Irradiation modified amylose and application thereof in embedding lycopene microcapsules

Abstract

The invention discloses irradiation modified amylose and application thereof in embedding lycopene microcapsules in the field of starch processing. The irradiation modified amylose is prepared by a preparation method comprising the following steps: dissolving amylose in deionized water, adjusting the pH value, heating, stirring, neutralizing, centrifugally washing, and drying in vacuum to obtain modified amylose; modified amylose is taken and dissolved in deionized water, the dispersion liquid is subjected to electron beam irradiation, and the electron beam irradiation is divided into a first stage with a low dosage rate and a second stage with a high dosage rate; and taking the dispersion liquid after electron beam irradiation, and carrying out centrifugal water washing and vacuum drying to obtain the product. The amylose is firstly subjected to mild acidolysis, so that a molecular chain is partially hydrolyzed, the polymerization degree is reduced, the solubility is improved, and irradiation is facilitated; meanwhile, a staged mode is adopted in the irradiation process, so that the molecular weight distribution of the starch is more concentrated, the film forming uniformity and compactness of the microcapsules are remarkably improved on the whole, and the stability of the capsules is further improved.

Description

Technical Field

[0001] The present invention relates to the field of starch processing, and in particular to irradiation-modified amylose and application thereof in lycopene-embedding microcapsules. Background Art

[0002] Lycopene is a natural plant pigment found primarily in the ripe fruit of tomatoes, a member of the Solanaceae family. It is one of the strongest antioxidants currently found in natural plants. Furthermore, as a carotenoid, lycopene is gaining increasing attention for its diverse physiological functions, including quenching reactive oxygen species, eliminating free radicals, anti-aging, preventing various cancers, and providing cardiovascular protection. It is now used in a variety of applications, including daily chemicals and food.

[0003] Lycopene, a conjugated polyene compound composed of carbon and hydrogen, possesses excellent antioxidant properties but is also highly unstable. Especially after artificial purification, without the protective effects of other media, it is easily oxidized and degraded under the influence of light, high temperature, and oxygen. Furthermore, lycopene is a fat-soluble carotenoid that is insoluble in water, making it difficult to uniformly incorporate into water-soluble products such as food, medicine, and cosmetics. Lycopene's instability and insolubility significantly limit its application and promotion. However, encapsulation using microencapsulation technology can improve its stability and suitability for use in functional products. Microencapsulation technology involves encapsulating and solidifying solid particles, liquid droplets, or bubbles using natural or synthetic polymer film-forming materials to form tiny particles. For example, patent publication number CN101803739B discloses a method for producing lycopene microcapsules. The method utilizes gum arabic, dextrin, and sucrose as wall materials, and produces lycopene microcapsules through steps such as emulsion preparation and spray drying.

[0004] Amylose is a polysaccharide chain composed of D-glucose groups connected by α-(1,4) glycosidic bonds. It has the advantages of being biodegradable, having a high gelatinization temperature, good film-forming properties and anti-swelling properties, being widely available, and being low-cost. It can be used as a wall material for lycopene microcapsules. However, conventional amylose has the following defects when used as a wall material: (1) conventional amylose has poor solubility and is difficult to form a uniform and stable solution or sol, which directly affects the efficiency and stability of the emulsification encapsulation process; (2) conventional amylose has a large molecular weight and a wide distribution, which easily leads to uneven thickness and poor density of the formed wall film, affecting the protective effect of the core material.

[0005] Therefore, the present invention aims to provide a method for processing amylose that can be used as the wall material of lycopene microcapsules. Summary of the Invention

[0006] The present invention aims to provide an irradiated modified amylose and its use in lycopene encapsulation microcapsules, which solves the defects of conventional amylose, such as poor solubility, large molecular weight and wide distribution, which easily lead to uneven wall thickness and poor density.

[0007] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0008] An irradiation-modified amylose starch is prepared by the following preparation method:

[0009] S1. Preprocessing

[0010] Dissolve amylose in 2-4 times its mass of deionized water, adjust the pH to 3-4 with HCl solution, heat to 45-55°C and stir for 35-45 minutes, then neutralize with NaOH solution, wash with water by centrifugation, and vacuum dry to obtain modified amylose;

[0011] S2. Irradiation treatment

[0012] The modified amylose is dissolved in 3-5 times the mass of deionized water, stirred evenly to obtain a dispersion, and the dispersion is subjected to electron beam irradiation. The electron beam irradiation is divided into a first stage and a second stage. The dose rate of the first stage is 2.5-3.5 kGy / s and the dose is 8-12 kGy. The dose rate of the second stage is 0.3-0.6 kGy / s and the dose is 28-32 kGy.

[0013] S3, post-processing

[0014] The dispersion after electron beam irradiation is taken, washed with water by centrifugation and dried in vacuum to obtain irradiation-modified amylose.

[0015] A further improvement is that in step S1, the concentration of the HCl solution is 0.08-0.12M, and the concentration of the NaOH solution is 0.8-1.2M.

[0016] A further improvement is that in step S2, the energy of the electron beam irradiation is 4-6 MeV.

[0017] A further improvement is that in step S2, before electron beam irradiation, an irradiation accelerator is added to the dispersion in an amount of 0.1-0.3% by mass of the dispersion, wherein the irradiation accelerator is ozone-activated ferritin.

[0018] A further improvement is that the preparation steps of the ozone-activated ferritin are as follows: recombinant ferritin is dissolved in Tris-HCl buffer to control the dissolved concentration to 4-6 mg / mL, FeCl2 solution is added to the solution, stirred for reaction, and dialyzed for 36-48 hours to remove free Fe 2+Then, ozone is introduced into the solution to make the dissolved ozone concentration reach 0.08-0.15ppm, and the solution is allowed to react for 6-8 minutes to activate the ferritin surface. Finally, the solution is freeze-dried to obtain ozone-activated ferritin.

[0019] A further improvement is that the stirring reaction is specifically carried out at 24-26° C. and 60-120 rpm in the dark for 1.5-2 hours.

[0020] A further improvement is that the flow rate of the ozone is 0.4-0.6 L / min and the time is 4-6 minutes.

[0021] A further improvement is that the freeze-drying temperature is -50°C and the pressure is 0.08-0.1Pa.

[0022] A further improvement is that in steps S1 and S3, the vacuum drying temperature is 48-52° C., the pressure is 0.06-0.08 MPa, and the time is 4-6 h.

[0023] The present invention also provides an application of the irradiated modified amylose in encapsulating lycopene microcapsules, wherein the specific method of the application is as follows:

[0024] (1) Preparation: Dissolve lycopene in soybean oil at a ratio of 1 g: 4-6 mL to obtain a core material, then dissolve the irradiated modified amylose in water at a ratio of 1 g: 8-12 mL, and heat to 58-62° C. for gelatinization to obtain a wall material;

[0025] (2) Emulsification: The core material and the wall material were mixed, and Tween 80 emulsifier accounting for 8-12% of the mass of the irradiated modified amylose was added, and homogenized at a speed of 14000-16000 rpm for 3-6 minutes to form an O / W emulsion;

[0026] (3) Coagulation: The pH of the O / W emulsion was adjusted to 4-5 with citric acid solution and stirred at 50-55 °C for 1-1.5 h to induce starch cross-linking;

[0027] (4) Spray drying: Use a spray dryer with the inlet temperature set at 175-185°C and the outlet temperature set at 75-85°C to spray dry the cross-linked O / W emulsion to obtain microcapsule powder.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention first performs mild acid hydrolysis on the amylose to partially hydrolyze the molecular chain, reduce the degree of polymerization, and improve the solubility, which is conducive to the irradiation process; at the same time, a staged approach is adopted during the irradiation process, with the first stage mainly crushing and the second stage mainly modifying. In this way, the molecular weight distribution of the starch is more concentrated, and the overall uniformity and density of the microcapsule film are significantly improved, thereby improving the stability of the capsule.

[0030] (2) In a preferred embodiment of the present invention, ozone-activated ferritin is used as an irradiation accelerator, which utilizes ozone to oxidize the tyrosine residues on the surface of ferritin to generate protein semiquinone free radicals (Tyr-O·), and then produces a cascade reaction (Tyr-O·+Fe 2+ →Tyr+Fe 3+ + O2 - ;·O2 - +H + →HO2·→H2O2;H2O2+Fe 2+ → OH+OH - +Fe 3 + ), generating a large number of ·OH free radicals, which act on the sensitizing sites of amylose, increase solubility, and enhance the overall radiation modification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a scanning electron microscope image of the microcapsule powder prepared in Example 8 of the present invention;

[0032] Figure 2 The graph shows the retention rate of lycopene microcapsules in each group. DETAILED DESCRIPTION

[0033] The present application is described in further detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0034] 1. Main Materials

[0035] Amylose: Potato starch was purchased from Dacheng Group in Changchun, Jilin Province. The amylose was separated and purified by n-butanol precipitation method. The amylose content was determined to be 86.2%.

[0036] Lycopene standard: purity 99%, purchased from Hebei Chenguang Biological Company.

[0037] 2. Implementation of the Experiment

[0038] Example 1

[0039] An irradiation-modified amylose starch is prepared by the following preparation method:

[0040] S1. Preprocessing

[0041] The modified amylose was obtained by dissolving amylose in deionized water twice its mass, adjusting the pH to 3 with 0.08 M HCl solution, heating to 45°C and stirring for 45 minutes, then neutralizing with 0.8 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 48°C, pressure is 0.06 MPa, and time is 6 hours).

[0042] S2. Irradiation treatment

[0043] The modified amylose was dissolved in 3 times the mass of deionized water and stirred to obtain a dispersion. The dispersion was subjected to electron beam irradiation at an energy of 4 MeV. The irradiation was divided into a first stage and a second stage. The dose rate of the first stage was 2.5 kGy / s and the dose was 8 kGy. The dose rate of the second stage was 0.3 kGy / s and the dose was 28 kGy.

[0044] S3, post-processing

[0045] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 48° C., the pressure was 0.06 MPa, and the time was 4 h) to obtain irradiated modified amylose.

[0046] Example 2

[0047] An irradiation-modified amylose starch is prepared by the following preparation method:

[0048] S1. Preprocessing

[0049] The modified amylose was obtained by dissolving amylose in 3 times the mass of deionized water, adjusting the pH to 3.5 with 0.1 M HCl solution, heating to 50°C and stirring for 40 min, then neutralizing with 1 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 50°C, pressure is 0.07 MPa, and time is 5 h);

[0050] S2. Irradiation treatment

[0051] The modified amylose was dissolved in 3.5 times the mass of deionized water, and the mixture was stirred to obtain a dispersion. The dispersion was subjected to electron beam irradiation at an energy of 5 MeV. The irradiation was divided into a first stage and a second stage. The dose rate of the first stage was 3 kGy / s and the dose was 10 kGy. The dose rate of the second stage was 0.5 kGy / s and the dose was 30 kGy.

[0052] S3, post-processing

[0053] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 50° C., the pressure was 0.07 MPa, and the time was 5 h) to obtain irradiated modified amylose.

[0054] Example 3

[0055] An irradiation-modified amylose starch is prepared by the following preparation method:

[0056] S1. Preprocessing

[0057] The modified amylose was obtained by dissolving amylose in 4 times the mass of deionized water, adjusting the pH to 4 with 0.12 M HCl solution, heating to 55°C and stirring for 35 minutes, then neutralizing with 1.2 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 52°C, pressure is 0.08 MPa, and time is 4 hours);

[0058] S2. Irradiation treatment

[0059] The modified amylose was dissolved in 5 times the mass of deionized water and stirred to obtain a dispersion. The dispersion was subjected to electron beam irradiation at an energy of 6 MeV. The irradiation was divided into a first stage and a second stage. The dose rate of the first stage was 3.5 kGy / s and the dose was 12 kGy. The dose rate of the second stage was 0.6 kGy / s and the dose was 32 kGy.

[0060] S3, post-processing

[0061] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 52° C., the pressure was 0.08 MPa, and the time was 6 h) to obtain irradiated modified amylose.

[0062] Example 4

[0063] An irradiation-modified amylose starch is prepared by the following preparation method:

[0064] S1. Preprocessing

[0065] The modified amylose was obtained by dissolving amylose in 3 times the mass of deionized water, adjusting the pH to 3.5 with 0.1 M HCl solution, heating to 50°C and stirring for 40 min, then neutralizing with 1 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 50°C, pressure is 0.07 MPa, and time is 5 h);

[0066] S2. Irradiation treatment

[0067] The modified amylose is dissolved in 3.5 times the mass of deionized water and stirred to obtain a dispersion. An irradiation accelerator is added to the dispersion at a mass of 0.1%, wherein the irradiation accelerator is ozone-activated ferritin. The dispersion is subjected to electron beam irradiation at an energy of 5 MeV. The irradiation is divided into a first stage and a second stage. The dose rate of the first stage is 3 kGy / s and the dose is 10 kGy. The dose rate of the second stage is 0.5 kGy / s and the dose is 30 kGy.

[0068] The preparation steps of ozone-activated ferritin are as follows: recombinant ferritin is dissolved in Tris-HCl buffer to control the dissolution concentration to 4 mg / mL, FeCl2 solution is added to the solution, stirred at 60 rpm in the dark at 24 ° C for 2 h, and dialyzed for 36 h to remove free Fe 2+ Then, ozone was introduced into the solution at a flow rate of 0.4 L / min for 4 minutes until the ozone concentration reached 0.08 ppm. The solution was allowed to react for 6 minutes to activate the ferritin surface. Finally, the solution was freeze-dried (temperature: -50°C, pressure: 0.08 Pa) to obtain ozone-activated ferritin.

[0069] S3, post-processing

[0070] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 50° C., the pressure was 0.07 MPa, and the time was 5 h) to obtain irradiated modified amylose.

[0071] Example 5

[0072] An irradiation-modified amylose starch is prepared by the following preparation method:

[0073] S1. Preprocessing

[0074] The modified amylose was obtained by dissolving amylose in 3 times the mass of deionized water, adjusting the pH to 3.5 with 0.1 M HCl solution, heating to 50°C and stirring for 40 min, then neutralizing with 1 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 50°C, pressure is 0.07 MPa, and time is 5 h);

[0075] S2. Irradiation treatment

[0076] The modified amylose is dissolved in 3.5 times the mass of deionized water and stirred to obtain a dispersion. An irradiation accelerator is added to the dispersion at a concentration of 0.2% by mass of the dispersion, wherein the irradiation accelerator is ozone-activated ferritin. The dispersion is subjected to electron beam irradiation at an energy of 5 MeV. The irradiation is divided into a first stage and a second stage. The dose rate of the first stage is 3 kGy / s and the dose is 10 kGy. The dose rate of the second stage is 0.5 kGy / s and the dose is 30 kGy.

[0077] The preparation steps of ozone-activated ferritin are as follows: recombinant ferritin is dissolved in Tris-HCl buffer to control the dissolution concentration to 5 mg / mL, FeCl2 solution is added to the solution, stirred at 90 rpm in the dark at 25 ° C for 1.8 h, and dialyzed for 45 h to remove free Fe 2+ Then, ozone was introduced into the solution at a flow rate of 0.5 L / min for 5 minutes until the ozone concentration reached 0.12 ppm. The solution was allowed to react for 7 minutes to activate the ferritin surface. Finally, the solution was freeze-dried (temperature: -50°C, pressure: 0.09 Pa) to obtain ozone-activated ferritin.

[0078] S3, post-processing

[0079] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 50° C., the pressure was 0.07 MPa, and the time was 5 h) to obtain irradiated modified amylose.

[0080] Example 6

[0081] An irradiation-modified amylose starch is prepared by the following preparation method:

[0082] S1. Preprocessing

[0083] The modified amylose was obtained by dissolving amylose in 3 times the mass of deionized water, adjusting the pH to 3.5 with 0.1 M HCl solution, heating to 50°C and stirring for 40 min, then neutralizing with 1 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 50°C, pressure is 0.07 MPa, and time is 5 h);

[0084] S2. Irradiation treatment

[0085] The modified amylose is dissolved in 3.5 times the mass of deionized water and stirred to obtain a dispersion. An irradiation accelerator is added to the dispersion at a concentration of 0.3% by mass of the dispersion, wherein the irradiation accelerator is ozone-activated ferritin. The dispersion is subjected to electron beam irradiation at an energy of 5 MeV. The irradiation is divided into a first stage and a second stage. The dose rate of the first stage is 3 kGy / s and the dose is 10 kGy. The dose rate of the second stage is 0.5 kGy / s and the dose is 30 kGy.

[0086] The preparation steps of ozone-activated ferritin are as follows: recombinant ferritin is dissolved in Tris-HCl buffer to control the dissolution concentration to 6 mg / mL, FeCl2 solution is added to the solution, stirred at 120 rpm in the dark at 26 ° C for 1.5 h, and dialyzed for 48 h to remove free Fe 2+ Then, ozone was introduced into the solution at a flow rate of 0.6 L / min for 6 minutes until the ozone concentration reached 0.15 ppm. The solution was allowed to react for 8 minutes to activate the ferritin surface. Finally, the solution was freeze-dried (temperature at -50°C, pressure at 0.1 Pa) to obtain ozone-activated ferritin.

[0087] S3, post-processing

[0088] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 50° C., the pressure was 0.07 MPa, and the time was 5 h) to obtain irradiated modified amylose.

[0089] Example 7

[0090] An application of irradiated modified amylose in lycopene-encapsulating microcapsules, wherein the specific method of the application is as follows:

[0091] (1) Preparation: 1 g of lycopene was dissolved in soybean oil at a ratio of 5 mL to obtain a core material. 1 g of the irradiated amylose prepared in Example 2 was dissolved in water at a ratio of 10 mL to obtain a wall material. The mixture was heated to 60° C. for gelatinization.

[0092] (2) Emulsification: The core material and the wall material were mixed, and Tween 80 emulsifier accounting for 10% of the mass of the irradiated modified amylose was added, and homogenized at a speed of 15000 rpm for 5 min to form an O / W emulsion;

[0093] (3) Coagulation: The pH of the O / W emulsion was adjusted to 4 with citric acid solution and stirred at 52 °C for 1.2 h to induce starch cross-linking;

[0094] (4) Spray drying: A spray dryer was used with the inlet temperature set at 180°C and the outlet temperature set at 80°C to spray dry the cross-linked O / W emulsion to obtain microcapsule powder.

[0095] Example 8

[0096] An application of irradiated modified amylose in lycopene-encapsulating microcapsules, wherein the specific method of the application is as follows:

[0097] (1) Preparation: Dissolve lycopene in soybean oil at a ratio of 1 g:5 mL to obtain the core material. Dissolve the irradiated amylose prepared in Example 5 in water at a ratio of 1 g:10 mL and heat to 60° C. for gelatinization to obtain the wall material.

[0098] (2) Emulsification: The core material and the wall material were mixed, and Tween 80 emulsifier accounting for 10% of the mass of the irradiated modified amylose was added, and homogenized at a speed of 15000 rpm for 5 min to form an O / W emulsion;

[0099] (3) Coagulation: The pH of the O / W emulsion was adjusted to 4 with citric acid solution and stirred at 52 °C for 1.2 h to induce starch cross-linking;

[0100] (4) Spray drying: A spray dryer was used with the inlet temperature set at 180°C and the outlet temperature set at 80°C to spray dry the cross-linked O / W emulsion to obtain microcapsule powder.

[0101] The microcapsule powder prepared in Example 8 was observed using a scanning electron microscope (TM 4000plus, Hitachi, Japan). The scanning electron microscope image is as follows: Figure 1 As shown,

[0102] Comparative Example 1

[0103] An irradiation-modified amylose starch is prepared by the following preparation method:

[0104] S1. Preprocessing

[0105] The modified amylose was obtained by dissolving amylose in 3 times the mass of deionized water, adjusting the pH to 3.5 with 0.1 M HCl solution, heating to 50°C and stirring for 40 min, then neutralizing with 1 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 50°C, pressure is 0.07 MPa, and time is 5 h);

[0106] S2. Irradiation treatment

[0107] The modified amylose is dissolved in 3.5 times the mass of deionized water, stirred evenly to obtain a dispersion, and the dispersion is subjected to electron beam irradiation. The electron beam irradiation energy is 5 MeV, without stage, the dose rate is 1 kGy / s, and the dose is 40 kGy;

[0108] S3, post-processing

[0109] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 50° C., the pressure was 0.07 MPa, and the time was 5 h) to obtain irradiated modified amylose.

[0110] Comparative Example 2

[0111] An irradiation-modified amylose starch is prepared by the following preparation method:

[0112] S1. Preprocessing

[0113] The modified amylose was obtained by dissolving amylose in 3 times the mass of deionized water, adjusting the pH to 3.5 with 0.1 M HCl solution, heating to 50°C and stirring for 40 min, then neutralizing with 1 M NaOH solution, washing with water by centrifugation, and vacuum drying (vacuum drying temperature is 50°C, pressure is 0.07 MPa, and time is 5 h);

[0114] S2. Irradiation treatment

[0115] The modified amylose is dissolved in 3.5 times the mass of deionized water and stirred to obtain a dispersion. An irradiation accelerator is added to the dispersion at a concentration of 0.2% by mass of the dispersion, wherein the irradiation accelerator is ferritin. The dispersion is subjected to electron beam irradiation at an energy of 5 MeV. The irradiation is divided into a first stage and a second stage. The dose rate of the first stage is 3 kGy / s and the dose is 10 kGy. The dose rate of the second stage is 0.5 kGy / s and the dose is 30 kGy.

[0116] The preparation steps of the ferritin are as follows: recombinant ferritin is dissolved in Tris-HCl buffer to control the dissolution concentration to 5 mg / mL, FeCl2 solution is added to the solution, stirred at 90 rpm in the dark at 25 ° C for 1.8 h, and then dialyzed for 45 h to remove free Fe 2+ Finally, the solution was freeze-dried (temperature: -50°C, pressure: 0.09 Pa) to obtain ozone-activated ferritin.

[0117] S3, post-processing

[0118] The dispersion after electron beam irradiation was taken, washed with water by centrifugation, and vacuum dried (the vacuum drying temperature was 50° C., the pressure was 0.07 MPa, and the time was 5 h) to obtain irradiated modified amylose.

[0119] Comparative Example 3

[0120] An application of irradiated modified amylose in lycopene-encapsulating microcapsules, wherein the specific method of the application is as follows:

[0121] (1) Preparation: 1 g of lycopene was dissolved in soybean oil at a ratio of 5 mL to obtain a core material. 1 g of the irradiated amylose prepared in Comparative Example 1 was dissolved in water at a ratio of 10 mL to obtain a wall material. The mixture was heated to 60° C. for gelatinization.

[0122] (2) Emulsification: The core material and the wall material were mixed, and Tween 80 emulsifier accounting for 10% of the mass of the irradiated modified amylose was added, and homogenized at a speed of 15000 rpm for 5 min to form an O / W emulsion;

[0123] (3) Coagulation: The pH of the O / W emulsion was adjusted to 4 with citric acid solution and stirred at 52 °C for 1.2 h to induce starch cross-linking;

[0124] (4) Spray drying: A spray dryer was used with the inlet temperature set at 180°C and the outlet temperature set at 80°C to spray dry the cross-linked O / W emulsion to obtain microcapsule powder.

[0125] Comparative Example 4

[0126] An application of irradiated modified amylose in lycopene-encapsulating microcapsules, wherein the specific method of the application is as follows:

[0127] (1) Preparation: 1 g of lycopene was dissolved in soybean oil at a ratio of 5 mL to obtain a core material. 1 g of the irradiated amylose prepared in Comparative Example 2 was dissolved in water at a ratio of 10 mL to obtain a wall material. The mixture was heated to 60° C. for gelatinization.

[0128] (2) Emulsification: The core material and the wall material were mixed, and Tween 80 emulsifier accounting for 10% of the mass of the irradiated modified amylose was added, and homogenized at a speed of 15000 rpm for 5 min to form an O / W emulsion;

[0129] (3) Coagulation: The pH of the O / W emulsion was adjusted to 4 with citric acid solution and stirred at 52 °C for 1.2 h to induce starch cross-linking;

[0130] (4) Spray drying: A spray dryer was used with the inlet temperature set at 180°C and the outlet temperature set at 80°C to spray dry the cross-linked O / W emulsion to obtain microcapsule powder.

[0131] 3. Performance Testing

[0132] (1) Starch molecular weight

[0133] Take 100 mg of the untreated amylose sample (blank group) and the irradiated modified amylose samples prepared in Example 2, Example 5, Comparative Example 1 and Comparative Example 2, respectively, add 1 mL of anhydrous ethanol (to moisten the sample), 2 mL of distilled water, and 2 mL of a 3 mol / L NaOH solution. The resulting solution is fully vibrated and evenly mixed, and then 5 mL of distilled water is gradually added. The mixture is heated in a boiling water bath for 30 min until the sample is completely dissolved, neutralized with hydrochloric acid to pH 7.0, and then diluted to 50 mL with distilled water. The solution is filtered through a 0.45 μm microporous membrane. Chromatographic conditions: The chromatographic column was a 79911GF-MXA aqueous phase mixed column, the column temperature was 35°C, a differential refractive index detector and a multi-angle laser scattering detector were used, the mobile phase was 0.05 mol / L NaCl, the flow rate was 0.5 mL / min, the injection volume was 50 μL, and the data acquisition time was 30 min. The weight average molecular weight (Mw), number average molecular weight (Mn) and dispersion index (Mw / Mn) of each group were calculated respectively.

[0134] (2) Starch solubility

[0135] Take the untreated amylose sample (blank group) and the irradiated amylose samples prepared in Example 2, Example 5, Comparative Example 1 and Comparative Example 2, respectively. Dissolve the starch sample (W0) in 10 mL of distilled water, then heat in a 90°C water bath and continue stirring for 30 minutes. The starch suspension is then cooled to 25°C and centrifuged (4500×g, 20 minutes). The supernatant is poured into an aluminum plate and dried in an oven at 105°C to constant weight (W1). The solubility W of the irradiated amylose is calculated as follows:

[0136]

[0137] Wherein: W0 is the mass of the starch sample, g; W1 is the mass of the starch sample dried to constant weight at 105℃, g.

[0138] (3) Lycopene microcapsule encapsulation efficiency

[0139] 10 mg of microcapsule powder prepared from an untreated amylose sample (blank group, prepared as above) and the microcapsule powders prepared in Example 7, Example 8, Comparative Example 3, and Comparative Example 4 were dissolved in deionized water to obtain capsule solutions. Two 1 mL portions of capsule solutions were respectively dissolved in 10 mL centrifuge tubes. 3 mL of n-hexane was added to one portion, mixed evenly, and centrifuged to obtain the supernatant. After dilution, the absorbance was measured at a wavelength of 471 nm. According to the lycopene standard curve (y = 0.2891x - 0.0029, R 2=0.9998) to calculate the mass concentration of lycopene in the sample, which represents the mass concentration of unencapsulated lycopene. Another sample was first ground using a pestle and mortar to destroy the microcapsule membrane. Then, 1 mL of anhydrous ethanol and 2 mL of n-hexane were added. Similarly, the mass concentration of lycopene in the supernatant was measured, which represents the mass concentration of total lycopene in the microcapsules. The lycopene microcapsule encapsulation efficiency E was calculated using the following formula:

[0140]

[0141] Where C1 is the mass concentration of unencapsulated lycopene, μg / mL; C0 is the mass concentration of total lycopene in the microcapsules, μg / mL.

[0142] (4) Storage stability of lycopene microcapsules

[0143] The microcapsule powder prepared from the untreated amylose sample (blank group, prepared as above), as well as the microcapsule powders prepared in Example 7, Example 8, Comparative Example 3 and Comparative Example 4, were placed in brown glass bottles, and then stored in a 55°C thermostat filled with nitrogen. Every 1 day, a certain amount of microcapsule powder was placed in a test tube and extracted three times with ethanol-n-hexane (volume ratio 1:2). The upper n-hexane extracts were combined and the absorbance at a wavelength of 471 nm was measured using an ultraviolet spectrophotometer. According to the lycopene standard curve (y = 0.2891x - 0.0029, R 2 =0.9998) to calculate the lycopene concentration in the sample, and evaluate its storage stability by the retention rate of lycopene. The retention rate Q is calculated as follows:

[0144]

[0145] Where, C3 is the initial mass concentration of lycopene, μg / mL; C2 is the mass concentration of lycopene after treatment, μg / mL.

[0146] 4. Results Analysis

[0147] (1) Starch molecular weight

[0148] Table 1: Molecular weight results of starch in each group

[0149]

[0150] (2) Starch solubility

[0151] Table 2: Starch solubility results of each group

[0152]

[0153] (3) Lycopene microcapsule encapsulation efficiency

[0154] Table 3: Lycopene microcapsule encapsulation efficiency results of each group

[0155]

[0156] (4) Storage stability of lycopene microcapsules

[0157] The results of lycopene microcapsule retention rate in each group are as follows Figure 2 shown.

[0158] Comprehensive analysis: According to Table 1-3 and Figure 2 As can be seen, the irradiated amylose prepared in Example 2 of the present invention exhibited an increased number-average molecular weight (Mn) compared to the blank, while the weight-average molecular weight (Mw) significantly decreased, resulting in a significantly lower dispersion index (Mw / Mn). This indicates a narrower molecular weight distribution and improved uniformity, which is beneficial for improving subsequent film-forming quality. The solubility of Example 2 was also significantly improved compared to the blank, resolving the issue of poor solubility of conventional amylose. Regarding lycopene microcapsules, Example 7, prepared using the irradiated amylose of Example 2, exhibited a 26.0% increase in encapsulation efficiency compared to the blank. Storage stability was also significantly improved, with the 7-day retention rate at 55°C increasing from 32.4% to 67.5%.

[0159] Example 5 of the present invention further utilizes ozone-activated ferritin as an irradiation accelerator, significantly improving starch molecular weight compared to Example 2, significantly reducing the Mw / Mn dispersion index, and further enhancing solubility. Regarding lycopene microcapsules, Example 8, prepared from the irradiated amylose modified in Example 5, achieved a significant 12.2% increase in encapsulation efficiency compared to Example 7. The 7-day retention rate at 55°C increased from 67.5% to 75.1%.

[0160] Comparative Example 1, based on Example 2, eliminated the staged irradiation method and adopted a single dose rate without changing the total dose. This resulted in a significant increase in the dispersion index (Mw / Mn) compared to Example 2, a wider molecular weight distribution, and a slight decrease in solubility. Regarding lycopene microcapsules, Comparative Example 3, prepared using the irradiated amylose modified from Example 1, showed a significant 10.6% decrease in encapsulation efficiency compared to Example 7. The 7-day retention rate at 55°C decreased from 67.5% to 58.3%.

[0161] Comparative Example 2, based on Example 5, eliminated the ozone dissolution step, using ordinary ferritin as the irradiation accelerator. This resulted in a significant increase in the dispersion index Mw / Mn compared to Example 5, while significantly decreasing the solubility. Regarding lycopene microcapsules, Comparative Example 4, prepared using the irradiation-modified amylose of Comparative Example 2, showed a 9.5% decrease in encapsulation efficiency compared to Example 8, and a 7-day retention rate at 55°C decreased from 75.1% to 69.2%, comparable to that of Example 2. This indicates that using only ordinary ferritin as an irradiation accelerator does not significantly enhance irradiation, requiring ozone activation.

[0162] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. An irradiation-modified amylose starch, characterized in that: It is prepared by the following preparation method: S1. Preprocessing Dissolve amylose in 2-4 times its mass of deionized water, adjust the pH to 3-4 with HCl solution, heat to 45-55°C and stir for 35-45 minutes, then neutralize with NaOH solution, wash with water by centrifugation, and vacuum dry to obtain modified amylose; S2. Irradiation treatment The modified amylose is dissolved in 3-5 times the mass of deionized water, stirred evenly to obtain a dispersion, and the dispersion is subjected to electron beam irradiation. The electron beam irradiation is divided into a first stage and a second stage. The dose rate of the first stage is 2.5-3.5 kGy / s and the dose is 8-12 kGy. The dose rate of the second stage is 0.3-0.6 kGy / s and the dose is 28-32 kGy. S3, post-processing The dispersion after electron beam irradiation is taken, washed with water by centrifugation and dried in vacuum to obtain irradiation-modified amylose.

2. The irradiation-modified amylose according to claim 1, characterized in that: In step S1, the concentration of the HCl solution is 0.08-0.12M, and the concentration of the NaOH solution is 0.8-1.2M.

3. The irradiation-modified amylose according to claim 1, characterized in that: In step S2, the energy of the electron beam irradiation is 4-6 MeV.

4. The irradiation-modified amylose according to claim 1, characterized in that: In step S2, before electron beam irradiation, an irradiation accelerator is added to the dispersion in an amount of 0.1-0.3% by mass of the dispersion, wherein the irradiation accelerator is ozone-activated ferritin.

5. The irradiation-modified amylose according to claim 4, characterized in that: The preparation steps of the ozone-activated ferritin are as follows: recombinant ferritin is dissolved in Tris-HCl buffer to control the dissolved concentration to 4-6 mg / mL, FeCl2 solution is added to the solution, stirred for reaction, and dialyzed for 36-48 hours to remove free Fe 2+ Then, ozone is introduced into the solution to make the dissolved ozone concentration reach 0.08-0.15ppm, and the solution is allowed to react for 6-8 minutes to activate the ferritin surface. Finally, the solution is freeze-dried to obtain ozone-activated ferritin.

6. The irradiation-modified amylose according to claim 5, characterized in that: The stirring reaction is specifically carried out at 24-26° C. and 60-120 rpm in the dark for 1.5-2 hours.

7. The irradiation-modified amylose according to claim 5, characterized in that: The ozone is introduced at a flow rate of 0.4-0.6 L / min for 4-6 minutes.

8. The irradiation-modified amylose according to claim 5, characterized in that: The freeze-drying temperature is -50°C and the pressure is 0.08-0.1Pa.

9. The irradiation-modified amylose according to claim 1, characterized in that: In steps S1 and S3, the vacuum drying temperature is 48-52° C., the pressure is 0.06-0.08 MPa, and the time is 4-6 hours.

10. Use of the irradiated modified amylose according to any one of claims 1 to 9 in encapsulating lycopene in microcapsules, characterized in that: The specific method of the application is: (1) Preparation: Dissolve lycopene in soybean oil at a ratio of 1 g: 4-6 mL to obtain a core material, then dissolve the irradiated modified amylose in water at a ratio of 1 g: 8-12 mL, and heat to 58-62° C. for gelatinization to obtain a wall material; (2) Emulsification: The core material and the wall material were mixed, and Tween 80 emulsifier was added at a concentration of 8-12% by weight of the irradiated modified amylose, and homogenized at a speed of 14,000-16,000 rpm for 3-6 minutes to form an O / W emulsion; (3) Coagulation: The pH of the O / W emulsion was adjusted to 4-5 with citric acid solution and stirred at 50-55 °C for 1-1.5 h to induce starch cross-linking; (4) Spray drying: Use a spray dryer with the inlet temperature set at 175-185°C and the outlet temperature set at 75-85°C to spray dry the cross-linked O / W emulsion to obtain microcapsule powder.

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