A method for preparing diglyceride powder using animal fat as raw material

Abstract

The present invention provides a method for preparing diglyceride powder using animal fat as raw material, and belongs to the field of biotechnology. The method for preparing diglyceride powder using animal fat as raw material comprises the following steps: 1) melting the animal fat in a water bath and then ultrasonically treating it to obtain a treatment liquid; 2) filtering the treatment liquid, adding glycerol and lipase, and then adding amino-modified activated carbon to obtain a crude diglyceride liquid after high-pressure homogenization and enzymolysis; 3) mixing the crude diglyceride liquid with adsorption particles and adsorbing them, and then filtering to obtain diglyceride; 4) mixing the diglyceride with soy protein, maltodextrin, and an emulsifier, and then vacuum freeze-drying and crushing to obtain diglyceride powder. The present invention uses animal fat to prepare diglyceride at a low temperature, and uses adsorption to remove triglycerides during the purification process, which greatly retains the original flavor and has less harmful substances; preparing diglyceride into freeze-dried powder prolongs the shelf life and expands the scope of use.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and in particular relates to a method for preparing diglyceride powder by taking animal fat as raw material. Background Art

[0002] Compared with vegetable oil, animal oil has a special aroma, which helps to increase consumers' appetite and promote the absorption of fat-soluble vitamins. Refined animal oil is white or yellow-white in color, with a uniform and delicate texture and a rich and mellow aroma. Similar to the glyceride composition of vegetable oil, the main component of livestock and poultry animal oil is also TAG, and the fatty acid composition is mainly saturated fatty acids, monounsaturated fatty acids and a small amount of polyunsaturated fatty acids. Because animal oil contains a large amount of SFA, it has a high melting point (20-50°C), is solid at room temperature, and has good stability. Animal oil also contains a large number of flavor components that vegetable oil does not have, such as hydroxyls, alcohols, ethers, aldehydes, ketones, carboxylic acids, amines, furans and other flavor substances. This special aroma can effectively increase appetite. In addition, compared with the refining or processing of vegetable oil, the hydrogenation and refining and deodorization process of animal oil is not easy to produce harmful factors such as trans fats and 3-chloro-1,2-propanediol fatty acid esters.

[0003] Diacylcerol (DAG) is a trace component of natural plant oils and an endogenous intermediate product of fat metabolism in the body. It is an intermediate substance in the intracellular inositol phospholipid signaling pathway and is a recognized safe food ingredient. DAG and TG oils are highly versatile and have safety equivalent to traditional oils. No adverse side effects have been found to the human body, and the intake of DAG does not affect the absorption of fat-soluble vitamins. DAG has many advantages such as safety, nutrition, good processing suitability, and high human compatibility. Its taste and color are no different from ordinary triglycerides. Edible DAG has the effects of reducing visceral fat, inhibiting weight gain, and lowering blood lipids. It has received widespread attention and is also a type of multifunctional additive that has been widely used in food, medicine, chemicals, cosmetics and other industries.

[0004] However, the high heating temperature of diglyceride prepared from animal fats will significantly affect the flavor and taste, and the molecular distillation temperature during the purification process is above 200°C. Glycidyl esters may be produced during the production process, which may be harmful to human health. In addition, the purity of diglyceride is relatively low due to the presence of triglycerides. Diglyceride is usually stored in liquid form, which has problems such as short storage time and inconvenient storage. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a method for preparing diglyceride powder using animal fat as raw material, which can prepare diglyceride at a lower temperature to ensure the flavor, and avoid the destruction of diglyceride by high temperature through adsorption purification method, and can increase the storage time and storage cost by preparing diglyceride into freeze-dried powder.

[0006] The present invention provides a method for preparing diglyceride powder using animal fat as raw material, comprising the following steps:

[0007] 1) melting animal fat in a water bath and then subjecting it to ultrasonic treatment to obtain a treatment solution;

[0008] 2) filtering the treated liquid, adding glycerol and lipase, performing high-pressure homogenization enzymolysis, and then adding amino-modified activated carbon to obtain a crude diglyceride solution;

[0009] 3) mixing the crude diglyceride liquid with the adsorption particles, adsorbing the mixture, and filtering the mixture to obtain diglyceride;

[0010] 4) The diglyceride is mixed with soybean protein, maltodextrin and an emulsifier, and then freeze-dried in vacuum and crushed to obtain diglyceride powder.

[0011] Preferably, the animal fats in step 1) include but are not limited to duck fat, lard, sheep fat, goose fat, and chicken fat.

[0012] Preferably, the power of the ultrasonic treatment in step 1) is 500-600w, and the ultrasonic treatment time is 3-5min. By adopting the above technical solution, the present invention melts the animal fat and preliminarily weakens the ester bond of the fat through ultrasound, thereby improving the subsequent enzymatic hydrolysis efficiency.

[0013] Preferably, in step 2), the mass ratio of the treatment liquid, glycerol, lipase and amino-modified activated carbon is 10-15:1:0.1-0.5:0.1-0.3; the lipase is Novozym 435 or Lipozyme TL IM.

[0014] Preferably, the pressure of the high-pressure homogenization in step 2) is 40-60 MPa, and the time is 10-20 min. By adopting the above technical solution, high-pressure homogenization can help to disperse the lipase more effectively in the reaction system, increase the contact area between the enzyme and the substrate, thereby improving the activity and catalytic efficiency of the enzyme, promoting the interaction between the enzyme and the substrate, and accelerating the process of the lipolysis reaction.

[0015] Preferably, the preparation method of the amino-modified activated carbon in step 2) is: firstly, the activated carbon particles are mixed with a sodium hydroxide solution and then washed, and then the alkalized activated carbon particles are mixed with a urea solution in a mass ratio of 1:1, heated and filtered to obtain the amino-modified activated carbon. By adopting the above technical scheme, the amino-modified activated carbon generally has a higher specific surface area and specific surface functional groups, and the amino-modified activated carbon may combine with glycidyl esters through a chemical adsorption mechanism to remove glycidyl esters in the production process.

[0016] Preferably, the enzymatic hydrolysis temperature in step 2) is 30-50°C.

[0017] Preferably, in step 3), the mass ratio of the crude diglyceride liquid to the adsorption particles is 10:1-3.

[0018] Preferably, the preparation method of the adsorption particles is: triglyceride is mixed with chloroform, methacrylic acid and diethylene glycol diacrylate are added, the mixture is mixed at 60°C for 12 hours, and then eluted with ethanol to obtain adsorption particles; the mass ratio of triglyceride, chloroform, methacrylic acid and diethylene glycol diacrylate is 1:1:6:10. By adopting the above technical scheme, the adsorption particles prepared by the present invention have a highly specific recognition ability for triglyceride through the imprinting method, thereby achieving the adsorption and removal of triglyceride, and after the adsorption is completed, it can be reused after elution, which can reduce the purification cost.

[0019] Preferably, in step 4), the mass ratio of diglyceride, soy protein, maltodextrin and emulsifier is 10:5-10:5-10:1-3. By adopting the above technical scheme, the embedding ratio adopted in the present invention has the characteristics of high embedding rate and stable structure. Soy protein can be used as an embedding material, and it can be combined with hydrophobic bioactive small molecules through its hydrophobic interaction to form microcapsules, thereby protecting these active substances from damage during the freeze-drying process and maintaining their biological activity after rehydration; maltodextrin can form an amphiphilic complex with the hydrophilic active ingredient, and embed it through intermolecular forces to provide a stable encapsulation environment, preventing it from direct contact with the external environment, thereby effectively improving its stability.

[0020] Preferably, the emulsifier is diacetyl tartaric acid mono- and di-glycerol, succinic acid mono-glycerol, and mono- and di-glycerol fatty acid esters.

[0021] Preferably, the particle size of the diglyceride powder in step 4) is 50-150 μm.

[0022] Beneficial technical effects:

[0023] 1) The temperature for preparing diglyceride from animal fats is low, and triglyceride is removed by adsorption during the purification process, thereby greatly retaining the original flavor.

[0024] 2) In the production process of the present invention, harmful substances in diglyceride are further reduced by adsorbing glycidyl ester.

[0025] 3) The present invention prepares diglyceride into freeze-dried powder, thereby extending the shelf life and expanding the scope of use.

[0026] 4) The preparation method of the present invention is simple, does not require the use of high-temperature equipment, reduces carbon emissions, and has a safe production process and low cost. DETAILED DESCRIPTION

[0027] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0028] Preparation of amino-modified active agent: firstly, the activated carbon particles are mixed with sodium hydroxide solution and then washed, and then the alkalinized activated carbon particles are mixed with urea solution in a mass ratio of 1:1, heated and filtered to obtain amino-modified activated carbon.

[0029] Preparation of adsorption particles: triglyceride and chloroform were mixed, methacrylic acid and diethylene glycol diacrylate were added, the mixture was mixed at 60°C for 12 hours, and then eluted with ethanol to obtain adsorption particles; the mass ratio of triglyceride, chloroform, methacrylic acid and diethylene glycol diacrylate was 1:1:6:10.

[0030] Example 1

[0031] This embodiment provides a method for preparing diglyceride powder using animal fat as raw material, comprising the following steps:

[0032] 1) Melt lard in a water bath and then perform ultrasonic treatment at an ultrasonic power of 500 W for 3 min to obtain a treatment solution;

[0033] 2) After filtering the treated liquid, glycerol and lipase Novozym 435 (enzyme activity 5000U / mL) were added, and the mixture was homogenized under high pressure at 40MPa for 10min. After enzymatic hydrolysis at 30°C for 4h, amino-modified activated carbon was added to obtain a crude diglyceride solution; wherein the mass ratio of the treated liquid, glycerol, lipase, and amino-modified activated carbon was 10:1:0.1:0.1;

[0034] 3) mixing the crude diglyceride liquid with the adsorption particles in a mass ratio of 10:1, adsorbing the mixture, and then filtering to obtain diglyceride;

[0035] 4) diglyceride was mixed with soy protein, maltodextrin and diacetyl tartaric acid mono- and diglycerides in a mass ratio of 10:5:5:1, freeze-dried in vacuum and then pulverized to obtain diglyceride powder with a particle size of 50 μm.

[0036] Example 2

[0037] This embodiment provides a method for preparing diglyceride powder using animal fat as raw material, comprising the following steps:

[0038] 1) Melt lard in a water bath and then perform ultrasonic treatment at an ultrasonic power of 600 W for 5 min to obtain a treatment solution;

[0039] 2) After filtering the treated liquid, glycerol and lipase Novozym 435 (enzyme activity 5000U / mL) were added, and the mixture was homogenized under high pressure at 60MPa for 20min. After enzymolysis at 50°C for 6h, amino-modified activated carbon was added to obtain a crude diglyceride solution; wherein the mass ratio of the treated liquid, glycerol, lipase, and amino-modified activated carbon was 15:1:0.5:0.2;

[0040] 3) mixing the crude diglyceride liquid with the adsorption particles in a mass ratio of 10:3, adsorbing the mixture, and filtering to obtain diglyceride;

[0041] 4) diglyceride was mixed with soy protein, maltodextrin and succinic acid monoglyceride in a mass ratio of 10:10:10:3, freeze-dried in vacuum and then pulverized to obtain diglyceride powder with a particle size of 150 μm.

[0042] Example 3

[0043] This embodiment provides a method for preparing diglyceride powder using animal fat as raw material, comprising the following steps:

[0044] 1) Melt lard in a water bath and then perform ultrasonic treatment at an ultrasonic power of 550 W for 4 min to obtain a treatment solution;

[0045] 2) After filtering the treated liquid, glycerol and lipase Novozym 435 (enzyme activity 5000U / mL) were added, and the mixture was homogenized under high pressure at 50MPa for 15min. After enzymatic hydrolysis at 40°C for 5h, amino-modified activated carbon was added to obtain a crude diglyceride solution; wherein the mass ratio of the treated liquid, glycerol, lipase, and amino-modified activated carbon was 12:1:0.3:0.15;

[0046] 3) mixing the crude diglyceride liquid with the adsorption particles in a mass ratio of 10:2, adsorbing the mixture, and then filtering to obtain diglyceride;

[0047] 4) diglyceride was mixed with soy protein, maltodextrin and mono- and diglycerol fatty acid esters in a mass ratio of 10:8:8:2, and the mixture was freeze-dried in vacuum and then pulverized to obtain diglyceride powder with a particle size of 100 μm.

[0048] Example 4

[0049] The method of this example is the same as that of Example 1, except that the enzyme used is Lipozyme TL IM (enzyme activity 5000 U / mL).

[0050] Example 5

[0051] The method of this embodiment is the same as that of embodiment 1, except that duck fat is used.

[0052] Comparative Example 1

[0053] The method of this comparative example is the same as that of Example 3, except that step 1) is not subjected to ultrasonic treatment.

[0054] Comparative Example 2

[0055] The method of this comparative example is the same as that of Example 3, except that step 2) does not undergo high pressure homogenization.

[0056] Comparative Example 3

[0057] The method of this comparative example is the same as that of Example 3, except that amino-modified activated carbon is not used in step 2).

[0058] Comparative Example 4

[0059] The method of this comparative example is the same as that of Example 3, except that no adsorption particles are used in step 3).

[0060] Comparative Example 5

[0061] The method of this comparative example is the same as that of Example 3, except that the diglyceride is not prepared into a freeze-dried powder.

[0062] Comparative Example 6

[0063] The method of this comparative example is the same as that of Example 3, except that in step 3), no adsorption particles are used to purify diglyceride by molecular distillation, and the specific conditions of the distillation are vacuum 0.1-10 Pa, distillation temperature 225° C., rotation speed 200 r / min, and dripping speed 2 drops per second.

[0064] Experimental Example 1

[0065] The liquid diglycerides prepared in Examples 1-4 and Comparative Examples 1-4 were sampled and tested. The test results are shown in Table 1.

[0066] Table 1

[0067]

[0068] As can be seen from Table 1, the diglyceride obtained by the preparation method of the present invention has a high purity and very few harmful substances; in Comparative Example 4, the content of triglyceride is as high as 16.7% without using an adsorbent, which shows that the adsorbent of the present invention can effectively remove triglyceride.

[0069] Experimental Example 2

[0070] The embedding efficiency of the diglyceride powders prepared in Examples 1-3 was measured.

[0071] Embedding rate = (1-surface oil content) / total oil content × 100%;

[0072] Surface oil content determination method: weigh 1g of lyophilized diglyceride sample and place it in a beaker, rinse with an appropriate amount of petroleum ether, stir thoroughly with a constant temperature heating magnetic stirrer, slowly filter the solution, drip the filtrate into a conical flask, rinse the beaker and filter paper with an appropriate amount of petroleum ether several times, place the washing solution in a conical flask, and dry the conical flask to constant mass. Repeat 3 times for each group and take the average value.

[0073] The calculation formula is as follows: surface oil content = (m1-m2) / m3×100%, where: m1 is the mass of the conical flask, g; m2 is the total mass of the surface oil and the conical flask after constant mass, g; m3 is the mass of the diglyceride powder sample, g.

[0074] Total oil content determination method: weigh 1g of lyophilized diglyceride powder sample and place it in a beaker, rinse with an appropriate amount of petroleum ether, stir thoroughly with a constant temperature heating magnetic stirrer, and then use a homogenizer to homogenize the broken solution for 10 minutes, slowly pour the broken solution into the filter paper, drip the filtrate into a conical flask, wash the beaker and filter paper with an appropriate amount of petroleum ether for several times, place the washing solution in a conical flask, and dry the conical flask to constant mass. Repeat 3 times for each group and take the average value.

[0075] The calculation formula is as follows: Total oil content = (m5-m4) / m6×100% (3) Wherein: m4 is the mass of the conical flask, g; m5 is the total mass of the lard and the conical flask after constant mass, g; m6 is the mass of the diglyceride powder sample, g.

[0076] The test results are shown in Table 2.

[0077] Table 2

[0078] Group Embedding rate % Example 1 91 Example 2 89 Example 3 91

[0079] Experimental Example 3

[0080] Storage time test: The diglyceride powders prepared in Examples 1-5 and the diglyceride of Comparative Example 5 were sealed and placed at 30° C. for 30 days to measure the changes in embedding efficiency and physical changes, as shown in Table 3.

[0081] Table 3

[0082]

[0083] Experimental Example 4

[0084] 50 volunteers were selected to conduct sensory evaluation on the diglycerides of Examples 1-3 and Comparative Example 6, see Table 4.

[0085] Table 4 Evaluation report

[0086] Group Rich and mellow aroma Example 1 Distinctive fragrance Example 2 Distinctive fragrance Example 3 Distinctive fragrance Comparative Example 6 Slightly scented

[0087] As shown in Table 4, the preparation method of the present invention can retain the unique aroma of diglyceride without high-temperature distillation.

[0088] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing diglyceride powder using animal fat as raw material, characterized in that: The following steps are involved: 1) melting animal fat in a water bath and then subjecting it to ultrasonic treatment to obtain a treatment solution; 2) filtering the treated liquid, adding glycerol and lipase, performing high-pressure homogenization enzymolysis, and then adding amino-modified activated carbon to obtain a crude diglyceride solution; 3) mixing the crude diglyceride liquid with the adsorption particles, adsorbing the mixture, and filtering the mixture to obtain diglyceride; 4) mixing diglyceride with soy protein, maltodextrin and an emulsifier, freeze-drying the mixture in vacuum, and then grinding the mixture to obtain diglyceride powder; The preparation method of the amino-modified activated carbon in step 2) is as follows: firstly, the activated carbon particles are mixed with a sodium hydroxide solution and then washed, and then the alkalized activated carbon particles are mixed with a urea solution in a mass ratio of 1:1, heated and filtered to obtain the amino-modified activated carbon; The preparation method of the adsorption particles in step 3) is as follows: triglyceride is mixed with chloroform, methacrylic acid and diethylene glycol diacrylate are added, the mixture is mixed at 60° C. for 12 hours, and then eluted with ethanol to obtain the adsorption particles; the mass ratio of the triglyceride, chloroform, methacrylic acid and diethylene glycol diacrylate is 1:1:6:

10.

2. The method according to claim 1, characterized in that: The animal fats in step 1) include but are not limited to duck fat, lard, sheep fat, goose fat, and chicken fat.

3. The method according to claim 1, characterized in that The power of the ultrasonic treatment in step 1) is 500-600w, and the ultrasonic time is 3-5min.

4. The method according to claim 1, characterized in that: In the step 2), the mass ratio of the treatment liquid, glycerol, lipase, and amino-modified activated carbon is 10-15:1:0.1-0.5:0.1-0.3; the lipase is Novozym 435 or LipozymeTL IM.

5. The method according to claim 1, characterized in that: In the step 2), the pressure of the high pressure homogenization is 40-60 MPa and the time is 10-20 min.

6. The method according to claim 1, characterized in that In the step 3), the mass ratio of the diglyceride crude liquid to the adsorption particles is 10:1-3.

7. The method according to claim 1, characterized in that In the step 4), the mass ratio of diglyceride, soy protein, maltodextrin and emulsifier is 10:5-10:5-10:1-3.

8. The method according to claim 1, characterized in that The particle size of the diglyceride powder in step 4) is 50-150 μm.

Images