阅读说明：本技术 一种提高酶促反应过程中脂肪酶使用效率的方法 (Method for improving lipase use efficiency in enzymatic reaction process ) 是由 王小三 黄卓能 陈烨 江聪 黄雅祺 王笑寒 于 2021-08-18 设计创作，主要内容包括：本发明公开了一种提高酶促反应过程中脂肪酶使用效率的方法,属于食品加工技术领域。本发明利用蒸馏法或吸附法来降低酶法合成结构脂所需原料的过氧化值后,再和脂肪酶发生催化反应合成结构脂,由此维持脂肪酶活性,增加酶的重复利用率,其中,蒸馏法包括脱臭、分子蒸馏中的一种或两种。本发明提供了一种高效率、低成本酶法合成结构脂方法,避免了传统工业化生产中酶法合成结构脂过程酶消耗大、酶成本昂贵且酶利用效率低等弊端,具有一定发展潜力和实际意义。(The invention discloses a method for improving the use efficiency of lipase in an enzymatic reaction process, and belongs to the technical field of food processing. The invention utilizes a distillation method or an adsorption method to reduce the peroxide value of raw materials required by enzymatic synthesis of structural lipid, and then the raw materials and lipase are subjected to catalytic reaction to synthesize the structural lipid, thereby maintaining the activity of the lipase and increasing the recycling rate of the enzyme, wherein the distillation method comprises one or two of deodorization and molecular distillation. The invention provides a method for synthesizing structural lipid by an enzyme method with high efficiency and low cost, which avoids the defects of large enzyme consumption, high enzyme cost, low enzyme utilization efficiency and the like in the process of synthesizing structural lipid by the enzyme method in the traditional industrial production and has certain development potential and practical significance.)

1. A method for improving the use efficiency of lipase in an enzymatic reaction process, which is characterized by comprising the following steps: and (2) carrying out peroxide value reduction treatment on a substrate used for synthesizing the structural lipid, and then carrying out catalytic reaction on the substrate and lipase to synthesize the structural lipid, wherein the peroxide value reduction method comprises one or two of a distillation method and an adsorption method, and the distillation method comprises one or two of deodorization and molecular distillation.

2. The method according to claim 1, characterized in that the deodorization temperature is 220-270 ℃ and the deodorization time is 30-150 min.

3. The method according to claim 2, characterized in that the deodorization temperature is 240-270 ℃.

4. The method according to any one of claims 1 to 3, wherein the evaporation surface temperature of the molecular distillation is 200 to 290 ℃.

5. The method according to any one of claims 1 to 4, wherein the adsorbent used in the adsorption method comprises one or more of silica gel, activated clay, activated carbon, silica, zeolite, diatomite and attapulgite, and is preferably silica gel, silica or activated carbon.

6. The method of claim 5, wherein the adsorbent is added in an amount of 0.5% to 6% by mass of the substrate.

7. The method according to claim 6, wherein the adsorption process has an adsorption time of 60min or less, preferably 30min or less.

8. The method according to any one of claims 1 to 7, wherein the lipase comprises any one of lipases for catalyzing a hydrolysis reaction, a transesterification reaction or an esterification reaction.

9. The method according to any one of claims 1 to 8, wherein the structural lipids comprise one or more of human milk substitute lipids, diglycerides, cocoa butter substitutes, medium-long-chain fatty acid structural lipids, and triglycerides containing polyunsaturated fatty acids.

10. Use of the preparation method according to any one of claims 1 to 9 in the fields of preparation of structured fats and foods.

Technical Field

The invention belongs to the technical field of food processing, and particularly relates to a method for improving the use efficiency of lipase in an enzymatic reaction process.

Background

Fat is an essential nutrient for the human body and is widely present in numerous food products. The most abundant component in fat is triglycerides (Triacylglycerols), which are esterified with glycerol and various fatty acids. In recent years, researchers have conducted many studies on medium-chain fatty acid triglycerides and long-chain fatty acid triglycerides, and structural lipids have emerged in order to integrate their respective advantages. Structural lipids currently studied to be hotter include human milk substitute lipids, cocoa butter substitutes, medium-long chain fatty acid structural lipids, triglycerides containing polyunsaturated fatty acids, and the like. The human milk substitutes for lipids such as OPO, OPL and the like, and is added into the infant formula milk powder, so that the composition of human milk fat can be effectively simulated, the lipid absorption of infants is facilitated, the mineral content balance in the infants is better maintained, and constipation is reduced. The cocoa butter substitute is also a structural lipid with a large demand, and can relieve the resource shortage of the cocoa butter raw material. And the medium-long carbon chain fatty acid structural lipid simultaneously integrates the advantages of faster metabolism and energy supply of medium-chain fatty acid triglyceride and high nutrition of long-chain fatty acid triglyceride, and has great benefit to human body. The triglyceride containing polyunsaturated fatty acid can effectively provide essential fatty acid for human body, and has effect of reducing blood lipid.

The method which is most widely used for synthesizing the structural lipid in the industrial production at present is an enzymatic synthesis method, compared with the traditional inorganic or organic catalytic synthesis method, the lipase catalytic structural lipid synthesis has the advantages of mild condition, high catalytic efficiency, less by-products and high selectivity, however, the lipase has the problem of high price, and some immobilized lipases such as Novozym 435, Lipozyme TL IM and Lipozyme RM IM are frequently applied to the processing and production of human milk fat substitutes, however, the enzymes are generally expensive, and people are always looking for methods for recycling lipase to improve the utilization rate of the enzymes and reduce the cost, such as treatment by an electric field method, an organic solvent and a mixed oil soaking method, however, these methods are disadvantageous for continuous production, and the treatment is performed once every time the enzyme is used, which is cumbersome to operate, environmentally unfriendly, and inefficient.

Disclosure of Invention

[ problem ] to provide a method for producing a semiconductor device

The lipase used in the existing synthesis of structural lipid has high cost and low repeated utilization rate.

[ technical solution ] A

In order to solve the problems, the invention utilizes the advantages of reducing the peroxide value of raw materials required for synthesizing the structural lipid, better retaining the activity of the lipase, increasing the recycling times of the enzyme, providing a structural lipase method synthesis method with high efficiency and low cost for industrial production, and having certain practical significance.

Specifically, the invention provides the following technical scheme: a method for improving the use efficiency of lipase in an enzymatic reaction process comprises the steps of carrying out peroxide value reduction treatment on a substrate used for synthesizing structural fat, and then carrying out catalytic reaction on the substrate and the lipase to synthesize the structural fat, wherein the peroxide value reduction method comprises one or two of a distillation method and an adsorption method.

Preferably, the distillation method comprises one or both of deodorization and molecular distillation.

Preferably, the deodorization temperature is 220-270 ℃, preferably 240-270 ℃.

Preferably, the deodorization time is 30 min-150 min, and the operating pressure is less than 8 mbar.

Preferably, the temperature of the evaporation surface of the molecular distillation is 200-290 ℃, preferably 220-250 ℃, and the operating pressure is less than 10 mbar.

Preferably, the adsorbent used in the adsorption method comprises one or more of silica gel, activated clay, activated carbon, silica, zeolite, diatomite and attapulgite, and more preferably silica gel, activated carbon and silica.

Preferably, the addition amount of the adsorbent is 0.5 to 6%, preferably 1 to 3% of the mass of the substrate.

Preferably, the adsorption time of the adsorption method is 60min or less, preferably 30min or less.

Preferably, the lipase includes any one of lipases for catalyzing a hydrolysis reaction, a transesterification reaction or an esterification reaction.

Preferably, the lipase used for catalyzing the hydrolysis reaction includes, but is not limited to, any one or more of lipases derived from Candida cylindracea (Candida cylindracea), Pseudomonas fluorescens (Pseudomonas fluorescens), Rhizopus oryzae (Rhizopus oryzae), Pseudomonas cepacia (Pseudomonas cepacia).

Preferably, the lipase used for catalyzing the transesterification reaction includes, but is not limited to, any one or more of lipases derived from Candida antarctica (Candida antarctica), Thermomyces lanuginosus (Thermomyces lanuginosus), Rhizopus oryzae (Rhizopus oryzae), Rhizopus oryzae (Rhizomucor miehei).

Preferably, the lipase used for catalyzing the esterification reaction includes, but is not limited to, any one or more of lipases derived from Rhizomucor miehei (Rhizomucor miehei), Thermomyces lanuginosus (Thermomyces lanuginosus), Burkholderia cepacia (Burheleria cepacia), Candida antarctica (Candida antarctica), Rhizopus oryzae (Rhizopus oryzae), Pseudomonas cepacia (Pseudomonas cepacia), Aspergillus niger (Aspergillus niger).

Preferably, the conditions of the catalytic reaction may be consistent according to the catalytic reaction conditions disclosed in the prior art.

Preferably, the substrate for the transesterification reaction and the hydrolysis reaction comprises a lipid or a fraction thereof.

Preferably, the substrate comprises any one or more of vegetable oil and fat, animal oil and fat and microbial oil and fat.

Preferably, the vegetable oil includes, but is not limited to, one or more of soybean oil, peanut oil, castor oil, sunflower oil, olive oil, coconut oil, linseed oil, palm oil or its fraction, palm kernel oil, rapeseed oil, and the like.

Preferably, the animal fat includes but is not limited to one or more of lard, fish oil, chicken oil, beef tallow, duck oil and the like.

Preferably, the microbial oil includes, but is not limited to, any one or more of ARA-rich oil and DHA-rich oil.

Preferably, the substrate of the esterification reaction is an acyl donor, including but not limited to free fatty acids such as oleic acid, linoleic acid, medium chain fatty acids, and the like.

Preferably, the catalytic transesterification reaction includes an acidolysis reaction, an alcoholysis reaction and a transesterification reaction.

Preferably, the structural lipids include, but are not limited to, human milk substitute lipids, diglycerides, cocoa butter substitutes, medium and long chain fatty acid structural lipids, triglycerides containing polyunsaturated fatty acids, and the like.

The invention also provides application of the method in the fields of preparation of structured fat and food.

The invention has the beneficial effects that:

the method performs peroxide value reduction treatment on the raw materials required by the enzymatic synthesis of the structural lipid, so that the activity of the lipase in the enzymatic synthesis of the structural lipid can be better retained, the recycling times of the enzyme can be effectively increased, the utilization rate of the lipase is improved, the problems of high cost and low utilization rate of the lipase in the industrial production process can be effectively solved, and the method has great significance.

Drawings

FIG. 1 shows the number of times of recycling of lipase before and after the peroxide number reducing treatment of the raw material of the present invention, wherein a is the number of times of recycling of the enzyme under the conditions of comparative example 1, and b is the number of times of recycling of the enzyme under the conditions of example 1.

FIG. 2 is a liquid chromatogram (differential detector) of 2-monoglyceride obtained after 10 times of lipase use in alcoholysis reaction before and after reduction of peroxide number of raw material according to the present invention, wherein a is a liquid chromatogram of the alcoholysis crude product under the conditions of comparative example 2, and b is a liquid chromatogram of the alcoholysis crude product under the deodorization conditions of example 2.

FIG. 3 is a liquid chromatogram (difference detector) of a diglyceride obtained after 10 times of use of a lipase for use in hydrolysis reactions before and after the peroxide number decreasing treatment of a raw material of the present invention, wherein a is a liquid chromatogram of a crude product hydrolyzed under the conditions of comparative example 3, and b is a liquid chromatogram of a crude product hydrolyzed under the adsorption conditions of example 4.

Detailed Description

The present invention is further described below with reference to examples, but the embodiments of the present invention are not limited thereto.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

1. Structural lipid analysis method:

operating method and parameters of HPLC-ELSD detection: referring to the study of highlighting et al (highlighting, assaha, zhouying, etc.. study of enzymatic synthesis of 1-oleic-2-palmitic-3-linoleic triglyceride structured lipids [ J ]. chinese oils, 2020,45(08):66-70.), a reversed phase high performance liquid chromatograph (RP-HPLC) was used with an evaporative light detector to detect and analyze TAG composition in sample oils. 20mg of sample is taken and dissolved in 1.0mL of chromatographic grade n-hexane, and the solution is subjected to membrane filtration and then placed in a high performance liquid chromatograph for analysis. High performance liquid chromatography conditions: lichrospher C18 chromatography column (250 mm. times.4.6 mm. times.5 μm); the evaporative light detector temperature was 55 ℃; setting the air flow rate to be 1.8mL/min and the gain value to be 1; the elution flow rate is 0.8 mL/min; the injection concentration is 20mg/mL, and the injection amount is 20 mu L.

High performance liquid chromatography procedure: the mobile phase elution procedure is shown in table 1, and the quantification is performed in combination with peak area normalization.

TABLE 1 HPLC mobile phase elution procedure

Operation method and parameters of HPLC-RID analysis: with reference to Wang et al (Wang W F, Li, T, Qin, X L, et al.production of lipase SMG1 and its application in synthesizing diacetylgylcol [ J ]. Journal of Molecular Catalysis B-enzyme, 2012,77(6):87-91.), quantitative analysis of lipid components in the reacted system was performed by HPLC-RID. The chromatographic conditions are as follows: chromatographic column Sepax HP-Silica (4.6mm X250 mm X5 μm), column temperature 30 deg.C; the sample concentration is 10mg/mL, and the sample injection amount is 15 mu L; mobile phase n-hexane: isopropyl alcohol: the ratio of formic acid was 15:1:0.03(v/v/v) and the flow rate was 1 mL/min. The lipid components were characterized by standards, the sample concentrations were linear with peak area, and the relative compositions of the substances were expressed by area normalization (%)

2. Peroxide value analysis method: the peroxide value is determined by referring to a method of GB 5009.227-2016 determination of peroxide value in food safety national standard food.

3. Determination of enzyme Activity: taking the content of triglyceride (or diglyceride structural lipid content and monoglyceride structural lipid) of C52 in the product as ordinate, and the remaining 80% activity of the enzyme is 80% multiplied by the content of triglyceride (or diglyceride structural lipid content and monoglyceride structural lipid) of C52 obtained by the first enzyme reaction.

Example 1: (ester interchange-acidolysis reaction to prepare OPO)

And (3) peroxide value reduction treatment: the raw material of palm stearin (i.e. palm oil fraction) with peroxide value of 7.4mmol/kg was subjected to peroxide value reduction treatment, the treatment method is shown in Table 2.

Ester exchange synthesis of structural lipids: mixing palm stearin and oleic acid (molar ratio is 1:10) after peroxide reduction treatment in a 25mL reaction kettle, adding Lipozyme RM (derived from Rhizomucor miehei of Rhizomucor miehei) accounting for 10% of the total mass of a raw material system when a reaction substrate is dissolved and stable, and reacting for 6h at 60 ℃. And after the reaction is finished, centrifuging for 3min at the rotating speed of 4000r/min, recovering the lipase, removing free fatty acid to obtain C52-structure fat with rich content, and detecting the content of C52 triglyceride by using HPLC-ELSD (high performance liquid chromatography-electrostatic spinning), namely the content of C52 triglyceride obtained by the first enzyme method reaction. Adding the recovered lipase into the next synthesis reaction of the structural lipase, wherein the condition is consistent with that of the first reaction, after a certain number of times of repeated use, 80% of activity of the enzyme is remained, stopping use, and calculating the repeated use times of the enzyme.

The influence of different peroxide value reduction treatment methods and different conditions on the recycling times of the enzyme under the methods is explored: the raw materials were treated by molecular distillation, deodorization and adsorption, and the number of times of enzyme reuse was measured by controlled variables under each process condition, respectively, as shown in Table 2. The control group used the same starting material as the initial peroxide value and did not undergo any peroxide value reduction treatment.

TABLE 2 number of reuses of the enzyme in example 1 in acidolysis reaction (with or without peroxide number reduction of the reaction substrate)

As can be seen from Table 2, the use of both distillation and adsorption methods can effectively increase the number of times of enzyme recycling, increase the utilization rate of enzyme, and the adsorption method brings the most significant effect, especially the use of silica gel and activated carbon for adsorption.

Example 2: (transesterification-alcoholysis reaction to prepare 2-monoglyceride)

And (3) peroxide value reduction treatment: a high oleic sunflower oil feedstock with a peroxide number of 8.2mmol/kg was subjected to a peroxide number reduction treatment (see Table 3).

Ester exchange synthesis of structural lipids: mixing the treated high-oleic acid sunflower seed oil with ethanol (the molar ratio is 1:60) in a 25mL reaction kettle, adding Lipozyme TL IM (derived from Thermomyces lanuginosus of Thermomyces lanuginosus) accounting for 10% of the total mass of a raw material system when a reaction substrate is dissolved and stable, and reacting for 5 hours at 30 ℃. After the reaction is finished, centrifuging for 3min at the rotating speed of 4000r/min, recovering the lipase, removing free fatty acid to obtain a certain amount of 2-monoglyceride (2-MAG), and detecting the content of 2-MAG by using HPLC-RID (high performance liquid chromatography-induced degradation), namely the content of 2-MAG obtained by the first enzymatic reaction. Adding the recovered lipase into the next synthesis reaction of the structural lipase, wherein the condition is consistent with that of the first reaction, after a certain number of times of repeated use, 80% of activity of the enzyme is remained, stopping use, and calculating the repeated use times of the enzyme. The number of enzyme reuses under each condition is shown in Table 3.

TABLE 3 number of reuses of the enzyme in example 2 in the alcoholysis reaction (with or without peroxide reduction of the reaction substrate)

Example 3: (esterification reaction-preparation of triglyceride)

And (3) peroxide value reduction treatment: oleic acid with a peroxide number of 7.8mmol/kg was subjected to peroxide number reduction treatment (see Table 4).

Esterification synthesis of structural grease: taking the treated oleic acid and glycerol (the molar ratio is 3:1), adding Lipozyme435 lipase (derived from Candida antarctica) with the mass of 10% of the system to synthesize structural fat, wherein the reaction temperature of the system is 55 ℃, and the reaction time is 6 h. And (3) recovering the lipase used in the step after the reaction is finished to obtain the triolein triglyceride (OOO) structure fat with rich content, and detecting the OOO content by using HPLC-ELSD (high performance liquid chromatography-electrostatic spinning), namely the OOO content obtained by the first enzymatic reaction. Adding the recovered lipase into the next synthesis reaction of the structural lipase, wherein the condition is consistent with that of the first reaction, after a certain number of times of repeated use, 80% of activity of the enzyme is remained, stopping use, and calculating the repeated use times of the enzyme. The number of enzyme reuses under each condition is shown in Table 4.

TABLE 4 number of reuses of the enzyme in example 3 in the esterification reaction (with or without treatment of the reaction substrate with peroxide reduction)

Example 4: (hydrolysis reaction-preparation of diglycerides)

And (3) peroxide value reduction treatment: soybean oil material with peroxide number of 9.3mmol/kg was subjected to peroxide number reduction treatment (see Table 5).

Hydrolysis to form structural lipids: taking the treated soybean oil raw material to react with water (the mass ratio of oil to water is 1:1), adding 10% of Lipase DF IM Lipase (taking Rhizopus oryzae as a source), and carrying out the reaction under the condition of stirring, wherein the reaction temperature is controlled at 35 ℃ and the hydrolysis time is 1 h. Centrifuging at 8000r/min for 15min after the reaction is finished, taking supernate to obtain Diglyceride (DAG), recovering the used lipase, and detecting the DAG content by using HPLC-RID, namely the DAG content obtained by the first enzymatic reaction. Adding the recovered lipase into the next synthesis reaction of the structural lipase, wherein the condition is consistent with that of the first reaction, after a certain number of times of repeated use, 80% of activity of the enzyme is remained, stopping use, and calculating the repeated use times of the enzyme. The number of enzyme reuses under each condition is shown in Table 5.

TABLE 5 number of reuses of the enzyme in example 4 in the hydrolysis reaction (with or without treatment of the reaction substrate with peroxide reduction)

Example 5: (optimization of enzyme)

And (3) peroxide value reduction treatment: raw palm stearin having peroxide number of 7.4mmol/kg was deodorized at 4mbar, 90min, 250 ℃ (see table 6).

Structural lipid synthesis: mixing the processed palm stearin raw material and oleic acid (the molar ratio is 1:10) in a 25mL reaction kettle, adding lipase which catalyzes ester exchange reaction and accounts for 10% of the total mass of the raw material system when a reaction substrate is dissolved and stable, and reacting for 6h at 60 ℃. And after the reaction is finished, centrifuging for 3min at the rotating speed of 4000r/min, recovering the lipase, removing free fatty acid to obtain C52-structure fat with rich content, and detecting the content of C52 triglyceride by using HPLC-ELSD (high performance liquid chromatography-electrostatic spinning), namely the content of C52 triglyceride obtained by the first enzyme method reaction. Adding the recovered lipase into the next synthesis reaction of the structural lipase, wherein the condition is consistent with that of the first reaction, after a certain number of times of repeated use, 80% of activity of the enzyme is remained, stopping use, and calculating the repeated use times of the enzyme.

The influence of different lipases on the number of reuses was explored: the reactions were carried out using different lipases, respectively, with the remaining conditions being maintained, and the number of reuses of the different lipases was determined, respectively, with the control group being the raw material of each lipase without treatment, as shown in Table 6.

TABLE 6 number of reuses of different lipases participating in the reaction obtained in example 5

Comparative example 1: (comparison with example 1)

The difference from example 1 is that comparative example 1 uses a raw material which has not been subjected to the oxidation number reduction treatment. The experimental conditions and procedures for synthesizing the structural ester by ester exchange acidolysis are the same as those of example 1.

Comparing the enzymes used in the raw material treated under the optimal conditions of molecular distillation (6mbar, 230 ℃) in example 1, as shown in FIG. 1, FIG. 1a shows the recycling times and product contents of the unprocessed lipase in the raw material in the acidolysis reaction by ester exchange, and FIG. 1b shows the recycling times and product contents of the lipase after the raw material is treated by molecular distillation in the acidolysis reaction by ester exchange. It is shown that the reduction of the peroxide value of the raw material is very beneficial to the maintenance of the enzyme activity, and the recycling frequency of the enzyme can be increased to a certain extent.

Comparative example 2: (comparison with example 2)

The difference from example 2 is that comparative example 2 uses a raw material which has not been subjected to peroxide number reduction treatment. The experimental conditions and procedures for the synthesis of structured fat by transesterification and alcoholysis were the same as in example 2.

The enzyme recovered from the alcoholysis of the starting material of example 2 after treatment under optimum deodorization conditions (4mbar, 90min, 250 ℃) was used for 10 times and the 2-MAG content obtained after 10 uses of the enzyme was compared with the 2-MAG content obtained after 10 uses of the enzyme of comparative example 2, see FIG. 2. Wherein, FIG. 2a is a liquid chromatogram obtained by the reaction of raw material without reducing peroxide number, and FIG. 2b is a liquid chromatogram obtained by the reaction of raw material after deodorization. The 2-MAG content of FIG. 2a was lower by 15.27%; the 2-MAG content of FIG. 2b was 21.87%, which is summarized in Table 7. The method shows that in the ester exchange alcoholysis reaction, after the same raw material is subjected to peroxide reduction treatment, the persistence of enzyme activity is obviously improved, and the specific embodiment is that after the lipase is used for 10 times, the content of generated 2-MAG is higher than that of the lipase used for the raw material without deodorization treatment.

TABLE 7 Effect of deodorizing and non-deodorizing the raw materials on the 2-monoglyceride content of the crude transesterified product

Note: the enzymes have been used 10 times

Comparative example 3: (comparison with example 4)

The difference from example 4 is that comparative example 3 uses a feedstock which has not been treated to reduce the peroxide number. The experimental conditions and procedures for hydrolysis synthesis of structured lipids were the same as in example 4.

The enzyme recovered by hydrolysis after the treatment of the starting material in example 4 under optimum adsorption conditions (2% silica gel, room temperature, 20min) was used and the 2-MAG content obtained after 10 uses of the enzyme was compared with the 2-MAG content obtained after 10 uses of the enzyme of comparative example 3, as shown in FIG. 3. Wherein, fig. 3a is a liquid chromatogram obtained by the reaction of raw materials without reducing peroxide number, and fig. 3b is a liquid chromatogram obtained by the reaction of raw materials with adsorption treatment. The DAG content of FIG. 3a is 27.74%; the DAG content of FIG. 3b was 33.78%, which is summarized in Table 8. The results show that in the hydrolysis reaction, after the raw material is subjected to peroxide number reduction treatment, the activity of the lipase can be effectively retained, and particularly, after the lipase is used for 10 times, the content of the generated DAG is higher than that of the lipase used for treating the raw material without adsorption.

TABLE 8 Effect of raw materials on diglyceride content in raw hydrolysate with and without adsorption

Note: the enzymes have been used 10 times

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.