CN114586922B

CN114586922B - Preparation method of leak-free water-soluble pigment gel microsphere

Info

Publication number: CN114586922B
Application number: CN202210236436.5A
Authority: CN
Inventors: 黄国晃; 张陈莉; 钟芳; 陈羚
Original assignee: Suzhou Fresh Drink Co ltd
Current assignee: Suzhou Fresh Drink Co ltd
Priority date: 2022-03-11
Filing date: 2022-03-11
Publication date: 2023-09-22
Anticipated expiration: 2042-03-11
Also published as: CN114586922A

Abstract

The application provides a preparation method of a leak-free water-soluble pigment gel microsphere, which comprises the following steps: the pigment is dissolved in the rice protein solution under alkaline condition, pH is regulated to be changed to acidic condition instantaneously, the pigment and the rice protein are combined with polysaccharide molecules in the coprecipitation process together to form rice protein-pigment-polysaccharide particles with excellent stability, and the rice protein-pigment-polysaccharide particles are applied to hydrogel microspheres to reduce migration of the pigment, improve stability and enrich application characteristics of the water-soluble pigment in aqueous phase medium.

Description

Preparation method of leak-free water-soluble pigment gel microsphere

Technical Field

The application relates to the technical field of food additives, in particular to a preparation method of a water-soluble pigment gel microsphere without leakage.

Background

Calcium alginate hydrogel microspheres have been increasingly attracting attention in various fields as a class of foods with unique mouthfeel and as a potential carrier for nutritional flavors. With the increasing demand of people for beverage loving degree and sensory enjoyment in recent years, the demand of calcium alginate microspheres with multiple tastes, multiple flavors and multiple colors in beverage ingredients is also increasing year by year. In view of the fact that most pigments currently used are water-soluble pigments, the pigments gradually permeate from one medium to another aqueous medium in the storage process, and even permeate into different particles of the same medium, the requirements of product compounding and diversification are limited. The preparation of water-soluble, readily-permeable pigments into impermeable, carrier-borne pigments by stabilization techniques may be necessary to enhance the practical application of the water-soluble pigments.

Rice protein is a hydrophobic protein containing a large number of uncharged amino acid residues and is therefore insoluble in deionized water, but is soluble in 50-95% ethanol solution, high concentration urea, pH extreme solutions (e.g., sodium hydroxide solution at pH > 11, glacial acetic acid) and anionic surfactant solutions. Rice proteins have good self-assembly, bioadhesion and biocompatibility properties, and have been widely used as carriers for nano-transport substances in foods.

The patent discovers that the rice protein is used as a pigment carrier, a thickening agent is added, and the pigment can be dispersed and fixed by utilizing the principle that pH induces protein molecules, pigments and polysaccharide molecules to be assembled together to form insoluble complexes. The principle of the patent is that pigment is dissolved in rice protein solution under alkaline condition, pH is regulated to be instantaneously changed to neutral or acidic condition, protein structure is contracted and aggregated, pigment and rice protein are combined with polysaccharide molecules through electrostatic interaction in the coprecipitation process, so that rice protein-pigment-polysaccharide particles with excellent stability are formed, and the pigment is applied to sodium alginate hydrogel microspheres, so that migration of pigment can be reduced, and stability of pigment in the sodium alginate hydrogel microspheres is improved.

Disclosure of Invention

This section is intended to outline some aspects of embodiments of the application and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description of the application and in the title of the application, which may not be used to limit the scope of the application.

The present application has been made in view of the problems occurring in the above-mentioned water-soluble pigment hydrogel microsphere products.

Therefore, one of the purposes of the application is to overcome the defect that the existing water-soluble pigment is easy to migrate in an aqueous medium, and provide a preparation method of the water-soluble pigment gel microsphere without leakage.

In order to solve the technical problems, according to one aspect of the present application, the following technical solutions are provided: a preparation method of a leak-free water-soluble pigment gel microsphere comprises the following steps:

preparation of rice protein-pigment complex: dissolving 0.1-10% rice protein in alkaline solution with pH of 12, adding appropriate amount of pigment and thickener, dissolving and hydrating, and regulating pH to below 4-5 under uniform stirring to obtain rice protein-pigment complex;

preparation of pigment preparation: homogenizing the prepared suspension to obtain pigment-rice protein granule suspension, and drying the suspension to obtain pigment preparation;

preparation of pigment hydrogel microspheres: dispersing 0.1-10% pigment preparation in 0.5-5% sodium alginate solution, dropwise adding into 1-5% calcium chloride solution by using a double-barrel syringe, filtering, washing with deionized water, and storing in preservation solution to prepare the calcium alginate hydrogel microsphere.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the addition amount of pigment in the preparation of the rice protein-pigment compound is 0.001-1%, and one of edible pigments such as brilliant blue, lemon yellow, allure red, carmine and the like or a green, purple and caramel pigment compound product obtained by mutually mixing the pigments is selected.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the application comprises the following steps: the thickener selected in the preparation of the rice protein-pigment complex is one or more of common food thickeners such as guar gum, locust bean gum, konjac gum, xanthan gum, etc., and the addition amount is 0.01-2%.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the application comprises the following steps: the duration of dissolution and hydration in the preparation of the rice protein-pigment complex is 1-24 h.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the application comprises the following steps: the homogenizing means in the preparation of pigment preparation is ultrasonic crushing or high pressure homogenizing.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the application comprises the following steps: the operation condition of ultrasonic crushing is that the ultrasonic power is 80 percent and the ultrasonic duration is 2-5 minutes.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the application comprises the following steps: the conditions of high-pressure homogenization are as follows: homogenizing for 2-7 times under 50-100 MPa.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the application comprises the following steps: the drying means in the preparation of the pigment preparation is spray drying or freeze drying.

As a preferable scheme of the preparation method of the leak-free water-soluble pigment gel microsphere, the application comprises the following steps: the spray drying condition is that the inlet temperature is 150-180 ℃ and the flow rate is 400-800 mL/h.

The preparation method of the leak-free water-soluble pigment gel microsphere provided by the application ensures that pigment in the prepared hydrogel microsphere does not fade and does not permeate each other, the stability reaches more than one year, the application of the water-soluble pigment in food processing production is improved, the selected raw materials and the addition amount meet the national food additive standard, no organic reagent is contained, the safety and the cost performance are high, the process is simple, the large-scale production is convenient, and the method is a method suitable for stabilizing the industrialized water-soluble pigment.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:

FIG. 1 is a graph showing the effect of preservative solution pH on pigment migration in hydrogel microspheres;

FIG. 2 is a schematic product diagram of a leak-free water-soluble pigment hydrogel microsphere;

FIG. 3 shows the morphology of hydrogel microspheres and pigment leakage for different pigment preparations;

FIG. 4 shows the morphology of hydrogel microspheres with different thickener addition.

Detailed Description

In order that the above-recited objects, features and advantages of the present application will become more apparent, a more particular description of the application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present application is not limited to the specific embodiments disclosed below.

Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic can be included in at least one implementation of the application. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

Example 1

1 g rice protein is taken and dissolved in 100 mL deionized water, and the pH is adjusted to be between 11.5 and 12 by using 1 mol/L NaOH solution, so that 1% (w/v) rice protein solution is obtained. 0.1. 0.1 g brilliant blue pigment was weighed and dissolved in 20 mL deionized water to give a 0.5% (w/v) brilliant blue solution. Taking 49 mL alkaline rice protein solution, adding 1 mL brilliant blue solution, uniformly mixing to obtain rice protein solution with pigment content of 0.01% (w/v), adding 0.3% (w/v) xanthan gum, uniformly mixing, regulating pH of the solution to 4 with 1 mol/L HCl solution, and uniformly stirring. The suspension is subjected to ultrasonic probe treatment at 80% power for 3 min, and spray drying is carried out at inlet temperature of 180deg.C and flow rate of 500 mL/h. The resulting formulation was added to a 1.5% sodium alginate solution at a concentration of 1%, added dropwise to a 2% (w/v) calcium chloride solution, calcium alginate hydrogel microspheres were filtered out with a nylon mesh, and the coagulation bath solution remaining on the surface of the hydrogel microspheres was rinsed off with deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Example 2

2 g rice protein is taken and dissolved in 100 mL deionized water, and the pH is adjusted to be between 11.5 and 12 by using 1 mol/L NaOH solution, so that 2% (w/v) rice protein solution is obtained. 0.1. 0.1 g brilliant blue pigment was weighed and dissolved in 20 mL deionized water to give a 0.5% (w/v) brilliant blue solution. Taking 49 mL alkaline rice protein solution, adding 1 mL brilliant blue solution, uniformly mixing to obtain rice protein solution with pigment content of 0.01% (w/v), adding 0.3% (w/v) xanthan gum, uniformly mixing, regulating pH of the solution to 4 with 1 mol/L HCl solution, and uniformly stirring. The suspension is subjected to ultrasonic probe treatment at 80% power for 3 min, and spray drying is carried out at inlet temperature of 180deg.C and flow rate of 500 mL/h. The resulting formulation was added to a 1.5% sodium alginate solution at a concentration of 1%, added dropwise to a 2% (w/v) calcium chloride solution, calcium alginate hydrogel microspheres were filtered out with a nylon mesh, and the coagulation bath solution remaining on the surface of the hydrogel microspheres was rinsed off with deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Example 3

1 g rice protein is taken and dissolved in 100 mL deionized water, and the pH is adjusted to be between 11.5 and 12 by using 1 mol/L NaOH solution, so that 1% (w/v) rice protein solution is obtained. 0.1. 0.1 g brilliant blue pigment was weighed and dissolved in 20 mL deionized water to give a 0.5% (w/v) brilliant blue solution. Taking 49 mL alkaline rice protein solution, adding 1 mL brilliant blue solution, uniformly mixing to obtain rice protein solution with pigment content of 0.01% (w/v), adding 0.1% (w/v) xanthan gum, uniformly mixing, regulating pH of the solution to 4 with 1 mol/L HCl solution, and uniformly stirring. The suspension is subjected to ultrasonic probe treatment at 80% power for 3 min, and spray drying is carried out at inlet temperature of 180deg.C and flow rate of 500 mL/h. The resulting formulation was added to a 1.5% sodium alginate solution at a concentration of 1%, added dropwise to a 2% (w/v) calcium chloride solution, calcium alginate hydrogel microspheres were filtered out with a nylon mesh, and the coagulation bath solution remaining on the surface of the hydrogel microspheres was rinsed off with deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Example 4

1 g rice protein is taken and dissolved in 100 mL deionized water, and the pH is adjusted to be between 11.5 and 12 by using 1 mol/L NaOH solution, so that 1% (w/v) rice protein solution is obtained. 0.1. 0.1 g brilliant blue pigment was weighed and dissolved in 20 mL deionized water to give a 0.5% (w/v) brilliant blue solution. Taking 49 mL alkaline rice protein solution, adding 1 mL brilliant blue solution, uniformly mixing to obtain rice protein solution with pigment content of 0.01% (w/v), adding 0.3% (w/v) xanthan gum, uniformly mixing, regulating pH of the solution to 5 with 1 mol/L HCl solution, and uniformly stirring. The suspension is subjected to ultrasonic probe treatment at 80% power for 3 min, and spray drying is carried out at inlet temperature of 180deg.C and flow rate of 500 mL/h. The resulting formulation was added to a 1.5% sodium alginate solution at a concentration of 1%, added dropwise to a 2% (w/v) calcium chloride solution, calcium alginate hydrogel microspheres were filtered out with a nylon mesh, and the coagulation bath solution remaining on the surface of the hydrogel microspheres was rinsed off with deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Example 5

1 g rice protein is taken and dissolved in 100 mL deionized water, and the pH is adjusted to be between 11.5 and 12 by using 1 mol/L NaOH solution, so that 1% (w/v) rice protein solution is obtained. 0.1. 0.1 g brilliant blue pigment was weighed and dissolved in 20 mL deionized water to give a 0.5% (w/v) brilliant blue solution. Taking 49 mL alkaline rice protein solution, adding 1 mL brilliant blue solution, uniformly mixing to obtain rice protein solution with pigment content of 0.01% (w/v), adding 0.3% (w/v) konjak gum, uniformly mixing, regulating pH of the solution to 4 with 1 mol/L HCl solution, and uniformly stirring. The suspension is subjected to ultrasonic probe treatment at 80% power for 3 min, and spray drying is carried out at inlet temperature of 180deg.C and flow rate of 500 mL/h. The resulting formulation was added to a 1.5% sodium alginate solution at a concentration of 1%, added dropwise to a 2% (w/v) calcium chloride solution, calcium alginate hydrogel microspheres were filtered out with a nylon mesh, and the coagulation bath solution remaining on the surface of the hydrogel microspheres was rinsed off with deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Example 6

The method for measuring the permeability in the hydrogel microsphere comprises the following steps: preparing brilliant blue solution standard curve under the concentration of 0.0001-0.05% aqueous phase. The hydrogel microsphere preservation solution of 1 mL was withdrawn on days 0 and 7, the absorbance of the preservation solution at 630 nm was measured, and the amount of brilliant blue released was determined from the standard curve.

Permeability (%) = (content of brilliant blue released on day 7-content of brilliant blue in preservation solution on day 0)/addition amount of brilliant blue

Comparative example 1

1 g rice protein is taken and dissolved in 100 mL deionized water, and the pH is adjusted to be between 11.5 and 12 by using 1 mol/L NaOH solution, so that 1% (w/v) rice protein solution is obtained. 0.1. 0.1 g brilliant blue pigment was weighed and dissolved in 20 mL deionized water to give a 0.5% (w/v) brilliant blue solution. Taking 49 mL alkaline rice protein solution, adding 1 mL brilliant blue solution, uniformly mixing to obtain rice protein solution with pigment content of 0.01% (w/v), adding 0.3% (w/v) xanthan gum, uniformly mixing, regulating pH of the solution to 7 with 1 mol/L HCl solution, and uniformly stirring. The suspension is subjected to ultrasonic probe treatment at 80% power for 3 min, and spray drying is carried out at inlet temperature of 180deg.C and flow rate of 500 mL/h. The resulting formulation was added to a 1.5% sodium alginate solution at a concentration of 1%, added dropwise to a 2% (w/v) calcium chloride solution, calcium alginate hydrogel microspheres were filtered out with a nylon mesh, and the coagulation bath solution remaining on the surface of the hydrogel microspheres was rinsed off with deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Comparative example 2

2 g whey protein isolate, 0.2 g Bright blue, 5 g gelatin, 3 g sodium chloride in 100 mL water as the water phase, 5 g polyglycerol ricinoleate in 100 mL corn oil as the oil phase were weighed out. In the oil-water ratio of 4:1, mixing the oil phase and the water phase in proportion, fully stirring and mixing, and then performing probe ultrasonic treatment for 3 min under 80% of power. The prepared W/O emulsion was prepared at 1:4 and 2% of whey protein isolate aqueous phase solution, and performing ultrasonic treatment for 3 min at 80% of power to obtain W/O/W pigment emulsion. The emulsion was prepared by mixing the above emulsion with 1:1 and 3% sodium alginate solution are mixed and stirred uniformly, the mixture is added into 2% (w/v) calcium chloride solution drop by drop, the calcium alginate hydrogel microspheres are filtered out by nylon net, and the coagulating bath solution remained on the surfaces of the hydrogel microspheres is washed out by deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Comparative example 3

0.1. 0.1 g brilliant blue pigment is weighed and dissolved in 20 mL deionized water to obtain 0.5% (w/v) brilliant blue solution, the solution is diluted 50 times to obtain aqueous phase solution with pigment content of 0.01% (w/v), and the obtained pigment solution is prepared by the following steps: 1 and 3% sodium alginate solution are mixed and stirred uniformly, the mixture is added into 2% (w/v) calcium chloride solution drop by drop, the calcium alginate hydrogel microspheres are filtered out by nylon net, and the coagulating bath solution remained on the surfaces of the hydrogel microspheres is washed out by deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Comparative example 4

1 g rice protein is taken and dissolved in 100 mL deionized water, and the pH is adjusted to be between 11.5 and 12 by using 1 mol/L NaOH solution, so that 1% (w/v) rice protein solution is obtained. 0.1. 0.1 g brilliant blue pigment was weighed and dissolved in 20 mL deionized water to give a 0.5% (w/v) brilliant blue solution. Taking 49 mL alkaline rice protein solution, adding 1 mL brilliant blue solution, uniformly mixing to obtain rice protein solution with pigment content of 0.01% (w/v), adding 0.3% (w/v) sodium carboxymethylcellulose (CMC), uniformly mixing, regulating pH of the solution to 4 with 1 mol/L HCl solution, and uniformly stirring. The suspension is subjected to ultrasonic probe treatment at 80% power for 3 min, and spray drying is carried out at inlet temperature of 180deg.C and flow rate of 500 mL/h. The resulting formulation was added to a 1.5% sodium alginate solution at a concentration of 1%, added dropwise to a 2% (w/v) calcium chloride solution, calcium alginate hydrogel microspheres were filtered out with a nylon mesh, and the coagulation bath solution remaining on the surface of the hydrogel microspheres was rinsed off with deionized water. The prepared hydrogel microspheres were immersed in a storage solution (aqueous solution at pH 4) of 35 mL, and the migration of the pigment was observed. After a period of time, the absorbance and pH of the solution were measured.

Table 1 penetration rates of pigments in the hydrogel microspheres prepared in examples 1 to 5 and comparative examples 1 to 4

Examples	Pigment permeability (%)	Core liquid morphology
			Example 1	0.05±0.01%	The core liquid is uniform
Example 2	0.12±0.07%	The core liquid is uniform
			Example 3	2.49±0.89%	The core liquid is uniform and slightly flocculated
Example 4	8.65±1.73%	The core liquid is uniform
			Example 5	7.58±2.31%	The core liquid is uniform and has flocculation
Comparative example 1	56.87±5.64%	The core liquid is uniform and has leakage
			Comparative example 2	15.62±2.56%	The core liquid is uniform, milky white and obvious in shading
Comparative example 3	87.26±9.63%	Pigment complete leakage
			Comparative example 4	4.56±0.98%	The core liquid has serious flocculation and is not uniform

According to Table 1, the pigment hydrogel microspheres prepared in example 1 had the lowest leakage rate and uniform color and shape of the core liquid, and were the best optimized formulation. Comparing table 1 with comparative example 1 of fig. 1, it was found that the preservation solution was insufficient to resist leakage of pigment under neutral bias conditions; comparing the comparative example 2 in Table 1 and FIG. 3, it was found that the W/O/W emulsion had too high color shading ability and hardly developed color in spite of having a certain leakage resistance; comparing table 1 with comparative example 3 of fig. 3, it was found that the direct application of pigment to sodium alginate microspheres leaked a large amount of pigment; comparing table 1 with comparative example 4 of fig. 4, it can be found that CMC does not have the ability to uniformly disperse pigment as a thickener.

The leakage rate and the morphology comparison data of the pigment hydrogel microspheres prepared according to the examples 1 and 2 in Table 1 can be obtained, the addition concentration of the rice protein can achieve the effect of almost no leakage at 1-2%, and the addition amount of 1% is more excellent on the premise of maximizing the economic benefit.

The leakage rate and morphology comparison data of the pigment hydrogel microspheres prepared according to examples 1 and 3 of table 1 are available, and the addition amount of xanthan gum is preferably 0.3%.

The pigment hydrogel microspheres prepared according to examples 1 and 4 of table 1 are available in terms of leakage rate and morphology contrast, and the pH of the preservation solution is preferably 4.

The leakage rate and morphology contrast data of the pigment hydrogel microspheres prepared according to examples 1, 5 of table 1 are available, and the thickener is preferably xanthan gum.

It should be noted that the above embodiments are only for illustrating the technical solution of the present application and not for limiting the same, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present application may be modified or substituted without departing from the spirit and scope of the technical solution of the present application, which is intended to be covered in the scope of the claims of the present application.

Claims

1. A preparation method of a leak-free water-soluble pigment gel microsphere is characterized by comprising the following steps: the method comprises the following steps:

preparation of rice protein-pigment complex: dissolving rice protein in alkali liquor with pH of 12 to obtain rice protein solution with 1% -2%, adding a proper amount of pigment and thickener, dissolving and hydrating, and regulating pH to 4-5 under the condition of uniform stirring to obtain rice protein-pigment compound; the thickening agent is one or more of konjac glucomannan and xanthan gum, and the addition amount is 0.1% -0.3%;

preparation of pigment preparation: homogenizing rice protein-pigment complex to obtain pigment-rice protein granule suspension, and drying the suspension to obtain pigment preparation;

preparation of pigment hydrogel microspheres: dispersing 0.1-10% pigment preparation in 0.5-5% sodium alginate solution, dropwise adding into 1-5% calcium chloride solution by using a double-barrel syringe, filtering, washing with deionized water, and storing in preservation solution to obtain calcium alginate hydrogel microsphere.

2. The method for preparing the water-soluble pigment gel microsphere according to claim 1, wherein the method comprises the following steps: the addition amount of pigment in the preparation of rice protein-pigment compound is 0.001-1%, and pigment is selected from one of brilliant blue, lemon yellow, allure red and carmine edible pigment, or green, purple and caramel pigment compound product obtained by mixing the above pigments.

3. The method for preparing the water-soluble pigment gel microsphere according to claim 1, wherein the method comprises the following steps: the duration of dissolution and hydration in the preparation of the rice protein-pigment complex is 1-24 h.

4. The method for preparing the water-soluble pigment gel microsphere according to claim 1, wherein the method comprises the following steps: the homogenizing means in the preparation of pigment preparation is ultrasonic crushing or high pressure homogenizing.

5. The method for preparing the water-soluble pigment gel microsphere according to claim 4, wherein the method comprises the following steps: the operation condition of ultrasonic crushing is that the ultrasonic power is 80 percent, and the ultrasonic duration is 2-5 minutes;

the conditions of high-pressure homogenization are as follows: homogenizing for 2-7 times under 50-100 MPa.

6. The method for preparing the water-soluble pigment gel microsphere according to claim 1, wherein the method comprises the following steps: the drying means in the preparation of the pigment preparation is spray drying or freeze drying.

7. The method for preparing the water-soluble pigment gel microsphere according to claim 6, wherein the method comprises the following steps: the spray drying condition is that the inlet temperature is 150-180 ℃ and the flow rate is 400-800 mL/h.