High-lutein eggs, processed food ingredients, egg production methods, and feed for laying hens.

Abstract

The present invention provides eggs containing a high concentration of lutein, processed food products made from these eggs, a method for producing these eggs, and feed for laying hens used in the production method. [Solution] A method for producing eggs containing a high concentration of lutein by preparing feed for laying hens, comprising feeding laying hens a xylanase-rich feed containing 100 mg or more of lutein and 1000 EPU or more of xylanase per kg of feed, and allowing the hens to lay eggs after being fed the xylanase-rich feed for a predetermined period of time or longer from the start of feeding. Since eggs containing a high concentration of lutein can be produced, if people consume eggs produced by this method on a daily basis, it will be possible to protect people's eyes from light stimuli and contribute to maintaining eye health, thus helping to reduce the risk of eye diseases and prevent eye diseases.

Description

Technical Field

[0001] The present invention relates to a high-lutein egg, a processed food material, an egg production method, and a feed for laying hens.

Background Art

[0002] Eggs are inexpensive food materials with extremely high nutritional value, which contain the five major nutrients required for the human body, namely carbohydrates, lipids, proteins, minerals and vitamins, and also contain amino acids that cannot be produced by the human body.

[0003] For example, eggs contain lutein, and lutein is known to have an antioxidant function. In recent years, it has been reported that intake of lutein may lead to increase of pigments in the macula and prevention of diseases such as macular degeneration and cataract. In particular, it has been reported that the desirable daily intake of lutein for increasing macular pigments is 10 mg. Examples of methods for humans to ingest lutein include a method of ingesting lutein from eggs, and a method of ingesting lutein from spinach or supplements. However, it has been reported that the absorption rate into the human body for the method of ingesting from spinach or supplements is reduced to about 1 / 2 to 1 / 3 as compared with the case of ingesting from eggs. Therefore, to allow lutein to be effectively absorbed by the human body, it is desirable to ingest lutein from eggs. However, the lutein contained in ordinary eggs is at most about 0.4 mg per 100 g of edible part, and it is difficult to ingest a sufficient amount of lutein from eggs.

[0004] Accordingly, 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 is increased by adjusting the feed given to laying hens (see Patent Documents 1 to 3)

[0005] 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 marigolds, oregano, etc., 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 together with lutein to feed. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-20510 [Patent Document 2] Japanese Patent Publication No. 2003-102395 [Patent Document 3] Special Publication No. 2014-524914 [Patent Document 4] Publication number CN103070311 [Patent Document 5] WO98 / 18345 publication [Non-patent literature]

[0007] [Non-Patent Document 1] European Food Safely Authority (EFSA), "Scientific Opinion on the safety and efficacy of Hostazym doi;10.2903 / j.efsa.2013.3105. [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the eggs produced using the methods described in Patent Documents 1 and 2 still do not contain enough lutein to obtain the necessary amount from the eggs. The method disclosed in Patent Document 3 can increase the amount of lutein to some extent, but it involves adding meso-zeaxanthin, which is not normally used in animal 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 commonly used in animal feed.

[0009] Meanwhile, various attempts have been made to prepare feed for laying hens. 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 adding xylanase to feed can improve egg weight and egg-laying rate. Patent Document 4 also discloses the addition of xylanase enzyme to feed as a method for producing eggs rich in xanthophyll. Furthermore, Patent Document 5 discloses a technique for using a carbohydrate-degrading enzyme to promote pigment absorption in poultry feed, and xylanase is disclosed as the carbohydrate-degrading enzyme. However, while Patent Documents 4 and 5 and Non-Patent Document 1 describe that certain effects can be obtained by adding xylanase to feed, they do not provide specific information on the effect of the xylanase addition rate on the amount of lutein contained in eggs.

[0010] In view of the above circumstances, the present invention aims to provide eggs containing a high concentration of lutein, processed food ingredients made from eggs containing high concentrations of lutein, a method for producing eggs containing high concentrations of lutein, and feed for laying hens used in the production method. [Means for solving the problem]

[0011] The present invention relates to an egg production method for obtaining eggs containing a high concentration of lutein by preparing feed for laying hens, characterized in that the laying hens are fed a xylanase-rich feed containing 100 mg or more of lutein and 1000 EPU or more of xylanase per kg of feed, and the hens are allowed to lay eggs after being fed the xylanase-rich feed for a predetermined period of time or longer from the start of feeding. The egg-laying hen feed 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 and 1000 EPU or more of xylanase per kg. The high-lutein-containing eggs of the present invention are eggs laid by laying hens fed a xylanase-rich feed containing 100 mg to 200 mg of lutein per kg and 1000 EPU or more of xylanase per kg, characterized in that the lutein content is 2.8 mg or more per 100 g of edible portion of the egg. The processed food ingredient of the present invention is characterized by being processed from the high-lutein-containing eggs of the present invention. [Effects of the Invention]

[0012] The egg production method and feed for laying hens of the present invention can produce eggs containing a high concentration of lutein. The eggs and processed foods of this invention contain a high concentration of lutein, which can help prevent the risk of eye diseases through daily consumption. Furthermore, they can improve the appearance of the food when cooked. [Brief explanation of the drawing]

[0013] [Figure 1] (A) is a table showing the experimental results for Examples 1-3 and Comparative Examples 1-4, and (B) is a table showing the results of confirming the relationship between the preparation period and the amount of lutein. [Figure 2] (A) is a graph showing the experimental results for Examples 1-3 and Comparative Examples 2-4, and (B) is a graph showing the results of confirming the relationship between the preparation period and the amount of lutein. [Figure 3]This is a table showing the experimental results of yolk color evaluation. [Modes for Carrying Out the Invention]

[0014] Hereinafter, the high-lutein-containing egg, the processed food material, the method for producing the egg of the present embodiment, and the feed for laying hens of the present embodiment will be described.

[0015] <Feed for Laying Hens of the Present Embodiment> First, the feed used for producing the high-lutein-containing egg of the present embodiment, that is, the feed for laying hens of the present embodiment will be described. The feed for laying hens of the present embodiment is a feed used for rearing laying hens. That is, the feed for laying hens of the present embodiment is a feed used in the method for producing eggs of the present embodiment, and is produced by blending an additive feed with a basal feed.

[0016] The basal feed is one that is commonly used as feed for poultry. The basal feed is, for example, mainly composed of corn, and is prepared by blending other components such as animal feed raw materials (fish meal and the like), vegetable oil meals (soybean oil meal, rapeseed oil meal and the like), cereals (wheat and the like), rice bran and bran (wheat bran, rice bran and the like), calcium carbonate, oyster shells and the like. For example, the basal feed can be produced by adjusting the blending ratios of various commercially available feeds. The components contained in the basal feed are not limited to those described above, and any component commonly adopted as a component of feed used for rearing laying hens can be adopted. In addition, the blending ratio of each component contained in the basal feed can be set to the blending ratio adopted in general feeds, but the blending ratio of each component is not particularly limited. It can be appropriately adjusted according to the growth state, environment and other conditions of the laying hens to which the feed is administered. For example, by adjusting the blending ratio of each component, the amount of protein contained in the basal feed or the feed for laying hens of the present embodiment can be appropriately adjusted.

[0017] The additive feeds added to the basic feed are added to the basic feed to prepare the components contained in the entire egg-laying hen feed of this embodiment. In the egg-laying hen feed of this embodiment, an additive feed is used that can increase the amount of lutein contained in the egg-laying hen feed. In other words, the egg-laying hen feed of this embodiment can use an additive feed that contains raw materials containing lutein as an ingredient. Examples of raw materials containing lutein include marigold (flowers, petals, leaves), yellow corn (fruit), green leafy vegetables such as kale and spinach, chlorella, and fruits such as kiwifruit and grapes. The form in which the lutein-containing raw materials are added to the basic feed as additive feed is not particularly limited. For example, if marigold is added as an additive feed, dried marigold petals may be crushed and added, or an extract obtained by extracting marigold petals with an organic solvent may be added. Furthermore, as for the lutein-containing raw materials, those derived from natural products as described above may be used, but they may also be chemically synthesized.

[0018] The additive feeds mixed into the basic feed are prepared so that the total amount of lutein and zexanthin in the laying hen feed, that is, the feed in which the additive feed is mixed with the basic feed, is above a certain level. For example, the amount of additive feed mixed into the basic feed is prepared so that the lutein content is 100 mg or more per 1 kg of laying hen feed, preferably 120 mg or more per 1 kg of laying hen feed, and more preferably 150 mg or more per 1 kg of laying hen feed. There is no particular upper limit to the lutein content in the total laying hen feed when the additive feed is mixed with the basic feed. However, if a large amount of additive feed is added, the feed cost will increase and the egg production efficiency will decrease, so it is desirable that the lutein content be 200 mg or less.

[0019] Furthermore, the supplementary feed added to the basic feed contains enzymes that have the function of hydrolyzing xylan. For example, it is desirable that the supplementary feed contains enzymes such as xylanase or amylase (from Aspergillus oryzae). When xylanase is included in the supplementary feed, the amount of supplementary feed added to the basic feed is adjusted so that the xylanase content is 1000 EPU (Endopentsanase Units) or more per 1 kg of laying hen feed, preferably 1200 EPU or more per 1 kg of laying hen feed, and more preferably 1500 EPU or more per 1 kg of laying hen feed. There is no particular upper limit to the xylanase content in the total laying hen feed when the supplementary feed is added to the basic feed. However, if a large amount of supplementary feed is added, the feed cost will increase and the egg production efficiency will decrease, and the improvement in the effect of increasing lutein in proportion to the increase in the amount added will be low, so it is desirable that the xylanase content be 3000 EPU or less.

[0020] Furthermore, EPU, the unit of addition for xylanase, refers to the amount of enzyme required to release 0.0083 μmol of reducing sugar equivalent (xylose equivalent) per minute from autospermoxylan at pH 4.7 and 50°C.

[0021] As described above, the egg-laying hen feed of this embodiment is formulated by adding an additive to the base feed so that it contains the amount of lutein described above, and by adding an additive to the base feed so that it contains the amount of xylanase described above, eggs containing a high concentration of lutein can be produced by supplying the egg-laying hen feed of this embodiment to egg-laying hens. In other words, by formulating an additive to the base feed so that it contains a predetermined amount of xylanase, it is possible to transfer a large amount of lutein to the eggs, which could not be achieved by simply increasing the amount of lutein contained in the egg-laying hen feed.

[0022] <Egg production method according to this embodiment> Next, the egg production method of this embodiment (hereinafter sometimes simply referred to as "this production method") will be described. This production method involves feeding laying hens the laying hen feed of this embodiment described above (hereinafter sometimes simply referred to as "this laying hen feed") to induce egg laying. By adopting this production method, it becomes possible to promote the transfer of lutein to the eggs, and eggs containing a high concentration of lutein (i.e., the high-lutein eggs of this embodiment, hereinafter sometimes referred to as "this high-lutein eggs") can be produced efficiently.

[0023] In this production method, first, the laying hens that produce eggs with high lutein content (target laying hens) are fed this laying hen feed. For a specified period after starting to feed this laying hen feed, the eggs laid by the target laying hens will not contain sufficient lutein, so these eggs will be treated as normal eggs. After a specified period has elapsed since the start of feeding this laying hen feed, the eggs laid by the target laying hens will become high-lutein eggs containing sufficient lutein. Therefore, by continuing to feed the target laying hens this egg-laying hen feed while harvesting eggs, it is possible to harvest (i.e., produce) eggs with high lutein content.

[0024] Furthermore, in this production method, there is no particular limit to when the feeding of this laying hen feed to the target laying hens begins. For example, the feeding of this laying hen feed may begin from the time the chicks are brought in, or it may begin after the target laying hens have reached maturity. Furthermore, the period during which the target laying hens are fed the main laying hen feed may be adjusted as appropriate depending on the molting stage. For example, the main laying hen feed may be given from the time the chicks that will become the target laying hens are introduced to the nest, and the feeding of the main laying hen feed may be stopped during the molting period, with a feed suitable for the molting period being given during that time. Then, the feeding of the main laying hen feed may be resumed when the egg quality becomes appropriate after molting (for example, 7 weeks to 70 days after molting).

[0025] The period from the start of feeding the target laying hens with this laying hen feed to the start of harvesting the high-lutein eggs (hereinafter sometimes referred to as the "preparation period") is not particularly limited. The preparation period should be long enough to raise the blood lutein concentration and blood zeaxanthin concentration of the target laying hens to a level that promotes the transfer of lutein and zeaxanthin into the eggs. For example, if you feed white Leghorn laying hens this laying hen feed with the prescribed formulation for 60 days or more, they will then be able to lay eggs containing 2.9 mg or more of lutein per 100 g of edible portion of the high-lutein eggs.

[0026] The preparation period should be set to an appropriate duration depending on the amount of lutein and xylanase contained in this laying hen feed, the rearing environment, and the type of laying hen being fed, and may be 40 days or longer, 45 days or longer, or 50 days or longer. If the laying hens have been fed a feed containing lutein before being given this laying hen feed, the preparation period tends to be shorter than 60 days.

[0027] Furthermore, while it is desirable to continuously feed the target laying hens with the main laying hen feed during the preparation period, it is not necessarily required to continuously feed them with the main laying hen feed during the preparation period, and there may be periods (for example, several days) during which the target laying hens are not fed the main laying hen feed. In other words, the target laying hens may be fed the main laying hen feed intermittently during the preparation period. In this case, other feeds will be given to the target laying hens during the periods when the main laying hen feed is not provided, but it is desirable that the period during which the target laying hens are fed the main laying hen feed is longer than the period during which other feeds are provided.

[0028] Furthermore, while it is desirable to continuously feed the target laying hens this laying hen feed during the period in which these high-lutein eggs are being collected (hereinafter sometimes referred to as the "collection period"), it is not necessarily required to continuously feed them this laying hen feed even during the collection period. In other words, there may be periods (for example, several days) during the collection period when the target laying hens are not being fed this laying hen feed. That is, the target laying hens may be fed this laying hen feed intermittently even during the collection period. In this case, other feeds will be given to the target laying hens during the periods when this laying hen feed is not being given, but it is desirable that the period during which the target laying hens are being fed this laying hen feed is longer than the period during which other feeds are being given, within a continuous period (such as one week or one month).

[0029] The types of laying hens raised using this production method include, but are not limited to, commonly raised breeds such as the White Leghorn and Rhode Island Red (so-called red chickens).

[0030] <High-lutein-containing eggs of this embodiment> The high-lutein-containing egg of this embodiment (this high-lutein-containing egg) is an egg that contains lutein at a high concentration. Specifically, this high-lutein-containing egg is an egg that contains 2.8 mg or more of lutein per 100 g of edible portion. The lutein content per 100 g of edible portion of this high-lutein-containing egg is 2.8 mg or more, preferably 2.9 mg or more, and more preferably 3.0 mg or more of lutein.

[0031] As described above, the high-lutein eggs of this embodiment contain the above-mentioned concentration of lutein, so if a person consumes these eggs, it is expected that the amount of retinal (macular) pigment, which is said to protect the eyes from light stimuli, will increase. In other words, by consuming these eggs, it is possible to obtain the effect of protecting the eyes from light stimuli and contributing to the maintenance of eye health. That is, by consuming these eggs, it is possible to reduce the risk of eye diseases and help prevent eye diseases. For example, by replacing the eggs that a person generally consumes in a day with these eggs, it is possible to reduce the risk of eye diseases and prevent eye diseases.

[0032] Specifically, the recommended daily intake of lutein, which is expected to increase macular pigment, is thought to be around 10 mg. In the case of typical medium-sized or larger eggs (eggs with an average weight of about 58-64 g), eating about 2.5 or more eggs, preferably 3 eggs, per day will allow you to consume about 5 mg of the functional ingredient, which is half the amount of the functional ingredient generally used per day in the guidelines for functional foods, using the high-lutein eggs of this embodiment.

[0033] Furthermore, since the high-lutein eggs of this embodiment contain lutein above the above-mentioned value, the yellowness of the egg yolk can be improved. When the yellowness of the egg yolk is improved, the appetite for food prepared using these eggs can be increased. 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 for use in dishes that involve heat.

[0034] Generally speaking, eggs are composed of approximately 10% shell, 60% egg white, and 30% yolk by weight. Since most of the lutein in eggs is stored in the yolk, consuming only the yolk of the high-lutein-containing eggs in this embodiment allows for more efficient lutein intake.

[0035] Furthermore, the high-lutein eggs of this embodiment can be produced by raising laying hens using the laying hen feed of this embodiment as described above. As mentioned above, the high-lutein eggs of this embodiment obtained by this production method can contain lutein at concentrations far higher than previously anticipated.

[0036] In this specification, when numerical ranges are described using "~", unless otherwise specified, both the lower limit and the upper limit are included. For example, the description "1~10" includes both the lower limit "1" and the upper limit "10". That is, "1~10" This has the same meaning as "1 or more, and 10 or less". In this specification, values ​​of "%" and "ppm" refer to weight ratios. In this specification, "1 mg / kg" is equivalent to "1 ppm". In this specification, content is expressed by mass or weight ratio unless otherwise specified.

[0037] <Processed food ingredients of this embodiment> The processed food of this embodiment is a food processed using the high-lutein-containing eggs of this embodiment, and is a food containing a large amount of lutein. The processed food of this embodiment is not particularly limited to any food manufactured using the high-lutein-containing eggs of this embodiment. For example, processed foods made directly from eggs, such as boiled eggs and omelets, and seasonings and sauces such as mayonnaise, pasta sauces, and dressings, which are manufactured using the high-lutein-containing eggs of this embodiment as a raw material, can be cited as processed food of this embodiment.

[0038] Furthermore, frozen eggs produced from eggs, that is, frozen eggs produced from the high-lutein-containing eggs of this embodiment, are also included as processed ingredients in this embodiment. Frozen eggs are those in which the shell is cracked, only the edible portion is removed, this edible portion is filtered to remove the shell and other debris, and then frozen. In other words, frozen eggs produced by cracking the shell of the high-lutein-containing eggs of this embodiment, only the edible portion is removed, this edible portion is filtered to remove the shell and other debris, and then frozen are also included as processed ingredients in this embodiment. [Examples]

[0039] The lutein content in eggs (corresponding to the high-lutein eggs of this embodiment) harvested from poultry (test chickens) that were continuously fed egg-laying hen feed (corresponding to the egg-laying hen feed of this embodiment) for 60 days or more was confirmed.

[0040] In the experiment, laying hens of the White Leghorn breed were used as test subjects, and they were given a fixed amount of laying hen feed at a rate of 110g per hen per day.

[0041] In the experiment, the lutein content of eggs harvested 60 days after changing the feed given to the test chickens from basic feed only (Progress only) to laying hen feed was checked. The lutein content of the eggs was determined by high-performance liquid chromatography (see the "Analysis Method for Carotene" in "Analysis Methods for Nutritional Components, etc." (refer to the "Analysis Methods for Nutritional Components, etc." attached to "Regarding Food Labeling Standards" (Consumer Affairs Agency Deputy Director-General's Notification No. 139, dated March 30, 2015))). The lutein content of the eggs was calculated as the average value of multiple eggs of the same size collected on the same day. Egg sizes were classified as follows: M size (58-64g), LM size (61-67g), and L size (64-70g).

[0042] The laying hen feed provided to the test chickens was prepared by combining a basic feed with additive feeds. The additive feeds used included ingredients containing lutein and ingredients containing xylanase. The basic feed used was a corn-based feed (product name: Progress, manufactured by Hiyori Sangyo Co., Ltd.). Among the supplemental feeds, the raw material containing lutein was marigold petal extract (distributor: EW Nutrition Japan Co., Ltd., product name: Summer Call 40B, lutein content 34.0 g / kg). Among the feed additives, 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).

[0043] Laying hens were fed several laying hen feeds (Feed A, Aran 19, Aran 19α) containing the aforementioned basic feed, marigold petal extract, and Hostazyme X (registered trademark) in the following proportions, and the lutein content of the eggs laid under each condition was confirmed. The proportions of the basic feed, summer cole, and Hostazyme X (registered trademark) in each laying hen feed are as follows.

[0044] In Example 1, feed A was provided; in Example 2, aran 19 was provided; and in Example 3, aran 19α was provided. Furthermore, the harvest dates for the eggs in each example were January 4, 2022 for Example 1, June 26, 2023 for Example 2, and July 1, 2024 for Example 3.

[0045] <Feed A> Feed A was prepared by adding 3.0 kg of Summercol and 100 g of Hostazyme X (registered trademark) per ton of laying hen feed. In other words, Feed A was prepared by adding Summercol and Hostazyme X so that the amount of lutein per 1 kg of laying hen feed was 102 mg and the amount of xylanase per 1 kg of laying hen feed was 1500 EPU.

[0046] <Aran19> Aran 19 was prepared by adding 4.5 kg of Summercol and 100 g of Hostazyme X (registered trademark) per ton of laying hen feed. In other words, Aran 19 was prepared by adding Summercol and Hostazyme X so that the amount of lutein per 1 kg of laying hen feed is 153 mg and the amount of xylanase per 1 kg of laying hen feed is 1500 EPU. Furthermore, Aran 19 was prepared so that the protein content in the laying hen feed is 19-19.3%.

[0047] <Aran19α> Aran 19α was prepared by adding 4.95 kg of summer coulis and 100 g of hostazyme X (registered trademark) per ton of laying hen feed. In other words, Aran 19α was prepared by adding summer coulis and hostazyme X so that the amount of lutein in the laying hen feed per 1 kg was 168.3 mg and the amount of xylanase in the laying hen feed per 1 kg was 1500 EPU. Furthermore, Aran 19α was prepared so that the protein content in the laying hen feed was 19-19.3%.

[0048] In Comparative Example 1, Summer Coal was not added to the basic feed (Progress only), and the feed was adjusted by adding 200g of Hostazyme X (registered trademark) per ton of laying hen feed (i.e., 3000 EPU of xylanase per 1kg of feed). The eggs for Comparative Example 3 were harvested on March 2, 2025. Comparative Example 2 was prepared by not adding Hostazyme X (registered trademark) to the basic feed (Progress only), but by adding 3.0 kg of Summercol per ton of laying hen feed (i.e., 102 mg of lutein per 1 kg of feed). The eggs for Comparative Example 4 were harvested on July 30, 2021. Comparative Example 3 was prepared by not adding Hostazyme X (registered trademark) to the basic feed (Progress only), but by adding 4.5 kg of Summercol per ton of laying hen feed (i.e., 153 mg of lutein per 1 kg of feed). The eggs for Comparative Example 4 were harvested on October 15, 2021. Comparative Example 4 was prepared by not adding Hostazyme X (registered trademark) to the basic feed (Progress only), but by adding 6.0 kg of Summercol per ton of laying hen feed (i.e., 204 mg of lutein per 1 kg of feed). The eggs from Comparative Example 4 were harvested on October 15, 2021. Comparative Examples 1-4 show the results of measurements taken from eggs harvested 60 days after switching the feed given to the test chickens from basic feed only (Progress only) to the aforementioned feed.

[0049] <Confirmation of the effects of xylanase> As shown in Figure 1(A), in Comparative Example 1, where only Hostazyme X (registered trademark) was added without Summercol, the amount of lutein in the edible portion of the egg was small, equivalent to that of a typical egg. In other words, it can be seen that simply adding xylanase does not have the effect of increasing the amount of lutein in the edible portion of an egg.

[0050] In comparative examples 2-4, where only summer cole was added to the basic feed, the amount of lutein in the edible portion of the eggs increased, confirming that an increase in lutein in the feed leads to the transfer of lutein to the edible portion of the eggs. However, comparing Comparative Example 2 with Comparative Example 4, even though the amount of lutein in the feed was doubled, the amount of lutein in 100g of edible portion only increased by about 1.24 times. Furthermore, comparing Comparative Example 3 with Comparative Example 4, even though the amount of lutein in the feed increased by 51mg, the amount of lutein in 100g of edible portion only increased by 0.02mg. In other words, simply increasing the amount of lutein in the feed has limitations in terms of lutein transfer to the edible portion of the egg; it has been confirmed that at best, less than 2.9 mg of lutein can be transferred per 100 g of edible portion.

[0051] In Examples 1-3, where Summercol and Hostazyme X (registered trademark) were added to the basic feed, the amount of lutein in the edible portion of the eggs increased, similar to Comparative Examples 2-4. This confirms that if the amount of lutein in the feed increases, lutein is transferred to the edible portion of the eggs. Furthermore, in Examples 1-3, the amount of lutein per 100g of edible portion was higher compared to the comparative example with the same amount of lutein in the feed. Even in Example 1, which had the lowest amount of lutein in the feed, the amount of lutein per 100g of edible portion was higher than in Comparative Example 4, which was given feed containing twice the amount of lutein as Example 1. In other words, it can be confirmed that xylanase promotes the transfer of lutein to eggs. Furthermore, comparing Example 1 and Example 3, the amount of lutein contained in the feed increased by approximately 1.65 times, yet the amount of lutein contained in 100g of edible portion increased by about 1.1 times. Comparing Example 2 and Example 3, although the amount of lutein contained in the feed increased by only 15mg, the amount of lutein contained in 100g of edible portion increased by as much as 0.12mg. In other words, it has been confirmed that by incorporating xylanase into the feed, the amount of lutein contained in 100g of edible portion increases, and more lutein can be transferred to the eggs than the limit when xylanase is not incorporated. Moreover, it has been confirmed that even when the amount of lutein incorporated into the feed increases, the effect of transferring lutein to the eggs can be maintained in proportion to the increase.

[0052] <The effect of the preparation period on the transfer of lutein to eggs> We investigated the ideal preparation period. In the experiment, we determined how long of a preparation period is necessary to ensure that the amount of lutein in 100g of edible egg is 2.9mg or more.

[0053] In the experiment, the test chickens were raised under the same conditions as in Example 3 described above, and the transfer of lutein to the eggs was checked 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).

[0054] The results are shown in Figures 1(B) and 2(B). As shown in Figure 1, it can be confirmed that a certain amount of lutein is transferred to the eggs even with a preparation period of 40 or 50 days, but at the 40 or 50-day mark, the amount of lutein contained in 100g of edible portion was only about 2.6mg. On the other hand, after 60 days, the amount of lutein contained in 100g of edible portion was 2.9mg, confirming that a preparation period of 60 days or more is desirable in order to achieve a lutein content of 2.9mg per 100g of edible portion.

[0055] <Evaluation of egg yolk color> The color of the egg yolk of the sample was evaluated for the high-lutein-containing eggs of the present invention. The eggs used as samples were harvested from test chickens raised using the same feed (feed A) as in Example 1 (Example 4).

[0056] For color measurement, the following measuring instruments were used: CR-400 / DP-400 (manufactured by Konica Minolta; CR is the model number for the colorimeter, and DP is the model number for 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 higher values ​​indicating stronger redness; and the b value indicates yellowness, with higher values ​​indicating stronger yellowness.

[0057] The measurement method using whole eggs is as follows: The sample eggs were cracked one by one into plastic cups, and while the chalazas remained attached, they were gently mixed with a glass rod. Then, they were stirred using a Polytron (15,000 rpm, 30 seconds). 16g to 17g of the stirred sample was placed into an aluminum cup (size 6) (approximately 2 / 3 of the cup's capacity), and the surface foam was removed. The liquid surface after foam removal was then measured at one point using 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 a single point of the cross-section of the heated food, cut horizontally to the cooked surface, was measured using a colorimeter (the table shows the measurement results for the heated egg).

[0058] The measurement method using only egg yolk is as follows: The yolk liquid was separated from the sample eggs, and each separated yolk was placed in a single aluminum cup (size 6). The yolks were thoroughly stirred in the aluminum cups with a glass rod to remove any foam from the surface. The liquid surface, after the foam had been removed, was then measured at one point using 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 a single point of the cross-section of the heated food, cut horizontally to the cooked surface, was measured using a colorimeter (the table shows the measurement results for the heated egg).

[0059] The results are shown in Figure 3. As shown in Figure 3, the whole eggs in Example 4 were significantly yellower and more vibrant in appearance compared to the comparative example, both for raw and cooked eggs. In particular, the difference in yellowness (b value) in cooked eggs was approximately twice that of the comparative example, showing a remarkable difference. Furthermore, in the measurement results of only the egg yolk in Example 4, the raw egg appeared to be slightly redder, but the cooked egg was significantly yellower and more vivid in appearance compared to the comparative example.

[0060] From the above results, it was confirmed that by using the egg production method of the present invention and continuously feeding the laying hen feed of the present invention to laying hens, the transfer of lutein to eggs can be appropriately promoted. Furthermore, it was confirmed that the high-lutein-containing eggs produced by the egg production method of the present invention can have their lutein concentration increased to a level that could not be achieved with conventional techniques. For example, it became possible to achieve a lutein concentration of 2.9 mg or more per 100 g of edible portion in high-lutein-containing eggs. Therefore, the high-lutein eggs of the present invention are suitable as a food for consuming lutein, and eating about three eggs weighing approximately 60g or more per day can be expected to reduce the risk of eye diseases or prevent eye diseases. [Industrial applicability]

[0061] The high-lutein eggs of the present invention are suitable as a food for consuming lutein. Furthermore, the feed for laying hens and the method for producing eggs of the present invention are suitable for producing eggs containing high concentrations of lutein.

Claims

1. A method for producing eggs containing a high concentration of lutein by preparing feed for laying hens, Laying hens are fed a xylanase-rich feed containing 100 mg or more of lutein and 1000 EPU or more of xylanase per kg of feed. To induce egg-laying in chickens that have been fed xylanase-rich feed for a specified period or longer from the start of supply. A method for producing eggs characterized by the features described herein.

2. The lutein content in the egg is 2.9 mg or more per 100 g of edible portion of the egg. The method for producing eggs according to claim 1, characterized by the features described above.

3. The laying hens are of the White Leghorn breed. The method for producing eggs according to claim 1, characterized by the features described above.

4. A feed used in the egg production method of claims 1 to 3, Contains 100 mg or more of lutein and 1000 EPU or more of xylanase per kg. A feed for laying hens characterized by the following features.

5. Eggs laid by laying hens fed a xylanase-rich feed containing 100 mg to 200 mg of lutein per kg and 1000 EPU or more of xylanase per kg, The lutein content is 2.8 mg or more per 100 g of edible portion of the egg. Eggs characterized by their high lutein content.

6. The lutein content is 2.9 mg or more per 100 g of edible portion of the egg. The high-lutein-containing egg according to feature 5.

7. The zeaxanthin content is 0.35 mg or more per 100 g of edible portion of the egg. The high-lutein-containing egg according to feature 5.

8. The zeaxanthin content is 0.38 mg or more per 100 g of edible portion of the egg. The high-lutein-containing egg according to feature 7.

9. The b value of egg yolk measured using a colorimeter after heating at 100°C for 30 minutes is more than twice the b value of egg yolk measured using a colorimeter before heating. The b value, measured using the colorimeter for the egg yolk before heating, is: This value is measured using a colorimeter at the liquid level after stirring the egg yolk separated from the egg in a container. The b value, measured using the colorimeter for the heated egg yolk, is: This value is measured using a colorimeter on the cross-section of a heated egg yolk after it has been removed from the container. The high-lutein-containing egg according to feature 5.

10. The laying hens are of the White Leghorn breed. The high-lutein-containing egg according to feature 5.

11. This is a processed version of the high-lutein-containing eggs described in claims 5 to 10. A processed food ingredient characterized by the following features.

12. The edible parts have been frozen. The processed food ingredient according to feature 11.

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