by adding lipase, characterized in that: The crushed and pulped cereal system is treated with enzymes using a mixed enzyme, and then dried and powdered; the mixed enzyme is prepared by mixing lipase 1, lipase 2, phospholipase A1, phospholipase C, phosphoinositide phospholipase C, and esterase in a mass ratio of 3-7: 0.1-3: 0.1-3: 0.1-1: 0.1-1: 0.1-1, and the added amount of the mixed enzyme is 0.1-0.3% of the mass of the cereal system.
2. The method for extending the shelf life of cooked cereal flour by adding lipase according to claim 1, characterized in that: The mixed enzyme is prepared by mixing lipase 1, lipoxygenase, phospholipase A1, phospholipase C, phosphoinositide phospholipase C and esterase in a mass ratio of 4.5:1:0.85:1:1:
1.
3. The method for extending the shelf life of cooked cereal flour by adding lipase according to claim 2, characterized in that: The drying method is roller drying.
4. The method of claim 3 for extending the shelf life of cooked cereal flour by adding lipase, characterized in that: The conditions for the roller drying are as follows: steam pressure of 0.2-0.5 MPa, temperature of 140-180° C., roller speed of 28-32 rpm, and feeding frequency of 10-50 Hz.
5. The method for extending the shelf life of cooked cereal flour by adding lipase according to claim 4, characterized in that: In the pulverizing step, the grain size after pulverization is 60 to 100 meshes.
6. The method of claim 5 for extending the shelf life of cooked cereal flour by adding lipase, characterized in that: The pulping process uses hot water at 65-75° C. to adjust the pulp according to a solid-liquid ratio of 1:0-1.8, and then grinds it with a colloid mill.
7. The method of claim 6 for extending the shelf life of cooked cereal flour by adding lipase, characterized in that: The drying step is preceded by a homogenization treatment, wherein mono- and di-glycerol fatty acid esters are added into the system before the homogenization, and the addition amount of mono- and di-glycerol fatty acid esters is 0.05-3%.
8. The method of claim 7 for extending the shelf life of cooked cereal flour by adding lipase, characterized in that: The homogenization treatment conditions are as follows: a homogenization temperature of 45 to 75° C. and a homogenization time of 45 to 90 min.