Method for extracting hawthorn pectin by using natural deep eutectic solvent and sequential microwave-ultrasonic assisted method

Abstract

The invention provides a method for extracting hawthorn pectin by using a natural deep eutectic solvent and a sequential microwave-ultrasonic assisted method. The method comprises the following steps: preparing choline chloride, glucose and water into the natural deep eutectic solvent according to a mass ratio of (5-8): (2-4): (5-8); and soaking hawthorn in the natural deep eutectic solvent, extracting by adopting an ultrasonic-microwave-assisted extraction method, filtering to obtain wet pectin, and drying to obtain the hawthorn pectin. According to the invention, a choline chloride-glucose-water (5: 2: 5) solvent system and a sequential microwave-ultrasonic assisted extraction method are used to successfully extract high-methoxyl pectin from hawthorn. The method has the characteristics superior to those of commercial pectin and other extraction methods in the aspects of pH, solubility, equivalent weight, molecular weight, antioxidant activity, viscosity and the like.

Description

Technical Field

[0001] The invention belongs to the field of food, and particularly relates to a method for extracting hawthorn pectin by using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Pectin is a complex heteropolysaccharide composed mainly of 1,4-linked-α-D-galacturonic acid, present in the cell walls of plant tissues and commonly used as a food additive (E440).

[0004] The main sources of commercial pectin are usually citrus peels and apple pomace, and other hawthorn fruits such as pomegranate, grapefruit and banana have also been found to be potential materials for extracting pectin. Currently, hawthorn is considered to be a promising source for commercial-scale production of pectin.

[0005] Pectin is divided into high methoxy pectin (DE greater than 50%) and low methoxy pectin according to the degree of esterification (DE). They have different physical and chemical properties and applications. High methoxy pectin can form gels in acidic conditions (pH 2-3.5) and high sugar solutions (concentration 55-75%), and is commonly used in the food and beverage industry as a gelling agent, stabilizer, emulsifier and thickener; low methoxy pectin can form gels in the presence of divalent cations (such as Ca 2+ ) in the presence of , it forms gels over a wider pH range (2-6) with or without small amounts of sugar and is often used in fat replacers, ice cream, emulsified meat or low-calorie products.

[0006] Green extraction technology has become an alternative to traditional extraction methods due to its advantages such as time saving, solvent saving, high yield and good quality, but the effects of different green solvents and auxiliary technologies on the physicochemical properties, chemical structure and rheological properties of extracted pectin need to be critically analyzed. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] The first aspect of the present invention provides a method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method, comprising:

[0010] preparing a natural deep eutectic solvent by mixing choline chloride, glucose and water in a mass ratio of 5-8:2-4:5-8;

[0011] The hawthorn is immersed in the natural deep eutectic solvent, extracted by ultrasonic-microwave assisted extraction, filtered to obtain wet pectin, and dried to obtain the product.

[0012] In some embodiments, the liquid-to-solid ratio of the hawthorn to the natural deep eutectic solvent is 3.5-4.0:1.

[0013] In some embodiments, the microwave power is 240-500W.

[0014] In some embodiments, the microwave treatment time is 14-20 min.

[0015] In some embodiments, the temperature of the ultrasonic treatment is 70°C-80°C.

[0016] In some embodiments, the power of ultrasound is 300W-350W.

[0017] In some embodiments, the duration of sonication is 46-50 min.

[0018] In some embodiments, the drying temperature is 60-65° C. and the drying time is 3-5 h.

[0019] The second aspect of the present invention provides pectin prepared by the above method.

[0020] The third aspect of the present invention provides the use of a natural deep eutectic solvent in pectin extraction, wherein the natural deep eutectic solvent is prepared from choline chloride, glucose and water in a mass ratio of 5-8:2-4:5-8.

[0021] Beneficial effects of the present invention

[0022] (1) The present invention successfully extracts high methoxyl pectin from hawthorn using a choline chloride-glucose-water solvent system and a sequential microwave-ultrasound-assisted extraction method.

[0023] (2) The PC-MUAE method of the present invention exhibits superior properties to commercial pectin and other extraction methods in terms of pH, solubility, equivalent weight, molecular weight, antioxidant activity and viscosity.

[0024] (3) The extraction method of the present invention provides favorable properties for the application of hawthorn pectin, which can be used in the food industry as a food additive, such as a stabilizer, emulsifier and gelling agent, and can also be used for encapsulation in pharmaceutical distribution, wound healing and biomedical engineering, and as a component in the production of biodegradable films.

[0025] (4) The preparation method of the present invention is simple, practical and easy to promote. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0027] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0028] In the following examples, the ultrasonic power is 300W.

[0029] Example 1

[0030] 1. Preparation of materials: Hawthorn was peeled, cut into small pieces, dried in an air circulation oven at 40° C. to a moisture content of less than 10%, and then ground into fine powder passing through a 60-mesh sieve (0.25 mm aperture) to obtain hawthorn powder.

[0031] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-glucose-water (5:2:5), dilute with water to (water / CGW) of 3.4 mL / mL, immerse the hawthorn powder in the deep eutectic solvent (liquid-solid ratio of 3.5:1), and perform sequential microwave-ultrasound-assisted extraction (PC-MUAE) (microwave irradiation for 14 minutes at a power of 240 W, followed by ultrasonic treatment at 70°C for 46 minutes). The filtered wet pectin was dried at 60°C to constant weight (about 3-5 hours).

[0032] Example 2

[0033] 1. Preparation of materials: Hawthorn, peeled, cut into small pieces, dried in an air circulation oven at 40°C to a moisture content of less than 10%, and then ground into fine powder that passes through a 60-mesh sieve (0.25 mm aperture).

[0034] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-glucose-water (5:2:5), diluted with water to a (water / CGW ratio) of 7.8 mL / mL, the hawthorn powder was immersed in the deep eutectic solvent (liquid-solid ratio of 4.0:1) and subjected to sequential microwave-ultrasound-assisted extraction (PC-MUAE) (microwave irradiation for 14 minutes at a power of 480 W, followed by ultrasonic treatment at 70°C for 46 minutes). The filtered wet pectin was dried at 60°C to constant weight.

[0035] Example 3

[0036] 1. Preparation of materials: Hawthorn, peeled, cut into small pieces, dried in an air circulation oven at 40°C to a moisture content of less than 10%, and then ground into fine powder that passes through a 60-mesh sieve (0.25 mm aperture).

[0037] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-glucose-water (5:2:5), diluted with water to a (water / CGW ratio) of 3.4 mL / mL, the hawthorn powder was immersed in the deep eutectic solvent (liquid-solid ratio of 3.5:1) and subjected to sequential microwave-ultrasound-assisted extraction (PC-MUAE) (microwave irradiation for 20 minutes at a power of 500 W, followed by ultrasonic treatment at 70°C for 46 minutes). The filtered wet pectin was dried at 60°C to constant weight.

[0038] Comparative Example 1

[0039] 1. Preparation of materials: Hawthorn, peeled, cut into small pieces, dried in an air circulation oven at 40°C to a moisture content of less than 10%, and then ground into fine powder that passes through a 60-mesh sieve (0.25 mm aperture).

[0040] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-sucrose-water (5:2:5), dilute with water to (water / CGW) of 3.4 mL / mL, immerse the hawthorn powder in the deep eutectic solvent (liquid-solid ratio of 3.5:1), and perform sequential microwave-ultrasound-assisted extraction (PC-MUAE) (microwave irradiation for 14 minutes at a power of 240 W, followed by ultrasonic treatment at 70°C for 46 minutes). The filtered wet pectin was dried at 60°C to constant weight (about 3-5 hours).

[0041] Comparative Example 2

[0042] 1. Preparation of materials: Hawthorn, peeled, cut into small pieces, dried in an air circulation oven at 40°C to a moisture content of less than 10%, and then ground into fine powder that passes through a 60-mesh sieve (0.25 mm aperture).

[0043] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-maltose-water (5:2:5), dilute with water to (water / CGW) of 3.4 mL / mL, immerse the hawthorn powder in the deep eutectic solvent (liquid-solid ratio of 3.5:1), and perform sequential microwave-ultrasound-assisted extraction (PC-MUAE) (microwave irradiation for 14 minutes at a power of 240 W, followed by ultrasonic treatment at 70°C for 46 minutes). The filtered wet pectin was dried at 60°C to constant weight (about 3-5 hours).

[0044] Comparative Example 3

[0045] 1. Preparation of materials: Hawthorn, peeled, cut into small pieces, dried in an air circulation oven at 40°C to a moisture content of less than 10%, and then ground into fine powder that passes through a 60-mesh sieve (0.25 mm aperture).

[0046] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-urea-water (5:2:5), dilute with water to (water / CGW) of 3.4 mL / mL, immerse the hawthorn powder in the deep eutectic solvent (liquid-solid ratio of 3.5:1), and perform sequential microwave-ultrasound-assisted extraction (PC-MUAE) (microwave irradiation for 14 minutes at a power of 240 W, followed by ultrasonic treatment at 70°C for 46 minutes). The filtered wet pectin was dried at 60°C to constant weight (about 3-5 hours).

[0047] Comparative Example 4

[0048] 1. Preparation of materials: Hawthorn, peeled, cut into small pieces, dried in an air circulation oven at 40°C to a moisture content of less than 10%, and then ground into fine powder that passes through a 60-mesh sieve (0.25 mm aperture).

[0049] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-glycerol-water (5:2:5), dilute with water to (water / CGW) of 3.4 mL / mL, immerse the hawthorn powder in the deep eutectic solvent (liquid-solid ratio of 3.5:1), and perform sequential microwave-ultrasound-assisted extraction (PC-MUAE) (microwave irradiation for 14 minutes at a power of 240 W, followed by ultrasonic treatment at 70°C for 46 minutes). The filtered wet pectin was dried at 60°C to constant weight (about 3-5 hours).

[0050] Table 1 Pectin quality data of the embodiments and comparative examples

[0051]

[0052] It can be seen from Examples 1-3 that the method of the present invention is superior to conventional (PW) and PW-MUAE in terms of methoxy content, anhydrogalacturonic acid content, esterification degree and equivalent weight.

[0053] From the comparison of the deep eutectic solvent systems (CGW) of Example 1 and Comparative Examples 1-4, it can be seen that compared with other deep eutectic solvent systems (CGW), the deep eutectic solvent system (CGW) composed of choline chloride, glucose and water has better indicators such as methoxy content, anhydrogalacturonic acid content, esterification degree and equivalent weight.

[0054] Table 2 Total phenol content and antioxidant data of pectin in Examples and Comparative Examples

[0055]

[0056] It can be seen from Examples 1-3 that the method of the present invention is significantly higher than the conventional method (PW) and PW-MUAE in terms of antioxidant activity indicators such as total phenol content and DPPH free radical scavenging ability.

[0057] From the comparison of the deep eutectic solvent systems (CGW) of Example 1 and Comparative Examples 1-4, it can be seen that compared with other deep eutectic solvent systems (CGW), the deep eutectic solvent system (CGW) composed of choline chloride, glucose and water is better in terms of antioxidant activity indicators such as total phenol content and DPPH free radical scavenging ability.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method, characterized in that: include: preparing a natural deep eutectic solvent by mixing choline chloride, glucose and water in a mass ratio of 5-8:2-4:5-8; The hawthorn is immersed in the natural deep eutectic solvent, extracted by ultrasonic-microwave assisted extraction, filtered to obtain wet pectin, and dried to obtain the product.

2. The method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method as claimed in claim 1, characterized in that: The liquid-to-solid ratio of the hawthorn and the natural deep eutectic solvent is 3.5-4.0:

1.

3. The method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method as claimed in claim 1, characterized in that: The microwave power is 240-500W.

4. The method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method as claimed in claim 1, characterized in that: The microwave treatment time is 14-20 min.

5. The method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method as claimed in claim 1, characterized in that: The temperature of ultrasonic treatment is 70°C-80°C.

6. The method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method as claimed in claim 1, characterized in that: The power of ultrasound is 300-350W.

7. The method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method as claimed in claim 1, characterized in that: The ultrasound duration is 46-50 minutes.

8. The method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method as claimed in claim 1, characterized in that: The drying temperature is 60-65° C. and the drying time is 3-5 hours.

9. Pectin prepared by the method described in any one of claims 1 to 8.

10. Application of natural deep eutectic solvent in pectin extraction, characterized in that: The natural deep eutectic solvent is prepared from choline chloride, glucose and water in a mass ratio of 5-8:2-4:5-8.

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