Sea urchin cultivating feed

Abstract

To solve a problem that a gonad of sea urchin that was bred by assorted feed lacks rich flavor or sweetness and has stronger bitterness comparing with sea urchin that grew by eating only natural seaweed, and provide a cultivation feed for sea urchin by which a high-quality gonad of sea urchin can be obtained.SOLUTION: A sea urchin cultivating feed does not contain animal protein, but contains protein derived from seaweed and wheat flour, in which 90 wt.% to 100 wt.% of protein contained in the sea urchin cultivating feed is derived from seaweed and wheat flour. Further, a sea urchin quality improver has cellulose and / or carboxymethyl cellulose as an active ingredient, and the sea urchin cultivating feed contains the sea urchin quality improver.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a feed for sea urchin farming that can increase the edible part yield of sea urchins in a short period and produce high-quality sea urchins.

Background Art

[0002] Compound feeds for sea urchin farming aimed at breeding sea urchins and enlarging the gonads, which are the edible parts, for shipment have been developed (see Patent Documents 1 to 8 and Non-Patent Document 1). In Non-Patent Document 1, when sea urchins are stocked for a short period, animal protein is necessary, and a method of promoting growth with slices of fish with less bitterness and finishing with kombu to increase umami is said to be effective (see page 80 of the same document). In the examples disclosed in Patent Documents 2 to 5, 7, and 8, compound feeds containing animal proteins such as fish meal, casein, and egg white as protein sources are disclosed.

[0003] In addition, Patent Document 1 discloses a feed for sea urchins containing sea urchin viscera, which is an animal raw material. In this document, the compositions of feeds containing and not containing the residue (i.e., sea urchin viscera) after collecting the gonads from sea urchins are disclosed (see paragraph number

[0033] of the specification of the same document), and it is disclosed that the feed not containing sea urchin viscera contains 68.6% by weight of crab ash, 6.9% by weight of corn gluten, and 1.0% by weight of paprika powder on a dry weight basis.

[0004] The feed disclosed in Patent Document 6 does not contain animal raw materials, but it is disclosed that it contains 50% by weight of kombu powder, 30% by weight of defatted soy flour, and 10% by weight of wheat gluten on a dry weight basis (see paragraph number [Example 1] of the specification of the same document). In addition, in Non-Patent Document 1, although the existence of compound feeds containing cut ends of edible kombu and wakame and not using fish meat or fish oil is briefly mentioned, it is not clear what other raw materials are contained besides the cut ends of wakame (see page 80 of the same document).

[0005] Furthermore, Patent Documents 3, 6, and 8 disclose sea urchin aquaculture feed formulated with carboxymethylcellulose for the purpose of functioning as a thickener or binder. Patent Document 3 discloses a compound feed using carboxymethylcellulose as one of the raw materials, but the content is 2.9% by weight. Patent Documents 6 and 8 describe carboxymethylcellulose as an example of a binder, but the content in the feed is not specified. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-187337 [Patent Document 2] Japanese Patent Application Publication No. 06-098691 [Patent Document 3] Japanese Patent Application Publication No. 02-053446 [Patent Document 4] Japanese Patent Application Publication No. 02-020253 [Patent Document 5] Japanese Patent Application Publication No. 02-039861 [Patent Document 6] Japanese Patent Application Publication No. 01-231854 [Patent Document 7] Japanese Patent Application Publication No. 55-021779 [Patent Document 8] Japanese Patent Application Publication No. 54-004766 [Non-patent literature]

[0007] [Non-Patent Document 1] Behind-the-scenes thinking, The story of coastal barrenness 14: Coastal barrenness and the massive outbreak of fleshless sea urchins (2), Environmental Facilities, No. 161, Japan, pp. 76-81, https: / / greenlynx2.sakura.ne.jp / wp-content / uploads / 2021 / 02 / 98e7e474ca8e28a2b688ab4e81052829.pdf [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] A challenge with sea urchins raised on compound feed was that their gonads lacked umami and sweetness, and were bitter, compared to those raised solely on natural seaweed. In particular, compound feeds containing animal proteins such as fishmeal, casein, and sea urchin innards resulted in lower quality sea urchins, including increased bitterness. Therefore, there was a need for a compound feed that could improve the yield of edible sea urchins and produce high-quality sea urchins in a short period of 2-3 months, as well as a cultivation method using such a compound feed. [Means for solving the problem]

[0009] The inventors discovered that by using a compound feed in which the protein content is mainly derived from seaweed and wheat flour, the yield of edible sea urchins increases in a short period of time, and high-quality sea urchins can be produced. Furthermore, they revealed that cellulose and / or carboxymethylcellulose have the effect of improving the quality of sea urchins, and by finding new applications for these substances, they arrived at the present invention.

[0010] In other words, the present invention is a feed for sea urchin farming that does not contain animal protein but contains protein derived from seaweed and wheat flour.

[0011] Furthermore, the present invention relates to a sea urchin aquaculture feed in which 90% to 100% by weight of the protein contained in the sea urchin aquaculture feed is derived from seaweed and wheat flour, and also to a sea urchin aquaculture feed in which 95% to 100% by weight, or 97% to 100% by weight, of the protein contained in the sea urchin aquaculture feed is derived from seaweed and wheat flour. The present invention also relates to a sea urchin aquaculture feed in which 25% to 85% by weight of the protein contained in the sea urchin aquaculture feed is derived from wheat flour. The present invention also relates to a sea urchin aquaculture feed in which the protein content is 3% to 15% by weight per dry weight.

[0012] Furthermore, another aspect of the present invention is a sea urchin quality improver containing cellulose and / or carboxymethyl cellulose as an active ingredient, and provides a sea urchin feed for aquaculture containing the sea urchin quality improver. The sea urchin feed for aquaculture may contain 4% to 8% by weight of the sea urchin quality improver. Also, the active ingredient of the sea urchin quality improver may be carboxymethyl cellulose.

[0013] Furthermore, another aspect of the present invention is a sea urchin feed for aquaculture that does not contain soybeans and does not contain corn.

[0014] Furthermore, another aspect of the present invention is a method for producing cultured sea urchins including a feeding step of feeding a sea urchin feed for aquaculture to sea urchins, wherein the edible portion yield of the sea urchins before feeding is 5% by weight or less, the edible portion yield of the produced cultured sea urchins is 10% by weight or more, and the culture period is 2 to 3 months.

Advantages of the Invention

[0015] By culturing sea urchins using the sea urchin feed for aquaculture of the present invention, high-quality sea urchins can be produced in a short period. Furthermore, by using a sea urchin feed for aquaculture containing a sea urchin quality improver, the quality of the cultured sea urchins is further improved. It was confirmed that the gonads of sea urchins grown with the feed for aquaculture of the present invention have a strong umami and sweetness and little bitterness.

Brief Description of the Drawings

[0016] [Figure 1] It is a diagram showing changes in the gonad somatic index of sea urchins fed with the feed for aquaculture of an example of the present invention. [Figure 2] It is a diagram showing the quality improvement effect by the feed for aquaculture of an example of the present invention. [Figure 3] It is a diagram showing changes in the gonad somatic index of sea urchins fed with the feed for aquaculture of an example of the present invention. [Figure 4] It is a diagram showing changes in the gonad somatic index of sea urchins fed with the feed for aquaculture of an example of the present invention. [Figure 5]It is a diagram showing the quality improvement effect of the aquaculture feed of the embodiment of the present invention. [Figure 6] It is a diagram showing the quality improvement effect of the aquaculture feed of the embodiment of the present invention. [Figure 7] It is a diagram showing the change in the gonad somatic index of sea urchins fed with the aquaculture feed of the embodiment of the present invention. [Figure 8] It is a diagram showing the quality improvement effect of the aquaculture feed of the embodiment of the present invention. [Figure 9] It is a diagram showing the change in the gonad somatic index of sea urchins fed with the aquaculture feed of the embodiment of the present invention.

Mode for Carrying Out the Invention

[0017] The present invention will be described in detail based on the mode for carrying out the invention, but the present invention is not limited to the embodiments.

[0018] The aquaculture feed of the present invention can be a pelletized compound feed formed by mixing a plurality of types of feed raw materials and molding them by a method such as extrusion molding. The aquaculture feed of the present invention can be an extruded pellet (also referred to as EP) or a dry pellet (also referred to as DP).

[0019] The aquaculture feed of the present invention is a sea urchin aquaculture feed that does not contain animal protein and uses seaweed and wheat flour as the main protein sources. Animal protein refers to the protein contained in raw materials (animal raw materials) derived from animals. Specific examples of raw materials derived from animals and containing protein include fish meal, meat and bone meal, chicken meal, feather meal, casein, egg yolk and egg white, and sea urchin viscera.

[0020] That is, the aquaculture feed of the present invention does not contain raw materials derived from animals and containing protein, such as fish meal, meat and bone meal, chicken meal, feather meal, casein, gelatin, collagen, egg yolk, egg white, and sea urchin viscera. The protein contained in the aquaculture feed of the present invention is composed of proteins derived from plants (including seaweed).

[0021] On the other hand, even if the raw materials are animal-derived, it is permissible for the aquaculture feed of the present invention to incorporate raw materials that do not substantially contain protein, such as fish oil, beef tallow, or pork tallow.

[0022] One embodiment of the present invention is an aquaculture feed in which the protein contained in the feed is mainly composed of proteins derived from seaweed and wheat flour. In this embodiment, multiple plant raw materials including seaweed and wheat flour may be blended, but raw materials containing protein other than wheat flour and seaweed are either not blended or are blended in a very small proportion. Examples of raw materials blended in a very small proportion include vegetables and microalgae that are rich in carotenoids effective in improving the color of the edible part of sea urchins, such as paprika powder, pumpkin powder, and carrot powder, and a very small proportion refers to, for example, a range of 0.01% to 5% by weight per dry weight.

[0023] Furthermore, in this embodiment, seaweed and wheat flour are the main protein sources, and the aquaculture feed is composed mainly of proteins derived from seaweed and wheat flour. It is preferable not to include any feed ingredients with a high protein content other than seaweed and wheat flour, even if they are plant-derived. In this embodiment, by feeding sea urchins a feed with seaweed and wheat flour as the main protein sources, high-quality sea urchins can be produced in a short period of time.

[0024] Examples of feed ingredients with a high protein content include corn gluten and defatted soybeans (soybean meal). In other words, in one embodiment of the aquaculture feed of the present invention, ingredients derived from corn or soybeans and with a high protein content, such as corn gluten and defatted soybeans, are not included. Specifically, ingredients with a high protein content refer to ingredients containing 30% or more protein by weight per dry weight, preferably ingredients containing 40% or more protein by weight per dry weight, and more preferably ingredients containing 50% or more protein by weight per dry weight.

[0025] In this embodiment, the ingredients other than seaweed and wheat flour mainly consist of ingredients that are substantially free of protein or have a low protein content, and ingredients containing protein are included in a very small proportion. Specifically, ingredients that are free of protein or have a low protein content include oils and fats, carbohydrates such as starch, cellulose, and carboxymethylcellulose, inorganic substances such as salt (sodium chloride), calcium chloride, magnesium chloride, and phosphorus, as well as minerals and vitamins.

[0026] In another embodiment, the aquaculture feed contains proteins mainly derived from wheat flour and seaweed powder. For example, the feed contains 20% to 60% by weight of wheat flour and 60% to 20% by weight of seaweed powder. Generally, wheat flour contains 8% to 15% by weight of protein per dry weight, and seaweed powder contains 5% to 20% by weight of protein per dry weight. Therefore, when 20% by weight of wheat flour and 60% by weight of seaweed powder are blended into the aquaculture feed, the feed contains 1.6% to 3.0% by weight of wheat flour-derived protein and 3.0% to 12.0% by weight of seaweed powder-derived protein per dry weight, resulting in a total of 4.6% to 15.0% by weight of protein derived from wheat flour and seaweed powder per dry weight in the aquaculture feed.

[0027] Furthermore, when 60% by weight of wheat flour and 20% by weight of seaweed powder are added to the aquaculture feed, the feed will contain 4.8% to 9.0% by weight of wheat flour-derived protein and 1.0% to 4.0% by weight of seaweed powder-derived protein per dry weight. Therefore, the aquaculture feed will contain 5.8% to 13.0% by weight of wheat flour and seaweed powder-derived protein per dry weight.

[0028] In a preferred embodiment of the present invention, proteins derived from seaweed and wheat flour constitute almost all or all of the proteins contained in the aquaculture feed. Specifically, of the proteins contained in the aquaculture feed, 80% to 100% by weight are proteins derived from seaweed and wheat flour, preferably 90% to 100% by weight are proteins derived from seaweed and wheat flour, more preferably 95% to 100% by weight are proteins derived from seaweed and wheat flour, and even more preferably 97% to 100% by weight are proteins derived from seaweed and wheat flour.

[0029] In one embodiment of the aquaculture feed of the present invention, the feed contains 3.0% to 14.5% by weight of protein per dry weight. In this embodiment, when the aquaculture feed contains 3.0% to 11.6% by weight of protein derived from seaweed and wheat flour per dry weight, 100% to 80% by weight of the protein contained in the aquaculture feed is derived from wheat flour and seaweed.

[0030] In this embodiment, the aquaculture feed contains virtually no protein-containing ingredients other than wheat flour and seaweed powder, or if any are included, only in very small proportions. As mentioned above, vegetable powders can be used as ingredients other than wheat flour and seaweed powder, but for example, paprika powder contains 15.5% by weight of protein per dry weight. When paprika powder is added as an ingredient containing protein other than wheat flour and seaweed powder at a concentration of 0.01% to 5% by weight, the amount of protein other than that derived from wheat flour and seaweed powder will be 0.002% to 0.78% by weight per dry weight.

[0031] The seaweed used in the aquaculture feed of the present invention contains at least protein, and specifically includes seaweed powder obtained by drying and crushing seaweed, or agar extracted from seaweed or its powder. In addition to seaweed harvested or cultivated for feed, it may also include parts of edible seaweed that are not suitable for consumption, or by-products and residues from processing seaweed for food.

[0032] Examples of seaweeds that are suitable for consumption by sea urchins include Saccharina japonica, Saccharina sculpera, and Macrocystis pyrifera, all belonging to the Laminariaceae family; U. pinnatifida, belonging to the Undaria genus of the Alariaceae family; Ascophyllum nodosum, belonging to the Fucusaceae family; S. fulvellum, S. fusiforme, and S. horneri, belonging to the Sargassum genus of the Sargassaceae family; and Lessonia nigrescens and Lessonia trabeculata, which belong to the Lessonia genus. However, it will be clear to those skilled in the art that sea urchins are not limited to these species as long as they are seaweeds that they can consume.

[0033] The wheat flour used in the aquaculture feed of the present invention is classified into strong flour, medium flour, weak flour, etc., based on its protein content, but any type of wheat flour can be suitably used. This is because the proportion of wheat flour used should be adjusted so that the protein content derived from wheat flour in the aquaculture feed falls within the aforementioned numerical range.

[0034] In the embodiment of the sea urchin aquaculture feed of the present invention, 5% to 90% by weight of the protein contained in the feed is derived from wheat flour, preferably 25% to 85% by weight, and more preferably 35% to 85% by weight. Since glutenin and gliadin, which are proteins derived from wheat flour, form gluten, aquaculture feed containing these has the characteristic of maintaining a shape that is easy for sea urchins to consume in water.

[0035] The moisture, protein, lipid, and ash content values ​​of the aquaculture feed of the present invention and the feed ingredients incorporated into the aquaculture feed can be obtained by known analytical methods such as the Feed Analysis Standards (Director-General of the Consumer and Food Safety Bureau, Ministry of Agriculture, Forestry and Fisheries). The protein content can be obtained by analyzing it using official methods such as the Kjeldahl method or the Dumas method. As an example of the protein and other components of the aquaculture feed of the present invention, the moisture content is 3% to 25% by weight per total weight, the protein is 3% to 15% by weight per dry weight, the lipid content is 1% to 5% by weight per dry weight, and the ash content is 10% to 30% by weight per dry weight.

[0036] Furthermore, the present invention provides a quality-improving agent for sea urchins comprising cellulose and / or carboxymethylcellulose as an active ingredient. The sea urchin quality-improving agent of the present invention, when incorporated into aquaculture feed that does not contain animal protein and contains 3% to 15% by weight of protein per dry weight, has been confirmed to have a remarkable quality-improving effect on farmed sea urchins.

[0037] Cellulose is a polysaccharide that is the main component of plant fiber. The inventors discovered that high-quality sea urchin gonads can be obtained by cultivating sea urchins by feeding them feed containing cellulose or its derivatives.

[0038] Carboxymethylcellulose, also known as CMC, is a type of cellulose derivative and a polysaccharide having a structure in which the hydroxyl groups of cellulose are replaced with carboxyl groups. The carboxymethylcellulose contained in the present invention may be a salt that is acceptable for feed production. Specifically, examples include carboxymethylcellulose sodium salt and carboxymethylcellulose calcium salt.

[0039] The degree of etherification of carboxymethylcellulose is not limited, but specifically, it can be between 0.1 and 3.0, although a degree of etherification of 0.5 to 1.6, which is typical for carboxymethylcellulose, is acceptable.

[0040] Carboxymethylcellulose has traditionally been used as a binder in compound feed, but its effect on improving the quality of sea urchins was not known. The inventors discovered that by feeding sea urchins a diet containing carboxymethylcellulose, high-quality sea urchin gonads can be obtained.

[0041] The aquaculture feed of the present invention contains the sea urchin quality improver of the present invention. The content of the sea urchin quality improver in the feed is not limited as long as it provides an effect of improving the quality of sea urchins, but it is preferably 1% to 20% by weight per dry weight, and more preferably 4% to 8% by weight per dry weight.

[0042] Furthermore, the present invention relates to a method for producing farmed sea urchins, which includes a feeding step of feeding the sea urchin farming feed of the present invention to the sea urchins. In this method for producing farmed sea urchins, the feed is given to sea urchins with a low edible portion yield. Preferably, the edible portion yield of the sea urchins before feeding is 10% by weight or less on average, and may be 9, 8, 7, 6, 5, 4, or 3% by weight or less. The farming period is 1 to 6 months, preferably 2 to 3 months. By feeding 1 to 3 times a week, preferably once a week, and feeding 5 to 20 times, preferably 6 to 10 times, during the farming period, it is possible to produce farmed sea urchins with an edible portion yield of 10% by weight or more on average, preferably 15% by weight or more. [Examples]

[0043] The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0044] Preparation of compound feed for sea urchin aquaculture and sea urchin aquaculture trials using said compound feed (1) Example 1 and Comparative Example 1 of compound feed for sea urchin farming were prepared. The seaweed powder used was derived from Ascophyllum nodosum, which belongs to the Fucusceae family. Table 1 shows the protein content of the raw materials used in the compound feed of Example 1 and Comparative Example 1, and the composition of the compound feed of Example 1 and Comparative Example 1. Example 1 was formulated with wheat flour, seaweed powder, and paprika powder as protein-containing feed ingredients. Comparative Example 1 was formulated with wheat flour, seaweed powder, and paprika powder, in addition to corn gluten as protein-containing feed ingredients. The feed ingredients were mixed with an appropriate amount of water, molded into discs with a diameter of approximately 2 cm and a thickness of approximately 1 cm, and then dried overnight in a dryer at 70°C to obtain the compound feed.

[0045] [Table 1]

[0046] Table 2 shows the analysis results of the general components of Example 1 and Comparative Example 1. Moisture was measured by atmospheric pressure heating and drying, protein by the Kjeldahl method, lipid by the Soxhlet method, and ash by dry ashing. Fiber and soluble non-nitrogenous substances are the weight remaining after subtracting protein, lipid, and ash from the dry weight. Protein, lipid, ash, fiber, and soluble nitrogenous inorganic substances were calculated per dry weight excluding moisture. The compound feed of Example 1 contained 4.5% by weight of protein per dry weight, while Comparative Example 1 contained 19.0% by weight of protein per dry weight.

[0047] [Table 2]

[0048] Table 1 shows the protein content of the raw materials used in the feeds of Example 1 and Comparative Example 1. When calculating the percentage of the total protein content (predicted value calculated from the protein content of the raw materials) in each feed, the percentage was 95.3% by weight for Example 1 and 27.3% by weight for Comparative Example 1, as shown in Table 3. In addition, for Example 1, the percentage of protein from wheat flour in the total protein of the feed was 47.5% by weight, and the percentage of protein from seaweed in the total protein of the feed was 47.9% by weight.

[0049] [Table 3]

[0050] Next, sea urchin aquaculture trials were conducted using the feeds of Example 1 and Comparative Example 1. Ten sea urchins (average total weight at the start: 53.3 ± 3.2 g) collected in Kumaishi-Kumoishi-cho, Yakumo-cho, Futami-gun, Hokkaido were placed in 50x35x30cm cages in a 2500 L tank and reared by continuously circulating sterilized seawater. Once a week, they were fed aquaculture feed at a rate of 15% by weight per total weight of the sea urchins, and leftover feed and feces were removed once a week. The seawater temperature during the rearing period was 12.7 ± 1.4℃. Feeding was carried out 9 times from the start of rearing, and rearing was terminated after 10 weeks.

[0051] The gonad somatic index (GSI) was calculated at the start and end of rearing. After measuring the total weight of the sea urchins, the gonads were removed, their weight was measured, and the GSI (weight %) was calculated for each individual. Figure 1 shows the GSI at the start and at the end of rearing with each feed. Dunnett's multiple comparison test was used for statistical testing after one-way ANOVA. Asterisks (***) in the figure indicate a p-value of less than 0.001. In all cases, the gonads of the purple sea urchins fed with each feed showed significant enlargement compared to the start.

[0052] The sensory evaluation was conducted on nine men and women aged 20 to 50 who regularly eat sea urchins. Participants blindly tasted the gonads of sea urchins at the end of the rearing period and evaluated the intensity of umami, sweetness, and bitterness on a 5-point scale. The results for the umami / bitterness ratio (umami / bitterness ratio) and sweetness / bitterness ratio (sweetness / bitterness ratio) for each group are shown in Figure 2. A t-test was used for statistical testing, and asterisks (***) in the figure indicate a p-value of less than 0.001. The gonads of sea urchins fed Example 1 were shown to be of significantly higher quality than those of sea urchins fed Comparative Example 1.

[0053] Preparation of compound feed for sea urchin aquaculture and sea urchin aquaculture trials using said compound feed (2) Examples and comparative examples of compound feed for sea urchin farming were prepared. The seaweed powder used was derived from Ascophyllum nodosum, a member of the Fucusceae family. The composition of the compound feeds for the examples and comparative examples is shown in Table 4. The examples included wheat flour, seaweed powder, and paprika powder as protein-containing feed ingredients. The comparative examples included wheat flour, seaweed powder, and paprika powder, in addition to corn gluten, as protein-containing feed ingredients. The composition is shown in Table 4. The feed ingredients were mixed with an appropriate amount of water, molded into discs approximately 2 cm in diameter and 1 cm thick, and then dried overnight in a dryer at 70°C to obtain the compound feed.

[0054] [Table 4]

[0055] Table 5 shows the analysis results of the general components of the examples and comparative examples. Moisture was measured by atmospheric pressure heating and drying, protein by the Kjeldahl method, lipid by the Soxhlet method, and ash by dry ashing. Protein, lipid, ash, and fiber and soluble nitrogenous inorganic matter were calculated on a dry weight basis excluding moisture. The compound feeds of Examples 2 to 4 contained 3.5% to 8.2% by weight of protein per dry weight, while Comparative Example 2 contained 12.7% by weight of protein per dry weight.

[0056] [Table 5]

[0057] The amount of protein contained in the raw materials used in the feeds of Examples 2-4 and Comparative Example 2 was analyzed. Wheat flour contained 11.5% by weight (per dry weight), seaweed powder contained 12.0% by weight (per dry weight), and paprika powder contained 15.5% by weight (per dry weight). Corn gluten, which was incorporated into Comparative Example 2, contained 60.5% by weight (per dry weight). CMC, salt, and oils did not contain protein. Therefore, from the compositions listed in Table 4, the proportion of protein derived from seaweed powder and wheat flour in the protein content of each feed (predicted value calculated from the protein content of the raw materials) was calculated, as shown in Table 6. Examples 2-4 contained 96.1-98.2% by weight, and Comparative Example 2 contained 74.2% by weight. In addition, the proportion of protein derived from wheat flour in Examples 3 and 4 was 36.5% by weight and 27.2% by weight, respectively.

[0058] [Table 6]

[0059] A feeding experiment was conducted using purple sea urchins (average total weight 79.7 g) collected in Ainan Town, Ehime Prefecture. In addition to the test groups fed with Examples 2-4 and the comparative example, a control group fed with kelp was also established. Fifteen individuals were placed in 60L rectangular tanks, with two tanks set up for each group. The sea urchins were fed 5-6 times a week until they were saturated, and the experiment was completed after 11 weeks.

[0060] The Gonad Somatic Index (GSI) was calculated at the start and end of rearing. After measuring the total weight of the sea urchins, the gonads were removed, their weight was measured, and the GSI (weight %) was calculated for each individual. Figure 3 shows the GSI at the start and at the end of rearing with each feed. For statistical testing, the Bonferroni method after one-way ANOVA was used, and groups shown with different letters indicate a p-value of less than 0.01. Examples 2-4 showed a significantly higher GSI than kelp. Despite having a lower protein content than the comparative example feed, the feeds of Examples 2-4 showed a higher GSI than Comparative Example 2. In particular, Examples 3 and 4, in which 97.5-98.2% by weight of the protein contained in the feed came from seaweed and wheat flour, and 27.2-36.5% by weight came from wheat flour, showed a higher trend of increasing GSI than Example 2.

[0061] The sensory evaluation was conducted with five men and women aged 20 to 50 who regularly eat sea urchins. When the gonads of the sea urchins were tasted blind at the end of the rearing period, it was revealed that Examples 2-4 produced sea urchins with less bitterness and of higher quality.

[0062] Preparation of compound feed for sea urchin aquaculture and sea urchin aquaculture trials using said compound feed (3) Compound feeds for sea urchin aquaculture were prepared containing carboxymethylcellulose (hereinafter referred to as "CMC") at 2%, 4%, and 8% by weight per dry weight as a quality improver. The CMC used was a product manufactured by Nippon Paper Industries Ltd. (etherification degree 0.5-1.6 mol / C6). The seaweed powder used in the feed was derived from Ascophyllum nodosum, a member of the Fucusceae family. The composition of the prepared compound feeds is shown in Table 7. For each compound feed, the total proportion of ingredients other than CMC was changed according to the CMC content, but the ratios of the ingredients other than CMC were not changed. The feed ingredients were mixed while adding an appropriate amount of water, molded into discs with a diameter of approximately 2 cm and a thickness of approximately 1 cm, and then dried overnight in a dryer at 70°C to obtain the compound feed.

[0063] [Table 7]

[0064] Table 8 shows the analysis results for moisture, protein, lipids, ash, fiber, and soluble non-nitrogenous substances of the prepared compound feed. Moisture was measured by atmospheric pressure heating and drying, protein by the Kjeldahl method, lipid by the Soxhlet method, and ash by dry ashing. Protein, lipids, ash, fiber, and soluble non-nitrogenous substances were calculated on a dry weight basis, excluding moisture.

[0065] [Table 8]

[0066] Furthermore, the protein content of the raw materials used in the feed was analyzed. Wheat flour contained 11.5% by weight (per dry weight), seaweed powder contained 10.4% by weight (per dry weight), and paprika powder contained 15.5% by weight (per dry weight). Other raw materials such as CMC, salt, and oils and fats did not contain protein. Therefore, from the composition listed in Table 8, the proportion of protein derived from seaweed powder and wheat flour in the total protein content of each feed (predicted value calculated from the protein content of the raw materials) was calculated to be 97.40% by weight, as shown in Table 9. The proportion of protein derived from wheat flour was 68.54% by weight.

[0067] [Table 9]

[0068] A sea urchin farming trial was conducted using three types of feed prepared. Ten purple sea urchins (average total weight 65.20 ± 2.02 g) collected in Kumaishi-Kumoishi-cho, Yakumo-cho, Futami-gun, Hokkaido, were placed in 50 × 35 × 30 cm cages in a 2500 L tank and reared with a continuous flow of sterilized seawater. Once a week, they were fed aquaculture feed equivalent to 15% by weight of their total weight, and leftover feed and feces were removed once a week. The seawater temperature during the rearing period was 12.9 ± 0.1℃. Feeding was carried out 8 times from the start of rearing, and rearing was terminated after 10 weeks.

[0069] The Gonad Somatic Index (GSI) was calculated at the start and end of rearing. After measuring the total weight of the sea urchins, the gonads were removed, their weight was measured, and the GSI (weight %) was calculated for each individual. Figure 4 shows the GSI at the start and at the end of rearing with each feed. The Turkey-Kramer method was used for statistical testing, and groups shown with different letters indicate a p-value of less than 0.05. In all feeds, the gonads of the sea urchins significantly enlarged compared to the start.

[0070] The sensory evaluation was conducted with 11 men and women aged 20 to 60 who regularly eat sea urchins. Participants blind-tasted sea urchin gonads at the end of the rearing period and evaluated the intensity of umami, sweetness, and bitterness on a 5-point scale. The umami / bitterness ratio (umami / bitterness ratio) for each group is shown in Figure 5, and the sweetness / bitterness ratio (sweetness / bitterness ratio) is shown in Figure 6. Multiple comparisons were performed using the Kruskal-Wallis method for statistical testing, and the Steel method was used for post-hoc tests.

[0071] The gonads of sea urchins farmed on feed containing 4% by weight of CMC and feed containing 8% by weight of CMC showed significantly higher umami / bitterness ratios and sweet / bitterness ratios compared to the gonads of sea urchins farmed on feed containing 2% by weight of CMC. Therefore, it was shown that by including 4% or more by weight of CMC in sea urchin farming feed containing approximately 8% crude protein per dry weight, high-quality sea urchins with strong umami and sweetness and weak bitterness were produced. These sea urchins were confirmed to be of comparable quality to wild sea urchins.

[0072] Preparation of compound feed for sea urchin aquaculture and sea urchin aquaculture trials using said compound feed (4) A compound feed for sea urchin aquaculture was prepared containing 5% by weight of carboxymethylcellulose (hereinafter referred to as "CMC") by dry weight as a quality improver. Each raw material was extruded using a twin-screw extruder to produce EP feed. The composition of the compound feed is shown in Table 10. Two types of compound feed were prepared using the seaweed powder to be incorporated into the feed: one using powder from Ascophyllum nodosum, which belongs to the Fucusaceae family, and the other using powder from the rhizoids (Ganiashi) of Saccharina japonica.

[0073] [Table 10]

[0074] Furthermore, the protein content of the raw materials used in the feed was analyzed. Wheat flour contained 15.5% by weight (per dry weight), seaweed powder contained 15.0% by weight (per dry weight) for A. nodsum powder, 12.2% by weight (per dry weight) for Ganoderma lucidum powder, and 15.5% by weight (per dry weight) for paprika powder. Other raw materials such as CMC, salt, and oils and fats did not contain protein. Therefore, from the composition listed in Table 10, the proportion of protein derived from seaweed powder and wheat flour in the total protein content of each feed (predicted value calculated from the protein content of the raw materials) was calculated to be 97.40% by weight, as shown in Table 11. The proportion of protein derived from wheat flour was 68.54% by weight.

[0075] [Table 11]

[0076] A sea urchin farming trial was conducted using the feed prepared in the example. 100 individuals of *Scomber japonicus* (average total weight 75.9 ± 18.7 g), collected in Hirono-cho, Kunohe-gun, Iwate Prefecture, were placed in cages fixed to the seabed. The feed was administered once a week, at a rate of approximately 15% of the total weight of the sea urchins, with the amount adjusted each time based on the amount of leftover feed. Feeding was carried out eight times from the start of rearing, and rearing was terminated after 10 weeks.

[0077] The Gonad Somatic Index (GSI) was calculated at the start and end of rearing. After measuring the total weight of the sea urchins, the gonads were removed, their weight was measured, and the GSI (weight %) was calculated for each individual. Figure 7 shows the GSI at the start and at the end of rearing with each feed. A t-test was used for statistical testing, and asterisks (**) in the figure indicate a p-value of less than 0.01. The GSI, which was 3.5% by weight before rearing, increased significantly to 19.4% by weight at the end of rearing.

[0078] The sensory evaluation was conducted with eight men and women aged 20 to 60 who regularly eat sea urchins. Participants blind-tasted sea urchin gonads at the end of the rearing period and evaluated the intensity of umami, sweetness, and bitterness on a 5-point scale. Statistical testing was performed using the Kruskal-Wallis method for multiple comparisons, and the Steel-Dwass method was used for post-hoc tests. The evaluation results are shown in Figure 8. Groups indicated by different letters have a p-value of less than 0.01. This example demonstrates that the EP feed produced sea urchins with strong umami and sweetness and weak bitterness, i.e., high quality sea urchins. These sea urchins were confirmed to be of comparable quality to wild sea urchins.

[0079] Preparation of compound feed for sea urchin aquaculture and sea urchin aquaculture trials using said compound feed (5) Instead of CMC, feeds containing 4% and 8% by weight of cellulose per dry weight were prepared. The seaweed powder used was the rhizoid (Ganiashi) of Saccharina japonica, a species belonging to the Laminariaceae family. The composition of each feed is shown in Table 12. For the cellulose, powdered cellulose (average particle size approximately 45 μm) manufactured by Nippon Paper Industries Co., Ltd. was used. The feed ingredients were mixed while adding an appropriate amount of water, molded into discs with a diameter of approximately 2 cm and a thickness of approximately 1 cm, and then dried overnight in a dryer at 70°C to obtain the compound feed.

[0080] [Table 12]

[0081] Furthermore, the protein content of the raw materials used in the feed was analyzed. Wheat flour contained 11.5% by weight (per dry weight), seaweed powder contained 12.2% by weight (per dry weight), and paprika powder contained 15.5% by weight (per dry weight). Other raw materials such as CMC, salt, and oils and fats did not contain protein. Therefore, from the composition listed in Table 9, the proportion of protein derived from seaweed powder and wheat flour in the total protein content of each feed (predicted value calculated from the protein content of the raw materials) was calculated to be 97.36 to 97.47% by weight, as shown in Table 13, and the proportion of protein derived from wheat flour was 65.17 to 65.27% by weight.

[0082] [Table 13]

[0083] A feeding trial was conducted using purple sea urchins (average total weight 95.4 g) collected in Oshima, Yawatahama City, Ehime Prefecture. The results showed that the feed also had an effect on enlarging the sea urchins' gonads. Furthermore, the sea urchins' gonads had a strong umami and sweetness and a weak bitterness, indicating a significant improvement in quality.

[0084] Preparation of compound feed for sea urchin aquaculture and sea urchin aquaculture trials using said compound feed (6) A compound feed for sea urchin farming was prepared containing 5% by weight of carboxymethylcellulose (hereinafter referred to as "CMC") by dry weight as a quality improver. The seaweed powder used in the feed consisted of powder derived from Ascophyllum nodosum, which belongs to the Fucusaceae family, and powder derived from seaweed belonging to the Lessonia genus. The composition of the prepared compound feed is shown in Table 14. The feed ingredients were mixed while adding an appropriate amount of water, molded into discs with a diameter of approximately 2 cm and a thickness of approximately 1 cm, and then dried overnight in a dryer at 70°C to obtain the compound feed.

[0085] [Table 14]

[0086] Table 15 shows the results of the analysis of the general components of the compound feed used in the example. Moisture was measured by atmospheric pressure heating and drying, protein by the Kjeldahl method, lipid by the Soxhlet method, and ash by dry ashing. Protein, lipid, ash, fiber, and soluble nitrogenous inorganic matter were calculated on a dry weight basis, excluding moisture.

[0087] [Table 15]

[0088] Furthermore, the protein content of the raw materials used in the feed was analyzed. Wheat flour contained 14.5% by weight (per dry weight), seaweed powder derived from A. nodosum contained 4.9% by weight (per dry weight), seaweed powder derived from Lessonia contained 16.9% by weight (per dry weight), and paprika powder contained 15.5% by weight (per dry weight). Other raw materials such as CMC, salt, and oils and fats did not contain protein. Therefore, from the composition listed in Table 14, the proportion of protein derived from seaweed powder and wheat flour in the total protein content of each feed (predicted value calculated from the protein content of the raw materials) was calculated to be 97.0-97.8% by weight, as shown in Table 16. The proportion of protein derived from wheat flour was 60.8-82.6% by weight.

[0089] [Table 16]

[0090] We conducted sea urchin farming trials using three types of feed we prepared. Nine Northern Purple Sea Urchins (average total weight 74.6 ± 13.7 g) collected in Nagaiso, Setana-cho, Kudo-gun, Hokkaido were placed in 60L tanks and reared with a continuous flow of sterilized seawater. They were fed 2-3 times a week with farming feed at a rate of 15% by weight of the total weight of the sea urchins per week, and leftover feed and feces were removed 6 times a week. Feeding was carried out 8 times from the start of rearing, and after the last feeding, feeding was stopped for 4 weeks, and rearing was terminated after 12 weeks.

[0091] The gonad somatic index (GSI) was calculated at the start and end of rearing. After measuring the total weight of the sea urchins, the gonads were removed, their weight was measured, and the GSI (weight %) was calculated for each individual. Figure 9 shows the GSI at the start and at the end of rearing with each feed. Dunnett's multiple comparison test was used for statistical testing after one-way ANOVA. Asterisks (***) in the figure indicate a p-value of less than 0.001. In all species of sea urchin fed with any of the feeds, the gonads of the sea urchins significantly enlarged compared to the start.

[0092] The sensory evaluation was conducted with a total of six men and women in their 20s to 50s who regularly eat sea urchins. When the gonads of the sea urchins were tasted blind at the end of the cultivation period, it was revealed that the sea urchins raised in all of the examples had little bitterness and were of high quality, comparable to wild sea urchins.

Claims

1. Feed for sea urchin farming, containing proteins derived from seaweed and wheat flour, wherein 90% to 100% by weight of the proteins contained in the feed for sea urchin farming are derived from seaweed and wheat flour.

2. Feed for sea urchin farming, containing proteins derived from seaweed and wheat flour, wherein 95% to 100% by weight of the proteins contained in the feed for sea urchin farming are derived from seaweed and wheat flour.

3. Feed for sea urchin farming, containing proteins derived from seaweed and wheat flour, wherein 97% to 100% by weight of the proteins contained in the feed for sea urchin farming are derived from seaweed and wheat flour.

4. The feed for sea urchin culture according to any one of claims 1 to 3, wherein 25% by weight to 85% by weight of the protein contained in the feed for sea urchin culture is derived from wheat flour.

5. The feed for sea urchin aquaculture according to any one of claims 1 to 3, wherein the protein content of the feed for sea urchin aquaculture is 3% by weight to 15% by weight per dry weight.

6. The feed for sea urchin farming according to any one of claims 1 to 3, further containing cellulose and / or carboxymethyl cellulose.

7. The feed for sea urchin farming according to claim 6, containing 4% by weight to 8% by weight of the cellulose and / or carboxymethyl cellulose.

8. Feed for sea urchin farming that does not contain animal protein but contains proteins derived from seaweed and wheat flour.

9. The feed for sea urchin farming according to any one of claims 1 to 3 and 8, which does not contain corn and / or soybeans.

10. A method for producing cultured sea urchins, comprising a feeding step of feeding sea urchins the sea urchin culture feed according to any one of claims 1 to 3 and 8.

11. A method for producing farmed sea urchins as described in claim 10, wherein the edible portion yield of the sea urchins before feeding is 5% by weight or less, the edible portion yield of the farmed sea urchins produced is 10% by weight or more, and the farming period is 2 to 3 months.

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