A method for extracting hawthorn pectin using natural deep eutectic solvent and sequential microwave-ultrasound assisted method

Abstract

The present application provides a method for extracting hawthorn pectin using natural deep eutectic solvent and sequential microwave-ultrasonic assisted method, comprising: preparing a natural deep eutectic solvent by mixing choline chloride, glucose and water in a mass ratio of 5-8:2-4:5-8; immersing hawthorn in the natural deep eutectic solvent, and extracting by ultrasonic-microwave assisted extraction method, filtering, obtaining wet pectin, and drying to obtain the product. The present application uses choline chloride-glucose-water (5:2:5) solvent system and sequential microwave-ultrasonic assisted extraction method, successfully extracts high methoxyl pectin from hawthorn. The present application shows better characteristics than commercial pectin and other extraction methods in terms of pH, solubility, equivalent weight, molecular weight, antioxidant activity and viscosity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of food, in particular relates to a method for extracting hawthorn pectin using natural deep eutectic solvent and sequential microwave-ultrasound assisted method. BACKGROUND

[0002] The information disclosed in this Background section is for the purpose of increasing the understanding of the background of the application without admitting that such information constitutes prior art.

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

[0004] The main source of commercial pectin is usually citrus peel and apple pomace, and other hawthorns such as pomegranate, grapefruit and banana are also found to be potential materials for extracting pectin. At present, hawthorn is considered as a promising source for commercial scale production of pectin.

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

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

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

[0008] In order to achieve the above purpose, the present application adopts the following technical solutions:

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

[0010] Choline chloride, glucose and water are prepared into natural deep eutectic solvent according to the mass ratio of 5-8:2-4:5-8;

[0011] Crataegus pinnatifida Bunge is immersed in the natural deep eutectic solvent, and extracted by ultrasonic-microwave assisted extraction method, filtered, and dried to obtain wet pectin.

[0012] In some embodiments, the liquid-solid ratio of the Crataegus pinnatifida Bunge 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 14-20min.

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

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

[0017] In some embodiments, the ultrasonic time is 46-50min.

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

[0019] In a second aspect of the present application, the pectin prepared by the above method is provided.

[0020] In a third aspect of the present application, the natural deep eutectic solvent prepared by choline chloride, glucose and water according to the mass ratio of 5-8:2-4:5-8 is applied in pectin extraction.

[0021] Advantages of the present application

[0022] (1) The present application uses choline chloride-glucose-water solvent system and sequential microwave-ultrasonic assisted extraction method to successfully extract high methoxyl pectin from Crataegus pinnatifida Bunge.

[0023] (2) The PC-MUAE method of the present application shows better characteristics than 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 application provides favorable characteristics for the application of Crataegus pinnatifida Bunge pectin, which can be used as a food additive in the food industry, such as stabilizer, emulsifier and gelling agent, and can also be used in medical distribution, wound healing and packaging in biomedical engineering, and as a component for producing biodegradable films.

[0025] (4) The preparation method is simple, practical, and easy to popularize. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0027] The application will be described in further detail below with reference to specific embodiments. It should be noted that the specific embodiments described are illustrative in nature and are not intended to limit the application.

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

[0029] Example 1

[0030] 1. Preparation of material: hawthorn, peeled, cut into small pieces, dried in an air-circulating oven at 40°C to a moisture content of less than 10%, then ground to a fine powder that passes through a 60-mesh sieve (0.25 mm pore size), obtaining hawthorn powder.

[0031] 2. Pectin extraction: using a deep eutectic solvent system of choline chloride-glucose-water (5:2:5) (CGW), 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-ultrasonic 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 a constant weight (about 3-5 hours).

[0032] Example 2

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

[0034] 2. Pectin extraction: using a deep eutectic solvent system of choline chloride-glucose-water (5:2:5) (CGW), 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-ultrasonic 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 a constant weight.

[0035] Example 3

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

[0037] 2. Pectin extraction: Using a deep eutectic solvent system of choline chloride-glucose-water (5:2:5) (CGW), diluted with water to a (water / CGW) ratio of 3.4 mL / mL, the hawthorn powder was immersed in the deep eutectic solvent (liquid to 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 ultrasound treatment at 70 °C for 46 minutes). The wet pectin after filtration was dried to constant weight at 60 °C.

[0038] Comparative Example 1

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

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

[0041] Comparative Example 2

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

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

[0044] Comparative Example 3

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

[0046] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-urea-water (5:2:5), diluted with water to (water / CGW) 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 14 minutes at a power of 240 W, followed by ultrasonic treatment at 70 °C for 46 minutes). The wet pectin after filtration was dried at 60 °C to a constant weight (about 3-5 hours).

[0047] Comparative Example 4

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

[0049] 2. Pectin extraction: Using a deep eutectic solvent system (CGW) of choline chloride-glycerol-water (5:2:5), diluted with water to (water / CGW) 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 14 minutes at a power of 240 W, followed by ultrasonic treatment at 70 °C for 46 minutes). The wet pectin after filtration was dried at 60 °C to a constant weight (about 3-5 hours).

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

[0051]

[0052] As can be seen from Examples 1-3, the method of the present application is superior to conventional (PW) and PW-MUAE in terms of methoxyl content, dehydrogalacturonics acid content, esterification degree and equivalent weight, etc.

[0053] As can be seen from the comparison of the deep eutectic solvent system (CGW) of Example 1 and Comparative Examples 1-4, the deep eutectic solvent system (CGW) composed of choline chloride, glucose and water is superior to other deep eutectic solvent systems (CGW) in terms of methoxyl content, dehydrogalacturonics acid content, esterification degree and equivalent weight, etc.

[0054] Table 2 Total phenol content and antioxidant properties data of pectin of examples and comparative examples

[0055]

[0056] As can be seen from Examples 1-3, the method of the present application is significantly higher than the conventional method (PW) and PW-MUAE in terms of total phenol content, DPPH radical scavenging capacity and other indicators of antioxidant activity.

[0057] As can be seen from the comparison of Example 1 with the deep eutectic solvent system (CGW) of Comparative Examples 1-4, the deep eutectic solvent system (CGW) composed of choline chloride, glucose and water is more superior in terms of total phenol content, DPPH radical scavenging capacity and other indicators of antioxidant activity than other deep eutectic solvent systems (CGW).

[0058] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

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: S1: Hawthorn, peeled, cut into small pieces, dried in an air-circulating oven at 40℃ until the moisture content is less than 10%, then ground into fine powder that passes through a 60-mesh sieve to obtain hawthorn powder; S2: A deep eutectic solvent system CGW was prepared using choline chloride-glucose-water in a mass ratio of 5:2:

5. The system was diluted with water to a water / CGW ratio of 3.4 mL / mL. Hawthorn powder was then immersed in the deep eutectic solvent at a liquid-solid ratio of 3.5:1 and subjected to sequential microwave-ultrasound assisted extraction. The mixture was microwaved 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.

2. A method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method, characterized in that, include: S1: Hawthorn, peeled, cut into small pieces, dried in an air-circulating oven at 40℃ until the moisture content is less than 10%, and then ground into fine powder that passes through a 60-mesh sieve; S2: A deep eutectic solvent system CGW was prepared using choline chloride-glucose-water in a mass ratio of 5:2:

5. The system was diluted with water to a water / CGW ratio of 7.8 mL / mL. Hawthorn powder was then immersed in the deep eutectic solvent at a liquid-solid ratio of 4.0:1 and subjected to sequential microwave-ultrasound assisted extraction. The mixture was microwaved 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.

3. A method for extracting hawthorn pectin using a natural deep eutectic solvent and a sequential microwave-ultrasound assisted method, characterized in that, include: S1: Hawthorn, peeled, cut into small pieces, dried in an air-circulating oven at 40℃ until the moisture content is less than 10%, and then ground into fine powder that passes through a 60-mesh sieve; S2: A deep eutectic solvent system CGW was prepared using choline chloride-glucose-water in a mass ratio of 5:2:

5. The system was diluted with water to a water / CGW ratio of 3.4 mL / mL. Hawthorn powder was then immersed in the deep eutectic solvent at a liquid-solid ratio of 3.5:1 and subjected to sequential microwave-ultrasound assisted extraction. The mixture was microwaved 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.

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