JP7699411B1 - High lutein-containing eggs, processed food ingredients, egg production method and feed for laying hens - Google Patents

Abstract

The present invention provides high-lutein-containing eggs that contain a high concentration of lutein, a processed food material produced from the eggs, a method for producing the eggs, and feed for laying hens used in the production method.
[Solution] A method for producing eggs in which eggs containing a high concentration of lutein are obtained by preparing feed for laying hens, and a xylanase-enriched feed containing 100 mg or more of lutein per kg of feed and 1000 EPU or more of xylanase per kg of feed is fed to laying hens, and the hens fed the xylanase-enriched feed for a predetermined period from the start of feeding are allowed to lay eggs. Since eggs containing a high concentration of lutein can be produced, if a person ingests the eggs produced by this production method daily, it is possible to protect the person's eyes from the irritation of light and contribute to maintaining eye health, which can be useful for reducing the risk of eye disease and preventing eye disease.
[Selected Figure] Figure 1

Description

The present invention relates to eggs with high lutein content, processed food ingredients, egg production methods, and feed for laying hens.

Eggs are inexpensive and contain the five major nutrients required by the human body: carbohydrates, lipids, protein, minerals, and vitamins. They are also a highly nutritious food, containing amino acids that the human body cannot produce.

For example, eggs contain lutein, which is known to have antioxidant properties. In recent years, it has been reported that ingesting lutein may prevent diseases such as increased pigmentation in the macular, macular degeneration, and cataracts. In particular, it has been reported that the recommended intake amount for increasing pigmentation in the macular is 10 mg of lutein per day. Methods for humans to ingest lutein include, for example, ingesting lutein-containing foods from eggs, and ingesting lutein from spinach or supplements. However, it has been reported that the absorption rate in the human body is reduced to about one-third that of lutein ingested from eggs when ingested from spinach or supplements. Therefore, if lutein is to be effectively absorbed by the human body, it is desirable to ingest lutein from eggs. However, the amount of lutein contained in normal eggs is at most about 0.4 mg per 100 g of edible portion, making it difficult to ingest a sufficient amount of lutein from eggs.

Therefore, in order to increase the amount of lutein ingested from eggs, attempts have been made to increase the amount of lutein contained in eggs. For example, the amount of lutein contained in eggs has been increased by adjusting the feed given to laying hens (see Patent Documents 1 to 3).

For example, Patent Document 1 discloses that the amount of lutein can be increased to 0.72 mg per 100 g of edible portion by adding marigold or oregano to general feed. Patent Document 2 discloses that the amount of lutein can be increased to 1.95 mg per 100 g of edible portion (6.5 mg per 100 g of egg yolk) by adding marigold extract to general feed. Patent Document 3 discloses that the amount of lutein contained in egg yolk can be increased by adding meso-zeaxanthin to feed together with lutein.

JP 2007-20510 A JP 2003-102395 A Special table 2014-524914 publication CN103070311 publication WO98/18345 publication

European Food Safely Authority (EFSA), "Scientific Opinion on the safety and efficacy of Hostazym doi;10.2903/j.efsa.2013.3105.

However, the eggs produced by the methods of Patent Documents 1 and 2 still do not contain enough lutein to allow for the necessary amount of lutein to be ingested from eggs. The method disclosed in Patent Document 3 can increase the amount of lutein to a certain extent, but adds meso-zeaxanthin, which is not normally used in feed, to the feed. In other words, eggs with a sufficiently high lutein content (for example, 2.0 mg or more per 100 g of edible portion) have not been produced using substances generally used in feed.

Meanwhile, various attempts have been made to prepare feed for laying hens, and for example, Patent Documents 4 and 5 and Non-Patent Document 1 disclose the addition of xylanase to feed. Non-Patent Document 1 discloses that egg weight and egg laying rate can be improved by adding xylanase to feed. Furthermore, Patent Document 4 discloses the addition of xylanase enzyme to feed as a method for producing eggs rich in xanthophyll. Furthermore, Patent Document 5 discloses a technology using a carbohydrate decomposing enzyme to promote pigment absorption in poultry feed, and discloses xylanase as the carbohydrate decomposing enzyme.
However, although Patent Documents 4 and 5 and Non-Patent Document 1 state that a certain effect can be obtained by adding xylanase to feed, there is no specific description of the effect that the ratio of xylanase added has on the amount of lutein contained in eggs.

In view of the above circumstances, the present invention aims to provide high-lutein-containing eggs that contain a high concentration of lutein, processed food materials made from high-lutein-containing eggs, a method for producing high-lutein-containing eggs, and feed for laying hens to be used in the production method.

The egg production method of the present invention is a method for producing eggs in which feed to be given to laying hens is prepared to obtain eggs containing a high concentration of lutein, and is characterized in that a xylanase-enriched feed containing 100 mg or more of lutein per kg of feed and 1,000 EPU or more of xylanase per kg of feed is fed to laying hens, and the hens that have been fed the xylanase-enriched feed for a predetermined period or more from the start of feeding are allowed to lay eggs.
The feed for layer hens of the present invention is a feed used in the egg production method of the present invention, and is characterized by containing 100 mg or more of lutein per kg and 1,000 EPU or more of xylanase per kg.

The egg production method and egg-laying hen feed of the present invention make it possible to produce eggs containing a high concentration of lutein.

1A is a table showing the experimental results of Examples 1 to 3 and Comparative Examples 1 to 4, and FIG. 1B is a table showing the results of confirming the relationship between the preparation period and the amount of lutein. Graph (A) is a graph showing the experimental results of Examples 1 to 3 and Comparative Examples 2 to 4, and graph (B) is a graph showing the results of confirming the relationship between the preparation period and the amount of lutein. 1 is a table showing the experimental results of evaluating the color of egg yolk.

The following describes the high lutein-containing eggs, processed food materials, egg production method, and egg-laying hens feed of this embodiment.

<Feed for egg-laying hens according to this embodiment>
First, the feed used for producing eggs with high lutein content of this embodiment, that is, the feed for layer hens of this embodiment, will be described.
The feed for layer hens of this embodiment is a feed used for raising layer hens. That is, the feed for layer hens of this embodiment is a feed used in the egg production method of this embodiment, and is produced by mixing additive feed with basal feed.

The basic feed is normally used as a feed for poultry. The basic feed is prepared by blending, for example, corn as the main component with other animal feed ingredients (fish meal, etc.), vegetable oil cake (soybean oil cake, rapeseed oil cake, etc.), grains (wheat, etc.), bran (bran, rice bran, etc.), calcium carbonate, oyster shells, etc. For example, the basic feed can be manufactured by adjusting the blending ratio of various commercially available feeds. The components contained in the basic feed are not limited to those described above, and any components that are generally adopted as components of feed used for raising egg-laying hens can be adopted. In addition, the blending ratio of each component contained in the basic feed can be the blending ratio adopted in general feeds, but the blending ratio of each component is not particularly limited. It can be appropriately prepared according to the growth state and environment of the egg-laying hens to which the feed is given. For example, by adjusting the blending ratio of each component, the amount of protein contained in the basic feed and the egg-laying hens feed of this embodiment can be appropriately adjusted.

The additive feed to be mixed with the basic feed is added to the basic feed to prepare the components contained in the entire layer feed of this embodiment. In the layer feed of this embodiment, additive feed capable of increasing the amount of lutein contained in the layer feed is used. In other words, the layer feed of this embodiment can use a material containing a lutein-containing ingredient as an additive feed. Examples of raw materials containing lutein include marigold (flowers, petals, leaves), yellow corn (fruit), green leafy vegetables such as kale and spinach, chlorella, kiwi fruit, grapes, and the like. The form in which the raw material containing lutein is mixed as an additive feed with the basic feed is not particularly limited. For example, when marigold is mixed as an additive feed, dried marigold petals may be crushed and mixed, or an extract obtained by extracting marigold petals with an organic solvent may be mixed. In addition, the raw material containing lutein may be derived from a natural product as described above, but may also be chemically synthesized.

The additive feed to be mixed with the basic feed is prepared so that the total egg-laying hen feed, i.e., the additive feed is mixed with the basic feed, contains a certain amount of lutein or xanthin. For example, the amount of additive feed to be mixed with the basic feed is prepared so that the total egg-laying hen feed contains 100 mg or more of lutein per kg of egg-laying hen feed, preferably 120 mg or more of lutein per kg of egg-laying hen feed, and more preferably 150 mg or more of lutein per kg of egg-laying hen feed. Note that, when the additive feed is mixed with the basic feed, there is no particular upper limit for the amount of lutein in the total egg-laying hen feed. However, mixing a large amount of additive feed increases the cost of the feed and reduces egg production efficiency, so it is desirable for the lutein content to be 200 mg or less.

In addition, the additive feed to be mixed with the basic feed contains an enzyme that has the function of hydrolyzing xylan. For example, it is desirable that the additive feed contains enzymes such as xylanase and amylase (aspergillus oryzae). When xylanase is contained in the additive feed, the amount of the additive feed to be mixed with the basic feed is prepared so that the xylanase is 1000 EPU (Endopentsanase Units) or more per 1 kg of the feed for layer hens, preferably 1200 EPU or more per 1 kg of the feed for layer hens, and more preferably 1500 EPU or more per 1 kg of the feed for layer hens. In addition, when the additive feed is mixed with the basic feed, the upper limit of the content of xylanase in the entire feed for layer hens is not particularly limited. However, if a large amount of additive feed is mixed, the cost of the feed will increase and the egg production efficiency will decrease, and the effect of increasing lutein with an increase in the amount of additive will be reduced, so it is desirable that the xylanase content be 3000 EPU or less.

The xylanase addition unit, EPU, refers to the amount of enzyme required to liberate 0.0083 μmol of reducing sugar equivalent (xylose equivalent) from oat spelt xylan per minute at pH 4.7 and 50°C.

As described above, in the feed for layer hens of this embodiment, the additive feed is mixed into the basic feed so as to contain the amount of lutein described above, and the additive feed is mixed into the basic feed so as to contain the amount of xylanase described above, so that eggs containing a high concentration of lutein can be produced by feeding the feed for layer hens of this embodiment to layer hens. In other words, by mixing the additive feed into the basic feed so as to contain a predetermined amount of xylanase, a large amount of lutein can be transferred to the eggs, which could not be achieved by simply increasing the amount of lutein contained in the feed for layer hens.

<Egg production method according to the present embodiment>
Next, the egg production method of this embodiment (hereinafter, sometimes simply referred to as this production method) will be described. This production method is a method in which laying hens are fed the layer feed of this embodiment (hereinafter, sometimes simply referred to as "the layer feed") to lay eggs. By employing this production method, it is possible to promote the transfer of lutein to eggs, and eggs containing a high concentration of lutein (i.e., the high-lutein-containing eggs of this embodiment, hereinafter, sometimes referred to as "the high-lutein-containing eggs") can be efficiently produced.

In this production method, first, the feeding of the present feed for egg-laying hens is started to the egg-laying hens (target egg-laying hens) that will produce the eggs with high lutein content. Note that for a certain period of time after the feeding of the present feed for egg-laying hens is started, the eggs laid by the target egg-laying hens do not contain sufficient lutein, so the eggs laid are treated as normal eggs.
After a certain period of time has passed since the start of feeding the present feed for egg-laying hens, the eggs laid by the target egg-laying hens will contain sufficient lutein and will be the present high-lutein eggs.
Therefore, by continuing to feed the subject layer feed to the layer hens and harvesting the eggs, it is possible to harvest (i.e. produce) the eggs with high lutein content.

In the present production method, the timing for starting feeding the present egg-laying hen feed to the target egg-laying hens is not particularly limited. For example, feeding of the present egg-laying hen feed to the target egg-laying hens may start from the chick-entry stage, or may start from the adult stage.
In addition, the period for feeding the subject layer feed to the subject layer hens during rearing may be appropriately adjusted depending on the molting situation. For example, the subject layer feed is fed from the time when the chicks that will become the subject layer hens enter the chicks, and the feeding of the subject layer feed is stopped during the molting period, during which time feed suitable for the molting period is fed. Then, the feeding of the subject layer feed to the subject layer hens may be resumed when the egg quality of the eggs becomes suitable after molting (for example, 7 weeks to 70 days after molting).

The period from the start of feeding the subject layer feed to the subject layer hens until the start of harvesting the subject high lutein-containing eggs (hereinafter sometimes referred to as the "preparation period") is not particularly limited. The preparation period may be a period during which the subject layer hens' blood lutein and zeaxanthin concentrations increase to a level that promotes the transfer of lutein and zeaxanthin to eggs. For example, White Leghorn layer hens can be made to lay eggs containing 2.9 mg or more of lutein per 100 g of the edible portion of the subject high lutein-containing eggs by feeding the subject layer feed with a specified composition for 60 days or more.

The preparation period may be set to an appropriate period depending on the amount of lutein and xylanase contained in the present layer feed, the rearing environment, the type of target layer hens, etc., and may be 40 days or more, 45 days or more, or 50 days or more. If the target layer hens are fed a feed containing lutein before feeding the present layer feed, the preparation period tends to be shorter than 60 days.

In addition, it is desirable to feed the target egg-laying hens with the present egg-laying hen feed continuously during the preparation period, but it is not necessary to feed the target egg-laying hens with the present egg-laying hen feed continuously during the preparation period, and there may be a period (e.g., several days) during which the target egg-laying hens are not fed with the present egg-laying hen feed. In other words, the present egg-laying hen feed may be fed to the target egg-laying hens intermittently during the preparation period. In this case, other feed will be fed to the target egg-laying hens during the period during which the present egg-laying hen feed is not fed, but it is desirable that the period during which the present egg-laying hen feed is fed to the target egg-laying hens during the preparation period is longer than the period during which the other feed is fed.

Furthermore, it is desirable to continuously feed the subject egg-laying hens with the subject egg-laying hens feed during the period when the subject eggs containing high lutein are harvested (hereinafter sometimes referred to as the "harvesting period"), but it is not necessary to continuously feed the subject egg-laying hens with the subject egg-laying hens feed during the harvesting period. In other words, there may be periods (e.g., several days) during the harvesting period when the subject egg-laying hens feed is not fed. In other words, the subject egg-laying hens feed may be fed intermittently during the harvesting period. In this case, other feed will be fed to the subject egg-laying hens during the periods when the subject egg-laying hens feed is not fed, but it is desirable that the period during which the subject egg-laying hens feed the subject egg-laying hens feed within a certain continuous period (such as one week or one month) is longer than the period during which the other feed is fed.

The types of egg-laying hens that can be raised using this production method include commonly raised White Leghorns and Rhode Island Reds (so-called red chickens), but are not limited to these types.

<Eggs with high lutein content according to the present embodiment>
The high lutein-containing egg of this embodiment (the present high lutein-containing egg) is an egg that contains lutein at a high concentration in the egg. Specifically, the present high lutein-containing egg is an egg that contains 2.8 mg or more of lutein per 100 g of edible portion. The present high lutein-containing egg is an egg that contains 2.8 mg or more of lutein, preferably 2.9 mg or more, more preferably 3.0 mg or more of lutein per 100 g of edible portion.

As described above, since the high lutein-containing eggs of this embodiment contain the above-mentioned concentration of lutein, when a person ingests the high lutein-containing eggs of this embodiment, it is expected that the retinal (macular) pigment, which is said to protect the eyes from light stimuli, can be increased. In other words, when a person ingests the high lutein-containing eggs of this embodiment, it is possible to obtain the effect of protecting the person's eyes from light stimuli and contributing to the maintenance of eye health. In other words, when a person ingests the high lutein-containing eggs of this embodiment, it can be useful in reducing the risk of eye disease in the person's eyes and preventing eye disease. For example, by replacing the eggs that a person generally ingests per day with the high lutein-containing eggs of this embodiment, it is possible to reduce the risk of eye disease in the person's eyes and prevent eye disease.

Specifically, the amount of lutein that can be expected to increase pigmentation in the macular lutea is thought to be about 10 mg per day. In the case of regular medium-sized eggs or larger (eggs with an average weight of about 58 to 64 g), eating at least two and a half eggs, preferably three eggs, per day will allow you to ingest about 5 mg of functional ingredients per day, which is half the amount generally adopted in the guidelines for functional foods, from the high lutein content eggs of this embodiment.

In addition, since the high-lutein eggs of this embodiment contain lutein at or above the above value, the yellowness of the egg yolk can be improved. Improving the yellowness of the egg yolk can increase the appetite for food cooked using the eggs. In particular, when the high-lutein eggs of this embodiment are heated, the yellowness of the egg yolk becomes deeper and more vivid. For this reason, the high-lutein eggs of this embodiment are more suitable as eggs to be used in dishes that require heating.

In general, eggs are composed of approximately 10% shell, approximately 60% white, and approximately 30% yolk by weight. Most of the lutein in eggs is stored in the yolk, so if one ingests only the yolk of the high lutein-containing egg of this embodiment, one can ingest lutein more efficiently.

The high lutein-containing eggs of this embodiment can be produced by raising egg-laying hens according to this production method using the egg-laying hens feed of this embodiment described above. As described above, the high lutein-containing eggs of this embodiment obtained by this production method can contain lutein at a concentration that was previously unimaginable.

In this specification, when a numerical range is described using "to", the range includes both the lower limit and the upper limit unless otherwise specified. For example, "1 to 10" includes both the lower limit "1" and the upper limit "10". In other words, "1 to 10"
means the same as "1 or more and 10 or less."
In addition, in this specification, the values of "%" and "ppm" mean weight ratios. In this specification, "1 mg/kg" has the same meaning as "1 ppm". In this specification, the content is expressed by mass or weight ratio unless otherwise specified.

<Processed food material of this embodiment>
The processed food material of this embodiment is a food material processed using the high lutein-containing egg of this embodiment, and is a food material containing a large amount of lutein. The processed food material of this embodiment is not particularly limited as long as it is a food material produced using the high lutein-containing egg of this embodiment. For example, the processed food material of this embodiment can include food materials directly processed from eggs, such as boiled eggs and rolled eggs, and seasonings and sauces, such as mayonnaise, pasta sauce, and dressing, which are produced using the high lutein-containing egg of this embodiment as a raw material.

Frozen eggs produced from eggs, that is, frozen eggs produced from the high lutein-containing eggs of this embodiment, are also included in the processed food ingredients of this embodiment. Frozen eggs refer to eggs that have been cracked to extract only the edible portion, filtered to remove the egg shell, and then frozen. In other words, frozen eggs that have been cracked from the high lutein-containing eggs of this embodiment to extract only the edible portion, filtered to remove the egg shell, and then frozen are also included in the processed food ingredients of this embodiment.

Laying hen feed (corresponding to the laying hen feed of this embodiment) was fed to poultry (test hens) for more than 60 consecutive days, and the lutein content of the harvested eggs (corresponding to the high lutein-containing eggs of this embodiment) was confirmed.

In the experiment, White Leghorn layer hens were used as test hens, and each hen was given a fixed amount of layer feed, 110 g per day.

In the experiment, the feed given to the test hens was changed from the basic feed only (Progress only) to layer feed, and the lutein content of eggs harvested 60 days later was confirmed. The lutein content of the eggs was determined by high performance liquid chromatography (the analytical method for "carotene" in "analytical methods for nutritional components, etc." (see the appendix "analytical methods for nutritional components, etc." in "Food Labeling Standards" (Notice of the Deputy Director-General of the Consumer Affairs Agency, No. 139, dated March 30, 2015)).
The lutein content of eggs was calculated as the average value of multiple eggs of the same size collected on the same egg collection day. Egg sizes were classified as medium size (58-64g), LM size (61-67g), and large size (64-70g).

The layer feed provided to the test hens was prepared by mixing a basic feed with additive feed. The additive feed used was a raw material containing lutein and a raw material containing xylanase.
The basic feed used was a feed mainly composed of corn (product name: Progress, manufactured by Nichiwa Sangyo Co., Ltd.).
Of the additive feeds, the raw material containing lutein was a processed marigold petal extract (seller: ED Nutrition Japan Co., Ltd., product name: Summercol 40B, lutein content 34.0 g/kg).
Of the additive feeds, the raw material containing xylanase was a product containing xylanase as the main component (manufactured by Huvepharm Japan Co., Ltd., product name: Hostazyme X (registered trademark), xylanase content 1500 EPU/g).

Laying hens were given several egg-laying hen feeds (Feed A, Alan 19, Alan 19α) containing the above-mentioned basic feed, marigold petal extract, and Hostazyme X (registered trademark) in the following ratios, and the lutein content of eggs laid under each condition was confirmed. The ratios of basic feed, Summercol, and Hostazyme X (registered trademark) in each egg-laying hen feed are as follows:

In Example 1, feed A was provided, in Example 2, Alan 19, and in Example 3, Alan 19α.
In addition, the harvest time of the eggs in each example is January 4, 2022 for Example 1, June 26, 2023 for Example 2, and July 1, 2024 for Example 3.

<Feed A>
Feed A was prepared by blending 3.0 kg of Summercol and 100 g of Hostazyme X (registered trademark) per ton of layer feed. That is, Feed A was prepared by blending Summercol and Hostazyme X so that the amount of lutein per 1 kg of layer feed was 102 mg and the amount of xylanase per 1 kg of layer feed was 1500 EPU.

<Aran 19>
Alan 19 was prepared by mixing 4.5 kg of Summercol and 100 g of Hostazyme X (registered trademark) per ton of layer feed. That is, Summercol and Hostazyme X were mixed to obtain 153 mg of lutein per kg of layer feed and 1500 EPU of xylanase per kg of layer feed. Alan 19 was prepared so that the protein content in the layer feed would be 19-19.3%.

<Aran 19α>
Alan 19α was prepared by mixing 4.95 kg of Summercol and 100 g of Hostazyme X (registered trademark) per ton of layer feed. That is, Alan 19α was prepared by mixing Summercol and Hostazyme X so that the amount of lutein per 1 kg of layer feed was 168.3 mg and the amount of xylanase per 1 kg of layer feed was 1500 EPU. Alan 19α was prepared so that the protein ratio in the layer feed was 19 to 19.3%.

In Comparative Example 1, the basic feed (only Progress) was mixed with no Summercol, and Hostazyme X (registered trademark) was mixed in an amount of 200 g per ton of layer feed (i.e., the amount of xylanase per kg of feed was 3,000 EPU). The harvest time of the eggs in Comparative Example 3 is March 2, 2025.
In Comparative Example 2, the basic feed (only Progress) was mixed with no HostazymeX (registered trademark), and Summercol was mixed with 3.0 kg of egg-laying hen feed per ton (i.e., 102 mg of lutein per kg of feed). The eggs in Comparative Example 4 were harvested on July 30, 2021.
In Comparative Example 3, the basic feed (only Progress) was mixed with no HostazymeX (registered trademark), and Summercol was mixed with 4.5 kg of egg-laying hen feed per ton (i.e., 153 mg of lutein per kg of feed). The eggs in Comparative Example 4 were harvested on October 15, 2021.
In Comparative Example 4, the basic feed (only Progress) was mixed with no HostazymeX (registered trademark), and Summercol was mixed with 6.0 kg of egg-laying hen feed per ton (i.e., the amount of lutein per kg of feed was 204 mg). The eggs in Comparative Example 4 were harvested on October 15, 2021.
In addition, Comparative Examples 1 to 4 are the results of measurements on eggs harvested 60 days after the feed given to the test chickens was changed from only the basic feed (only Progress) to the above-mentioned feed.

<Confirmation of the effect of xylanase>
As shown in Figure 1 (A), in Comparative Example 1, in which only Hostazyme X (registered trademark) was added without blending Summercol, the amount of lutein contained in the edible part of the egg was small and was equivalent to that of a normal egg. In other words, it can be seen that the addition of xylanase alone has no effect of increasing the amount of lutein contained in the edible part of the egg.

In Comparative Examples 2 to 4, in which only summercol was added to the basic feed, the amount of lutein contained in the edible part of the eggs increased, and it was confirmed that as the lutein content in the feed increases, the lutein is transferred to the edible part of the eggs.
However, when comparing Comparative Example 2 with Comparative Example 4, although the amount of lutein contained in the feed was doubled, the amount of lutein contained in 100 g of the edible portion increased by only about 1.24 times. Also, when comparing Comparative Example 3 with Comparative Example 4, although the amount of lutein contained in the feed increased by 51 mg, the amount of lutein contained in 100 g of the edible portion increased by only 0.02 mg.
In other words, it has been confirmed that simply increasing the amount of lutein contained in the feed has a limit to the transfer of lutein to the edible portion of the egg, and at most less than 2.9 mg of lutein can be transferred per 100 g of edible portion.

In Examples 1 to 3, in which Summercol and Hostazyme X (registered trademark) were added to the basic feed, the amount of lutein contained in the edible part of the eggs increased, as in Comparative Examples 2 to 4. This confirms that as the amount of lutein in the feed increases, the lutein is transferred to the edible part of the eggs.
Moreover, in Examples 1 to 3, the amount of lutein contained in 100 g of the edible portion is greater than in Comparative Examples with the same amount of lutein contained in the feed. And even in Example 1, which contains the least amount of lutein in the feed, the amount of lutein contained in 100 g of the edible portion is greater than in Comparative Example 4, which contained feed containing twice as much lutein as in Example 1. In other words, it can be confirmed that the transfer of lutein to eggs is promoted by the effect of xylanase.
In addition, when comparing Example 1 with Example 3, the amount of lutein contained in the feed is about 1.65 times higher, yet the amount of lutein contained in 100 g of the edible portion increases by about 1.1 times. And when comparing Example 2 with Example 3, although the amount of lutein contained in the feed increases by only 15 mg, the amount of lutein contained in 100 g of the edible portion increases by 0.12 mg.
In other words, it has been confirmed that by adding xylanase to the feed, the amount of lutein contained in 100 g of the edible portion can be increased, and that more lutein can be transferred to eggs than the limit value when xylanase is not added. Moreover, it has been confirmed that even if the amount of lutein added to the feed increases, the effect of transferring lutein to eggs can be maintained in proportion to the increase.

<Effect of preparation period on transfer of lutein to eggs>
The desirable length of preparation period was confirmed. In the experiment, it was confirmed how long the preparation period was necessary to make the amount of lutein contained in 100 g of the edible part of an egg 2.9 mg or more.

In the experiment, the test hens were raised under the same conditions as in Example 3 described above, and the transfer of lutein to the eggs was confirmed at 40, 50, and 60 days. The eggs were harvested on January 13, 2025 (40 days), January 23, 2025 (50 days), and February 2, 2025 (60 days).

The results are shown in Figure 1(B) and Figure 2(B).
As shown in Figure 1, it can be confirmed that a certain amount of lutein is transferred to the eggs even when the preparation period is 40 or 50 days, but the amount of lutein contained in 100 g of the edible portion at 40 and 50 days was about 2.6 mg.
On the other hand, after 60 days, the amount of lutein contained in 100 g of edible portion was 2.9 mg, and it was confirmed that in order to achieve an amount of lutein of 2.9 mg per 100 g of edible portion, a preparation period of 60 days or more is desirable.

<Evaluation of egg yolk color>
The color of the egg yolk of the sample of the high lutein-containing egg of the present invention was evaluated.
The eggs used as samples were eggs (Example 4) harvested from test hens raised using the same feed (Feed A) as in Example 1.

The measuring equipment used to measure color was the CR-400/DP-400 (Konica Minolta, CR is a color difference meter, and DP is the model number of the data processor). In the evaluation, the L value indicates brightness, with black being 0 and white being 100, the a value indicates redness, with the higher the value indicating a stronger redness, and the b value indicates yellowness, with the higher the value indicating a stronger yellowness.

The measurement method using whole eggs is as follows.
The test eggs were cracked and placed one by one into a plastic cup, with the chalazion still attached, and then lightly mixed with a glass rod and stirred with a Polytron (15,000 rpm, 30 seconds). 16g to 17g of the stirred sample was placed in an aluminum cup (size 6) (about 2/3 of the aluminum cup) and the bubbles on the surface were removed. The liquid level after the bubbles were removed was then measured at one point with a color difference meter (the table shows the measurement results for raw eggs).
Next, after heating at 100° C. for 30 minutes, the aluminum cup was removed and the cross section of the heated product cut horizontally to the baking surface was measured at one point using a color difference meter (the table shows the measurement results for the heated egg).

The measurement method using only egg yolk is as follows.
The egg yolk liquid was separated from the test eggs and each separated egg yolk was placed in an aluminum cup (size 6). The egg yolk was thoroughly stirred in the aluminum cup with a glass rod to remove any bubbles on the surface. The liquid level after the bubbles were removed was then measured at one point with a colorimeter (the table shows the measurement results for raw eggs).
Next, after heating at 100° C. for 30 minutes, the aluminum cup was removed and the cross section of the heated product cut horizontally to the baking surface was measured at one point using a color difference meter (the table shows the measurement results for the heated egg).

The results are shown in Figure 3.
3, the whole eggs of Example 4 had a significantly higher yellowness and a brighter appearance than the comparative example, both for raw eggs and heated eggs. In particular, the yellowness (b value) of the heated eggs was about twice as high as that of the comparative example, showing a significant difference.
Furthermore, in the measurement results for only the egg yolk in Example 4, the raw eggs gave the impression of being slightly reddish, but the heated eggs were significantly more yellow than in the comparative example and looked more vivid.

From the above results, it was confirmed that the transfer of lutein to eggs can be appropriately promoted by continuously feeding the egg-laying hens with the egg-laying hens feed of the present invention using the egg production method of the present invention. It was also confirmed that the high-lutein-containing eggs produced by the egg production method of the present invention can increase the lutein concentration in the eggs to a value that could not be achieved by conventional techniques. For example, it is now possible to achieve a high-lutein-containing egg of 2.9 mg or more per 100 g of edible portion.
Therefore, the high lutein content eggs of the present invention are suitable as a food for ingesting lutein, and by eating about three eggs weighing about 60 g or more per day, it is expected that the risk of eye disease can be reduced and eye disease can be prevented.

The high lutein-containing eggs of the present invention are suitable as a food source for ingesting lutein. Furthermore, the feed for laying hens and the egg production method of the present invention are suitable for producing eggs that contain a high concentration of lutein.

Claims (4)

A method for producing eggs, comprising the steps of: preparing feed for laying hens to obtain eggs containing a high concentration of lutein,
Feeding laying hens with a xylanase-enriched feed containing 100 mg or more of lutein per kg of feed and 1000 EPU or more of xylanase per kg of feed;
A method for producing eggs, comprising: feeding chickens with xylanase-enriched feed for a predetermined period of time from the start of feeding the feed; and allowing the chickens to lay eggs. 2. The method for producing eggs according to claim 1, wherein the amount of lutein contained in the eggs is 2.9 mg or more per 100 g of edible portion of the eggs. 2. The method for producing eggs according to claim 1, wherein the laying hens are White Leghorns. A feed used in the egg production method according to claims 1 to 3,
A feed for laying hens, comprising 100 mg or more of lutein per kg and 1,000 EPU or more of xylanase per kg.

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