JP2749111B2 - Heat-resistant egg white and egg white composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to heat-resistant egg white and egg white composition.

[Background Art] Egg white solidifies when heated, and thus may not be suitable as a raw material for foods such as beverages and cosmetics such as shampoos produced through a heating process.

For this reason, attempts have been made to impart heat resistance to egg whites. As proposed in Japanese Patent Publication No. 57-54114, three times or more of fresh water is added to egg whites and stirred to improve heat coagulation. A method of agglutinating proteins having the same, separating and removing the aggregates, and drying the remaining solution to finish it into a powdery form has been adopted.

However, the heat-resistant egg white obtained by the above-mentioned conventional method is unsuitable as a raw material for foods and cosmetics because when heated with water, a large amount of hydrogen sulfide is generated and has an unpleasant odor.

Further, when dissolved in fresh water or the like, it lacks stability in a solution, and is insolubilized over time to form a precipitate, so that it is unsuitable as a raw material for liquid products such as beverages.

[Problems to be solved by the invention]

One invention of the present invention aims to provide a heat-resistant egg white which does not heat coagulate even when heated by being dissolved in a solution such as fresh water or the like, and does not generate any unpleasant odor. It is an object of the present invention to provide an egg white composition that has heat resistance and does not form a precipitate even when dissolved in fresh water or the like.

[Means for solving the problem]

The heat-resistant egg white of the present invention is composed of a polymer of egg white proteins, and no band is observed at the positions of ovalbumin and conalbumin by SDS-polyacrylamide electrophoresis, and a unique peak is observed by DSC analysis. Wherein the egg white composition comprises a complex of a polymer of egg white proteins and a saccharide, and SDS
-Characterized by the fact that no bands were observed at the positions of ovalbumin and conalbumin by polyacrylamide electrophoresis, and no specific peak was observed by DSC analysis.

In order to obtain the heat-resistant egg white of the present invention, first, a raw material egg white liquid is prepared.

The egg white may be a raw egg white obtained by breaking a shell egg to separate the yolk, a frozen egg white, a dried egg white, or the like.

Next, add fresh water to the egg white solution (usually, solid content is 10%)
After adding 1/2 to 3 times the weight and diluting, the pH of the obtained egg solution is adjusted to an alkaline range. By adjusting the egg solution to an alkaline range, the egg white protein is easily polymerized by heating in the next step. The pH of the egg solution is preferably adjusted to 8 to 10.

Next, the egg solution is heated at 80 to 120 ° C. for 30 seconds to 60 minutes, and then cooled. By this treatment, the egg white protein polymerizes to form a polymer.

Finally, the above-mentioned egg solution is concentrated on a membrane to remove an odor (unpleasant odor) component mainly composed of hydrogen sulfide generated during the heat treatment, so that the desired heat-resistant egg white can be obtained. Since the egg white protein of the egg solution becomes a polymer and is polymerized, only the odor component can be efficiently removed from the egg solution without passing through the membrane. Membrane concentration using a polymer membrane,
For example, an ultrafiltration method, a reverse osmosis method, a microfiltration method, or the like may be used.

The heat-resistant egg white of the present invention thus obtained has an average molecular weight of 500,000 to 10,000,000 (average molecular weight of raw egg white protein of 30,000 to 60,000) and may be a polymer of egg white protein. I understand. This heat-resistant egg white does not contain a reducing agent.
When analyzed by S-polyacrylamide electrophoresis,
No bands are observed at the positions of ovalbumin and conalbumin. Here, the fact that no band is observed at the positions of ovalbumin and conalbumin means that the distribution of the molecular weight of ovalbumin and conalbumin is determined by measuring the distribution of the molecular weight of ovalbumin and polyalbumin using polyacrylamide as a support. Means not included. In addition, when DSC analysis is performed on heat-resistant egg white, no specific peak is observed. DSC analysis refers to measuring the denaturation point of a protein by heating using differential heat.

In addition, the heat-resistant egg white has a heat-resistant, and is not insolubilized egg white composition because the polymer of the egg white protein is reassociated and becomes more polymerized and tends to be insolubilized if the solution is kept in a solution state. To obtain it, the aqueous solution in which the egg white protein polymer and the saccharide are dissolved may be heated at 70 to 100 ° C. for 20 seconds to 20 minutes, and then cooled. Examples of the saccharide used here include monosaccharides such as glucose and fructose, disaccharides such as lactose and sucrose, and polysaccharides such as dextrin, cyclodextrin and pullulan.

When dextrin is used as a saccharide, the egg white composition of the present invention thus obtained has an average molecular weight of 1,000,000 to 20,000,000, and is found to be a complex of an egg white protein polymer and a polysaccharide.

Further, in this egg white composition, no band was observed at the positions of ovalbumin and conalbumin in SDS-polyacrylamide electrophoresis without a reducing agent. Also DS
No specific peak is observed in C analysis.

[Action]

The heat-resistant egg white of the present invention, as shown in the test examples below,
It has heat resistance and is odorless. It is presumed that the heat resistance is due to the fact that egg white protein becomes a structurally stable polymer and this polymer does not denature even when heated.

It is odorless because odor components have been removed.

Further, the egg white composition of the present invention has heat resistance as shown in the test examples described later, and is stable even when stored in a solution state, and does not generate a precipitate. Although we did not pursue the mechanism in detail, the surface of the molecule of the complex consisting of the polymer of egg white protein and polysaccharide has hydrophilicity,
It is presumed that this is because it is difficult to aggregate.

〔Example〕

Example 1. 30 kg of fresh water was added to 20 kg of egg white solution desalted by a conventional method, and the pH of the obtained egg solution was adjusted to 9.5.
Heated for a minute and then cooled.

Next, the egg solution was subjected to ultrafiltration using a polysulfone-based tubular ultrafiltration membrane (trade name “NTU-3520”, manufactured by Nitto Electric Industry Co., Ltd.) according to a conventional method, and the egg solution was subjected to solid content. Is 12%
After concentration to 2.5 kg, the powder was spray-dried by a conventional method to obtain 2.5 kg of heat-resistant egg white powder having no unpleasant odor.

Example 2. 65 kg of fresh water was added to 5 kg of commercially available dried egg white (trade name: “Dry egg white K type”, manufactured by Kewpie Co., Ltd.), and the resulting egg solution was adjusted to pH 9.5. C. for 5 minutes, then cooled.

Next, the above egg solution was subjected to ultrafiltration using a polyolefin-based tubular ultrafiltration membrane (trade name “NTU-20100” manufactured by Nitto Denki Kogyo Co., Ltd.) by a conventional method to reduce the solid content of the egg solution. 13.3
%, Heat-resistant egg white liquid 4.5K without unpleasant odor
g was obtained.

Example 3. 90 kg of fresh water was added to 60 kg of egg white solution desalted by a conventional method, and the pH of the obtained egg solution was adjusted to 9.5.
Heated for a minute and then cooled.

Next, 0.6 kg of a commercially available dextrin (trade name “Pinedex” manufactured by Matsutani Chemical Co., Ltd.) was added to the egg solution, heated again at 100 ° C. for 10 minutes, and then cooled.

Next, the egg solution was spray-dried by a conventional method to obtain 8.0 kg of powder of an egg white composition.

Example 4. 65 kg of fresh water was added to 5 kg of commercially available dried egg white (manufactured by Kewpie Co., Ltd., trade name "Dried egg white K type"), and the resulting egg solution was adjusted to pH 8.0. C. for 5 minutes, then cooled.

Next, the egg solution was subjected to reverse osmosis concentration using a polysulfone composite membrane system (trade name “NTU-35100” manufactured by Nitto Electric Industries, Ltd.) by a conventional method, and the solid content of the egg solution was 13.5%. And concentrated to.

Then, 200 g of pullulan for food addition (trade name “Pullulan PF-200” manufactured by Hayashibara Co., Ltd.) was added to and mixed with the obtained concentrate to obtain 4.5 kg of powder of an egg white composition.

(Test example)

 Test Example 1. The following samples were prepared.

Control section 1: Raw egg white Control section 2: After adding and diluting 2.5 times the weight of fresh water to raw egg white,
The egg solution was adjusted to pH 9.5, heated at 70 ° C for 10 minutes, and then cooled.Test Section 1: After adding 2.5 times the weight of clear water to raw egg white and diluting,
After adjusting the egg solution to pH 9.5 and heating at 80 ° C. for 10 minutes, the obtained egg solution was subjected to ultrafiltration until the solid content became 8.1%. Test group 2: 2.5 times the weight of fresh egg white fresh water After adding and diluting,
The egg solution was adjusted to pH 9.5, heated at 90 ° C. for 10 minutes, cooled, and the resulting egg solution was subjected to ultrafiltration until the solid content became 10.2%. Test group 3: 2.5 times the raw egg white After adding the weight of Shimizu and diluting,
The egg solution was adjusted to pH 9.5, heated at 100 ° C for 10 minutes, cooled, and the obtained egg solution was subjected to ultrafiltration until the solid content became 13%. Analysis and SDS−
Polyacrylamide electrophoresis analysis was performed.

Further, for each sample, after observing the presence or absence of odor, the pH was adjusted to 7.5, and the heat resistance when heated at 100 ° C. for 30 minutes was observed. The results in Table 1 were obtained.

The symbols in the table indicate that, in DSC, + indicates that a specific peak was recognized, − indicates that no specific peak was recognized, and in electrophoresis, + indicates that a band was present at the position of ovalbumin. The sign "-" indicates that no band was observed at the position of ovalbumin.

In the smell, ○ indicates that all 10 well-trained panels did not feel unpleasant odor, and x indicates that eight or more of the 10 panelists felt unpleasant odor.

In the heat resistance, ○ indicates heat resistance (no coagulation), and X indicates no heat resistance (coagulation).

Test Example 2. The following sample was prepared.

Control: After adding 2.5 times the weight of fresh water to the raw egg white and diluting it,
The egg solution was adjusted to pH 9.5, heated at 100 ° C for 30 minutes, and cooled. Test group: Raw egg white was diluted by adding 2.5 times the weight of clear water,
The egg solution was adjusted to pH 9.5, heated at 100 ° C. for 30 minutes, cooled, and 1.5% by weight of cyclodextrin was added to the obtained egg solution, and the egg solution was further added at 100 ° C. for 10 minutes. After heating and cooling, each of the above samples was separately added and mixed in 50% by weight of fresh water, heated at 100 ° C. for 10 minutes, and then stopped at 5 ° C. for 30 days to observe the state of the solution. Similarly, 50% by weight was added to and mixed with milk, heated at 100 ° C. for 10 minutes, and then allowed to stand at 5 ° C. for 30 days to observe the state of the milk. The results in Table 2 were obtained.

In the table, the symbol ○ indicates that no precipitate was formed, Δ indicates that a precipitate was slightly generated, and x indicates that a large amount of precipitate was generated.

Test Example 3. After adding 2.5 times the weight of fresh water to fresh egg white and diluting it,
The mixture was adjusted to 9.5, heated at 100 ° C. for 20 minutes, and then cooled, and the obtained egg solution was divided into eight equal parts.

Then, after adding and mixing dextrins in the amounts shown in Table 3 to each egg solution,
After heating at 10 ° C. for 10 minutes, the mixture was cooled, and the obtained egg solution was spray-dried by an ordinary method.

Then, each sample was rehydrated by adding 20 times the weight of fresh water, heated at 100 ° C. for 10 minutes, and the obtained egg solution was allowed to stand at 5 ° C. for 7 days, and the state of the egg solution after 7 days was observed. As a result, the results shown in Table 3 were obtained.

In addition, the meaning of the symbol in a table | surface is the same as Table-2.

Test Example 4. SDS-polyacrylamide electrophoresis analysis without a reducing agent was performed on the sample in the test section of Test Example 2 by a conventional method, and the test results shown in FIG. 1 were obtained.

The same test was performed on raw egg white as a control, and the results are shown in FIG.

As is clear from FIG. 1, the egg white composition of the present invention comprises:
No band is observed at the positions of ovalbumin and conalbumin (= ovotransferrin).

〔The invention's effect〕

Since the heat-resistant egg white of the present invention has heat resistance and is odorless, it is suitable as a raw material for foods and cosmetics.

In addition, the egg white composition of the present invention has heat resistance and is stable in a solution, and thus is suitable for a raw material such as a beverage or a liquid cosmetic.

[Brief description of the drawings]

FIG. 1 shows that the egg white composition of the present invention and ordinary raw egg white were subjected to SDS-
FIG. 3 is a developed view obtained by performing polyacrylamide electrophoresis.

Claims (2)

(57) [Claims] (1) a band comprising ovalbumin and conalbumin by SDS-polyacrylamide electrophoresis, comprising a polymer of egg white proteins;
Heat-resistant egg white characterized by the fact that no specific peak is observed in C analysis. 2. A protein comprising a complex of a polymer of egg white proteins and a saccharide, and no band at ovalbumin and conalbumin in SDS-polyacrylamide electrophoresis. An egg white composition characterized in that no specific peak is observed.