阅读说明：本技术 一种微波提取龙须菜琼脂的方法 (microwave extraction method of asparagus agar ) 是由 黄荣涛 林文浩 王瑞涛 于 2019-12-03 设计创作，主要内容包括：本发明提供了一种微波提取龙须菜琼脂的方法,属于琼脂生产技术领域,本发明的方法利用微波对琼脂胶和琼脂糖分子的重整效应,使得碱处理效率提升,精准度提高,从而降低了碱用量,提高了产品均一性,提高了生产质量稳定性,在提高原料使用率的前提下,减小了产品流失,提高出成率,也缓解了污水处理压力,降低了用水量和污水处理量,使得整体提取成本下降6％～10％。(The invention provides a method for extracting asparagus agar by microwaves, which belongs to the technical field of agar production, and utilizes the reforming effect of microwaves on agar and agarose molecules to improve the alkali treatment efficiency and the accuracy, thereby reducing the alkali consumption, improving the property of a product, improving the production quality stability, reducing the product loss, improving the yield, relieving the sewage treatment pressure, reducing the water consumption and the sewage treatment capacity and reducing the overall extraction cost by 6-10% on the premise of improving the utilization rate of raw materials.)

1, method for extracting asparagus agar by microwave, comprising the following steps:

1) mixing asparagus and a sodium hydroxide aqueous solution, and performing microwave extraction for 1.5-2.5 h under the conditions of 600-1100W and 88-93 ℃ to obtain microwave-treated asparagus;

2) cleaning the microwave-treated asparagus to be neutral to obtain th asparagus, and stirring th asparagus in a sodium hypochlorite aqueous solution for 10-25 min to obtain bleached asparagus;

3) cleaning the bleached asparagus to obtain a second asparagus, placing the second asparagus in an oxalic acid aqueous solution, and stirring for 10-25 min at 35-65 rpm to obtain an acid-treated asparagus;

4) cleaning the acid-treated asparagus to obtain a third asparagus, mixing the third asparagus with water, and steaming at 90-100 ℃ for 10-35 min to obtain a glue solution;

5) mixing the glue solution and the filter aid at 85-95 ℃, performing th filter pressing at 85-95 ℃, under the pressure of 6-8 kg and under the condition that the aperture of the filter cloth is 200 meshes to obtain a crude filtrate, and performing second filter pressing on the crude filtrate at 80-95 ℃ and under the condition that the aperture of the filter cloth is 200 meshes to obtain a fine filtrate;

6) cooling the fine filtrate to 30-35 ℃ to obtain th gel, and standing th gel at 20-25 ℃ for 3-5 hours to obtain second gel;

7) carrying out third filter pressing on the second gel under the conditions that the pressure is 10-15 kg and the aperture of the filter cloth is 200 meshes to obtain a rubber cake;

8) and (3) crushing, granulating and drying the rubber cake to obtain the asparagus agar with the particle size of 150-200 meshes.

2. The method as claimed in claim 1, wherein the mass ratio of the asparagus to the aqueous solution of sodium hydroxide in step 1) is 1: 12 to 18; the mass percentage of the sodium hydroxide in the sodium hydroxide aqueous solution is 3-7%.

3. The method according to claim 1, wherein the mass percentage of the sodium hypochlorite in the sodium hypochlorite aqueous solution in the step 2) is 0.05-0.15%.

4. The method according to claim 1, wherein the ratio of the mass of oxalic acid in the aqueous oxalic acid solution to the volume of water in step 3) is 0.1-0.2 g: 100 mL.

5. The method according to claim 1, wherein the ratio of the mass of the third asparagus to the volume of water in step 4) is 1 g: 18-25 mL.

6. The method according to claim 1, wherein the filter aid in step 5) comprises perlite powder; the mixing mode of the glue solution and the filter aid comprises stirring and mixing; the rotating speed of the stirring is 50-70 rpm.

7. The method according to claim 1, wherein the standing time in step 6) is 4 hours.

8. The method according to claim 1, wherein the temperature of the third filter pressing in the step 7) is 20-30 ℃; the pressure was maintained for 4h with no water discharge.

Technical Field

The invention relates to the technical field of agar production, in particular to a method for extracting asparagus agar by kinds of microwaves.

Background

A technology for extracting agar (agar) from asparagus is characterized by comprising the main process flows of alkali treatment, rinsing, bleaching, acid treatment, rinsing, gum extraction, filtering, gelling, physical drying, crushing, granulating, drying and grinding, wherein is accompanied by three main problems of nonuniform acid-base action and complex and variable molecular structure of agar polysaccharide in the gum extraction process of the process, so that the product quality is not easy to control and the uniform property is poor, part of agar is lost along with hot alkali liquor in the process of high-temperature alkali liquor treatment in the traditional process, the yield of the product is reduced, and the process flow comprises the steps of different alkali treatment reaction rates and different reaction strengths in the traditional process, so that the alkali concentration is increased to ensure the utilization of raw materials, so that the alkali dosage is increased, and the water dosage in the subsequent rinsing process is increased and the sewage treatment pressure is increased.

Disclosure of Invention

The invention aims to provide methods for extracting asparagus agar by microwaves, which can reduce the alkali consumption and improve the uniform character and yield of the agar.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a method for extracting asparagus agar by kinds of microwaves, which comprises the following steps:

1) mixing asparagus and a sodium hydroxide aqueous solution, and performing microwave extraction for 1.5-2.5 h under the conditions of 600-1100W and 88-93 ℃ to obtain microwave-treated asparagus;

2) cleaning the microwave-treated asparagus to be neutral to obtain th asparagus, and stirring th asparagus in a sodium hypochlorite aqueous solution for 10-25 min to obtain bleached asparagus;

3) cleaning the bleached asparagus to obtain a second asparagus, placing the second asparagus in an oxalic acid aqueous solution, and stirring for 10-25 min at 35-65 rpm to obtain an acid-treated asparagus;

4) cleaning the acid-treated asparagus to obtain a third asparagus, mixing the third asparagus with water, and steaming at 90-100 ℃ for 10-35 min to obtain a glue solution;

5) mixing the glue solution and a filter aid at 85-95 ℃, performing th filter pressing at 85-95 ℃, under the pressure of 6-8 kg and under the condition that the aperture of the filter cloth is 200 meshes to obtain a crude filtrate, and performing second filter pressing on the crude filtrate at 80-95 ℃ and under the condition that the aperture of the filter cloth is 200 meshes to obtain a fine filtrate;

6) cooling the fine filtrate to 30-35 ℃ to obtain th gel, and standing th gel at 20-25 ℃ for 3-5 hours to obtain second gel;

7) carrying out third filter pressing on the second gel under the conditions that the pressure is 10-15 kg and the aperture of the filter cloth is 200 meshes to obtain a rubber cake;

8) and (3) crushing, granulating and drying the rubber cake to obtain the asparagus agar with the particle size of 150-200 meshes.

Preferably, the mass ratio of the asparagus to the sodium hydroxide aqueous solution in the step 1) is 1: 12 to 18; the mass percentage of the sodium hydroxide in the sodium hydroxide aqueous solution is 3-7%.

Preferably, the mass percentage of the sodium hypochlorite in the sodium hypochlorite aqueous solution in the step 2) is 0.05-0.15%.

Preferably, the ratio of the mass of oxalic acid in the oxalic acid water solution to the volume of water in the step 3) is 0.1-0.2 g: 100 mL.

Preferably, the ratio of the mass of the third asparagus to the volume of the water in the step 4) is 1 g: 18-25 mL.

Preferably, the filter aid in step 5) comprises perlite powder; the mixing mode of the glue solution and the filter aid comprises stirring and mixing; the rotating speed of the stirring is 50-70 rpm.

Preferably, the standing time in the step 6) is 4 h.

Preferably, the temperature of the third filter pressing in the step 7) is 20-30 ℃; the pressure was maintained for 4h with no water discharge.

The method has the beneficial effects that methods for extracting asparagus agar by microwaves are provided, the method utilizes the reforming effect of microwaves on agar gum and agarose molecules, so that the alkali treatment efficiency is improved, the accuracy is improved, the alkali consumption is reduced, the performance of a product is improved, the production quality stability is improved, the product loss is reduced on the premise of improving the utilization rate of raw materials, the yield is improved, the sewage treatment pressure is relieved, the water consumption and the sewage treatment amount are reduced, and the overall extraction cost is reduced by 6-10%.

Detailed Description

The invention provides a method for extracting asparagus agar by kinds of microwaves, which comprises the following steps:

1) mixing asparagus and a sodium hydroxide aqueous solution, and performing microwave extraction for 1.5-2.5 h under the conditions of 600-1100W and 88-93 ℃ to obtain microwave-treated asparagus;

2) cleaning the microwave-treated asparagus to be neutral to obtain th asparagus, and stirring th asparagus in a sodium hypochlorite aqueous solution for 10-25 min to obtain bleached asparagus;

3) cleaning the bleached asparagus to obtain a second asparagus, placing the second asparagus in an oxalic acid aqueous solution, and stirring for 10-25 min at 35-65 rpm to obtain an acid-treated asparagus;

4) cleaning the acid-treated asparagus to obtain a third asparagus, mixing the third asparagus with water, and steaming at 90-100 ℃ for 10-35 min to obtain a glue solution;

5) mixing the glue solution and a filter aid at 85-95 ℃, performing th filter pressing at 85-95 ℃, under the pressure of 6-8 kg and under the condition that the aperture of the filter cloth is 200 meshes to obtain a crude filtrate, and performing second filter pressing on the crude filtrate at 80-95 ℃ and under the condition that the aperture of the filter cloth is 200 meshes to obtain a fine filtrate;

6) cooling the fine filtrate to 30-35 ℃ to obtain th gel, and standing th gel at 20-25 ℃ for 3-5 hours to obtain second gel;

7) carrying out third filter pressing on the second gel under the conditions that the pressure is 10-15 kg and the aperture of the filter cloth is 200 meshes to obtain a rubber cake;

8) and (3) crushing, granulating and drying the rubber cake to obtain the asparagus agar with the particle size of 150-200 meshes.

Before the gardon asparagus and the sodium hydroxide aqueous solution are mixed, the method preferably also comprises the steps of cleaning and cutting the gardon asparagus to obtain gardon asparagus sections; the length of the asparagus section is preferably 4-6 cm, and more preferably 5 cm; the asparagus of the invention is from conventional market.

After the asparagus sections are obtained, mixing the asparagus sections with a sodium hydroxide aqueous solution, and performing microwave extraction for 1.5-2.5 hours at the temperature of 88-93 ℃ under the condition of 600-1100W to obtain the microwave-treated asparagus; the mass ratio of the asparagus sections to the sodium hydroxide aqueous solution is preferably 1: 12-18, more preferably 1: 15; the mass percentage content of sodium hydroxide in the sodium hydroxide aqueous solution is preferably 3-7%, and more preferably 5%; the microwave power for microwave extraction is preferably 800-1000W; the temperature of the microwave extraction is preferably 90 ℃; the time for microwave extraction is preferably 2 h; the invention utilizes the reforming effect of microwave on the agaragar and the agarose molecules to activate the agarose molecules, so that the alkali treatment efficiency is improved.

After the microwave-treated asparagus is obtained, the microwave-treated asparagus is cleaned to be neutral to obtain th asparagus, th asparagus is placed in a sodium hypochlorite aqueous solution and stirred for 10-25 min to obtain bleached asparagus, the cleaning mode is preferably rinsing, the cleaning reagent is water, the mass percentage of sodium hypochlorite in the sodium hypochlorite aqueous solution is preferably 0.05-0.15%, more preferably 0.1%, the ratio of the mass of the th asparagus to the volume of the sodium hypochlorite aqueous solution is 1: 8, the stirring time is preferably 15-20 min, and the stirring rotation speed is preferably 50-70 rpm.

After the bleached asparagus is obtained, cleaning the bleached asparagus to obtain a second asparagus, putting the second asparagus into an oxalic acid aqueous solution, and stirring for 10-25 min at 35-65 rpm to obtain an acid-treated asparagus; the ratio of the mass of oxalic acid in the oxalic acid water solution to the volume of water is preferably 0.1-0.2 g: 100mL, more preferably 0.15 g: 100 mL; the ratio of the mass of the second asparagus to the volume of the oxalic acid aqueous solution is 1: 10.

after the acid-treated asparagus is obtained, cleaning the acid-treated asparagus to obtain a third asparagus, mixing the third asparagus with water, and steaming at 90-100 ℃ for 10-35 min to obtain a glue solution; the ratio of the mass of the third asparagus to the volume of water is preferably 1 g: 18-25 mL, more preferably 1 g: 20 mL; the steaming temperature is preferably 95 ℃; the steaming time is preferably 15-30 min, more preferably 20-25 min, and the method is based on the condition that agar of the third asparagus is completely dissolved into a gel liquid.

After a glue solution is obtained, the glue solution and a filter aid are mixed at 85-95 ℃, filter pressing is carried out at 85-95 ℃ under the pressure of 6-8 kg and the aperture of a filter cloth is 200 meshes at to obtain a crude filtrate, the crude filtrate is compressed and drained without water at 80-95 ℃ and kept at the pressure for 4 hours to obtain a fine filtrate, the filter aid preferably comprises perlite powder, the perlite powder is commercially available, the mixing mode of the glue solution and the filter aid preferably comprises stirring and mixing, the stirring rotation speed is preferably 50-70 rpm and more preferably 60rpm, the mixing temperature is preferably 90 ℃, the filter pressing temperature of is preferably 90 ℃, the filter pressing pressure of is preferably 7kg, the filter pressing equipment of is preferably a filter press, and the temperature of the second filter pressing is preferably 85-90 ℃.

After the fine filtration liquid is obtained, the fine filtration liquid is cooled to 30-35 ℃ to obtain th gel, the th gel is placed at 20-25 ℃ and stands for 3-5 hours to obtain second gel, the standing time is preferably 4 hours, and the standing is used for enabling agar to be stably coagulated.

After the second gel is obtained, carrying out third filter pressing on the second gel under the conditions that the pressure is 10-15 kg and the aperture of the filter cloth is 200 meshes to obtain a rubber cake; the pressure of the third filter pressing is preferably 12 kg; the temperature of the third filter pressing is preferably 20-30 ℃; the water content of the rubber cake after the third filter pressing is 15-20%.

After obtaining the rubber cake, crushing, granulating and drying the rubber cake to obtain asparagus agar with the particle size of 150-200 meshes; the particle size of the particles obtained after granulation is preferably 8-12 mm, and more preferably 10 mm; the drying mode is preferably drying; the grain diameter of the asparagus agar is preferably 180 meshes; the water content of the asparagus agar is preferably 4-7%.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.