JPH05344869A - Method for producing processed egg yolk - Google Patents

Abstract

PURPOSE:To provide a method for producing a processed egg yolk capable of remarkably increasing the removal ratio of cholesterol in extracting cholesterol from egg yolk using oil and fat. CONSTITUTION:An egg yolk liquid prepared so as to have water content higher than that of natural fresh egg yolk is mixed with oils and fats to emulsify the egg yolk and then the oil phase is separated and removed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel method for producing processed egg yolk.

[0002]

2. Description of the Related Art Conventionally, as one of the methods for producing processed egg yolk with a reduced cholesterol content, a method using fats and oils as a cholesterol extraction solvent has been known. Specifically, for example, the oil and fat is directly added to the yolk liquid obtained by splitting and removing the egg white to thoroughly mix and then separate into an oil phase and an aqueous phase, and then the separated oil phase is removed. Then, a method of reducing the content of cholesterol in egg yolk is known. This method was able to reduce cholesterol in egg yolk to some extent.

[0003]

However, such a conventional method has a problem that the cholesterol removal rate in egg yolk is not always high enough. Therefore, it is an object of the present invention to provide a method for producing processed egg yolk which can further increase the cholesterol removal rate when extracting cholesterol from egg yolk using fats and oils.

[0004]

[Means for Solving the Problems] The present inventors have completed various studies in order to achieve the above object, and have completed the present invention. That is, the present invention provides a method for producing a processed egg yolk, which comprises mixing and emulsifying an egg yolk liquid with a water content higher than that of a natural raw egg yolk, and then separating and removing an oil phase. To do.

The present invention will be described in detail below. In the present invention, the "yolk liquid having a water content higher than that of natural raw yolk" means the water normally possessed by the yolk obtained by splitting and removing the egg white (usually about 50% of total yolk).
%) Refers to egg yolk liquid with a higher water content. Specific examples include those shown in the following relationship between the water addition ratio and the water content in the yolk liquid. In addition, water addition X
In the case of%, the water content in the yolk liquid after addition is determined by the formula (50 + X) / (100 + X). Addition rate of water X% Water content in yolk liquid 5% About 52% 10 About 55 20 About 58 30 About 62 40 About 64 50 About 67 60 About 69 70 About 71 80 About 72 90 About 74 100 About 75

From the viewpoint of increasing the removal rate of cholesterol, in the present invention, it is preferable to use an egg yolk liquid containing 5% or more of water, that is, a water content of 52% or more. Further, as is clear from the results of Examples described later, when the addition of water is more than 80%, that is, the water content is 7%.
When the yolk liquor more than 2% is used, the cholesterol removal rate can be increased compared with the conventional method, but when mixed emulsification with fats and oils, the water-in-oil emulsification tends to be reversed to the oil-in-water type Therefore, it is preferable to use the egg yolk liquid having a water content of 72% or less.

In the present invention, oils and fats include edible oils and fats which are liquid at room temperature and solid edible oils and fats which can be made liquid by heating. Liquid oil is preferable from the viewpoint of ease of mixing operation.

According to the method of the present invention, first, egg yolk liquid adjusted to a predetermined water content is mixed with oil and emulsified. At this time, the mixing ratio of the egg yolk liquid and the fats and oils is not particularly limited, but it is usually preferable that the ratio of the yolk liquid to the fats and oils is about 1: 0.2 to 1.5. The emulsification form may be either a water-in-oil type or an oil-in-water type, but the water-in-oil type emulsification is preferred from the viewpoint of the operation of the step following the emulsification, that is, the ease of separation and removal of the oil phase. The emulsification operation is specifically, for example, a homogenizer containing a fat or oil (or egg yolk liquid), a homomixer,
Or use a colloid mill for 8,000 to 15,000 rp
Egg yolk liquid (or fat) in it while stirring at about m
Can be preferably carried out by gradually adding and then continuing stirring for about 3 to 15 minutes. It should be noted that it is preferable to heat the egg yolk liquid and the fats and oils to about 50 to 60 ° C. during the emulsification because the cholesterol in the egg yolk easily migrates into the fats and oils.

According to the method of the present invention, the emulsion obtained by mixing and emulsifying egg yolk liquid and fats and oils is then subjected to a step of separating and removing the oil phase from which cholesterol has been extracted from the emulsion. When the emulsified form is water-in-oil type, the emulsified product obtained by emulsification is separated from the oil phase and the water phase after 20 to 40 minutes simply by allowing the emulsion to stand. For example, it is stored in a batch type tank and left standing for a predetermined time to separate the oil phase into the upper phase and the water phase into the lower phase, and then the lower phase water phase part is extracted from the lower part (or bottom part) of the tank. By removing the oil phase, or by directly introducing the emulsion into a centrifugal separator and subjecting it to centrifugal separation, for example, at 2,000 rpm for 15 minutes to separate the oil phase and the aqueous phase, and continuously according to a conventional method. The oil phase may be removed intentionally. When the emulsified form is an oil-in-water type, for example, the emulsified product is frozen to break the emulsification and separated into an oil phase and an aqueous phase according to a conventional method, and then the separated oil phase is separated into, for example, 2 It may be removed by centrifugation at about 1,000 rpm for about 15 minutes. As described above, since it takes time and labor for the operation to break the emulsion, the emulsified form in the present invention is preferably the water-in-oil type because the oil phase can be easily separated and removed.

Cholesterol existing in egg yolk is extracted in the separated and removed oil phase. Therefore, the cholesterol content in the egg yolk can be reduced by removing the oil phase. The aqueous phase obtained by removing the oil phase (egg yolk phase) may be subjected to the method of the present invention again or several times as necessary, that is, by emulsifying with a new oil and fat, and then separating and removing the oil phase. It may be repeated. The processed egg yolk obtained by the method of the present invention as described above may be used immediately as it is in a liquid state, or after refrigerated storage, or after freezing-thawing as it is. Since it is larger than the egg yolk liquid, it may be pulverized, for example, by freeze-drying, etc., in consideration of storability.

[0011]

According to the method of the present invention, the removal rate of cholesterol can be further enhanced as compared with the conventional method in which fats and oils are used as the solvent for extracting cholesterol, but this is probably because the natural raw egg yolk has a higher water content. By increasing the amount of water contained in the yolk liquid, the viscosity of the yolk liquid may be lowered, and thus the lipids of the yolk and the fats and oils may easily come into contact with each other during emulsification with the fats and oils, which may facilitate the extraction of cholesterol by the fats and oils. Conceivable.

[0012]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the present invention,% and parts are based on weight. Examples 1 to 70 To 100 parts of natural raw egg yolk (water content of about 50%) obtained by separating and removing egg white from egg white, fresh water in the ratio shown in the following table was added and mixed well. After this, 50 ℃
Heated to. Next, a homogenizer containing 150 parts of soybean salad oil separately heated to 50 ° C.
While stirring at 00 rpm, the above yolk liquid was gradually added thereto over 15 minutes, and stirring was continued for further 15 minutes to emulsify into a water-in-oil type. The emulsion obtained by stopping the stirring was allowed to stand, and after 30 minutes, the oil phase floated (about 150 parts)
Was removed from the aqueous phase by centrifugation (2,000 rpm × 15 minutes) to produce seven types of processed egg yolk of the present invention. For each processed egg yolk thus obtained, the removal rate of cholesterol in the egg yolk was determined according to a conventional method, and the results are also shown in the table below. The results of observing the state of emulsification in carrying out the method of the present invention are also shown in the same table. In addition, as a control, a processed processed yolk was produced in accordance with the above method except that natural raw yolk was used as the yolk liquid without any addition of water. The results of observing the emulsification status at the time of each are shown in the same table.

[0013] Table amount of the onset bright Way Method Item Control Method Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Water (parts) 0 5 10 20 40 60 80 100 about the moisture content of the liquid egg yolk (% ) 50 52 55 58 64 64 69 72 75 Cholesterol removal rate%) 52 56 60 67 63 63 63 60 58 Emulsification status ○ ○ ○ ○ ○ ○ ○ △ Note: The symbols in the table have the following meanings. ○… Emulsification is good and no reversal from water-in-oil type to oil-in-water type is observed. △… Reversal from water-in-oil type to oil-in-water type is partially observed.

[0014]

EFFECT OF THE INVENTION According to the method of the present invention, a method for producing processed egg yolk which can further increase the cholesterol removal rate when extracting cholesterol from egg yolk using oils and fats is provided. A further reduced amount of processed egg yolk can be obtained, and it can be expected that the use of the processed egg yolk in various foods will be expanded.

Claims (2)

[Claims] 1. A method for producing a processed egg yolk, which comprises mixing and emulsifying an egg yolk liquid having a water content higher than that of a natural raw egg yolk, and then separating and removing an oil phase. 2. The method for producing processed egg yolk according to claim 1, wherein an egg yolk liquid having a water content of about 52% to about 72% is used.