JPS5948609B2 - Method for producing sterilized food containing egg yolk - Google Patents

Description

[Detailed description of the invention] The present invention relates to a novel method for producing a sterilized food containing egg yolk.

Milkshake made by adding egg yolk etc. to milk, egg yolk, etc.
Egg yolk-containing foods, including raw material liquids such as raw material liquids for custard-flavored milk pudding made from carrageenan, sugar, etc., are sometimes heat-sterilized at temperatures of about 100°C or higher for preservation purposes.

However, in heat sterilization treatment at such high temperatures, the food easily coagulates due to the egg yolk contained therein.

Therefore, it is conceivable to treat the egg yolk in advance with protease in order to prevent such coagulation caused by the egg yolk.

However, papain, which is often used as a protease,
Even if egg yolks treated with pepsin or the like are used, satisfactory effects have not been obtained.

An object of the present invention is to provide a novel method for producing a sterilized food containing egg yolk, in which coagulation by egg yolk is less likely to occur during the production process.

The present invention achieves the above object by pre-treating egg yolk using trypsin, which is among the many proteases that exist. Specifically, food containing egg yolk is heat sterilized at a temperature of about 100°C or higher. To provide a method for producing a sterilized food containing egg yolk, which is characterized in that an egg yolk that has been previously treated with trypsin is used as the yolk when producing the sterilized food containing egg yolk.

The present invention is applied to foods containing egg yolk that require heat sterilization.

In the present invention, trypsin treatment of egg yolk may generally be carried out as follows.

Usually, egg yolk liquid is used as the egg yolk, and the pH is adjusted to the optimum value for trypsin, that is, pH 0 to 8.0, using trisodium phosphate or caustic soda. 5% by weight, the temperature is gradually increased to about 48-55°C, and the treatment is carried out at this temperature for about 16-70 hours.

In addition, if the egg yolk is treated with trypsin in the form of a whole egg, sufficient treatment cannot be expected, perhaps because trypsin does not work effectively, so using the egg yolk treated in this way However, it is difficult to obtain a final food product suitable for the purpose of the present invention.

The trypsin-treated egg yolk may be mixed with other food ingredients as it is to produce an egg yolk-containing food and then subjected to heat sterilization, but if it is not used immediately, it may be deactivated at a temperature of about 65°C. It's a good idea to keep it.

Furthermore, if necessary, it can be dried and powdered after deactivation.

Furthermore, trypsin-treated egg yolks or egg yolks that have been further deactivated can be preserved by adding approximately the same amount of sugar.

In the present invention, the method for producing an egg yolk-containing food using trypsin-treated egg yolk may be carried out in accordance with conventional methods depending on the desired food, such as a milkshake, a liquid raw material for custard-flavored milk pudding, etc.

In addition, by adding a phosphate, such as trisodium phosphate, at a ratio of approximately 0.3 to 1.0% by weight to the raw material to be removed, heat resistance can be imparted to the resulting food, and the resultant food can be given heat resistance. It is expected that the effect will be even more effective.

Next, the obtained egg yolk-containing food is heat sterilized at a temperature of about 100° C. or higher to obtain the desired final product.

Usually at 100℃ to ensure a certain degree of storage stability.
High temperature heat sterilization is required.

Such heat sterilization can be carried out by placing the egg yolk-containing food in a suitable container and sealing it in a conventional manner, or by introducing the obtained egg yolk-containing food directly into a plate heater or tubular heater for heat sterilization. Just go.

In this way, foods containing egg yolk that are made by using trypsin-treated egg yolks as part of the raw material for the desired food cannot be pasteurized even if they are subsequently heat sterilized at temperatures exceeding 100°C. The coagulation phenomenon caused by egg yolk is becoming difficult to recognize.

This means that the heat resistance of the sterilized egg yolk-containing food obtained by trypsin treatment was further improved compared to other general protease treatments.

The reason why such an effect is obtained by trypsin treatment is not clear, but trypsin enzyme and four other common proteases probably have different mechanisms for hydrolyzing egg yolk protein, such as the position of cleavage. Furthermore, it is presumed that this is because the trypsin enzyme has a selective action that is extremely effective in suppressing thermal coagulation and in terms of taste.

The present invention will be explained in more detail with reference to Examples below.

Example 1 Egg yolk liquid obtained by breaking eggs was mixed with trisodium phosphate [:pH
After adjusting the temperature to 7.0, commercially available trypsin (manufactured by Merck & Co., Ltd.) was added to this at a ratio of 0.3% by weight, and the temperature was adjusted to 8.0 at a temperature of 50°C.
Trypsinization was performed separately for 16 hours, 24 hours, 48 hours, and 72 hours.

The egg yolk liquid after each treatment was immediately used to prepare a milkshake with the following blending ratio.

Place the resulting milkshakes in 5 polyethylene bags each.
Each container was filled with 0 g each, sealed, and subjected to steam sterilization at 120° C. for 20 minutes.

The coagulation state of each heat-sterilized milkshake was as shown in the table below.

As a control, a milkshake obtained by blending egg yolk liquid treated in the same manner using other proteases shown in the table below was subjected to the same heat sterilization treatment as above.

The observation results for these foods are also shown in the table. Milkshake composition Protease treated egg yolk liquid 8% sugar by weight
15 tr Milk 77 n From the above table, it is understood that only when trypsin-treated egg yolk liquid is used, coagulation is less likely to occur even when subjected to the following heat sterilization treatment 1 at 100° C. or higher.

Example 2 Using egg yolk solution treated with trypsin for 24 hours according to Example 1 above, casta was prepared in the following blending ratio.

- A raw material solution for flavored milk pudding was prepared according to a conventional method.

During adjustment, the product temperature was set at 52° C., and the whole was thoroughly mixed and dissolved.

Next, this was introduced into a tubular heater and subjected to a heating film/image treatment at 130° C. for 30 seconds.

Next, the mixture was filled into a sterilized container, sealed, and cooled to obtain a custard-flavored milk pudding.

During this pudding production, no coagulation of egg yolk was observed in the tubular heater.

) Mixing ratio Trypsinized egg yolk liquid 7.5% by weight Milk
77.5 II Sugar 14,811 Carrageenan 0.15 111
locust bean gum 0.05
Custard flavoring agent: For custard flavored milk pudding in the same manner as in Example 1, except that as a control, egg yolk solution treated with papain for 24 hours was used instead of trypsin-treated egg yolk solution. A raw material solution was prepared.

This is guided to the tubular heater in the same way as above,
It was subjected to heat sterilization treatment under the same pass conditions at 130° C. for 30 seconds.

However, over time, the inner tube of the tubular heater became clogged.

Claims (1)

[Claims] 1. A method for producing a sterilized food containing egg yolk, which comprises using an egg yolk that has been previously treated with trypsin as the egg yolk when producing the sterilized food containing egg yolk by heat sterilizing the food containing egg yolk at a temperature of about 100° C. or higher.