An antioxidant lily polysaccharide food additive and a preparation method thereof

Abstract

The application discloses an antioxidant lily polysaccharide food additive and a preparation method thereof, and belongs to the field of food additives. The food additive is a microcapsule powder composed of a core material and a wall material. The core material is sulfated lily polysaccharide with a weight fraction of 30-40 parts, a sulfate group substitution degree of 0.8-1.3 and a weight average molecular weight of 10-100 kDa. The wall material is a composite wall material composed of malt dextrin, beta-cyclodextrin and gum arabic in a mass ratio of 5:3:2, with a weight fraction of 60-70 parts. The microcapsule powder has a particle size of 10-80 mu m and an embedding rate of not less than 85%. The preparation method comprises the following steps: steam explosion treatment, composite enzymatic extraction, ultrafiltration fractional purification, sulfate esterification modification and microcapsulation forming. The product has high antioxidant activity and good stability, and is suitable for food systems such as beverages, baked foods and dairy products.

Description

Technical Field

[0001] This invention relates to the field of food additives, specifically to an antioxidant lily polysaccharide food additive and its preparation method. Background Technology

[0002] Lily is a plant used for both food and medicine, and its bulbs are rich in various active ingredients such as polysaccharides, proteins, and saponins. Lily polysaccharides, as one of the main active ingredients of lily, have biological activities such as immunomodulation, antioxidation, and hypoglycemia, and have broad application prospects in the food, health product, and pharmaceutical fields.

[0003] However, natural lily polysaccharides have relatively weak antioxidant activity, and their molecules contain a large number of hydroxyl groups, making them prone to moisture absorption and browning. They are also susceptible to degradation in acidic or high-temperature environments, which significantly limits their application. Furthermore, lily polysaccharides themselves have a slightly bitter taste, and adding them directly to food can negatively impact the product's sensory quality.

[0004] To improve the functional properties of lily polysaccharides, researchers have explored structural modifications using chemical methods (such as sulfation and carboxymethylation) and physical methods (such as microencapsulation and nano-sizing). Sulfation modification introduces sulfate groups into the polysaccharide molecule, enhancing its free radical scavenging and metal ion chelating abilities, thereby significantly improving its antioxidant activity. Microencapsulation technology encapsulates the active ingredients within the wall material, isolating them from external environmental influences and improving product stability and palatability.

[0005] Currently, the development of lily polysaccharides in existing technologies mostly focuses on improvements in single aspects, such as optimizing extraction processes, chemical modification, or microencapsulation. There is a lack of integrated technologies that combine raw material pretreatment, targeted enrichment of active components, molecular structure modification, and dosage form formulation. Furthermore, existing microcapsule products often suffer from problems such as unreasonable core-to-wall material ratios and a lack of synergistic design in wall material selection, resulting in low encapsulation rates, poor activity retention, and inadequate rehydration properties.

[0006] Therefore, developing a lily polysaccharide food additive with clearly defined components, strong antioxidant activity, good physicochemical stability, and excellent sensory quality, and establishing a complete preparation process to support it, is of great significance for promoting the in-depth development and utilization of lily resources. Summary of the Invention

[0007] The purpose of this invention is to provide an antioxidant lily polysaccharide food additive. This product uses sulfated lily polysaccharide as the core material and is encapsulated with a composite wall material in a specific ratio. It has the characteristics of high antioxidant activity, good stability, and good palatability.

[0008] Another objective of this invention is to provide a method for preparing the above-mentioned antioxidant lily polysaccharide food additive. This method includes steps such as raw material pretreatment, enzymatic extraction, membrane fractionation purification, sulfation modification, and microencapsulation. The process is continuous and the parameters are controllable, making it suitable for industrial production.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: 1. An antioxidant lily polysaccharide food additive, characterized in that: the food additive is a microcapsule powder, composed of a core material and a wall material; The core material is sulfated lily polysaccharide, and the core material is 30-40 parts by weight. The wall material is a composite wall material made of maltodextrin, β-cyclodextrin and gum arabic in a mass ratio of 5:3:2, and the weight of the wall material is 60 to 70 parts. The sulfated lily polysaccharide is obtained by sulfation modification of lily polysaccharide, and the sulfated lily polysaccharide has a degree of sulfate substitution of 0.8 to 1.3 and a weight-average molecular weight of 10 to 100 kDa. The microcapsule powder has a particle size of 10–80 μm and an encapsulation rate of not less than 85%.

[0010] As an improvement, the sulfated lily polysaccharide has a sulfate group substitution degree of 1.0 to 1.2.

[0011] As an improvement, the mass ratio of the core material to the wall material is 35:65.

[0012] This invention also provides a method for preparing the above-mentioned antioxidant lily polysaccharide food additive, comprising the following steps: S1 Steam Explosion Treatment: Clean lily bulbs are pressurized at 1.0-1.5 MPa for 60-120 seconds and then instantly depressurized; S2 compound enzymatic hydrolysis extraction: Add water to the blasted material at a material-to-liquid ratio of 1:15 to 1:20 (w / v), add 0.8% to 1.5% of the compound enzyme by dry material mass, and hydrolyze at 50±2℃ and pH 5.0 for 1 to 2 hours; then heat to 90℃ and keep warm for 1 hour to inactivate the enzyme, centrifuge to collect the supernatant, and concentrate under reduced pressure; The complex enzyme is composed of cellulase and pectinase in a mass ratio of 2:1; S3 Ultrafiltration Fractionation and Purification: After microfiltration clarification, the concentrate was fractionated sequentially using ultrafiltration membranes with molecular weight cutoffs of 100kDa and 10kDa, and the 10-100kDa fraction was collected; the fraction was decolorized and deproteinized by macroporous adsorption resin, desalted by dialysis, and freeze-dried to obtain lily polysaccharide. S4 Sulfuric acid esterification modification: Lily polysaccharide was dissolved in anhydrous formamide, and after preheating, a freshly prepared esterifying agent made of chlorosulfonic acid and anhydrous pyridine in a volume ratio of 1:4 to 1:8 was added dropwise. The reaction was carried out at 60 to 70°C for 2 to 4 hours. After the reaction was completed, the mixture was cooled, neutralized with alkali, dialyzed, and freeze-dried to obtain sulfated lily polysaccharide. S5 Microencapsulation: 30-40 parts by weight of sulfated lily polysaccharide are used as the core material; 60-70 parts of a composite wall material, consisting of maltodextrin, β-cyclodextrin, and gum arabic in a mass ratio of 5:3:2, are dissolved in pure water at 60°C to prepare a wall material solution; after cooling, the core material is added to the wall material solution, pre-emulsified by high-speed shearing, then homogenized under high pressure at 30-50 MPa, cyclically repeated twice to form a stable emulsion; finally, spray drying is performed at an inlet air temperature of 180±5°C and an outlet air temperature of 85±5°C to obtain microencapsulated powdered antioxidant lily polysaccharide food additive. As an improvement, in step S1, the pressure is 1.2 to 1.5 MPa, and the pressure holding time is 90 to 120 seconds.

[0013] As an improvement, in step S2, the amount of the compound enzyme added accounts for 1.0% to 1.5% of the dry material mass, the enzymatic hydrolysis temperature is 50℃, and the enzymatic hydrolysis time is 1.5 to 2 hours.

[0014] As an improvement, in step S3, the dialysis desalination is performed using running water dialysis.

[0015] As an improvement, in step S4, the volume ratio of chlorosulfonic acid to anhydrous pyridine is 1:6 to 1:8, the reaction temperature is 65 to 70°C, and the reaction time is 2 to 3 hours.

[0016] As an improvement, in step S5, the pressure of the high-pressure homogenization is 40-50 MPa; the inlet air temperature of the spray drying is 180°C and the outlet air temperature is 85°C.

[0017] As an improvement, the sulfated lily polysaccharide has a sulfate group substitution degree of 1.0 to 1.2, and the mass ratio of the core material to the wall material is 35:65.

[0018] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: The advantages of this invention compared to the prior art are: This invention uses sulfated lily polysaccharides with specific degrees of substitution and molecular weight ranges as the core material, which exhibits significantly enhanced free radical scavenging ability compared to unmodified lily polysaccharides. Simultaneously, by limiting the ratio of core material to wall material, the product achieves both high encapsulation efficiency and sufficient active loading. In the composite wall material, maltodextrin provides filling support, β-cyclodextrin performs inclusion and flavor masking functions, and gum arabic enhances emulsification stability. The synergistic effect of these three components results in excellent rehydration properties and sensory qualities in the product.

[0019] This invention organically integrates unit operations such as steam explosion pretreatment, compound enzymatic extraction, ultrafiltration membrane fractionation, sulfation modification, and spray drying microencapsulation to form a complete process chain. Steam explosion treatment can effectively break down the dense structure of lily bulbs, improving the efficiency of subsequent enzymatic hydrolysis; ultrafiltration membrane fractionation can achieve targeted enrichment of active components; sulfation modification can directionally introduce functional groups; and microencapsulation can protect active ingredients from the influence of the external environment. The parameters of each step are clearly defined, facilitating industrial-scale production. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of a method for preparing an antioxidant lily polysaccharide food additive according to the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example

[0022] Steam explosion treatment: Take clean lily bulbs, place them in a steam explosion device, maintain the pressure at 1.2 MPa for 90 seconds, and then release the pressure instantly.

[0023] Compound enzymatic hydrolysis extraction: Water was added to the blasted material at a material-to-liquid ratio of 1:18 (w / v), and a compound enzyme (cellulase to pectinase mass ratio of 2:1) was added at 1.2% of the dry material mass. Enzymatic hydrolysis was carried out at 50℃ and pH 5.0 for 1.5 h. Then the temperature was raised to 90℃ and kept at this temperature for 1 h to inactivate the enzyme. The supernatant was collected by centrifugation and concentrated under reduced pressure.

[0024] Ultrafiltration fractionation and purification: After clarification by microfiltration, the concentrate was fractionated sequentially using ultrafiltration membranes with molecular weight cutoffs of 100 kDa and 10 kDa, collecting the 10–100 kDa fraction. This fraction was decolorized and deproteinized by macroporous adsorption resin, desalted by water dialysis, and freeze-dried to obtain lily polysaccharide.

[0025] Sulfuric acid esterification modification: Lily polysaccharide was dissolved in anhydrous formamide, preheated, and then a freshly prepared esterifying agent (chlorosulfonic acid and anhydrous pyridine, volume ratio 1:6) was added dropwise. The reaction was carried out at 65°C for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, neutralized with alkali, dialyzed against running water, and freeze-dried to obtain sulfated lily polysaccharide. The degree of sulfate substitution of the sulfated lily polysaccharide was determined to be 1.09.

[0026] Microencapsulation: 350g of sulfated lily polysaccharide was used as the core material; 500g of maltodextrin, 300g of β-cyclodextrin, and 200g of gum arabic were mixed evenly to obtain 1000g of composite wall material. The composite wall material was dissolved in 1.5L of pure water at 60℃, stirred until completely dissolved, and then cooled to room temperature. The core material was added to the wall material solution, emulsified at 10000rpm for 3min using a high-speed shearing machine, and then homogenized twice at 40MPa using a high-pressure homogenizer. The resulting emulsion was spray-dried at an inlet air temperature of 180℃ and an outlet air temperature of 85℃ to obtain a microencapsulated antioxidant lily polysaccharide food additive.

[0027] The product is a white to pale yellow powder with a moisture content of 4.1% and an encapsulation rate of 92.0%. Example

[0028] Following the method in Example 1, the mass ratio of sulfated lily polysaccharide (core material) to composite wall material was adjusted to 30:70, 35:65, and 40:60 to prepare three microcapsule food additives. These were added to a functional beverage at pH 3.0 at a concentration of 0.05% sulfated lily polysaccharide, and after storage at 37°C for 30 days, the activity retention rates were 96.2%, 94.5%, and 89.8%, respectively. The product with a core-to-wall ratio of 35:65 showed the best performance in terms of beverage turbidity and palatability. Example

[0029] A comparative example was set up to examine the impact of components on product performance: Comparative Example 1: β-cyclodextrin was omitted, and only maltodextrin and gum arabic (mass ratio 5:2) were used as wall materials, and the rest was the same as in Example 1.

[0030] Comparative Example 2: Unmodified lily polysaccharide was used instead of sulfated lily polysaccharide for the core material, and the rest was the same as in Example 1.

[0031] The product of Example 1, along with the products of Comparative Examples 1 and 2, were added to the oil system to investigate their ability to inhibit the increase of peroxide value. The results showed that the inhibitory effect of the product of Example 1 was significantly better than that of Comparative Example 1 (low encapsulation rate, faster decrease in activity) and Comparative Example 2 (weak antioxidant activity of the core material itself).

[0032] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. An antioxidant lily polysaccharide food additive, characterized in that: The food additive is a microcapsule powder, composed of a core material and a wall material; The core material is sulfated lily polysaccharide, and the core material is 30-40 parts by weight. The wall material is a composite wall material made of maltodextrin, β-cyclodextrin and gum arabic in a mass ratio of 5:3:2, and the weight of the wall material is 60 to 70 parts. The sulfated lily polysaccharide is obtained by sulfation modification of lily polysaccharide, and the sulfated lily polysaccharide has a degree of sulfate substitution of 0.8 to 1.3 and a weight-average molecular weight of 10 to 100 kDa. The microcapsule powder has a particle size of 10–80 μm and an encapsulation rate of not less than 85%.

2. The food additive according to claim 1, characterized in that: The sulfated lily polysaccharide has a degree of sulfate substitution of 1.0 to 1.

2.

3. The food additive according to claim 1, characterized in that: The mass ratio of the core material to the wall material is 35:

65.

4. A method for preparing the antioxidant lily polysaccharide food additive according to claim 1, characterized in that, Includes the following steps: S1 Steam Explosion Treatment: Clean lily bulbs are pressurized at 1.0-1.5 MPa for 60-120 seconds and then instantly depressurized; S2 compound enzymatic hydrolysis extraction: Add water to the blasted material at a material-to-liquid ratio of 1:15 to 1:20 (w / v), add 0.8% to 1.5% of the compound enzyme by dry material mass, and hydrolyze at 50±2℃ and pH 5.0 for 1 to 2 hours; then heat to 90℃ and keep warm for 1 hour to inactivate the enzyme, centrifuge to collect the supernatant, and concentrate under reduced pressure; The complex enzyme is composed of cellulase and pectinase in a mass ratio of 2:1; S3 Ultrafiltration Fractionation and Purification: After microfiltration clarification, the concentrate was fractionated sequentially using ultrafiltration membranes with molecular weight cutoffs of 100kDa and 10kDa, and the 10-100kDa fraction was collected; the fraction was decolorized and deproteinized by macroporous adsorption resin, desalted by dialysis, and freeze-dried to obtain lily polysaccharide. S4 Sulfuric acid esterification modification: Lily polysaccharide was dissolved in anhydrous formamide, and after preheating, a freshly prepared esterifying agent made of chlorosulfonic acid and anhydrous pyridine in a volume ratio of 1:4 to 1:8 was added dropwise. The reaction was carried out at 60 to 70°C for 2 to 4 hours. After the reaction was completed, the mixture was cooled, neutralized with alkali, dialyzed, and freeze-dried to obtain sulfated lily polysaccharide. S5 Microencapsulation: 30-40 parts by weight of sulfated lily polysaccharide are used as the core material; 60-70 parts of a composite wall material, consisting of maltodextrin, β-cyclodextrin, and gum arabic in a mass ratio of 5:3:2, are dissolved in pure water at 60°C to prepare a wall material solution; after cooling, the core material is added to the wall material solution, pre-emulsified by high-speed shearing, then homogenized under high pressure at 30-50 MPa, cyclically repeated twice to form a stable emulsion; finally, spray drying is performed at an inlet air temperature of 180±5°C and an outlet air temperature of 85±5°C to obtain microencapsulated powdered antioxidant lily polysaccharide food additive.

5. The preparation method according to claim 4, characterized in that, In step S1, the pressure is 1.2 to 1.5 MPa, and the pressure holding time is 90 to 120 seconds.

6. The preparation method according to claim 4, characterized in that, In step S2, the amount of the compound enzyme added accounts for 1.0% to 1.5% of the dry material mass, the enzymatic hydrolysis temperature is 50℃, and the enzymatic hydrolysis time is 1.5 to 2 hours.

7. The preparation method according to claim 4, characterized in that, In step S3, the dialysis desalination is performed using running water dialysis.

8. The preparation method according to claim 4, characterized in that, In step S4, the volume ratio of chlorosulfonic acid to anhydrous pyridine is 1:6 to 1:8, the reaction temperature is 65 to 70°C, and the reaction time is 2 to 3 hours.

9. The preparation method according to claim 4, characterized in that, In step S5, the pressure of the high-pressure homogenization is 40-50 MPa; the inlet air temperature of the spray drying is 180°C and the outlet air temperature is 85°C.

10. The preparation method according to claim 4, characterized in that, The sulfated lily polysaccharide has a sulfate group substitution degree of 1.0 to 1.2, and the mass ratio of the core material to the wall material is 35:65.

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