JP7609593B2 - Cooked egg product and its manufacturing method - Google Patents

Description

The present invention relates to a cooked product made from bird eggs (hereinafter, bird eggs are also referred to simply as "eggs") that is excellent in terms of texture, flavor, and/or water-releasing property, and a method for producing the same.

Eggs are an excellent food ingredient that is supplied steadily, and egg dishes are popular with many people; however, the texture of egg dishes served after cooking can easily change depending on the heating temperature, cooking time, and stirring method during cooking, and a chef's skilled techniques are required to provide a fluffy, creamy texture that is generally considered delicious. Furthermore, egg dishes tend to solidify due to the residual heat after cooking and the passage of time, and the fluffy, creamy texture is only maintained for a short period of time. For this reason, it is difficult to cook large quantities of eggs, and in the food service industry, such as restaurants, eggs are sometimes cooked for each order.

Fructans are polymers of fructose linked by fructosidic bonds, and are found in various plants as storage carbohydrates. In particular, inulin, a fructan polymerized by 1,2-fructosidic bonds found in chicory and Jerusalem artichoke, is becoming increasingly used as an important water-soluble dietary fiber.

Because inulin is indigestible, it is known to be delivered to the large intestine and contribute to the proliferation of intestinal bacteria, especially the beneficial bifidobacteria. It is also known to be low in calories and to have the effect of keeping the GI value low.

Various uses for inulin are being studied, but a paste made from a highly concentrated solution is used as a replacement for fat in some foods because of its thick, flavorless texture similar to lard. It is also known to have the effect of masking various bitternesses.

Patent Document 1 states that adding inulin to heat-sterilized or frozen eggs makes it less likely for denaturation such as clouding of the egg white, gelling of the egg yolk, or roughness to occur, but does not disclose whether the texture or taste is improved when the eggs are heated.

Patent Document 2 describes cooked egg products such as scrambled eggs, omelets, and rolled eggs, to which an oil-in-water emulsion with a total oil content of 5 to 50% by weight and adjusted to a pH of 4.0 to 6.8 has been added. The addition of this emulsion imparts a sufficient milky taste and rich flavor, while providing a fluffy, creamy, soft texture without requiring the skilled technique of a cook, and the texture can be maintained even after one hour has passed, but the addition of high-calorie lipids makes it difficult to use in low-calorie, healthy foods.
In addition, Patent Document 2 lists milk, mayonnaise, and butter as additives for obtaining fluffy omelets.

Patent Document 3 describes a composition that enhances the richness of eggs, which is obtained by adding trehalose to desugared liquid eggs and spray drying them. This composition does not solidify even when sterilized by heating, and there is no deterioration in flavor or roughness.

Furthermore, Non-Patent Document 1 describes a recipe for tamagoyaki (rolled egg) using eggs, whey inulin cream, salt, a gelling agent, and oil, provided by Obihiro Keiseien, a special nursing home run by the social welfare corporation Suiseikai.

JP 2008-206399 A JP 2018-143167 A JP 2005-000014 A

Tokachi ABC Project "Recipes using whey inulin cream", [Searched on September 23, 2020], Internet <URL: http://www.tokachi-zaidan.jp/t-cityarea_new/recipe/kaigo01.html>

The object of the present invention is to
To provide a cooked egg product having at least one of the following characteristics: a) a juicy feel; b) a reduced raw egg smell; c) a fluffy, creamy soft texture; and d) a texture that does not feel watery even after time has passed or after freezing and thawing is maintained.

Another object of the present invention is to provide a method for producing cooked egg products that allows a cook to produce cooked egg products having the above-mentioned characteristics even if the cook does not have advanced skills.

The present invention is a cooked egg product that does not contain whey and contains dissolved fructans with a weight-average molecular weight of 500 to 4,000.

The present invention also provides a method for producing a cooked egg product, comprising the steps of preparing liquid egg from eggs, dissolving whey-free fructan having a weight-average molecular weight of 500 to 4000 in the egg liquid to prepare a fructan-containing egg liquid, and heating the fructan-containing egg liquid to solidify at least a portion of it.

According to the cooked egg product of the present invention,
The effect of obtaining at least one of the following characteristics is obtained: a) it has a juicy feel; b) the raw smell of eggs is reduced; c) it has a fluffy, soft, creamy texture; and d) the texture is maintained without any sense of water separation even after the passage of time or after freezing and thawing.
Furthermore, the method for producing a cooked egg product of the present invention has the advantage that a cooked egg product having the above-mentioned properties can be obtained even if the cook does not have a high level of skill.

1 is a photograph showing scrambled eggs obtained in Comparative Example 1 after heating for 90 seconds. 1 is a photograph showing scrambled eggs obtained in Example 1 after heating for 90 seconds. 1 is a photograph showing scrambled eggs obtained in Example 2 after heating for 90 seconds. 1 is a photograph showing scrambled eggs obtained in Example 3 after heating for 90 seconds. 1 is a photograph showing scrambled eggs obtained in Example 4 after heating for 120 seconds. 1 is a photograph showing scrambled eggs obtained in Example 5 after heating for 120 seconds. 1 is a photograph showing a cross section of a thawed omelet obtained in Comparative Example 2. 1 is a photograph showing a cross section of a thawed omelet obtained in Example 6. 1 is a photograph showing a cross section of a thawed omelet obtained in Example 7. 1 is a photograph showing a cross section of a thawed omelet obtained in Example 8.

The present invention is a cooked egg product that does not contain whey and in which fructans having a weight-average molecular weight of 500 to 4000 are dissolved. Whey is also called "whey" or "whey".

The fructans used in the cooked food of the present invention are polymers whose monomers are fructose linked by fructosidic bonds. Natural fructosidic bonds include 1,2-fructosidic bonds and 1,6-fructosidic bonds, and linear and branched fructans exist depending on the combination of these.

The linear fructan used in the present invention is preferably inulin. Inulin is known to be commonly found in the rhizomes of Asteraceae plants, and inulin extracted from chicory is the most commonly used. In addition, linear fructans can also be synthesized enzymatically and are sold as food ingredients, so they can be used in the present invention.

On the other hand, branched fructans are often found in plants of the lily family, but agave inulin extracted from agave is widely used as a food ingredient and is also used in the present invention.

The fructan used in the present invention may be either linear or branched, but inulin with a linear molecular weight fractionated to a certain extent is particularly preferred. In terms of stable supply, inulin extracted from chicory is the most preferred.

The weight-average molecular weight of the fructan used in the present invention is preferably in the range of 500 to 4000, more preferably 500 to 1500, and most preferably 800 to 1500. When a low molecular weight fructan is used, a smaller amount can be used to obtain the desired coagulation, while a higher molecular weight requires a larger amount. On the other hand, low molecular weight fructans themselves have a sweet taste, and may not be suitable for use.

The amount of fructan used in the present invention is generally in the range of 0.5 to 20 parts by mass, based on 100 parts by mass of the eggs used. The range of the amount of fructan added to obtain a higher effect is also related to the molecular weight of the fructan used. As a guideline, the amount is 0.5 to 10 parts by mass when a fructan with a molecular weight of less than 1500 is used, and 0.5 to 5 parts by mass when a fructan with a molecular weight of 1500 to 4000 is used.

In the present invention, the addition of the fructan slows down the heating changes of eggs, which normally proceed rapidly, and the effect of the fructan also makes it difficult for water to separate. In particular, the effect of slowing down heating changes is stronger with lower molecular weight compounds, and this effect can be obtained even with smaller addition amounts.

The eggs used in the present invention are avian eggs, such as chicken eggs, quail eggs, and duck eggs.

The eggs used in the present invention may be whole eggs or a portion of them, or may be egg yolks only, egg whites only, or a mixture of egg yolks and egg whites in any ratio. Egg products and egg processes such as frozen eggs, sweetened eggs, and eggs with adjusted ingredients may also be used.

The fructan is dissolved in the cooked food of the present invention. That is, the fructan in the cooked food of the present invention is present in a dissolved state in the water contained in the cooked food.

The cooked food of the present invention may have an area in which the fructan is dissolved. For example, even if there is an area in which the fructan is no longer dissolved due to a loss of moisture in a part of the cooked food, as long as there is another area in which the fructan is dissolved, the cooked food of the present invention is still a cooked food of the present invention.

However, it is preferable that the fructan in the cooked food of the present invention is dissolved at a uniform concentration throughout the cooked food so that the texture is uniform.

The term "heating" in the context of the cooked food of the present invention refers to heating to the extent that at least a portion of the egg is coagulated by heating. In other words, the cooked food of the present invention may be a product in which the egg is heat-coagulated in part or in whole.

Here, egg coagulation refers to the eggs solidifying and losing their fluidity. The degree of coagulation is not important as long as it is visible to the human eye. Egg yolks usually begin to coagulate at around 65°C and are completely coagulated at 75°C or higher, while egg whites usually begin to coagulate at around 60°C and are completely coagulated at 80°C or higher.

In addition, the term "cooked product" is used in this specification, but this term is expressed as a typical example of the heating operation of eggs, and is synonymous with "heat-processed product," "heat-treated product," "heat-coagulated product," or "heat-denatured product," and all of these are included in the concept of the cooked product of the present invention as long as they contain the above-mentioned part of the egg that has been heat-coagulated. Therefore, the cooked product of the present invention is not limited to those produced using cooking utensils or kitchen equipment, but also includes those produced at the time of sale, for example, in food factories, research facilities, and food stores.

Common cooking methods include frying in a frying pan, heating in a microwave, heating in a pot, and heating in a water bath.

In addition to eggs, the cooked food of the present invention may or may not contain dairy products such as cheese, butter, milk, and cream, vegetables such as tomatoes and onions, food additives for nutritional value, food additives for improving storage stability, and food additives for improving texture (e.g., gelling agents).

Examples of cooked eggs of the present invention include scrambled eggs, omelets, and rolled eggs.

The present invention also provides a method for producing a cooked egg product, comprising the steps of preparing liquid egg from eggs, dissolving whey-free fructan having a weight-average molecular weight of 500 to 4000 in the egg liquid to prepare a fructan-containing egg liquid, and heating the fructan-containing egg liquid to solidify at least a portion of it.

The definitions, specific examples, and preferred examples of "egg" and "fructan" used in the manufacturing method of the present invention, as well as "heating," "coagulation," "cooking," and "cooked products" are all the same as those described above for the cooked products of the present invention.

The "liquid eggs" in the production method of the present invention can be prepared by cracking the eggs. Such cracking may be performed manually or using an egg cracking machine. The cracked eggs may also be fed to a device that automatically separates the eggs into yolk and white. If necessary, a filtration step may be added to remove small pieces of eggshell, chalaza, vitelline membrane, etc. When such a filtration operation is performed, it is preferable to appropriately cool the liquid eggs.

Liquid egg is usually homogenized by mixing, but the degree of homogenization varies depending on the cooked food to be produced, and insufficient homogenization may be preferable. Liquid egg may also be subjected to a low-temperature pasteurization process that does not cause coagulation due to heating.

The step of dissolving fructan in the egg liquid to prepare fructan-containing egg liquid may be performed manually or using a fructan feed device or a stirring device, as long as the egg liquid obtained contains the fructan dissolved therein. It is preferable that the fructan is dissolved uniformly in the liquid egg, but as long as the fructan is dissolved in at least a portion of the liquid egg, it is within the scope of the manufacturing method of the present invention.

The process of heating the fructan-containing egg liquid to solidify at least a portion of it may be carried out in a stationary state or with occasional or constant stirring.

The manufacturing method of the present invention includes a step of preparing liquid egg from eggs, a step of preparing fructan-containing egg liquid, and a step of heating and solidifying the fructan-containing egg liquid, and these steps are usually performed in the order listed.

However, for example, it is possible to carry out a step of dissolving fructan in liquid egg while carrying out a step of preparing the liquid egg, such as a stirring operation, and it is also possible to carry out a step of heating the liquid egg while carrying out an operation of adding fructan, and these are also included in the scope of the manufacturing method of the present invention.

In the following examples of the present invention, the following evaluation methods were employed.
(1) Weight average molecular weight: Measured by gel filtration chromatography under the following conditions.
Liquid chromatograph: Shimadzu Prominence, detector: RID-10A, column: Tosoh TSKgel G2500WXL, mobile phase: water.

(2) Flavor evaluation: A panel of 5 or 6 people evaluated the flavor of the food. Cooked foods without inulin were used as a control, and cooked foods with a specified amount of inulin added were evaluated. The evaluation criteria were as follows:
Moisture: Moist 2, slightly moist 1, almost the same 0
Fluffiness Fluffy 2, slightly fluffy 1, almost the same 0
Odor: Weaker 2, slightly weaker 1, almost the same 0
Texture: Very juicy 2, Slightly juicy 1, Almost the same 0
For these items, the snacks were evaluated 15 minutes and 2 hours after production, and after being frozen for one week and thawed at room temperature, and the average scores were calculated.

(3) Freezing resistance evaluation: Tamagoyaki (recipe below) was prepared, wrapped and frozen. After 2 days, it was thawed at room temperature and the state of the tissue and the flavor were evaluated by observing the cross section.
(4) Production of scrambled eggs Whole eggs, inulin, butter, and salt were mixed according to the composition shown in Tables 1-3 to prepare a base liquid for scrambled eggs. This was cooked in a ring placed on a frying pan heated to 120°C while stirring. The cooking time was measured by video measurement as an index of processability.
(5) Production of Tamagoyaki (Japanese Rolled Eggs) A whole chicken egg, stock, sugar, and inulin were mixed according to the composition shown in Tables 4 and 5 to prepare a base liquid for Tamagoyaki (Japanese Rolled Eggs). A tamagoyaki pan was heated to about 120°C, and half of the liquid was added at a time and rolled up while cooking to prepare a rolled egg.
For the rolled omelet, a sensory test was carried out by the method (2) above.

[Examples 1 to 5, Comparative Example 1]
Scrambled eggs having the compositions shown in Table 1-3 were produced as Comparative Example 1 and Examples 1 to 5, and the results are summarized in Table 1-3. The scrambled eggs of Examples 1 to 5 maintained a thicker texture than the scrambled eggs of Comparative Example 1 to which inulin was not added. In addition, the cooking time was not too short to make it difficult to control the target product, and sufficient processability was ensured.

[Examples 6 to 8, Comparative Example 2]
As Comparative Example 2 and Examples 6 to 8, rolled omelets having the compositions shown in Tables 4 and 5 were produced, frozen, and then thawed, and evaluated by the sensory test described in (2). The results are summarized in Tables 4 and 5. The rolled omelets of Examples 6 to 8 had less egg odor and maintained a juicy texture compared to the rolled omelet of Comparative Example 2 to which inulin was not added.

In addition, when the omelet of Comparative Example 2 was observed after thawing, many large holes were found on its cross section, whereas the cross sections of the omelets of Examples 6 to 8 were relatively dense even after thawing.

The present invention may be used, for example, in the manufacturing industry that produces cooked egg products for retail sale, and in the food service industry that provides cooked egg products.

Claims (3)

A cooked product made from whole avian eggs, containing no whey and having dissolved inulin having a weight-average molecular weight of 500 to 4000, said cooked product being scrambled eggs, omelets or rolled eggs, and containing 0.5 to 20 parts by mass of dissolved inulin per 100 parts by mass of whole avian eggs. 2. The cooked product according to claim 1, wherein the inulin is dissolved at a uniform concentration throughout the cooked product. A method for producing a cooked product from whole avian eggs, comprising the steps of: preparing an egg liquid from whole eggs from avian eggs; dissolving whey-free inulin having a weight-average molecular weight of 500 to 4000 in the egg liquid to prepare an inulin -containing egg liquid; and heating the inulin- containing egg liquid to coagulate at least a portion of it, wherein the cooked product is scrambled eggs, omelette or omelet, and the amount of inulin dissolved is 0.5 to 20 parts by mass per 100 parts by mass of the scrambled eggs, omelette or omelet.