阅读说明：本技术 一种乳清分离蛋白-单宁酸纳米颗粒稳定剂及其制备方法和油相Pickering乳液 (Whey protein isolate-tannic acid nanoparticle stabilizer, preparation method thereof and oil phase Pickering emulsion ) 是由 刘刚 胡中泽 秦新光 李宛蓉 王学东 于 2019-09-20 设计创作，主要内容包括：本发明公开了一种乳清分离蛋白-单宁酸纳米颗粒稳定剂及其制备方法和油相Pickering乳液。方法包括：1)将乳清分离蛋白溶于水中,使用酸碱调节剂调节体系pH至9-12,然后于2℃-8℃下至水合作用完全后得到第一溶液；2)将单宁酸溶于水中,使用酸碱调节剂调节体系pH至9-12,得到第二溶液；3)将第一溶液和第二溶液混合,于有氧条件充分反应,得到所述乳清分离蛋白-单宁酸纳米颗粒稳定剂。本发明的乳液体系具有较高的物理和氧化稳定性,所制备的WPI-TA纳米颗粒有望成为一种具有潜在优势的Pickering乳液稳定剂,具有良好的应用前景。(the invention discloses a whey protein isolate-tannic acid nanoparticle stabilizer, a preparation method thereof and an oil phase Pickering emulsion. The method comprises the following steps: 1) dissolving whey protein isolate in water, adjusting the pH of a system to 9-12 by using an acid-base regulator, and then obtaining a first solution after complete hydration at the temperature of 2-8 ℃; 2) dissolving tannic acid in water, and adjusting the pH of the system to 9-12 by using an acid-base regulator to obtain a second solution; 3) and mixing the first solution and the second solution, and fully reacting under aerobic conditions to obtain the whey protein isolate-tannin nanoparticle stabilizer. The emulsion system has higher physical and oxidation stability, and the prepared WPI-TA nano-particles are expected to become a Pickering emulsion stabilizer with potential advantages, so the emulsion system has good application prospect.)

1. A preparation method of whey protein isolate-tannin nanoparticle stabilizer is characterized by comprising the following steps:

1) Dissolving whey protein isolate in water, adjusting the pH of a system to 9-12 by using an acid-base regulator, and then obtaining a first solution after complete hydration at the temperature of 2-8 ℃;

2) Dissolving tannic acid in water, and adjusting the pH of the system to 9-12 by using an acid-base regulator to obtain a second solution;

3) mixing the first solution and the second solution, and fully reacting under aerobic conditions to obtain the whey protein isolate-tannin nanoparticle stabilizer;

The mass ratio of the whey protein isolate to the tannic acid is 0.5-6: 1.

2. The production method according to claim 1, wherein the mass ratio of the whey protein isolate to the tannic acid is 1 to 3: 1.

3. The preparation method according to claim 1, wherein in step 1), the pH modifier is 0.1M-5M sodium hydroxide solution.

4. The method according to claim 1, wherein in step 1), the ratio of whey protein isolate to water is (0.5-5) g: 100 mL.

5. the method according to claim 1, wherein in the step 2), the ratio of the tannic acid to the water is (0.5 to 5) g: 100 mL.

6. the preparation method according to claim 1, wherein the reaction time in step 3) is 12 to 24 hours.

7. whey protein isolate-tannin nanoparticle stabilizer prepared by the preparation method of any one of claims 1 to 6.

8. an oil-phase Pickering emulsion stabilized by whey protein isolate-tannic acid nanoparticles is characterized by being prepared by a preparation method comprising the following steps:

Adjusting the pH value of the whey protein isolate-tannin nanoparticle stabilizer to 3-7, mixing the whey protein isolate-tannin nanoparticle stabilizer with an oil phase, and shearing to obtain an oil phase Pickering emulsion stabilized by the whey protein isolate-tannin nanoparticles;

The whey protein-tannin nanoparticle stabilizer of claim 7.

9. The oil-phase Pickering emulsion of claim 8, wherein the mass ratio of the whey protein isolate-tannic acid nanoparticle stabilizer to the oil phase is 25-90: 10-75.

10. The oil phase Pickering emulsion as claimed in claim 8, wherein the mixing and shearing speed is 8000-.

Technical Field

the invention belongs to the technical field of food science and engineering, and particularly relates to a whey protein isolate-tannic acid nanoparticle stabilizer, a preparation method thereof and an oil phase Pickering emulsion.

background

Whey Protein Isolate (WPI) is a protein obtained by further extraction process on the basis of concentrated whey protein, has high nutritive value, is easy to digest and absorb, contains various active ingredients, and is mostly used as an emulsifier in the fields of food and cosmetics in industrial production. However, due to the environmental sensitivity of the protein, under the influence of certain specific conditions such as high temperature, high salt and the like, the stability of the WPI emulsion is greatly influenced, so that the WPI emulsion is easy to oxidize and is not suitable for storage. Therefore, there is a need to provide a new stabilizer to better prepare WPI protein based emulsions with high stability.

Disclosure of Invention

The invention aims to solve the problems that under the influence of certain specific conditions such as high temperature, high salt and the like, the stability of WPI emulsion is greatly influenced, is easy to oxidize and is not suitable for storage due to the environmental sensitivity of protein per se, and provides a whey protein isolate-tannic acid nanoparticle stabilizer, a preparation method thereof and an oil-phase Pickering emulsion.

In order to achieve the above object, a first aspect of the present invention provides a method for preparing a whey protein isolate-tannic acid nanoparticle stabilizer, the method comprising:

1) Dissolving whey protein isolate in water, adjusting the pH of a system to 9-12 by using an acid-base regulator, and then obtaining a first solution after complete hydration at the temperature of 2-8 ℃;

2) dissolving tannic acid in water, and adjusting the pH of the system to 9-12 by using an acid-base regulator to obtain a second solution;

3) Mixing the first solution and the second solution, and fully reacting under aerobic conditions to obtain the whey protein isolate-tannin nanoparticle stabilizer;

The mass ratio of the whey protein isolate to the tannic acid is 0.5-6: 1.

According to the invention, step 3) further comprises freeze-drying the mixed solution which is fully reacted to aerobic conditions, so as to facilitate storage. When used, the whey protein isolate-tannin nanoparticle stabilizer after freeze-drying is mixed with water to a concentration of 0.5-5%, and the pH is adjusted to a range, for example, pH 3-7.

preferably, the mass ratio of the whey protein isolate to the tannic acid is 1-3: 1.

The acid-base regulator can be an acid-base regulator conventionally adopted by a person skilled in the art, and as a preferable scheme, in the step 1), the acid-base regulator is a 0.1-5M sodium hydroxide solution.

Preferably, in the step 1), the feed-liquid ratio of the whey protein isolate to the water is (0.5-5) g: 100 mL.

Preferably, in the step 1), the time of hydration is 8-12 h.

Preferably, in the step 2), the material-liquid ratio of the tannic acid to the water is (0.5-5) g: 100 mL.

preferably, in the step 3), the reaction time is 12-24 h.

According to the present invention, in step 3), the first solution and the second solution may be mixed and exposed to air with continuous stirring to sufficiently react.

In the present invention, the water may be laboratory water conventionally used by those skilled in the art, such as deionized water, ultrapure water, and the like.

The second aspect of the present invention provides a whey protein isolate-tannin nanoparticle stabilizer prepared by the above-mentioned preparation method.

The third aspect of the invention provides an oil phase Pickering emulsion stabilized by whey protein isolate-tannic acid nanoparticles, which is prepared by a preparation method comprising the following steps:

Adjusting the pH value of the whey protein isolate-tannin nanoparticle stabilizer to 3-7, mixing the whey protein isolate-tannin nanoparticle stabilizer with an oil phase, and shearing to obtain an oil phase Pickering emulsion stabilized by the whey protein isolate-tannin nanoparticles;

The whey protein isolate-tannic acid nanoparticle stabilizer is the whey protein isolate-tannic acid nanoparticle stabilizer.

According to the invention, the oil phase may be one or more of rice oil, soybean oil, corn oil, rapeseed oil, olive oil, sunflower seed oil, peanut oil. Preferably, the mass ratio of the whey protein isolate-tannin nanoparticle stabilizer to the oil phase is 25-90: 10-75.

Preferably, the speed of mixing and shearing is 8000-.

The invention has the beneficial effects that:

According to the invention, WPI-TA nano-particles with the optimal composite proportion are selected as an emulsifier, the rice oil Pickering emulsion is prepared by adopting a simple shear induced emulsification technology, and the stable and appropriate WPI-TA nano-particles with the appropriate size are successfully prepared to construct a Pickering emulsion system for realizing the improvement of the emulsion stability.

The emulsion system prepared by the invention has higher physical and oxidation stability, and the prepared WPI-TA nano-particles are expected to become a Pickering emulsion stabilizer with potential advantages, thereby having good application prospect.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

Figure 1 shows microscopic images of WPI after 30min heat treatment at different temperatures and WPI-TA rice oil Pickering emulsion of example 1.

Figure 2 shows microscopic images of WPI and WPI-TA rice oil Pickering emulsions of example 1 at different salt ion concentrations.

figure 3 shows the formation of oil hydroperoxides within 7 days of storage for WPI and the WPI-TA nanoparticle stabilized rice oil Pickering emulsion of example 1.

Figure 4 shows the generation of thiobarbituric acid reaction products within 7 days of storage for WPI and the WPI-TA nanoparticle stabilized rice oil Pickering emulsion of example 1.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the examples of the present invention, whey protein isolate was used as purchased from Hilmar Ingredients, USA.