JP2006101801A - Heat resistant albumen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide heat resistant albumen moderately improved in heat resistant properties while maintaining desirable functional characteristics inherited from albumen such as coagulation property against high temperature or acid and foaming properties by stirring. <P>SOLUTION: The heat resistant albumen is such that ovotransferrin is selectively removed against ovalbumin from protein in the albumen. The albumen is obtained by fermentation treatment using metalloprotease. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat-resistant egg white that can be subjected to advanced sterilization without impairing the functional properties of egg white.

  Eggs are widely used in food as a low-priced, high-quality protein source, but recently, new epidemics of infectious diseases have been reported worldwide, and more advanced hygiene management has been required. Yes.

  That is, in the food industry, chicken eggs are often divided and distributed and used in the form of so-called liquid eggs. As a liquid egg hygiene management technique, heat sterilization (55-60 ° C., 3-10 minutes) capable of killing Salmonella is currently being performed, but it prevents a new epidemic in advance. In order to achieve this, it is desired to increase the sterilization temperature higher than the present level so that unknown pathogenic bacteria can be sterilized.

  However, egg white is more easily coagulated by heat than egg yolk or whole egg, and there is a problem that if the level of heat sterilization is higher than the present level, it cannot be distributed as liquid egg.

  Various attempts have been made to deal with this problem. For example, Patent Document 1 proposes performing enzyme treatment while maintaining egg white at 70 to 90 ° C.

Japanese Patent Publication No. 5-14543

  However, according to the conventional enzyme-treated egg white, it does not solidify even when heated to near 100 ° C., and the functional properties required for egg white such as coagulation with acid and foaming with stirring are impaired. For this reason, there arises a problem that the use of egg whites in the field of conventional egg white use such as sponge cakes and meringue confectionery and cooked products such as tea fumigation and omelettes is limited.

  On the other hand, an object of the present invention is to improve the heat resistance of egg white while maintaining the desired functional characteristics of egg white such as coagulation property and foaming property, and to enable higher heat sterilization than before. .

  The present inventor has found that egg white from which ovotransferrin has been selectively removed among ovotransferrin, ovalbumin, and lysozyme, which are the three main proteins contained in egg white, has moderately improved heat resistance and coagulation with acid. It has been found that the original functional properties of egg white such as foaming property against stirring and the like are retained.

  That is, the present invention provides a heat-resistant egg white in which ovotransferrin is selectively removed from the protein in egg white.

  In the heat-resistant egg white of the present invention, ovotransferrin is selectively removed from the three main proteins contained in egg white, ovotransferrin, ovalbumin, and lysozyme, so that the heat resistance is hardly or completely present. Even if it is heat sterilized at 63 ° C for 30 minutes, it does not solidify. Therefore, it becomes possible to perform heat sterilization higher than before without solidifying the liquid food containing egg white.

  In addition, since this heat-resistant egg white contains about the same amount of ovalbumin and lysozyme as normal egg white that has not been subjected to enzyme treatment, even after the above-mentioned heat sterilization at 60 ° C. for 30 minutes, Properties unique to egg white such as high temperature exceeding 70 ° C., coagulation with acid, and foaming with stirring are maintained. Therefore, it becomes possible to continue to use this heat-resistant egg white in the conventional field of egg white use such as confectionery such as sponge cake and meringue, and cooked products such as tea fumigation and omelet.

  In the present invention, “%” means “% by mass” unless otherwise specified.

  The heat-resistant egg white of the present invention is one in which ovotransferrin is selectively removed from the proteins constituting it.

  Here, the egg white refers to egg white in various forms such as egg white liquid, egg white liquid separated from egg yolk, dried egg white, frozen egg white, and heat sterilized egg white.

  In addition, ovotransferrin is selectively removed from the protein constituting the egg white. For example, when the protein of egg white is separated by SDS-polyacrylamide gel electrophoresis and detected by staining, Albumin and lysozyme bands are observed in the same way as normal egg whites, but ovotransferrin is not observed as a band at all or hardly observed.

  By removing ovotransferrin in this way, for example, heat resistance of 63 ° C. for 30 minutes that does not solidify against heat sterilization higher than conventional can be imparted to the egg white, and at 70 ° C. or higher for 10 minutes. Thermal solidification properties that solidify by heating can also be imparted. Therefore, the heat-resistant egg white of the present invention can continue to be used in the field of cooking products such as tea fumigation and omelet that utilize the thermocoagulation property of egg white.

  As a method for selectively removing ovotransferrin from the protein in egg white, a method of enzymatically degrading egg white using a so-called “metal protease”, which is a proteolytic enzyme having a metal at the active center, can be mentioned. Examples of such metalloproteases include orientase 90N, orientase ONS (HIBI), protin P, thermose, deskin (Daiwa Kasei), Neutase (Novozymes Japan), protease N “Amano”, protease A Commercially available products such as “Amano” and YL-NL “Amano” (Amano Enzyme) can be used. In addition, when using a proteolytic enzyme conventionally used to improve the heat resistance of egg white, the decomposition of the protein in egg white proceeds greatly, and not only ovotransferrin but also other proteins are decomposed, resulting in high temperature or acid resistance. This is not preferable because properties specific to egg white such as coagulation and foaming with respect to stirring are impaired.

  As a specific method for enzymatic degradation of egg white using the above-mentioned proteolytic enzyme, for example, 0.3 to 1.0% of protease N “Amano” (Amano Enzyme Co., Ltd.) with respect to egg white (solid content) is used. Mix with egg white and heat at pH 7.5-9.5, temperature 50-60 ° C. for 60-15 minutes.

  In this case, it is preferable to heat so that 63-70 degreeC may be maintained as a final processing temperature of an enzyme process for 30 to 1 minute. Since the enzyme is deactivated by this final treatment temperature, it is not necessary to carry out the enzyme deactivation treatment separately from the enzymatic degradation of ovotransferrin.

  In the above-mentioned heating at 50 to 60 ° C. for 60 to 15 minutes and at 63 to 70 ° C. for 30 to 1 minutes, it is not necessary to maintain a constant temperature. A method may be employed in which the temperature is increased in a temperature range of 50 to 60 ° C. and further in a temperature range of 63 to 70 ° C. over a predetermined time by heating.

  Moreover, you may perform an enzyme process on the salting conditions of 2-10% of salt. Thereby, the growth of heat-resistant bacteria during the enzyme treatment can be suppressed.

  When the enzyme-treated egg white protein is separated by SDS-polyacrylamide gel electrophoresis, ovotransferrin detected before enzyme treatment (content of egg white protein before enzyme treatment is about 12%, denaturation temperature 62 ° C.) Is detected, and a band of an obotransferrin degradation product that is not detected before the enzyme treatment is detected immediately below the band of ovalbumin in the molecular weight range of 31000-45000. The content of ovalbumin (denaturation temperature 84 ° C.) is 45-60%, the content of ovotransferrin degradation product is 25-31%, and lysozyme (denaturation temperature 73 ° C.) in all the proteins of egg white after enzyme treatment. The amount is about 3%, and the contents of ovalbumin and lysozyme are not different before and after the enzyme treatment.

  The egg white after the enzyme treatment may be stored refrigerated (10 ° C. or lower) or frozen.

Example 1 Preparation of Enzyme-treated Egg White 1 kg of 5% salted egg white solution and 6 g of a metalloprotease (Protease N “Amano”, Amano Enzyme) were heated with stirring over a period of 15 minutes from 50 ° C. to 60 ° C. The temperature was raised, and the temperature was further raised to 63 ° C. and held for 30 minutes, and then cooled to room temperature. The obtained enzyme-treated egg white was transparent and had a lower viscosity than the egg white liquid not subjected to enzyme treatment.

Comparative Example 1
1 kg of egg white liquid and 5 g of proteolytic enzyme having no metal at the active center (Proleather-FG-F (from Bacillus subtilis, LotPRA1251013CFG), Amano Enzyme) were reacted at 50 ° C. for 5 hours with stirring. After completion of the reaction, sodium chloride was added to 5%, and the mixture was heated with stirring. The temperature was raised from 50 ° C. to 60 ° C. over 15 minutes, further raised to 63 ° C. and held for 30 minutes. Then, it was cooled with water to room temperature. The obtained enzyme-treated egg white liquid was cloudy.

Comparative Example 2
1 kg of 5% salted egg white liquor, 6 g of purified papain for foods, which is a proteolytic enzyme that does not have a metal in the active center (derived from Papaya Carica papaya L, Lot2477574, Nagase ChemteX Corporation), are heated with stirring, 50 The temperature was raised from 0 ° C. to 60 ° C. over 15 minutes, further raised to 63 ° C., held for 30 minutes, and then cooled to room temperature. The obtained enzyme-treated egg white liquid was cloudy.

Evaluation (1) Heat resistance against heating at 100 ° C. 10 g each of the enzyme-treated egg white liquor of Example 1 and Comparative Examples 1 and 2 and 5% salted egg white liquor not subjected to enzyme treatment as a control sample were taken in a test tube. The sample was immersed in a boiling water bath and observed over time. As a result, the enzyme-treated egg white solution of Example 1 and the 5% salted egg white solution of the control example not subjected to the enzyme treatment were completely coagulated within 5 minutes. However, the enzyme-treated egg white solutions of Comparative Examples 1 and 2 did not coagulate even after 5 minutes.

(2) Foaming property against stirring 5% of the control-treated egg white solution of Example 1, Comparative Examples 1 and 2 heated to 20 ° C. in a mixer bowl of a Hobart mixer (10 quarts), or the control sample without enzyme treatment After adding 450 g of% salted egg white liquid and stirring for 1.5 minutes at medium speed using a wire whipper, the height of foam generated by stirring at high speed for 1.5 minutes was measured. The results are shown in Table 1. The unit of the numbers in the table is cm.

  From Table 1, the enzyme-treated egg white liquid of Example 1 has a foaming property equal to or higher than that of the non-enzyme-treated egg white liquid of the control example, but the enzyme-treated egg white liquid of Comparative Examples 1 and 2 is the control example. It turns out that foaming property is inferior compared with.

(3) Electrophoretic analysis The enzyme-treated egg white liquor of each Example and Comparative Example and the control example (5% salted egg white liquor without enzyme treatment) were each used as a sample buffer for SDS-polyacrylamide electrophoresis. The sample was diluted 10 to 40 times and heated on a boiling water bath for 5 minutes to prepare a sample for electrophoresis.

  SDS-polyacrylamide electrophoresis uses a commercially available polyacrylamide gel 10-20% PerfectntNT Gel A (DRC) and a dedicated electrophoresis tank ERICA-A (DRC). The test was performed under a constant voltage condition of 300V. SDS-PAGE standard (Broad) (Nippon Bio-Rad Laboratories) was used as a standard protein (molecular weight marker) for molecular weight measurement.

  When the labeled dye bromophenol blue in the sample buffer reached 5 mm from the lower end of the gel, the electrophoresis was terminated, the gel was taken out of the glass plate, and stained with Coomassie Brilliant Blue R-250 solution for 30 minutes at room temperature. The gel was decolorized with a decolorizing solution (25% ethanol, 8% acetic acid solution) until the background was clear. This electrophoresis pattern is shown in FIG.

  From FIG. 1, in the enzyme-treated egg white liquid of Comparative Example 1, ovotransferrin was not sufficiently decomposed and partially remained, and part of ovalbumin was also decomposed. Then, it turns out that all of the egg white major proteins of ovotransferrin, ovalbumin and lysozyme have been degraded. On the other hand, in the enzyme-treated egg white liquid of Example 1, only ovotransferrin is almost specifically decomposed and removed, and it can be seen that a new degradation product band is formed immediately below the ovalbumin band.

  In addition, the electrophoresis pattern of Example 1 shown in FIG. 1 is acquired as digital data using the ULTRA-CAN ANALYSIS SYSTEM (ULTRA-LUM), and Total LAB (ULTRA-LUM), which is image analysis software. Was used to calculate the molecular weight and quantity ratio of each band. As a result, the molecular weight of a band considered to be a degradation product of ovotransferrin existing directly under ovalbumin was calculated to be about 37,000.

  The amount ratio of each band was calculated as 18% for ovotransferrin, 77% for ovalbumin, and 4% for lysozyme in the control example, assuming that the total of each band was 100%. The protein estimated to be an ovotransferrin degradation product was 14%, and lysozyme was 4%. As a result, it was found that ovalbumin and lysozyme were hardly decomposed by the enzyme reaction, and that obotransferrin was selectively decomposed.

  In addition, in the preparation process of the enzyme-treated egg white liquid of Example 1, the enzyme was added and the heating reached 40 ° C., 50 ° C., 55 ° C., 55 ° C., held at 55 ° C. for 15 minutes, and then reached 63 ° C. The egg white solution sampled at each point after being held at 63 ° C. for 15 minutes and then held at 63 ° C. for 30 minutes, and a control example (5% salted egg white solution without enzyme treatment) were analyzed by SDS-polyacrylamide electrophoresis. The analysis results are shown in FIG. As can be seen from FIG. 2, ovotransferrin is decomposed as the enzyme reaction proceeds, and no new decomposition reaction occurs after reaching a temperature of 63 ° C.

(4) Production of Mayonnaise and Storage Test Using the enzyme-treated egg white liquor of the example and the egg white liquor of the control example not subjected to enzyme treatment, mayonnaise having the composition shown in Table 2 was produced as follows.

  First, raw materials other than salad oil were mixed well, and then the salad oil was injected while stirring while depressurizing with a degassing stirrer. The mayonnaise thus obtained was further passed through a colloid mill, subjected to finish emulsification, filled into a 500 g mayonnaise bottle, and subjected to a storage test at 35 ° C.

In the storage test, the viscosity of mayonnaise was measured from immediately after filling to 3 weeks after filling, using a D type of T-bar rotor for a B-type viscometer equipped with an elevator. The results are shown in Table 3.

  From Table 3, since the mayonnaise of the example in which the enzyme-treated egg white was blended, the enzyme-treated egg white of the raw material was acid-denatured and coagulated with brewed vinegar. It can be seen that the viscosity increases. That is, it is understood that the heat-resistant egg white of the present invention can be suitably used as a mayonnaise raw material in the same manner as ordinary egg white.

  The heat-resistant egg white of the present invention is moderately improved in heat resistance while maintaining the functional characteristics peculiar to egg white such as coagulation with high temperature or acid, and foaming with stirring. be able to. The heat-resistant egg white of the present invention is a conventional egg white in the field of conventional egg white use such as confectionery such as sponge cake, meringue, tea fumigation, omelet, and other beverages, health foods, seasonings, and pharmaceuticals. It can be used instead.

It is a drawing substitute photograph of the electrophoresis pattern about the enzyme-treated egg white of an Example and a comparative example. It is a drawing substitute photograph of the electrophoresis pattern about the enzyme-treated egg white of an Example.

Claims (4)

A heat-resistant egg white in which ovotransferrin is selectively removed from proteins in egg white. The heat-resistant egg white according to claim 1, wherein ovotransferrin is not detected by SDS-polyacrylamide gel electrophoresis, and a band of ovotransferrin degradation product is detected immediately below the band of ovalbumin in the molecular weight range of 31000-45000. The heat-resistant egg white according to claim 1 or 2, wherein ovotransferrin is selectively removed by an enzyme treatment using a metalloprotease. The heat-resistant egg white according to claim 3, wherein the enzyme treatment is performed at 50 to 60 ° C for 60 to 15 minutes and then at 63 to 70 ° C for 30 to 1 minutes.

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