A perilla oil alpha-linolenic acid microcapsule and a preparation method thereof

Abstract

A perilla oil α-linolenic acid microcapsule and its preparation method belong to the food processing field, including the following steps: (1) extraction of perilla oil; using a bio-enzyme-assisted low-temperature pressing method, a compound enzyme is added to perilla seeds for enzymatic hydrolysis, followed by low-temperature pressing to collect perilla seed oil; (2) enrichment and purification of α-linolenic acid; the perilla seed oil obtained in step (1) is purified by molecular distillation technology, and the perilla oil fraction enriched with α-linolenic acid is collected; (3) microencapsulation; using the perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, after selecting a suitable composite wall material, perilla oil α-linolenic acid microcapsules are obtained by spray drying. This invention improves the extraction efficiency of perilla oil, retains the natural activity of α-linolenic acid; efficiently enriches α-linolenic acid through molecular distillation technology, increasing the content of functional active ingredients in the product; and improves the oxidative stability and storage performance of α-linolenic acid.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically relating to a perilla oil α-linolenic acid microcapsule and its preparation method. Background Technology

[0002] Perilla (Latin name: Perilla frutescens (L.) Britt.) is a multifunctional plant whose seeds are rich in oil, with α-linolenic acid content as high as 53% to 68%, and has important nutritional and medicinal value. However, α-linolenic acid, as a polyunsaturated fatty acid, is easily affected by light, heat, oxygen and other factors and will undergo oxidation and deterioration, which limits its application in food, health products and other fields. In addition, traditional perilla oil extraction processes have problems such as low extraction efficiency and large loss of active ingredients. For example, Chinese patent with publication number CN107118843A discloses a method for preparing perilla oil from perilla leaves and perilla oil. The patent mainly includes the following steps: (1) Raw material processing: the dried perilla leaf raw material is chopped and put into the extraction tank; (2) Direct steam: the direct steam valve of the extraction tank is opened and steam is introduced into the extraction tank. At the same time, the steam pressure is adjusted and the direct heating time and the extraction temperature of the tank are controlled; (3) Separation: the oil-water mixture evaporated by the above steam is condensed and separated in an oil-water separator to collect the oil layer. The perilla oil extracted by this method contains a low amount of α-linolenic acid, and the steam and separation technology used in this patent has the problem of low extraction efficiency and significant loss of active ingredients, which is not conducive to the industrialization of α-linolenic acid in perilla oil.

[0003] Microencapsulation technology is an effective means to improve the stability of polyunsaturated fatty acids. However, there is still a lack of systematic research on the combined preparation method of efficient enrichment and microencapsulation of α-linolenic acid from perilla oil, especially in terms of wall material screening, process optimization, and product stability, which still need to be improved. Summary of the Invention

[0004] To address the problems of low extraction efficiency and significant loss of active ingredients in existing perilla oil extraction processes, this invention provides perilla oil α-linolenic acid microcapsules and their preparation method.

[0005] The technical solution adopted by this invention to solve the technical problem is as follows:

[0006] The first objective of this invention is to provide a method for preparing perilla oil α-linolenic acid microcapsules.

[0007] The present invention provides a method for preparing perilla oil α-linolenic acid microcapsules, which specifically includes the following steps:

[0008] (1) Extraction of perilla oil;

[0009] The perilla seed oil was collected by adding a compound enzyme to the perilla seeds for enzymatic hydrolysis using a bio-enzyme-assisted low-temperature pressing method.

[0010] (2) Enrichment and purification of α-linolenic acid;

[0011] The perilla seed oil obtained in step (1) was purified by molecular distillation, and the perilla oil fraction enriched with α-linolenic acid was collected.

[0012] (3) Microencapsulation;

[0013] Using the perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, and after selecting a suitable composite wall material, perilla oil α-linolenic acid microcapsules were prepared by spray drying.

[0014] As one specific embodiment, in step (1), the complex enzyme is composed of cellulase and pectinase.

[0015] In one more specific embodiment, the amount of cellulase and pectinase added is 0.5% to 1.5% and 0.3% to 1.0% of the weight of perilla seeds, respectively.

[0016] In one specific embodiment, in step (1), the enzymatic hydrolysis temperature is 45-55°C, the pH is 4.5-5.5, and the enzymatic hydrolysis time is 2-4 hours.

[0017] As one specific embodiment, in step (1), the pressing temperature is controlled at 50-60°C and the pressing pressure is 20-30 MPa.

[0018] In one specific embodiment, in step (2), the operating pressure is 0.1 to 1.0 Pa, the feed temperature is 60 to 80°C, the feed rate is 1 to 3 mL / min, and the scraping speed is 200 to 300 rpm.

[0019] In one specific embodiment, in step (3), the mass ratio of the core material to the composite wall material is 1:2 to 1:4.

[0020] As one specific embodiment, in step (3), the composite wall material is composed of modified starch, maltodextrin and gum arabic; the mass ratio of the modified starch, maltodextrin and gum arabic is (3-6):(2-5):(0.5-1.5).

[0021] As one specific embodiment, in step (3), the parameters of the spray drying method are as follows: solid content is 25% to 35%, air inlet temperature is 170 to 180°C, air outlet temperature is 75 to 85°C, homogenization pressure is 25 to 35 MPa, and atomization pressure is 0.3 to 0.4 MPa.

[0022] A second objective of this invention is to provide perilla oil α-linolenic acid microcapsules prepared by a method for preparing perilla oil α-linolenic acid microcapsules.

[0023] The present invention provides a perilla oil α-linolenic acid microcapsule with an encapsulation rate of not less than 85% and a peroxide value of less than 5.0 meq / kg within 60 days under accelerated storage conditions at 40℃.

[0024] The beneficial effects of this invention are:

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. This invention improves extraction efficiency;

[0027] This invention employs bio-enzyme-assisted low-temperature pressing technology, which significantly improves the extraction efficiency of perilla oil while preserving the natural activity of α-linolenic acid.

[0028] 2. This invention increases the content of active ingredients;

[0029] This invention utilizes molecular distillation technology to efficiently enrich α-linolenic acid, thereby increasing the content of functional active ingredients in the product and avoiding the loss of active ingredients.

[0030] 3. This invention improves the oxidative stability and storage performance of α-linolenic acid;

[0031] This invention uses composite wall materials and spray drying process to prepare microcapsules, which effectively improves the oxidative stability and storage performance of α-linolenic acid and broadens its application prospects in functional foods.

[0032] 4. This invention has certain industrial applicability;

[0033] The method for preparing perilla oil α-linolenic acid microcapsules provided by this invention is stable and easy to operate, and is suitable for large-scale production in the fields of functional foods, health products and pharmaceuticals, with good prospects for industrial application. Detailed Implementation

[0034] In a first aspect, the present invention provides a method for preparing perilla oil α-linolenic acid microcapsules.

[0035] The present invention provides a method for preparing perilla oil α-linolenic acid microcapsules, which specifically includes the following steps:

[0036] (1) Extraction of perilla oil;

[0037] A bio-enzyme-assisted low-temperature pressing method was adopted. A complex enzyme composed of cellulase and pectinase was added to perilla seeds for enzymatic hydrolysis. The hydrolysis temperature was 45-55℃, the pH was 4.5-5.5, and the hydrolysis time was 2-4 hours. The amount of cellulase and pectinase added to the complex enzyme was 0.5%-1.5% and 0.3%-1.0% of the mass of perilla seeds, respectively. Then, low-temperature pressing was carried out, with the pressing temperature controlled at 50-60℃ and the pressing pressure at 20-30 MPa. Perilla seed oil was collected.

[0038] This invention uses a bio-enzyme-assisted low-temperature pressing method to disrupt the cell wall structure of perilla seeds, thereby increasing the oil yield. At the same time, it retains heat-sensitive active ingredients such as α-linolenic acid under mild conditions, avoiding oxidation losses caused by traditional high-temperature pressing or solvent extraction.

[0039] This invention employs a composite enzyme consisting of cellulase and pectinase. Cellulase hydrolyzes the cellulose in the cell walls of perilla seeds, releasing intracellular oil; pectinase breaks down pectin in the cell walls, reducing viscosity and promoting oil flow. The synergistic effect of cellulase and pectinase improves extraction efficiency and reduces the damage to the oil caused by mechanical pressing.

[0040] Preferably, the enzymatic hydrolysis conditions are: hydrolysis temperature of 50°C, pH of 5.0, and hydrolysis time of 3 hours.

[0041] Preferably, in the compound enzyme, the amount of cellulase and pectinase added is 0.7% to 1.2% and 0.5% to 0.8% of the weight of perilla seeds, respectively.

[0042] More preferably, in the compound enzyme, the amount of cellulase and pectinase added is 1.0% and 0.6% of the weight of perilla seeds, respectively.

[0043] Preferably, the pressing temperature is controlled at 55°C and the pressing pressure is 25 MPa.

[0044] (2) Enrichment and purification of α-linolenic acid;

[0045] The perilla seed oil obtained in step (1) was purified by molecular distillation. The operating pressure was 0.1-1.0 Pa, the feed temperature was 60-80℃, the feed rate was 1-3 mL / min, and the scraper rotation speed was 200-300 rpm. The perilla oil fraction enriched with α-linolenic acid was collected.

[0046] This invention utilizes molecular distillation technology under high pressure and vacuum conditions to separate the light and heavy components in perilla oil based on the differences in their boiling points, efficiently enriching α-linolenic acid and significantly improving its purity while avoiding thermal oxidation losses. This step is a physical separation process, without the addition of additional chemical reagents; purification is achieved solely by controlling parameters such as temperature, pressure, and feed rate.

[0047] Preferably, the parameters of the molecular distillation technology are: operating pressure of 0.5 Pa, feed temperature of 70℃, feed rate of 2 mL / min, and scraper rotation speed of 250 rpm.

[0048] (3) Microencapsulation;

[0049] Using perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, and modified starch, maltodextrin and gum arabic as the composite wall material, perilla oil α-linolenic acid microcapsules were prepared by spray drying at a mass ratio of core material to composite wall material of 1:2 to 1:4. The parameters of spray drying were as follows: solid content of 25% to 35%, inlet air temperature of 170 to 180°C, outlet air temperature of 75 to 85°C, homogenization pressure of 25 to 35 MPa, and atomization pressure of 0.3 to 0.4 MPa.

[0050] This invention uses enriched perilla oil as the core material and selects composite wall material to form microcapsules through spray drying. The liquid oil is encapsulated in the solid wall material, which effectively isolates oxygen and light, improves the oxidation stability and storage stability of α-linolenic acid, and facilitates its application in food, health products and other fields.

[0051] The core material in this invention is perilla oil enriched with α-linolenic acid, which is encapsulated as a functional component. The composite wall material consists of modified starch, maltodextrin, and gum arabic. Modified starch has good emulsifying and film-forming properties, which helps to form a stable emulsion and encapsulate the oil. Maltodextrin can increase the solids content, improve drying efficiency, and enhance the solubility and flowability of the microcapsules. Gum arabic is a natural emulsifier that can form a stable film at the oil-water interface, enhancing the encapsulation effect and antioxidant capacity. The combination of modified starch, maltodextrin, and gum arabic can optimize the encapsulation rate, reduce the surface oil content, and improve the stability of the product under accelerated storage conditions.

[0052] Preferably, in the composite wall material, the mass ratio of modified starch, maltodextrin and gum arabic is (3-6):(2-5):(0.5-1.5).

[0053] More preferably, in the composite wall material, the mass ratio of modified starch, maltodextrin and gum arabic is 4.5:3.5:1.0.

[0054] Preferably, the mass ratio of the core material to the composite wall material is 1:3.

[0055] Preferably, the parameters of the spray drying method are as follows: solid content is 30%, inlet air temperature is 175°C, outlet air temperature is 80°C, homogenization pressure is 30 MPa, and atomization pressure is 0.35 MPa.

[0056] Secondly, the present invention provides perilla oil α-linolenic acid microcapsules prepared by the method for preparing perilla oil α-linolenic acid microcapsules provided in the first aspect.

[0057] According to the present invention, the encapsulation rate of the perilla oil α-linolenic acid microcapsules prepared by the present invention is not less than 85%, and the peroxide value is less than 5.0 meq / kg within 60 days under accelerated storage conditions at 40℃.

[0058] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0059] Example 1: Preparation of perilla oil α-linolenic acid microcapsules

[0060] (1) Extraction of perilla oil;

[0061] A bio-enzyme-assisted low-temperature pressing method was adopted. A complex enzyme composed of cellulase and pectinase was added to perilla seeds for enzymatic hydrolysis. The hydrolysis temperature was 50℃, the pH was 5.0, and the hydrolysis time was 3 hours. The amount of cellulase and pectinase added to the complex enzyme was 1.0% and 0.6% of the mass of perilla seeds, respectively. Then, low-temperature pressing was carried out, with the pressing temperature controlled at 55℃ and the pressing pressure at 25 MPa. Perilla seed oil was collected.

[0062] (2) Enrichment and purification of α-linolenic acid;

[0063] The perilla seed oil obtained in step (1) was purified by molecular distillation. The operating pressure was 0.5 Pa, the feed temperature was 70℃, the feed rate was 2 mL / min, and the scraper rotation speed was 250 rpm. The perilla oil fraction enriched with α-linolenic acid (content 80.5%) was collected.

[0064] (3) Microencapsulation;

[0065] Using the perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, and modified starch, maltodextrin and gum arabic as the composite wall material (the mass ratio of modified starch, maltodextrin and gum arabic is 4.5:3.5:1.0), perilla oil α-linolenic acid microcapsules were prepared by spray drying at a mass ratio of core material to composite wall material of 1:3. The parameters of spray drying are as follows: solid content is 30%, inlet air temperature is 175℃, outlet air temperature is 80℃, homogenization pressure is 30MPa, and atomization pressure is 0.35MPa.

[0066] Testing showed that the encapsulation rate of the perilla oil α-linolenic acid microcapsules prepared in this embodiment was 89.2%, and the peroxide value was below 4.6 meq / kg within 60 days under accelerated storage conditions at 40℃. The perilla oil α-linolenic acid microcapsules prepared in this embodiment had a smooth surface, good sphericity, and no obvious cracks.

[0067] Example 2: Preparation of perilla oil α-linolenic acid microcapsules

[0068] (1) Extraction of perilla oil;

[0069] A bio-enzyme-assisted low-temperature pressing method was adopted. A complex enzyme composed of cellulase and pectinase was added to perilla seeds for enzymatic hydrolysis. The hydrolysis temperature was 45℃, the pH was 5.5, and the hydrolysis time was 4 hours. The amount of cellulase and pectinase added to the complex enzyme was 0.5% and 0.3% of the mass of perilla seeds, respectively. Then, low-temperature pressing was carried out, with the pressing temperature controlled at 50℃ and the pressing pressure at 30 MPa. Perilla seed oil was collected.

[0070] (2) Enrichment and purification of α-linolenic acid;

[0071] The perilla seed oil obtained in step (1) was purified by molecular distillation. The operating pressure was 0.2 Pa, the feed temperature was 65℃, the feed rate was 1.5 mL / min, and the scraper rotation speed was 240 rpm. The perilla oil fraction enriched with α-linolenic acid (content 79.3%) was collected.

[0072] (3) Microencapsulation;

[0073] Using the perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, and modified starch, maltodextrin and gum arabic as the composite wall material (the mass ratio of modified starch, maltodextrin and gum arabic is 5:3.5:0.6), perilla oil α-linolenic acid microcapsules were prepared by spray drying at a mass ratio of core material to composite wall material of 1:2. The parameters of spray drying are as follows: solid content is 25%, inlet air temperature is 170℃, outlet air temperature is 75℃, homogenization pressure is 25MPa, and atomization pressure is 0.4MPa.

[0074] Testing showed that the encapsulation rate of the perilla oil α-linolenic acid microcapsules prepared in this embodiment was 87.5%, and the peroxide value was below 4.9 meq / kg within 60 days under accelerated storage conditions at 40℃. The perilla oil α-linolenic acid microcapsules prepared in this embodiment had a smooth surface, good sphericity, and no obvious cracks.

[0075] Example 3: Preparation of perilla oil α-linolenic acid microcapsules

[0076] (1) Extraction of perilla oil;

[0077] A bio-enzyme-assisted low-temperature pressing method was adopted. A complex enzyme composed of cellulase and pectinase was added to perilla seeds for enzymatic hydrolysis. The hydrolysis temperature was 55℃, the pH was 4.5, and the hydrolysis time was 2 hours. The amount of cellulase and pectinase added to the complex enzyme was 1.5% and 1.0% of the mass of perilla seeds, respectively. Then, low-temperature pressing was carried out, with the pressing temperature controlled at 60℃ and the pressing pressure at 20 MPa. Perilla seed oil was collected.

[0078] (2) Enrichment and purification of α-linolenic acid;

[0079] The perilla seed oil obtained in step (1) was purified by molecular distillation. The operating pressure was 0.3 Pa, the feed temperature was 80℃, the feed rate was 2.5 mL / min, and the scraper rotation speed was 300 rpm. The perilla oil fraction enriched with α-linolenic acid (content 78.5%) was collected.

[0080] (3) Microencapsulation;

[0081] Using the α-linolenic acid-enriched perilla oil obtained in step (2) as the core material, and modified starch, maltodextrin and gum arabic as the composite wall material (the mass ratio of modified starch, maltodextrin and gum arabic is 5.5:4:1.5), perilla oil α-linolenic acid microcapsules were prepared by spray drying at a mass ratio of core material to composite wall material of 1:4. The parameters of the spray drying method are as follows: solid content is 35%, inlet air temperature is 175℃, outlet air temperature is 80℃, homogenization pressure is 30MPa, and atomization pressure is 0.3MPa.

[0082] Testing showed that the encapsulation rate of the perilla oil α-linolenic acid microcapsules prepared in this embodiment was 88.3%, and the peroxide value was below 4.8 meq / kg within 60 days under accelerated storage conditions at 40℃. The perilla oil α-linolenic acid microcapsules prepared in this embodiment had a smooth surface, good sphericity, and no obvious cracks.

[0083] Example 4: Preparation of perilla oil α-linolenic acid microcapsules

[0084] (1) Extraction of perilla oil;

[0085] A bio-enzyme-assisted low-temperature pressing method was adopted. A complex enzyme composed of cellulase and pectinase was added to perilla seeds for enzymatic hydrolysis. The hydrolysis temperature was 55℃, the pH was 5.0, and the hydrolysis time was 3.5 hours. The amount of cellulase and pectinase added to the complex enzyme was 1.2% and 0.8% of the mass of perilla seeds, respectively. Then, low-temperature pressing was carried out, with the pressing temperature controlled at 52℃ and the pressing pressure at 22MPa. Perilla seed oil was collected.

[0086] (2) Enrichment and purification of α-linolenic acid;

[0087] The perilla seed oil obtained in step (1) was purified by molecular distillation. The operating pressure was 1.0 Pa, the feed temperature was 75℃, the feed rate was 2.5 mL / min, and the scraper rotation speed was 200 rpm. The perilla oil fraction enriched with α-linolenic acid (content 79.5%) was collected.

[0088] (3) Microencapsulation;

[0089] Using the perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, and modified starch, maltodextrin and gum arabic as the composite wall material (the mass ratio of modified starch, maltodextrin and gum arabic is 6.0:4.5:1.2), perilla oil α-linolenic acid microcapsules were prepared by spray drying at a mass ratio of core material to composite wall material of 1:3.5. The parameters of the spray drying method are as follows: solid content is 32%, inlet air temperature is 171℃, outlet air temperature is 78℃, homogenization pressure is 30MPa, and atomization pressure is 0.35MPa.

[0090] Testing showed that the encapsulation rate of the perilla oil α-linolenic acid microcapsules prepared in this embodiment was 88.5%, and the peroxide value was below 4.7 meq / kg within 60 days under accelerated storage conditions at 40℃. The perilla oil α-linolenic acid microcapsules prepared in this embodiment had a smooth surface, good sphericity, and no obvious cracks.

[0091] Example 5: Preparation of perilla oil α-linolenic acid microcapsules

[0092] (1) Extraction of perilla oil;

[0093] A bio-enzyme-assisted low-temperature pressing method was adopted. A complex enzyme composed of cellulase and pectinase was added to perilla seeds for enzymatic hydrolysis. The hydrolysis temperature was 48℃, the pH was 5.0, and the hydrolysis time was 3 hours. The amount of cellulase and pectinase added to the complex enzyme was 1.5% and 0.5% of the mass of perilla seeds, respectively. Then, low-temperature pressing was carried out, with the pressing temperature controlled at 55℃ and the pressing pressure at 25MPa. Perilla seed oil was collected.

[0094] (2) Enrichment and purification of α-linolenic acid;

[0095] The perilla seed oil obtained in step (1) was purified by molecular distillation. The operating pressure was 1.0 Pa, the feed temperature was 75℃, the feed rate was 2.5 mL / min, and the scraper rotation speed was 200 rpm. The perilla oil fraction enriched with α-linolenic acid (content 78.9%) was collected.

[0096] (3) Microencapsulation;

[0097] Using the perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, and modified starch, maltodextrin and gum arabic as the composite wall material (the mass ratio of modified starch, maltodextrin and gum arabic is 3.5:4.5:1.5), perilla oil α-linolenic acid microcapsules were prepared by spray drying at a mass ratio of core material to composite wall material of 1:4. The parameters of spray drying are as follows: solid content is 30%, inlet air temperature is 175℃, outlet air temperature is 80℃, homogenization pressure is 30MPa, and atomization pressure is 0.35MPa.

[0098] Testing showed that the encapsulation rate of the perilla oil α-linolenic acid microcapsules prepared in this embodiment was 87.8%, and the peroxide value was below 4.6 meq / kg within 60 days under accelerated storage conditions at 40℃. The perilla oil α-linolenic acid microcapsules prepared in this embodiment had a smooth surface, good sphericity, and no obvious cracks.

[0099] Comparative Example 1

[0100] The overall steps are the same as in Example 1, except that molecular distillation enrichment was not performed, and α-linolenic acid microcapsules were prepared directly using perilla seed oil as the core material.

[0101] Testing revealed that the α-linolenic acid content in the product prepared in this embodiment was only 58.3%, and the peroxide value was less than 7.8 meq / kg within 60 days under accelerated storage conditions at 40℃.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing perilla oil α-linolenic acid microcapsules, characterized in that, Includes the following steps: (1) Extraction of perilla oil; The perilla seed oil was collected by adding a compound enzyme to the perilla seeds for enzymatic hydrolysis using a bio-enzyme-assisted low-temperature pressing method. (2) Enrichment and purification of α-linolenic acid; The perilla seed oil obtained in step (1) was purified by molecular distillation, and the perilla oil fraction enriched with α-linolenic acid was collected. (3) Microencapsulation; Using the perilla oil enriched with α-linolenic acid obtained in step (2) as the core material, and after selecting a suitable composite wall material, perilla oil α-linolenic acid microcapsules were prepared by spray drying.

2. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 1, characterized in that, In step (1), the complex enzyme is composed of cellulase and pectinase.

3. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 2, characterized in that, The amounts of cellulase and pectinase added are 0.5%–1.5% and 0.3%–1.0% of the weight of perilla seeds, respectively.

4. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 1, characterized in that, In step (1), the enzymatic hydrolysis temperature is 45-55℃, the pH is 4.5-5.5, and the enzymatic hydrolysis time is 2-4 hours.

5. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 1, characterized in that, In step (1), the pressing temperature is controlled at 50-60℃ and the pressing pressure is 20-30 MPa.

6. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 1, characterized in that, In step (2), the operating pressure is 0.1 to 1.0 Pa, the feed temperature is 60 to 80°C, the feed rate is 1 to 3 mL / min, and the scraper rotation speed is 200 to 300 rpm.

7. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 1, characterized in that, In step (3), the mass ratio of the core material to the composite wall material is 1:2 to 1:

4.

8. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 1, characterized in that, In step (3), the composite wall material is composed of modified starch, maltodextrin and gum arabic; the mass ratio of the modified starch, maltodextrin and gum arabic is (3-6):(2-5):(0.5-1.5).

9. The method for preparing perilla oil α-linolenic acid microcapsules according to claim 1, characterized in that, In step (3), the parameters of the spray drying method are as follows: solid content is 25% to 35%, air inlet temperature is 170 to 180°C, air outlet temperature is 75 to 85°C, homogenization pressure is 25 to 35 MPa, and atomization pressure is 0.3 to 0.4 MPa.

10. The perilla oil α-linolenic acid microcapsules prepared by the method for preparing perilla oil α-linolenic acid microcapsules according to any one of claims 1-9, characterized in that, The encapsulation rate of the perilla oil α-linolenic acid microcapsules is not less than 85%, and the peroxide value is less than 5.0 meq / kg within 60 days under accelerated storage conditions at 40℃.