Method for preparing high-foaming sterilized egg white liquid through electrical stimulation and application of high-foaming sterilized egg white liquid

Abstract

The invention belongs to the technical field of food processing, and particularly relates to a method for preparing high-foaming sterilized egg white liquid through electrical stimulation and application of the high-foaming sterilized egg white liquid. The method comprises the following steps: cleaning fresh eggs to remove dirt and bacteria on the surfaces of eggshells; separating egg white and yolk by using an eggbeater to obtain egg white liquid; putting the separated egg white liquid under a low-temperature condition, adding sodium chloride, and stirring at a low speed by using a magnetic stirrer; and performing electrical stimulation treatment on the stirred egg white liquid. The prepared egg white liquid has good foamability, stability and antibacterial performance, the problems that natural egg white liquid is poor in foam stability and foamability are effectively solved, in addition, an egg white sample obtained after electrical stimulation has richer taste features, and the egg white liquid can be widely applied to aerated food. High-quality development of the egg product processing industry is promoted, and a new technical means is provided for the food processing industry.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a method for preparing high-foaming sterilized egg white liquid by electrical stimulation. Background Art

[0002] Egg white is widely used in the processing of foaming foods because of its good foaming, emulsifying and gelling properties. The foaming properties of egg white can make food fluffy and obtain better texture, and its strength depends mainly on the role of protein in egg white. The foam produced by egg white is rich and stable, and its effect on maintaining the quality of aerated food is better than that of proteins from other sources. It is often used as a natural foaming agent in cakes, breads and other foods. However, egg white liquid still faces problems such as deterioration of foaming performance and insufficient foam stability in actual application, which limits its application in the food industry. Therefore, in order to improve the quality of aerated foods based on egg white protein, it is necessary to improve the foaming performance of protein and maintain good stability during storage. Summary of the invention The technical problem to be solved by the present invention is to provide a method for preparing high-foaming sterilized egg white liquid by electrical stimulation. In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for preparing a high-foaming sterilized egg white liquid by electrical stimulation, characterized in that it comprises the following steps: (1) Wash fresh eggs to obtain clean eggs; (2) separating the egg white and the egg yolk obtained in step (1) to obtain egg white liquid, and stirring the egg white liquid; (3) mixing the uniformly stirred egg white liquid obtained in step (2) with water to obtain a diluted egg white liquid; (4) adding sodium chloride to the egg white solution obtained in step (3) and stirring the mixture; (5) electrically stimulating the egg white liquid obtained in step (4); and then storing the obtained egg white liquid.

[0003] Preferably, in step (2), the stirring speed is 200-300 r / min and the stirring time is 2-3 h.

[0004] Preferably, in step (3), the amount of water added when preparing the diluted egg white liquid is 30-70% of the volume of the egg white liquid.

[0005] Preferably, in step (4), the amount of sodium chloride added to the egg white liquid is 0.2-2% by mass concentration.

[0006] Preferably, in step (5), the electrical stimulation voltage intensity is 10-40V, the current intensity is 0.02A-0.2A, and the electrical stimulation time is 0.5-2min.

[0007] Preferably, in step (5), the egg white liquid is stored at a temperature of 0-8°C.

[0008] A high-foaming sterilized egg white liquid is prepared by the method.

[0009] The high-foaming sterilized egg white liquid prepared by the method is applied to food or health products. The present invention has the following beneficial effects: (1) The methods for treating egg white protein to change its properties are mainly concentrated on biological enzymatic hydrolysis, chemical modification and physical methods. However, since enzymes are proteins, when the environment changes (such as temperature, pH value, ion concentration, etc.), the conformation of enzyme molecules changes, thereby reducing the performance of the enzyme and causing it to fail to meet the demand. Chemical methods need to consider the toxicity of the chemical reagents used and the reaction residues, which limits their application in the food industry. The physical method of electrical stimulation has the advantages of low cost and no toxic side effects, which can minimize the impact on product flavor and nutritional content.

[0010] (2) The egg white liquid prepared by this method has higher effect and stability than the original egg white, and the processing technology is more in line with the current green, healthy and natural dietary concept.

[0011] (3) The egg white liquid prepared by the method has a good sterilization effect. It can not only be used for the treatment of fresh egg white, but also can play a sterilization effect during the storage of egg white. The electric stimulation sterilization of egg white liquid carried out by the present invention is a non-thermal sterilization technology, and the temperature is always kept within 8°C (such as Figure 3 As shown in the figure, non-thermal sterilization does not cause denaturation, and the technology unexpectedly found that the foaming property of egg white liquid was improved while sterilizing. The electrical stimulation technology achieves the dual effects of improving the functional properties of egg white liquid and sterilizing. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 The foam microstructure diagrams of the control example and the experimental example.

[0014] Figure 2 This is a diagram showing the sterilization effect after electrical stimulation.

[0015] Figure 3 The temperature test results of the egg white liquid of Examples 1-5 under electrical stimulation are shown. DETAILED DESCRIPTION

[0016] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0017] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0018] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0019] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0020] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0021] The raw materials used in the following examples are all commercially available conventional raw materials, and are not particularly limited thereto, and will not be described again.

[0022] Example 1 (1) Wash fresh eggs to obtain clean eggs; (2) Separate the egg white and yolk from the eggs to obtain egg white liquid, and stir the egg white liquid at 4°C and 200 r / min for 3 h; (3) Mix egg white liquid and water in a ratio of 1:1, i.e. dilute to 70% egg white liquid; (4) Sodium chloride was added to the egg white solution and stirred (at 4°C and 200 r / min for 1 h). The mass concentration of sodium chloride in the egg white solution was 1%; (5) The stirred egg white liquid was electrically stimulated at a voltage of 12.4 V, a current of 0.04 A, and a stimulation time of 1 min. The egg white liquid after electrical stimulation was stored at 4°C for further analysis.

[0023] Example 2 (1) Wash fresh eggs to obtain clean eggs; (2) Separate the egg white and yolk from the eggs to obtain egg white liquid, and stir the egg white liquid at 4°C and 200 r / min for 3 h; (3) Mix egg white liquid and water in a ratio of 1:1, i.e. dilute to 60% egg white liquid; (4) Sodium chloride was added to the egg white solution and stirred (at 4°C and 200 r / min for 1 h). The mass concentration of sodium chloride in the egg white solution was 0.7%; (5) The stirred egg white solution was electrically stimulated at a voltage of 19.6 V, a current of 0.08 A, and a stimulation time of 1 min. The egg white solution after electrical stimulation was stored at 4°C for further analysis.

[0024] Example 3 (1) Wash fresh eggs to obtain clean eggs; (2) Separate the egg white and yolk from the eggs to obtain egg white liquid, and stir the egg white liquid at 4°C and 200 r / min for 3 h; (3) Mix egg white liquid and water in a ratio of 1:1, i.e. dilute to 50% egg white liquid; (4) Sodium chloride was added to the egg white solution and stirred (at 4°C and 200 r / min for 1 h). The mass concentration of sodium chloride in the egg white solution was 0.5%; (5) The stirred egg white liquid was electrically stimulated at a voltage of 28.6 V, a current of 0.12 A, and a stimulation time of 1 min. The egg white liquid after electrical stimulation was stored at 4°C for further analysis.

[0025] Example 4 (1) Wash fresh eggs to obtain clean eggs; (2) Separate the egg white and yolk from the eggs to obtain egg white liquid, and stir the egg white liquid at 4°C and 200 r / min for 3 h; (3) Mix egg white liquid and water in a ratio of 1:1, i.e. dilute to 50% egg white liquid; (4) Sodium chloride was added to the egg white solution and stirred (at 4°C and 200 r / min for 1 h). The mass concentration of sodium chloride in the egg white solution was 0.5%; (5) The stirred egg white solution was electrically stimulated at a voltage of 31.1 V, a current of 0.16 A, and a stimulation time of 1 min. The egg white solution after electrical stimulation was stored at 4°C for further analysis.

[0026] Example 5 (1) Wash fresh eggs to obtain clean eggs; (2) Separate the egg white and yolk from the eggs to obtain egg white liquid, and stir the egg white liquid at 4°C and 200 r / min for 3 h; (3) Mix egg white liquid and water in a ratio of 1:1, i.e. dilute to 50% egg white liquid; (4) Sodium chloride was added to the egg white solution and stirred (at 4°C and 200 r / min for 1 h). The mass concentration of sodium chloride in the egg white solution was 0.5%; (5) The stirred egg white liquid was electrically stimulated at a voltage of 12.4 V, a current of 0.04 A, and a stimulation time of 1 min. The egg white liquid after electrical stimulation was stored at 4°C for further analysis.

[0027] Comparative Example 1 The steps (1), (2), and (3) for preparing the egg white liquid are the same as those in Example 3, but steps (4) and (5) are not performed.

[0028] Comparative Example 2 The steps (1), (2) and (3) for preparing the egg white liquid are the same as those in Example 3, but step (5) is not performed.

[0029] Comparative Example 3 The steps (1), (2) and (3) for preparing the egg white liquid are the same as those in Example 3, but step (4) is not performed.

[0030] Effect verification Test Example 1 Determination of foaming property and foam stability of electrically stimulated egg white liquid: Take 200 mL into a 100 mL measuring cylinder, then use a high-speed homogenizer at 9500 r / min at 25°C for 1 min, then immediately record its foam volume V0, and then record its foam volume V again after standing at room temperature for 60 min. 60 Then the foaming property (FA) and foam stability (FS) of the egg white liquid were calculated according to the formula. Foaming power (FA) =

[0031] Foam stability (FS) =

[0032] Where V0 and V 60 are the volumes of foam at 0 min and 60 min after whipping, respectively.

[0033] Table 1 Foaming stability

[0034] The effects of different electrical stimulation intensities on the foaming property and foam stability of egg white liquid are shown in Table 1. Compared with the control group, with the increase of current intensity, the foaming ability of egg white is improved, which is 130.0% (Example 1), 126.7% (Example 2), 158.7% (Example 3), 105.7% (Example 4), and 98.3% (Example 5), respectively. The foam stability is also significantly improved. In comparison, the current stimulation of Example 3 causes EWP to have the highest foaming ability of 158±8.50%, which is 1.10 times the foaming ability of the control example. The effect of electrical stimulation on the foaming stability of EWP shows a trend of first rising and then falling. The current stimulation of Example 3 has a good maintenance effect on the foam stability of EWP. However, high-intensity current stimulation is not conducive to the maintenance of foam stability. In general, the current intensity treatment of Example 3 can significantly promote the foaming ability and foam stability of EWP. The egg white liquid without adding sodium chloride for electrical stimulation treatment and the egg white liquid with sodium chloride but not electrical stimulation treatment have a certain degree of improvement in foaming ability and foam stability. However, the foaming ability and foam stability of Example 3 are significantly higher than those of Comparative Examples 2 and 3, which proves that the combination of electrical stimulation and sodium chloride can significantly enhance the effect of electrical stimulation on improving the foaming property of egg white.

[0035] Test Example 2 Electrostimulation of egg white protein microstructure: The state of freshly whipped foam (0 min, 60 min) was recorded using an optical microscope ( Figure 1 ). Compared with Comparative Example 1, the bubbles in the treatment group are small and dense, especially the egg white protein bubbles in Example 3 after 60 minutes of current treatment still maintain a spherical shape, and these small-diameter bubbles are evenly distributed, and the bubbles are also surrounded by a thick liquid film layer. The bubbles of natural egg white protein are polyhedral, which shows that electrical stimulation reduces the liquid drainage rate of egg white protein foam. Thereby, the stability of the foam is improved to maintain the shape of the foam. In addition, compared with Comparative Examples 2 and 3, the foam microstructure of Example 3 is more uniform and dense, proving that the addition of sodium chloride can improve the effect of electrical stimulation on the improvement of egg white foaming properties.

[0036] Test Example 3 Antibacterial experiment: Under sterile conditions, 6 groups of egg white samples stored for 15 days were diluted with physiological saline at appropriate dilutions and then counted on plates.

[0037] The results are as follows Figure 2 As shown. The inhibitory effect of electrical stimulation on the original bacterial colonies in egg white is shown. It can be seen that the number of bacterial colonies cultured in each treatment group after 24 hours is less than that in comparative examples 1 and 2, indicating that the growth of bacteria can be effectively inhibited after the egg white is treated with electrical stimulation. In addition, the number of bacterial colonies in Example 3 is less than that in comparative example 3, proving that sodium chloride can improve the uniform flow of current during electrical stimulation and improve the inhibitory ability of electrical stimulation technology on microorganisms. Test Example 4 Monitoring of egg white temperature during the electrical stimulation process: A near-infrared thermal imager was used to monitor the temperature changes of the egg white during the electrical stimulation process. Figure 3 The temperature of all the egg white liquids treated with electrical stimulation was lower than 8°C during the treatment process, which proved that the treatment was non-thermal processing modification. The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for preparing high-foaming sterilized egg white liquid by electrical stimulation, characterized in that: The following steps are involved: (1) Wash fresh eggs to obtain clean eggs; (2) separating the egg white and the egg yolk obtained in step (1) to obtain egg white liquid, and stirring the egg white liquid; (3) mixing the evenly stirred egg white liquid obtained in step (2) with water to obtain a diluted egg white liquid; (4) adding sodium chloride to the diluted egg white solution obtained in step (3) and stirring the mixture; (5) electrically stimulating the egg white liquid obtained in step (4); and then storing the obtained egg white liquid; thus completing the preparation of the high-foaming sterilized egg white liquid.

2. The method for preparing high-foaming sterilized egg white liquid by electrical stimulation according to claim 1, characterized in that: In step (2), the stirring speed is 200-300 r / min, the stirring time is 2-3h, and the stirring temperature is 0-8°C.

3. The method for preparing high-foaming sterilized egg white liquid by electrical stimulation according to claim 1, characterized in that: In step (3), when preparing the diluted egg white solution, the amount of water added is 30-70% of the volume of the egg white solution.

4. The method for preparing high-foaming sterilized egg white liquid by electrical stimulation according to claim 1, characterized in that: In step (4), the amount of sodium chloride added to the egg white liquid is 0.2-2% by mass concentration, and the stirring temperature is 0-8°C.

5. The method for preparing high-foaming sterilized egg white liquid by electrical stimulation according to claim 1, characterized in that: In step (5), the voltage intensity of the electrical stimulation is 10-40V, the current intensity is 0.02A-0.2A, and the electrical stimulation time is 0.5-2min.

6. The method for preparing high-foaming sterilized egg white liquid by electrical stimulation according to claim 1, characterized in that: In step (5), the egg white liquid is stored at a temperature of 0-8°C.

7. A high foaming sterilized egg white liquid, characterized in that: Prepared by the method described in claims 1-6.

8. The high foaming sterilized egg white liquid prepared by the method according to claims 1-6 is used in food or health care products.

Images