Method for constructing hollow porous material through jujube peel fibers and carrageenan, obtained product and application

Abstract

The invention relates to a method for constructing a hollow porous material through jujube peel fibers and carrageenan, an obtained product and application, and belongs to the technical field of food processing. The jujube peel fiber is combined with carrageenan, the fiber can serve as a framework support to form a stable hollow porous structure, the hollow porous structure provides larger surface area and pore volume, and the loading capacity of hydrophobic active ingredients can be increased. The inner surface of the prepared hollow porous structure material can adsorb hydrophobic active ingredients through non-covalent interaction such as physical adsorption and Van der Waals force. The structure can effectively protect the hydrophobic active component from being influenced by the external environment, so that the stability and bioavailability of the hydrophobic active component are improved. The structure not only can effectively load and protect hydrophobic components, but also can adjust the pore size by adjusting the ratio of the fibers to the carrageenan, and the smaller pore size can slow down the diffusion speed of the hydrophobic active components and prolong the release time, so that the hydrophobic active components can be released as required. The bioavailability of hydrophobic nutritional ingredients is improved.

Description

Technical Field

[0001] The invention relates to a method for constructing a hollow porous material through jujube peel fiber and carrageenan, and the obtained product and application, belonging to the technical field of food processing. Background Art

[0002] Due to the fast-paced modern living environment and bad eating and resting habits, the risk of diabetes, lipid metabolism disorders, cardiovascular and cerebrovascular diseases, etc. is increasing year by year. A reasonable diet and appropriate intake of functional nutrients can reduce the risk of disease. Many functional ingredients are hydrophobic ingredients, such as curcumin, resveratrol, carotene, etc., which have the disadvantages of being sensitive to light and heat conditions, easy to decompose, poor water solubility, and weak gastrointestinal absorption. Their physiological activity is easily destroyed under gastrointestinal conditions and their bioavailability is low. The use of encapsulation technology can effectively improve the undesirable properties of these hydrophobic ingredients. There are many common encapsulation methods at present, such as preparing emulsions using fiber-protein, preparing gels using pectin, encapsulating fat-soluble components by microspheres and nanospheres to form micron or nanoparticles, encapsulating fat-soluble components in the hydrophobic internal cavity of cyclodextrin, encapsulating fat-soluble and water-soluble components by liposomes, or using microencapsulation technology to encapsulate fat-soluble components in wall materials through spray drying, spray freeze drying, coprecipitation, etc.

[0003] Due to the amphiphilic nature of fiber and protein, a certain amount of hydrophobic components can be embedded, but the system constructed with protein materials has the main problem of instability. When exposed to enzymes, extreme pH, high ionic strength, temperature stress and other conditions, it is easy to denature, and protein aggregation will occur when the pH of the system reaches the isoelectric point, which may seriously damage the spatial structure of the system and lead to the collapse of the entire system. Gels prepared from natural single polysaccharides, such as carrageenan and curdlan, can load a certain amount of hydrophobic components, but because they are mainly composed of hydrophilic groups. The compatibility with hydrophobic components is poor. Hydrophobic components may not be well dissolved in carrageenan, resulting in uneven distribution or precipitation. The presence of hydrophobic components will also lead to problems such as reduced mechanical properties and viscosity of the gel, water loss, etc. There are often certain defects in the construction of biopolymer particles using a single material. For example, natural polysaccharide material molecules are difficult to extract and purify, the molecular weight and charge are not easy to control, the lack of hydrophobic groups makes it difficult to form particles, and the encapsulation efficiency is low. Therefore, when the protein-based biopolymer particle carrier passes through the digestive tract, it may disintegrate in the stomach, release most of the functional factors, and lose the protective effect. The preparation process of particles formed by microspheres and nanospheres is relatively complicated, and the conditions need to be strictly controlled to avoid component degradation. The inclusion efficiency and release control of cyclodextrin are relatively limited, and it is not suitable for all types of fat-soluble components. Liposomes have limited stability and are prone to leakage or fusion; in addition, their preparation and storage costs are high. The wall material selection and preparation conditions of microcapsules need to be precisely controlled to ensure effective encapsulation efficiency and component release characteristics.

[0004] Jujube peel is one of the main wastes in the deep processing of jujube products, most of which are discarded or piled up and incinerated, causing resource waste and environmental pollution. If the waste of jujube peel can be utilized, it will have a positive effect and far-reaching impact on the resource utilization of the jujube region's economy and the realization of "carbon peak" and "carbon neutrality". Summary of the invention

[0005] In view of the problems in the prior art, the present invention provides a method for constructing a hollow porous material by using jujube peel fiber and carrageenan.

[0006] The present invention also provides a hollow porous material prepared by the method.

[0007] The present invention further provides application of the hollow porous material.

[0008] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: The present invention provides a method for constructing a hollow porous material by using jujube peel fiber and carrageenan, comprising the following steps: (1) crushing the jujube peel, sieving to obtain jujube peel powder, adding deionized water, and treating in a water bath under stirring, and filtering to obtain a filter residue after the treatment; (2) adding cellulase and deionized water to the filter residue, performing enzymatic hydrolysis, and filtering to obtain a secondary filter residue; (3) adding deionized water to the secondary filter residue, subjecting it to colloid mill treatment, and then homogenizing it under high pressure, filtering it to obtain the jujube peel insoluble dietary fiber, and sieving it after freeze-drying to obtain the jujube peel fiber powder; (4) Adding jujube peel fiber powder to the carrageenan solution, mixing well and then heating, and then cooling in an ice bath to form a gel; adding deionized water to the gel, high-speed shearing and high-pressure homogenization to obtain a medium-controlled porous material.

[0009] Furthermore, in step (1), the mass ratio of the jujube peel powder to deionized water is 1:10; and the water bath treatment is carried out at a temperature of 100° C. for 1 hour.

[0010] Furthermore, in step (2), the amount of cellulase added is 2.5 g / 100 g of filter residue on a dry weight basis; the mass ratio of the filter residue to deionized water is 1:10; and the enzymatic hydrolysis is carried out in a stirring state in a 50° C. water bath for 4 h.

[0011] Furthermore, in step (3), the mass ratio of the secondary filter residue to deionized water is 1:10; the colloid mill treatment is performed for 30 minutes; and the high-pressure homogenization is performed at 120 MPa for 3 times.

[0012] Furthermore, in step (4), the concentration of the carrageenan solution is 1.5-3.5%; and the mass ratio of the carrageenan to the jujube peel fiber powder is 1.5-3.5:2.5-0.5.

[0013] Furthermore, the heating is heating in a 100° C. water bath for 3-6 min; the high-speed shearing is shearing at a rotation speed of 5000-20000 for 1-20 min; and the high-pressure homogenization is homogenizing at 100-120 Mpa for 10 min.

[0014] The present invention also provides a hollow porous material prepared by the method.

[0015] The present invention further provides the use of the hollow porous material as a carrier of a hydrophobic component, wherein the hydrophobic component is curcumin, lutein or carotene.

[0016] Preferably, when used, 0.1-0.3% of the hydrophobic component is added to the oil phase (linseed oil), stirred at 300 r / min for 6 h, and the resulting mixture is centrifuged at 3500 rpm for 10 minutes to remove the precipitate. The resulting mixture is added to the hollow porous material, wherein the added amount is 45-55% of the hollow porous material; preferably, the added amount is 50%. The beneficial effects of the present invention are: (1) In the present invention, by combining jujube peel fiber with carrageenan, the fiber can serve as a skeleton support to form a relatively stable hollow porous structure. The hollow porous structure provides a larger surface area and pore volume, which helps to increase the loading amount of hydrophobic active ingredients.

[0017] (2) The hollow porous structure material prepared by the present invention can adsorb hydrophobic active ingredients on its inner surface through non-covalent interactions such as physical adsorption and van der Waals force. This structure can effectively protect the hydrophobic active ingredients from the influence of the external environment, thereby improving their stability and bioavailability. This structure can not only effectively load and protect the hydrophobic ingredients, but also adjust the pore size by adjusting the ratio of fiber to carrageenan. The smaller pore size can slow down the diffusion rate of the hydrophobic active ingredients and prolong the release time, allowing them to be released when needed. The bioavailability of hydrophobic nutrients is improved.

[0018] (3) The hollow porous structure material provided by the present invention has a simple preparation process and can improve the utilization rate of jujube peels, etc., thus opening up a new path for its application and expanding the application field of by-products; and after being loaded with hydrophobic components, it has a wide range of applications and can be used in the form of additives in the fields of food, biomedicine, etc., with a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Laser confocal observation of the sample shows the internal oil, external water phase, and organic network framework structure; Figure 2 is the digestion release rate of curcumin loaded in the hollow porous material within 180 minutes. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further explained and illustrated by means of specific embodiments below.

[0021] When the hollow structure material is loaded with hydrophobic components such as curcumin, the curcumin is first dispersed in an oil phase, and the oil phase can be selected from at least one of linseed oil, peony seed oil, grape seed oil, rose seed oil, coconut oil, camellia oil, peanut oil, germ oil, walnut oil, sesame oil, sunflower seed oil, canola oil, olive oil, tomato seed oil, rapeseed oil, and deep-sea fish oil.

[0022] Example 1 1) Preparation of jujube peel fiber The jujube peel was crushed with a grinder, passed through a 100-mesh sieve, and deionized water was added at a solid-liquid ratio of 1:10. The residue was treated in a water bath at 100°C for 1 hour, stirred at 300 r / min, and filtered to obtain a filter residue for removing soluble impurities such as polysaccharides. Cellulase was added to the residue at a dry weight of 2.5g / 100g, deionized water was added at a ratio of 1:10, and the residue was water bathed at 50°C for 4 hours, stirred at 300 r / min, and used to remove the non-crystalline area of ​​the fiber. The residue was filtered to obtain a filter residue, and deionized water was added to the residue at a solid-liquid ratio of 1:10, then the colloid mill was used for 30 min, and the high-pressure homogenizer was homogenized 3 times at 120 Mpa. The insoluble dietary fiber of the jujube peel was filtered to obtain the jujube peel fiber powder after freeze-drying and passing through a 100-mesh sieve.

[0023] 2) Pretreatment of hollow porous structures The raw material of the gel is carrageenan. Carrageenan and jujube peel fiber powder are mixed in a ratio of 1:1 in a carrageenan with a concentration of 3.5%. The mixed solution is then placed in a 100°C water bath to heat for 3-6 minutes, and then placed in an ice water bath to cool and form.

[0024] The cooled gel was added with deionized water at a ratio of 1:5, and then sheared at 10,000 rpm for 10 minutes using a high-speed shearing method. The gel was then homogenized at 100-120 MPa for 10 minutes in a high-pressure homogenizer to obtain a restructured gel.

[0025] 3) Loading of hydrophobic components into hollow multi-porous structures 0.1% curcumin was added to the oil phase (linseed oil), stirred at 300 r / min for 6 h, and the resulting mixture was centrifuged at 3500 rpm for 10 minutes to remove the precipitate. The resulting mixture was added to the restructured gel, wherein the amount added was 50% of the restructured gel. After the solution was mixed, an ultrasonic probe was placed in the mixture or an ultrasonic device was used to ultrasonicate at 100-750W for 3 min; wherein, ultrasonication was performed for 5 s and stopped for 2 s. The mixed solution was then placed in a boiling water bath and heated for 20 min to solidify into an organic mesh framework structure loaded with curcumin.

[0026] The pore size can be adjusted by adjusting the proportion of oil and fat loaded with hydrophobic components.

[0027] Comparative Example 1 1) Fibers include citrus fiber 7000 and citrus fiber 7200 2) Pretreatment of hollow porous structures The raw material of the gel is carrageenan. Carrageenan with a concentration of 3.5% is mixed with citrus fiber powder in a ratio of 1:1. The mixed solution is then heated in a 100°C water bath for 3-6 minutes, and then placed in an ice water bath to cool and form.

[0028] The cooled gel was added with deionized water at a ratio of 1:5, and then sheared at 10,000 rpm for 10 minutes using a high-speed shearing method. The gel was then homogenized at 100-120 MPa for 10 minutes in a high-pressure homogenizer to obtain a restructured gel.

[0029] 3) Loading of hydrophobic components into hollow multi-porous structures 0.1% curcumin was added to the oil phase (linseed oil), stirred at 300 r / min for 6 h, and the resulting mixture was centrifuged at 3500 rpm for 10 minutes to remove the precipitate. The resulting mixture was added to the restructured gel, wherein the addition amount was 10% of the restructured gel. After the solution was mixed, an ultrasonic probe was placed in the mixture or an ultrasonic device was used to ultrasonicate at 100-750W for 3 min; wherein, ultrasonication was performed for 5 s and stopped for 2 s. The mixed solution was then placed in a boiling water bath and heated for 20 min to solidify into an organic mesh framework structure loaded with curcumin.

[0030] When the fiber is date peel fiber, the amount of oil phase added can be 50% of the restructured gel. When citrus fiber is used, when the amount of oil phase added is greater than 20%, stratification will occur in the material structure, the oil phase will dissolve, and the sustained release property will disappear.

[0031] Effect Example 1 (1) Use laser confocal microscopy to observe the sample, such as Figure 1 As shown in the figure, the red part is the oil loaded with curcumin inside, the green part is the external water phase, and the last part is the hollow porous material that can load the hydrophobic components.

[0032] (2) Stability of curcumin in materials The samples were stored at 25°C in the dark for 21 days. To measure the amount of loaded curcumin, the sample dispersion was centrifuged at 13870 g for 40 min at 25°C. Then, 0.2 mL of the upper phase was added to the microplate wells. The adsorption rate of the samples at 420 nm was read using a spectrophotometer, and the concentration of curcumin was calculated using Equation 1. The stability of curcumin (%) in the material was obtained as shown in Table 1.

[0033] Concentration of loaded curcumin % = (total amount - free amount) / total amount * 100% Formula 1 Table 1 Effect of oil phase addition amount on storage stability of materials loaded with curcumin (%).

[0034] (3) In vitro release of curcumin loaded with materials In a cork-stoppered conical flask, the sample was mixed with simulated gastric fluid (SGF: NaCl 2.0 mg / mL, pepsin 3.2 mg / mL, pH 1.2). The dispersion was then placed in a temperature-controlled shaking water bath (37.0 °C, 100 rpm, 60 min). Gastric digestion was terminated by raising the pH to 7.5 using 1.0 mol / L NaOH. Simulated intestinal fluid (SIF), containing bile salts (12.0 mg / mL), pancreatin (2.0 mg / mL), NaCl (8.8 mg / mL), and KH2PO4 (6.8 mg / mL), was then mixed with 30 mL of gastric digestion mixture. Samples were collected and examined at 0, 30, 60, 90, 120, 150, and 180 min after digestion in a stirring water bath (37 °C, 100 rpm). The samples obtained at different stages of digestion were centrifuged (10,000 rpm, 5 min).

[0035] Formula 2 is used to determine the digestion release rate of curcumin. The digestion release rate of curcumin in the material is obtained as Figure 2 shown.

[0036] Digestion release rate (%) = curcumin release amount / curcumin mass before digestion * 100% Formula 2 The curcumin in the material prepared by the present invention is gradually released in the simulated stomach (0-30 minutes) and small intestine (60-120 minutes), thereby improving the stability of curcumin in the gastrointestinal tract.

Claims

1. A method for constructing a hollow porous material by using jujube peel fiber and carrageenan, characterized in that: The following steps are involved: (1) crushing the jujube peel, sieving to obtain jujube peel powder, adding deionized water, and treating in a water bath under stirring, and filtering to obtain a filter residue after the treatment; (2) adding cellulase and deionized water to the filter residue, performing enzymatic hydrolysis, and filtering to obtain a secondary filter residue; (3) adding deionized water to the secondary filter residue, subjecting it to colloid mill treatment, and then high-pressure homogenization, filtering to obtain the jujube peel insoluble dietary fiber, and lyophilizing and sieving to obtain the jujube peel fiber powder; (4) Adding jujube peel fiber powder to the carrageenan solution, mixing well and then heating, and then cooling in an ice bath to form a gel; adding deionized water to the gel, high-speed shearing and high-pressure homogenization to obtain a medium-controlled porous material.

2. The method according to claim 1, characterized in that: In step (1), the mass ratio of the jujube peel powder to deionized water is 1:10; and the water bath treatment is performed at a temperature of 100° C. for 1 hour.

3. The method according to claim 1 or 2, characterized in that: In step (2), the amount of cellulase added is 2.5 g / 100 g of filter residue based on dry weight; the mass ratio of the filter residue to deionized water is 1:10; and the enzymatic hydrolysis is carried out in a stirring state in a 50° C. water bath for 4 h.

4. The method according to claim 1, characterized in that: In step (3), the mass ratio of the secondary filter residue to deionized water is 1:10; the colloid mill treatment is performed for 30 minutes; and the high-pressure homogenization is performed at 120 MPa for 3 times.

5. The method according to any one of claims 1 to 4, characterized in that: In step (4), the concentration of the carrageenan solution is 1.5-3.5%; the mass ratio of the carrageenan to the jujube peel fiber powder is 1.5-3.5:2.5-0.

5.

6. The method according to claim 1 or 5, characterized in that: The heating is heating in a 100° C. water bath for 3-6 min; the high-speed shearing is shearing at a rotation speed of 5000-20000 for 1-20 min; and the high-pressure homogenization is homogenizing at 100-120 Mpa for 10 min.

7. A hollow porous material prepared by the method according to any one of claims 1 to 6.

8. A use of the hollow porous material as claimed in claim 7 as a carrier of a hydrophobic component, characterized in that: The hydrophobic component is curcumin, lutein or carotene.

9. The use according to claim 8, characterized in that: 0.1-0.3% of the hydrophobic component is added to the oil phase, and the mixture is stirred at 300 r / min for 6 h to obtain a mixture; the mixture is centrifuged to remove the precipitate, and then the mixture is added to the hollow porous material in an amount of 45-55%.

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