阅读说明：本技术 一种通过超高压提高胶束酪蛋白粉体复水性的方法 (Method for improving rehydration of micellar casein powder through ultrahigh pressure ) 是由 季俊夫 倪丹丹 廖敏杰 马玲君 陈芳 胡小松 于 2021-01-11 设计创作，主要内容包括：本发明提供了一种通过超高压处理改变酪蛋白天然纳米胶束结构提高胶束酪蛋白粉体复水性的方法包括：制备胶束酪蛋白溶液,将其分装用于特定条件下超高压处理；将处理后的酪蛋白样品进行真空冷冻干燥得到粉体。本发明采用的超高压处理是一种新型绿色物理加工方法,通过高压下的物理压缩作用使酪蛋白中的胶体磷酸钙离子键解离,从而改善了胶束酪蛋白粉的复水性。本发明所利用的非热加工技术安全可靠、操作简单、高效节能、环境友好,所生产的胶束酪蛋白粉更易复水形成稳定均一体系的溶液,有利于其后续在食品加工中的更好应用。(The invention provides a method for improving the rehydration of micellar casein powder by changing a natural nano-micelle structure of casein through ultrahigh pressure treatment, which comprises the following steps: preparing a micellar casein solution, and subpackaging the micellar casein solution for ultrahigh pressure treatment under specific conditions; and (3) carrying out vacuum freeze drying on the treated casein sample to obtain powder. The ultrahigh pressure treatment adopted by the invention is a novel green physical processing method, and the colloid calcium phosphate ionic bond in the casein is dissociated under the physical compression action under high pressure, so that the rehydration of the micellar casein powder is improved. The non-thermal processing technology adopted by the invention is safe and reliable, the operation is simple, the efficiency and the energy are high, the environment is friendly, the produced micelle casein powder is easier to rehydrate to form a solution with a stable and uniform system, and the better subsequent application in food processing is facilitated.)

1. The method for improving the rehydration of the casein powder by ultrahigh pressure comprises the following steps:

1) preparing micellar casein solution, subpackaging, and performing ultrahigh pressure treatment;

2) and (3) carrying out vacuum freeze drying on the casein sample subjected to the ultrahigh pressure treatment to obtain powder.

2. The method of claim 1, wherein the casein powder is micellar casein powder.

3. The method according to claim 1 or 2, wherein in step 1), the micellar casein solution is prepared by: preparing 5% w/w micellar casein suspension, stirring at 500rpm at 40 ℃ for 12h, then centrifuging for 10min at 3000g, and taking supernatant fluid, namely micellar casein solution.

4. The method of claim 3, wherein the micellar casein solution has a solids content of 2.50 ± 0.02%.

5. The process according to any one of claims 1 to 4, wherein the pressure of the ultra-high pressure treatment is from 300MPa to 500 MPa.

6. The process according to any one of claims 1 to 5, wherein the ultra high pressure treatment has a dwell time of 15 min.

7. The method according to any one of claims 1 to 6, wherein the ultra-high pressure treatment has a pressure increase rate of 100MPa/min and an instantaneous pressure reduction.

8. The method according to any one of claims 1 to 7, wherein in the step 2), the vacuum freeze-drying method is to lay the casein sample subjected to ultra-high pressure in a petri dish to have a thickness of about 1cm, pre-freeze at-80 ℃ for 12 hours, and then freeze-dry in a freeze-dryer for 48 hours.

9. Casein powder with high rehydration capability prepared using a process according to any one of claims 1 to 8.

10. Use of the method according to any one of claims 1-8 or the high rehydration performance casein powder of claim 9 in food processing.

Technical Field

The invention belongs to the technical field of food science and engineering, and particularly relates to a method for improving rehydration of micellar casein powder through ultrahigh pressure.

Background

The micellar casein is a main protein in animal milk, contains 8 essential amino acids, can supplement high-quality protein and trace elements such as calcium, phosphorus and the like for human bodies, has the characteristics of good emulsification, foaming, flavor development, film formation, gel formation and the like, and has extremely high nutrition and application values. Micellar casein is generally circulated in global trade in the form of powder, which is due to the advantages of easy transportation, easy storage and easy processing of powder. Therefore, complete and rapid rehydration behavior of casein powder is a prerequisite and prerequisite for fully showing the functionality of casein powder. This puts strict requirements on the rehydration process (including wetting, dispersing and dissolving processes) of the casein powder in the water phase. But due to the existence of nano micelle clusters in the casein structure and the compact hydrophobic effect among surface particles, the rehydration behavior of the powder is seriously hindered and delayed. Therefore, how to improve the rehydration of the casein powder by changing the structure of the casein nano micelle is a scientific problem which needs to be solved urgently and has practical application significance.

At present, the method for changing the structure of the casein nano micelle is mainly chemical modification, and comprises adding chemical substances such as sodium carbonate, sodium chloride, sodium citrate, disodium phosphate and the like. The chemical calcium chelating agents are added into a micellar casein system to replace calcium ions in colloidal calcium phosphate, so that a micellar structure is broken down, and caseinate which is easier to rehydrate is formed. With the rise of the minimum processing concept of modern food, the novel physical processing technology of green food is gradually developed and matured day by day, and particularly the ultrahigh pressure technology has the advantages of high efficiency, energy conservation, environmental friendliness, safety, reliability and the like compared with the traditional chemical method. The principle of the ultrahigh pressure treatment is based on the physical compression effect, non-covalent bonds such as hydrogen bonds, ionic bonds, hydrophobic bonds and the like which contribute to the three-dimensional structure of the protein are destroyed, and covalent bonds of micromolecular compounds such as amino acids, flavor substances and the like are not destroyed, so that the original nutrition, color and flavor of the food are well maintained.

Disclosure of Invention

In order to solve the technical problem, the inventor uses ultrahigh pressure treatment to act on the ionic bond supporting the micellar casein structure, so that the colloidal calcium phosphate nanoclusters can be dissociated, calcium ions are dissociated from the micellar structure, and sub-micellar particles with more small sizes are formed. After the particles are dried into powder, the ionic bonds for maintaining the micelle structure are destroyed, so that the dispersing process of the micellar casein is greatly accelerated, and the powder with better solubility is finally obtained.

The invention aims to provide a method for improving the rehydration of casein powder by regulating the natural nano micelle structure of casein under ultrahigh pressure, so that casein raw materials can be widely applied in the food industry.

In one aspect, the invention provides a method for improving the rehydration of casein powder by ultrahigh pressure, which comprises the following steps:

1) preparing micellar casein solution, subpackaging, and performing ultrahigh pressure treatment;

2) and (3) carrying out vacuum freeze drying on the casein sample subjected to the ultrahigh pressure treatment to obtain powder.

Further, the casein powder is micellar casein powder.

Further, in step 1), the preparation method of the micellar casein solution comprises the following steps: preparing 5% w/w micellar casein suspension, stirring at 500rpm at 40 ℃ for 12h, then centrifuging for 10min at 3000g, and taking supernatant fluid, namely micellar casein solution.

Further, the solid content of the micellar casein solution is 2.50 +/-0.02%.

Further, the pressure of the ultrahigh pressure treatment is 300MPa-500 MPa.

Further, the pressure holding time of the ultrahigh pressure treatment is 15 min.

Further, the pressure increasing rate of the ultrahigh pressure treatment is 100MPa/min, and the pressure is instantaneously reduced.

Further, in step 2), the vacuum freeze-drying method comprises spreading the ultra-high pressure casein sample in a petri dish to a thickness of about 1cm, pre-freezing at-80 deg.C for 12h, and freeze-drying in a freeze-dryer for 48 h.

On the other hand, the invention provides the casein powder with high rehydration capability prepared by the method.

On the other hand, the invention provides the application of the method or the casein powder with high rehydration capability in food processing.

The dispensing methods described herein may use dispensing, sealing methods and containers known in the food, chemical arts; the solution is preferably filled into PET bottles and then sealed.

The method of the present application may further comprise operations for further processing and preserving the powder, including but not limited to collecting the obtained powder and sieving; and (5) putting the sieved powder into a dryer for storage.

The application objects of the method are not limited to pure casein powder, and the application of the method in other casein-containing food powder also belongs to the protection scope of the invention.

Rehydration properties described herein include, but are not limited to, dissolution properties, wetting properties, dispersion properties, turbidity, rehydration product stability, and the like.

The invention has the beneficial effects that: the invention utilizes the ultrahigh pressure treatment to act on the ionic bond in the micellar casein, so that the colloidal calcium phosphate is dissociated, the natural nano micelle structure is disintegrated therewith, more and smaller sub-micelle particles are formed, the micellar casein shows rapid wetting and dispersing behaviors after being dried into powder, and the solubility of the micellar casein is greatly improved. The micelle casein powder is prepared by adopting ultrahigh pressure pretreatment and vacuum freeze drying technology, so that the wetting and dispersing process of the micelle casein powder is accelerated, the solubility of the micelle casein powder is effectively improved, and the rehydration characteristic of the micelle casein powder is obviously improved. The full and comprehensive rehydration of the micellar casein powder is beneficial to better exerting the functional characteristics of casein, which has great significance for the efficient utilization of food ingredients. Meanwhile, the micellar casein powder prepared by the method disclosed by the invention is free of any chemical additive, has the advantages of greenness, naturalness, nutrition, health and the like, and is suitable for large-scale industrial production.

Drawings

FIG. 1: the technological process of the method of the invention comprises 1-powder dissolving container, 2-casein canned solution before high pressure, 3-ultrahigh pressure equipment, 4-casein canned solution after high pressure and 5-casein freeze-dried powder after high pressure.

FIG. 2: the dissolution power curve of the powder sample after different pressure treatments.

FIG. 3: d (50) change chart of powder samples within 90min after different pressure treatments.

FIG. 4: the contact angle of the powder sample after different pressure treatments changes with time.

FIG. 5: the weight of the powder sample absorbing water within 10min after different pressure treatments.

FIG. 6: change in free calcium content in casein solution after high hydrostatic pressure treatment.

FIG. 7: the appearance of the casein solution changed after the high hydrostatic pressure treatment (0 h).

Detailed Description

The present invention will be described below with reference to specific examples, but the present invention is not limited thereto.

The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.

Examples Main materials and instruments

The micelle casein powder is prepared by using a membrane separation micelle casein powder, a magnetic stirrer, a centrifugal machine, ultrahigh pressure equipment, a freeze dryer and the like.

Example 1

(1) Weighing 10g of micellar casein powder, adding into 190g of distilled water, stirring at 500rpm for 12h at 40 ℃, then centrifuging for 10min at 3000g, and taking supernatant fluid to obtain micellar casein solution with solid content of (2.50 +/-0.02)%.

(2) Subpackaging the micellar casein solution into PET bottles, treating for 15min under 300MPa, increasing the pressure at a rate of 100MPa/min, and instantly reducing the pressure.

(3) Spreading the sample subjected to ultrahigh pressure treatment in a culture dish, wherein the thickness of the sample is about 1cm, pre-freezing the sample at-80 ℃ for 12h, and then freeze-drying the sample in a freeze dryer for 48h to obtain casein powder.

Example 2

This example differs from example 1 in that the ultrahigh pressure was 400 MPa.

Example 3

This example differs from example 1 in that the ultrahigh pressure was 500 MPa.

Examples of effects

The powder samples of examples 1 to 3 and powder samples of other several processing conditions were subjected to physical property characterization and detection of solubility, dispersibility, and wettability (Washburn method and contact angle method); and (3) measuring the particle size, the polydispersity index, the potential and the turbidity of the micellar casein solution after the ultrahigh pressure and measuring the content of free calcium.

As can be seen in fig. 2: compared with a control sample, the powder samples of the high static pressure treatment group have obviously improved solubility, wherein the micelle casein powder subjected to 300MPa pressure treatment has the best solubility, the dissolution speed is greatly improved, and the final solubility is increased by about one time.

As can be seen in fig. 3: within the monitoring time of 90 minutes, the rate of particle size reduction of the micellar casein powder treated under the pressure of 300MPa is the fastest, which shows that the micellar casein powder has the best dispersibility.

As can be seen in fig. 4, 5, both detection methods show: after high-pressure treatment, the wettability of the powder is obviously improved.

The free calcium content measured in figure 6 is an important indicator of the change in colloidal calcium phosphate. Free calcium increased after autoclaving, indicating that the colloidal calcium phosphate dissociated and bound calcium to free calcium. The free calcium content was measured immediately after the sample was subjected to high hydrostatic pressure and found to be positively correlated with the pressure level. There is a tendency for the free calcium content to recover over a period of time after the pressure is released, especially for the 500MPa sample.

TABLE 1 changes in particle size, polydispersity index, potential and solution turbidity of casein after high hydrostatic pressure treatment

Note: alphabetic identity means no significant difference (p > 0.05); letter differences indicate significant differences (p < 0.05).

Increasing the pressure resulted in a gradual decrease in casein particle size, indicating that the casein micelles ruptured with pressure. The polydispersity index of the samples of 400 and 500MPa increased. The 500MPa treated samples had a reduced charge indicating a reduced stability. After the casein solution is subjected to high static pressure treatment, the change of turbidity is obvious. This is because the high hydrostatic pressure treatment of the casein solution protein destroys the integrity of the casein micelles, which appears to be more transparent in appearance and less hazy.

Table 2 physical properties of the powders.

Note: alphabetic identity means no significant difference (p > 0.05); letter differences indicate significant differences (p < 0.05).

The bulk densities of the six powder samples decreased with increasing pressure. The control sample showed the highest tap density and the 500MPa treated sample had the lowest tap density. The porosity of the sample is positively correlated to the pressure level. All six samples had high porosity. Porosity is closely related to wettability. Generally, the porosity increases and the wettability of the powder improves.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.