Method for producing processed algae material

Abstract

The purpose of the present invention is to provide a novel processing technique for decolorizing algae material. By treating an algae material with hydrogen peroxide, the algae material can be decolorized.

Description

Method for manufacturing processed algae material

[0001] The present invention relates to a processing technique for decolorizing algal material.

[0002] Against the backdrop of a protein crisis, where the balance between protein supply and demand is being disrupted, attention is being paid to sustainable proteins as alternatives to animal protein. Soybeans are widely used as a source of such alternative proteins, and other cereals such as chickpeas and oats are also being applied.

[0003] The health benefits of algae have been widely verified, and they are primarily used in supplements. However, in recent years, due to their high protein content, attempts have been made to use algae as a new protein source for a wider range of food and beverage applications.

[0004] However, unlike light-colored materials such as soybeans, algae have a dark color due to the presence of pigment proteins such as chlorophyll. This coloration hinders the application of algal proteins in a wide range of food and beverage applications. From this perspective, several methods for producing algal materials with reduced chlorophyll content have been proposed.

[0005] For example, Non-Patent Document 1 discloses a method for removing chlorophyll by subjecting algae to a combined treatment of saponification with sodium hydroxide and solubilization with ethanol, and Non-Patent Document 2 discloses a method for producing a Chlorella vulgaris mutant with a low chlorophyll content.

[0006] Li, T., Xu, J., Wu, H., Wang, G., Dai, S., Fan, J., He, H., & Xiang, W. (2016). A saponification method for chlorophyll removal from microalgae biomass as oil feedstock. Marine drugs, 14(9), 162. Schuler, L., Greque de Morais, E., Trovao, M., Machado, A., Carvalho, B., Carneiro, M., Maia I., Soares M., Duarte P., Barros A., Pereira H., Silva J., & Varela, J. (2020). Isolation and characterization of novel Chlorella vulgaris mutants with low chlorophyll and improved protein content for food applications. Frontiers in Bioengineering and Biotechnology, 8, 469.

[0007] Although the method described in Non-Patent Document 1 is low cost, it requires the imposition of harsh chemical conditions, places a heavy burden on the environment, and also degrades a large amount of protein. The method described in Non-Patent Document 2 cannot be applied to anything other than the mutant. Therefore, considering the application of algae as a protein material in a wider range of food and beverage applications, it would be desirable to treat commonly available algae in accordance with the method described in Non-Patent Document 1, thereby lightening the color. However, as described above, algae are highly difficult to decolorize, to the extent that pigments cannot be removed without the application of harsh chemical conditions. Furthermore, considering that algae can be used not only as a protein source but also as a source of oils, fats, and sugars, the same problem of difficulty in decolorization exists when considering the application of algae as a food ingredient that serves as a source of various nutrients in food and beverage applications.

[0008] Under these circumstances, the present invention aims to provide a new processing technology for decolorizing algal material.

[0009] The present inventors have discovered that treating algal material with hydrogen peroxide and water can decolorize and lighten the algal pigments contained in the algal material. It was unexpected that algal pigments can be lightened under such mild conditions without using harsh chemical conditions. Based on this discovery, the present invention was completed through further investigation.

[0010] That is, the present invention provides the following aspects of the invention: Item 1. A method for producing a processed algal material, comprising a decolorization step of treating algal material with hydrogen peroxide. Item 2. The production method according to Item 1, wherein the pigment to be decolorized is selected from the group consisting of chlorophyll and phycobilin. Item 3. The production method according to Item 1 or 2, wherein the algae is selected from the group consisting of cyanobacteria and green algae. Item 4. The production method according to any one of Items 1 to 3, wherein the algae is selected from the group consisting of chlorella and spirulina. Item 5. The production method according to any one of Items 1 to 4, wherein the algal material comprises crushed cell walls of the algae. Item 6. The production method according to any one of Items 1 to 5, wherein in the decolorization step, an algal material mixed composition containing the algal material, the hydrogen peroxide, and water is subjected to a decolorization reaction, and the content of the hydrogen peroxide in the algal material mixed composition is 0.5% by weight or more. Item 7. Item 6. The production method according to any one of Items 1 to 6, further comprising a hydrogen peroxide removal step in which a hydrogen peroxide-decomposing enzyme is reacted. Item 8. The production method according to Item 7, wherein the hydrogen peroxide-decomposing enzyme is catalase. Item 9. The production method according to Item 7 or 8, wherein the catalase is derived from the genus Aspergillus. Item 10. A method for decolorizing algal pigments in algal material, comprising a decolorization step of treating the algal material with hydrogen peroxide. Item 11. A method for improving the dispersibility of algal material, comprising a step of treating the algal material with hydrogen peroxide, wherein the algal material comprises crushed cell walls of the algae. Item 12. A food or drink comprising a processed algal material obtained by the production method according to any one of Items 1 to 9.

[0011] According to the present invention, the algal material can be decolorized, and therefore a decolorized algal material (processed algal material) can be obtained.

[0012] The appearance of the processed algae material (Example 1) obtained by treating cell-disintegrated chlorella powder with hydrogen peroxide water is shown in comparison with the appearance of an untreated product (Ctrl) treated with hydrogen peroxide water.

[0013] 1. Manufacturing Method of Processed Algal Material The manufacturing method of processed algal material of the present invention is characterized by including a decolorization step in which algal material is treated with hydrogen peroxide. According to the manufacturing method of processed algal material of the present invention, a decolorization effect is obtained in the resulting processed algal material, and in a preferred embodiment, at least one of the following effects is obtained: improved dispersibility, improved solubility (protein solubility, etc.), and suppression of raw material odor. The manufacturing method of processed algal material of the present invention is described in detail below.

[0014] In the bleaching process, the algal material is treated with hydrogen peroxide. Specifically, an algal material mixture composition containing the algal material, hydrogen peroxide, and water is prepared and subjected to a bleaching reaction. This results in a hydrogen peroxide-treated sample.

[0015] 1-1-1. Algal Material Mixed Composition The algal material mixed composition may be prepared by any method as long as it contains algal material, hydrogen peroxide, and water. Examples of the method include adding aqueous hydrogen peroxide to dry algal material, adding dry algal material to aqueous hydrogen peroxide, and mixing aqueous algal material with hydrogen peroxide.

[0016] 1-1-1-1 Algal Material The algal material is not particularly limited as long as it contains algal pigments and algae-derived components and is in a form that can be ingested by a living organism.

[0017] Algal pigments include pigments inherently present in the algae from which the algal material is derived. Examples of such algal pigments include chlorophyll and phycobilin. Specific examples of chlorophyll include chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll d, and chlorophyll f. Specific examples of phycobilin include phycocyanin, allophycocyanin, phycoerythrin, and phycoerythrocyanin.

[0018] The algal pigment may also be a derivative of a pigment naturally present in the algae from which the algal material is derived. Examples of such derivatization include converting the ester group in the pigment molecule to at least one of a carboxyl group and a salt-type carboxyl group (a carboxyl group having an alkali metal ion such as a sodium ion or a potassium ion as a counter cation), replacing the coordination metal of the pigment molecule with another metal (such as copper), and combinations thereof. Specific examples of derivatized algal pigments include pigments derived from chlorophyll, more specifically chlorophyllide, copper chlorophyll, copper chlorophyllin salt, etc.

[0019] The algal material may contain the above algal pigments alone or in combination of two or more. In the present invention, the algal material preferably contains at least one of copper chlorophyllin and phycocyanin. From the viewpoint of further enhancing the decolorizing effect, the algal material more preferably contains phycocyanin.

[0020] Examples of algae-derived components include proteins, oils and fats, and sugars (including carbohydrates that are digested in the body and dietary fiber that is not digested in the body). These components can be used as nutrient sources in food and beverage applications. The algae material may contain one of these components alone or a combination of two or more of them. In a preferred embodiment, the algae-derived component contains at least protein.

[0021] The origin of the algae material is not particularly limited, as long as it is algae. Specific examples include blue-green algae (cyanobacteria) [e.g., Arthrospira genus (Arthrospira maxima, Arthrospira platensis (Spirulina)), Synechococcus sp., Aphanizomenon sp., etc.]; green algae [e.g., Chlorella genus (Chlorella vulgaris), Scenedesmus genus (Scenedesmus obliquus), Spirogyra sp.]; etc.]; Diatoms [e.g., genus Phaeodactylum (Phaeodactylum tricornutum, etc.), genus Thalassiosira (Thalassiosira pseudonana, etc.]; Dinoflagellates [e.g., Alexandrium genus (Alexandrium fundyense, etc.), Dunaliella genus (Dunaliella Salina, Dunaliella bardawill, etc.), Haematococcus spp. Chrysophytes [e.g., Isochrysis genus (Isochrysis galbana, etc.), Pavlova genus lutheri et al.); prasinoalgae [e.g., Micromonas pusilla, etc., Ostreococcus spp. Euglena algae [eg, Euglena gracilis, etc.]; red algae [eg, Bangiophyceae, Rhodophyta, Porphyridium genus, etc.].

[0022] The algal material may be derived from one kind of algae selected from the above, or may be derived from a combination of two or more kinds of algae.

[0023] As the origin of the algal material, from the viewpoint of further enhancing the decolorizing effect, among the above, preferably blue-green algae and green algae are mentioned, more preferably the genus Arthrospira and Chlorella, even more preferably the genus Arthrospira, and even more preferably Arthrospira platensis. Furthermore, as the origin of the algal material, from the viewpoint of further enhancing the dispersibility improving effect, among the above, preferably blue-green algae and green algae are mentioned, more preferably the genus Arthrospira and Chlorella, even more preferably the genus Chlorella, and even more preferably Chlorella pyrenoidosa.

[0024] The content of algal pigment per 100 parts by weight of dry weight (weight after removing water) of algal material is, for example, 0.3 to 10% by weight, preferably 0.5 to 9% by weight, and more preferably 1 to 8% by weight.

[0025] When the algal material contains protein, the protein content per 100 parts by weight of the dry weight of the algal material may be, for example, 10 to 90 wt %, 20 to 85 wt %, 30 to 80 wt %, or 40 to 80 wt %, preferably 45 to 75 wt %, and more preferably 50 to 70 wt %.

[0026] The specific form of the algal material is not particularly limited, but examples of unorganized algal material include (i) dry algal powder, preferably dry algal powder in which the cell walls are crushed, and (ii) concentrates (e.g., powder, paste, liquid, etc.) obtained by processing to increase the content of at least one of the above-mentioned algae-derived components by removing some or all of the unnecessary components from the algae. Examples of organized algal material include (iii) organized protein concentrates (e.g., granular, fibrous, etc.).

[0027] Among these algae materials, preferred is the dry powder of algae (i) above, in which the cell walls have been crushed. This preferred algae material can be obtained, for example, by crushing algae using any crushing method (e.g., ultrasonic waves, microwaves, mechanical treatment (using a high-pressure homogenizer, mill, etc.), chemical treatment (using a solvent, acid, etc.), high temperature (using an autoclave), freeze-thaw cycles, extraction using a supercritical fluid and an ionic liquid, etc.), and then preparing the algae to a desired state without removing the crushed cell walls.

[0028] The content of algal material in the algal material mixture composition is not particularly limited, but may be, for example, 0.05 to 10 wt %, preferably 0.1 to 5 wt %, more preferably 0.5 to 5 wt %, 0.5 to 4 wt %, 0.5 to 3 wt %, 0.5 to 2 wt %, or 0.5 to 1 wt %, calculated as the dry weight of the algal material.

[0029] The content of the algal pigment in the algal material mixture composition is not particularly limited, but may be, for example, 0.001 to 1 wt %, preferably 0.003 to 0.5 wt %, more preferably 0.005 to 0.3 wt %, and even more preferably 0.01 to 0.25 wt %, 0.03 to 0.25 wt %, 0.05 to 0.25 wt %, or 0.1 to 0.25 wt %.

[0030] When the algal material contains protein, the protein content in the algal material mixture composition is not particularly limited, but may be, for example, 0.01 to 10 wt %, preferably 0.03 to 5 wt %, more preferably 0.05 to 3 wt %, and even more preferably 0.1 to 1 wt %, or 0.3 to 0.5 wt %.

[0031] 1-1-1-2. Hydrogen Peroxide In the present invention, hydrogen peroxide is used to decolorize the algal material. Because decolorization using hydrogen peroxide can proceed under mild conditions, it is possible to effectively lighten the algal material while suppressing the loss of proteins contained in the algal material.

[0032] The content of hydrogen peroxide in the algal material mixture composition is not limited as long as it achieves the effects of the present invention, but may be, for example, 0.5% by weight or more, specifically 0.5 to 50% by weight, preferably 1 to 45% by weight, more preferably 3 to 40% by weight, even more preferably 5 to 35% by weight, even more preferably 8 to 32% by weight, and even more preferably 14 to 26% by weight.

[0033] The amount of hydrogen peroxide used per algal material is not limited as long as the effects of the present invention are achieved, but examples of the amount of hydrogen peroxide used per 1 part by weight of dry weight of algal material include 0.8 parts by weight or more, specifically 0.8 to 80 parts by weight, preferably 1.5 to 75 parts by weight, more preferably 5 to 70 parts by weight, even more preferably 8 to 60 parts by weight, even more preferably 10 to 55 parts by weight, and even more preferably 20 to 45 parts by weight or 23 to 43 parts by weight.

[0034] The amount of hydrogen peroxide used per algal pigment is not limited as long as the effects of the present invention are achieved, but may be, for example, 1 to 5,000 parts by weight of hydrogen peroxide used per 1 part by weight of algal pigment. The lower limit of this range (1 to 5,000 parts by weight) may be 5 parts by weight, 10 parts by weight, 20 parts by weight, 50 parts by weight, 100 parts by weight, 200 parts by weight, 300 parts by weight, 400 parts by weight, or 500 parts by weight. The upper limit of this range (1 to 5,000 parts by weight) may be 4,000 parts by weight, 2,000 parts by weight, 1,000 parts by weight, 950 parts by weight, 900 parts by weight, 850 parts by weight, 800 parts by weight, or 750 parts by weight. These lower and upper limits can be combined in any way. Specific amounts of hydrogen peroxide used per part by weight of algal pigment include 5 to 5,000 parts by weight, 10 to 5,000 parts by weight, 20 to 5,000 parts by weight, 50 to 5,000 parts by weight, 100 to 5,000 parts by weight, 200 to 5,000 parts by weight, 300 to 5,000 parts by weight, 400 to 5,000 parts by weight, 500 to 5,000 parts by weight, 1 to 4,000 parts by weight, 1 to 2,000 parts by weight, 1 to 1,000 parts by weight, 1 to 950 parts by weight, 1 to 900 parts by weight, 1 to 850 parts by weight, 1 to 800 parts by weight, or 1 to 750 parts by weight.

[0035] 1-1-1-3. Water The amount of water contained in the algal material mixed composition is not particularly limited, but may be, for example, 60 to 98% by weight, and preferably 65 to 95% by weight.

[0036] 1-1-1-4. Other Components In addition to the algal material, hydrogen peroxide, and water, the algal material mixed composition may or may not contain other components as long as they do not impair the progress of the decolorization reaction. Examples of other components include antifoaming agents. Antifoaming agents can be used to suppress foaming due to the generation of oxygen associated with the decolorization reaction. When an antifoaming agent is used, its content in the algal material mixed composition is not particularly limited, but examples include 0.005 to 0.2 wt %, preferably 0.01 to 0.1 wt %, and more preferably 0.03 to 0.07 wt %.

[0037] 1-1-1-5. pH The pH (20°C) of the algal material mixed composition is not particularly limited, but may be, for example, 2 to 7, 3 to 7, preferably 3.5 to 7, 3.8 to 7, 4 to 6.8, preferably 4.3 to 6.5, more preferably 4.5 to 5.5, and even more preferably 4.8 to 5.2.

[0038] 1-1-2. Reaction Conditions The conditions for treating the algal material with hydrogen peroxide, i.e., the conditions for the decolorization reaction to which the algal material mixed composition is subjected, are not limited as long as they achieve the effects of the present invention, and are selected appropriately depending on the scale of the algal material mixed composition and / or the desired degree of decolorization, etc. Optimal treatment conditions can be determined through preliminary experiments.

[0039] Specific examples of reaction conditions include a reaction temperature of, for example, 5 to 120°C, 7 to 100°C, or 10 to 75°C, preferably 15 to 50°C, more preferably 20 to 30°C, and even more preferably 23 to 27°C; and a reaction time of, for example, 1 to 50 hours, preferably 10 to 40 hours, and more preferably 20 to 30 hours.

[0040] 1-2. Hydrogen Peroxide Removal Step When the present invention includes a hydrogen peroxide removal step, in the hydrogen peroxide removal step, a hydrogen peroxide-decomposing enzyme is allowed to act on the hydrogen peroxide-treated sample obtained in the above-mentioned decolorization step. Specifically, an enzyme mixture containing the hydrogen peroxide-treated sample obtained in the above-mentioned decolorization step and the hydrogen peroxide-decomposing enzyme is prepared, and this enzyme mixture is subjected to a hydrogen peroxide decomposition reaction in which the hydrogen peroxide-decomposing enzyme acts.

[0041] 1-2-1. Hydrogen Peroxide-Decomposing Enzyme The hydrogen peroxide-decomposing enzyme used in the present invention is not particularly limited as long as it is an enzyme capable of decomposing hydrogen peroxide. Examples of hydrogen peroxide-decomposing enzymes include catalase and peroxidase. These hydrogen peroxide-decomposing enzymes may be used alone or in combination. Of these hydrogen peroxide-decomposing enzymes, catalase is preferred.

[0042] Catalases are enzymes (EC 1.11.1.6.) that catalyze a reaction that produces water and oxygen. Specific examples of catalases include catalases derived from microorganisms such as fungi and bacteria, and more specifically, catalases derived from filamentous fungi such as the Aspergillus genus (e.g., Aspergillus niger) and the Trichoderma genus (e.g., Trichoderma reesei), and bacteria such as the Micrococcus genus (e.g., Micrococcus lysodeikticus).

[0043] These catalases may be used alone or in combination of two or more. Among these catalases, catalases derived from the genus Aspergillus, more preferably Aspergillus niger, are preferred from the viewpoint of further suppressing residual hydrogen peroxide.

[0044] The amount of catalase used is not particularly limited, but may be, for example, 1 to 5000 U, preferably 10 to 1000 U, more preferably 100 to 500 U per gram of hydrogen peroxide used in the decolorization step.

[0045] Regarding catalase activity, the amount of catalase that decomposes 1 μmol of hydrogen peroxide in 1 minute is defined as 1 unit (U).

[0046] 1-2-2. Other Components The enzyme mixture containing the hydrogen peroxide-treated sample and the hydrogen peroxide-decomposing enzyme may or may not contain other components in addition to the hydrogen peroxide-treated sample and the hydrogen peroxide-decomposing enzyme, as long as they do not impair the progress of the hydrogen peroxide decomposition reaction. Examples of other components include antifoaming agents. Antifoaming agents can be used to eliminate foaming caused by the generation of oxygen accompanying the decolorization reaction. When an antifoaming agent is used, its content in the enzyme mixture is not particularly limited, but examples include 0.005 to 0.2 wt %, preferably 0.01 to 0.1 wt %, and more preferably 0.03 to 0.07 wt %.

[0047] The pH (20°C) of the enzyme mixture is not particularly limited and may be set appropriately depending on the pH characteristics of the hydrogen peroxide decomposing enzyme, and may be, for example, 2 to 7, 3 to 7, preferably 3.5 to 7, 3.8 to 7, 4 to 6.8, preferably 4.5 to 6.8, more preferably 5 to 6.8, and even more preferably 5.5 to 6.8.

[0048] 1-2-4. Reaction Conditions The reaction conditions for the hydrogen peroxide removal process are not limited as long as they achieve the effects of the present invention, and are appropriately selected depending on the amount of scale and hydrogen peroxide in the algal material mixed composition used in the decolorization process, the thermal properties of the hydrogen peroxide-decomposing enzyme, the desired degree of hydrogen peroxide removal effect, etc. Optimal treatment conditions can be determined through preliminary experiments.

[0049] Specific examples of reaction conditions include a reaction temperature of 5 to 70°C, preferably 10 to 50°C, more preferably 15 to 30°C, and even more preferably 18 to 22°C, and a reaction time of 10 to 120 minutes, preferably 15 to 60 minutes, and more preferably 20 to 40 minutes.

[0050] 1-3. Other Steps The production method of the present invention may include other steps in addition to the above-described decolorization step and the optional hydrogen peroxide removal step. These other steps include a step of preparing algal material, a step of deactivating enzymes, a cooling step, a washing step, a filtering step, a drying step, etc. These other steps may be performed singly or in combination of two or more steps.

[0051] The step of preparing the algal material is performed before the decolorization step. The specific method for preparing the algal material is not particularly limited, and a preparation method can be appropriately selected depending on the specific form of the algal material. For example, algae can be crushed using any crushing method (e.g., ultrasonic waves, microwaves, mechanical treatment (using a high-pressure homogenizer, mill, etc.), chemical treatment (using a solvent, acid, etc.), high temperature (using an autoclave), freeze-thaw cycles, extraction using a supercritical fluid and an ionic liquid, etc.) and prepared to a desired profile. Dry algae powder with crushed cell walls can be obtained by preparing a powder without removing the crushed cell walls. Alternatively, a textured product can be obtained by subjecting an algae protein concentrate to a known texturization method (e.g., a method in which a raw material mixture containing the algae protein concentrate and water is extruded using an extruder, dried, or frozen to form a meat-like texture).

[0052] The enzyme deactivation step is carried out after the hydrogen peroxide removal step. The enzyme deactivation method may be appropriately selected from general deactivation methods depending on the thermal properties of the hydrogen peroxide-decomposing enzyme used in the hydrogen peroxide removal step, and is preferably performed by heat treatment.

[0053] The washing step can be carried out after the bleaching step and before the hydrogen peroxide removal step. Specifically, the processed algal material obtained by the bleaching step can be washed with water. The amount of water used can be, for example, 1 to 10 times the weight of the processed algal material obtained by the bleaching step. Furthermore, the number of washings is not particularly limited, and can be, for example, 1 to 3 times. Note that, since the production method of the present invention is excellent in the ability to suppress residual hydrogen peroxide and also has an excellent effect of improving protein solubility, in a preferred embodiment, the washing step is not carried out.

[0054] 1-4. Processed Algal Material The production method of the present invention can produce a bleached algal material (processed algal material).

[0055] In a preferred form of the processed algal material (especially when obtained by a manufacturing method that includes a hydrogen peroxide removal step), it is preferable that the processed algal material is substantially free of hydrogen peroxide, whereby the hydrogen peroxide content is less than 2 ppm.

[0056] In addition, in a preferred form of processed algal material, in addition to being decolorized, at least one of dispersibility (especially when the algal material is a powder containing crushed cell walls), protein solubility, and reduction of raw material odor (the odor unique to algae) is improved.

[0057] The present invention also provides foods and beverages containing the processed algal material obtained by the above-described manufacturing method. Note that, in the present invention, the term "foods and beverages" is not limited to those in the form in which they are consumed, but also includes those in the form of ingredients for foods and beverages.

[0058] The specific form of the food or drink of the present invention can be selected from any food or drink form.

[0059] Specific forms of the processed algal material of the present invention obtained using non-structured algal material include algal flour (used in the same manner as grain flour, or for nutritional enrichment of proteins, etc.), powdered beverages (dispersed in water for consumption), and liquid beverages. Because the food and beverage products of the present invention exhibit improved dispersibility even when obtained using algal material containing crushed cell walls, in a preferred form, food and beverage products obtained using algal material containing crushed cell walls (these food and beverage products can be designed to use the crushed cell walls as a dietary fiber source) can be used as powdered beverages or liquid beverages. Furthermore, powders of non-structured food and beverage products may be structured and molded into structured protein materials.

[0060] When a textured algal material is used, the form can conform to that of processed meat, poultry, and / or fish paste. That is, the processed algal material of the present invention includes meat-like processed foods (foods that imitate meat, poultry, and / or fish paste processed foods). More preferably, the processed algal material of the present invention includes meat- and / or poultry-like processed foods (foods that imitate meat and / or poultry processed foods). Such processed meat and / or poultry foods may be any food that is prepared by shaping and heating meat mixtures using meat and / or poultry, and specific examples thereof include hamburger steaks, meatballs, patties, meatloaf, minced meat cutlets, dim sum, etc.

[0061] The food and drink of the present invention can be obtained by subjecting the processed algal material obtained by the above-mentioned production method to any cooking step, which may include seasoning, adjusting the shape, molding, cooking with heat, fermentation, freezing, etc.

[0062] 3. Bleaching Method and Dispersibility Improvement Method By treating algal material with hydrogen peroxide, algal pigments contained in the algae can be bleached. Therefore, the present invention also provides a method for bleaching algal pigments in algal material, which includes a bleaching step of treating the algal material with hydrogen peroxide. The bleaching method of the present invention can further include a hydrogen peroxide removal step. The bleaching step, the hydrogen peroxide removal step that is optionally included, and / or other steps in the bleaching method of the present invention are as described in "1. Method for producing processed algal material."

[0063] Furthermore, by treating powdered algal material containing crushed algal cell walls with hydrogen peroxide, the dispersibility of the algal material in water can be improved. Therefore, the present invention also provides a method for improving the dispersibility of algal material, which includes a step of treating algal material with hydrogen peroxide, wherein the algal material contains crushed algal cell walls. The method for improving dispersibility of the present invention can further include a hydrogen peroxide removal step. Details of the step of treating algal material with hydrogen peroxide in the method for improving dispersibility of the present invention are the same as those in "1-1. Bleaching step" in "1. Method for producing a processed algal material" (however, the algal material used is a powdered algal material containing crushed algal cell walls). Furthermore, the hydrogen peroxide removal step and / or other steps that may be optionally included in the method for improving dispersibility of the present invention are also as described in "1. Method for producing a processed algal material."

[0064] The present invention will be specifically described below with reference to examples, but the present invention should not be construed as being limited to the following examples.

[0065] [Ingredients used] (1) Algae material: Cell wall-broken chlorella (Chlorella pyrenoidosa, protein content 50-67 w / w%, chlorophyll content 1-3 w / w%); Cell wall-broken spirulina (protein content 55 w / w% or more, phycocyanin content 5 w / w% or more, chlorophyll a content 1 w / w% or more) (2) Algae pigment: Chlorophyll ("Copper chlorophyllin sodium, powder", Fujifilm Wako Pure Chemical Industries, Ltd.); Phycocyanin ("Phycocyanin from Spirulina", Tokyo Chemical Industry Co., Ltd.) (3) Hydrogen peroxide: Hydrogen peroxide solution (hydrogen peroxide content 30 wt%, Fujifilm Wako Pure Chemical Industries, Ltd.) (4) Hydrogen peroxide-decomposing enzyme: Catalase (Aspergillus The enzyme activity of catalase was measured according to the method described in the Japanese Standards of Food Additives (9th edition). Specifically, it was measured as follows: 5 mL of 12.4 mM hydrogen peroxide solution (pH 7.0) was weighed into a test tube and left at 30°C for at least 5 minutes. 1 mL of aqueous enzyme solution was added and the mixture was shaken well to allow the reaction. Immediately after the reaction, the mixture was left at 30°C for exactly 5 minutes. 2 mL of 0.5 mol / L sulfuric acid solution was added and shaken well. 1 mL of 10 g / dL potassium iodide solution, one drop of ammonium molybdate solution (1 → 100), and five drops of starch solution as an indicator were added. While stirring with a stirrer, this solution was titrated with 0.005 mol / L sodium thiosulfate solution (for quantitative determination) (T5 (mL)). The endpoint of the titration was determined when the blue color of the solution disappeared and remained colorless for 30 seconds. Separately, a blank was prepared in the same manner using 1 mL of water instead of the enzyme solution (T0 (mL)). Based on the following formula, the amount of catalase required to decompose 1 μmol of hydrogen peroxide in 1 minute was defined as 1 unit (1 U).

[0066]

[0067] [Test Example 1] A mixed composition (pH 4.7 (20°C)) was prepared by adding algal pigments to a 30% aqueous hydrogen peroxide solution to the final concentration shown in Table 1. This was then left overnight at room temperature (25°C) to carry out a decolorization reaction, yielding a hydrogen peroxide-treated sample. Separately, a similar process was performed, except that purified water was used instead of the aqueous hydrogen peroxide solution, to obtain a corresponding control sample (Ctrl). The absorbance of the obtained hydrogen peroxide-treated sample and the corresponding control sample was measured at 650 nm for samples containing chlorophyll and at 670 nm for samples containing phycocyanin. The relative absorbance of the hydrogen peroxide-treated sample was calculated based on the following formula. A relative absorbance below 100% indicates decolorization, and a lower relative absorbance indicates a greater degree of decolorization.

[0068]

[0069] As shown in Table 1, all samples treated with hydrogen peroxide were found to be decolorized. Furthermore, even when the amount of hydrogen peroxide used for the algal pigment was taken into consideration, the decolorization effect of phycocyanin was found to be particularly high.

[0070] Test Example 2: A hydrogen peroxide-treated sample (processed algal material) was obtained by the same procedure as in Test Example 1, except that cell wall-broken chlorella or cell wall-broken spirulina was added instead of the algal pigment to the final concentration shown in Table 2. A corresponding control (Ctrl) sample was also obtained by the same procedure, except that purified water was used instead of the aqueous hydrogen peroxide solution. The resulting hydrogen peroxide-treated sample (processed algal material) was visually evaluated for decolorization and dispersibility improvement effects compared to the control sample. The algal odor reduction effect was also evaluated by olfactory comparison compared to the control. The algal odor reduction effect was evaluated using a 6-point visual analog scale (VAS), with 5 representing the level of the grassy odor characteristic of algae in the cell wall-broken chlorella control sample and 0 representing odorless. A lower score indicates a higher algal odor reduction effect. The results are shown in Table 2. The appearance of the hydrogen peroxide-treated sample (processed algal material) from Example 1 (cell wall-broken chlorella) is shown in FIG.

[0071]

[0072] As shown in Table 2, a decolorizing effect was observed in all hydrogen peroxide-treated samples (processed algae material) from the Examples. While precipitation of cell wall-broken algae was observed in the control, no precipitation was observed in the processed algae material from the Examples, demonstrating an improved dispersibility. While the control had a grassy smell characteristic of algae, the grassy smell disappeared in the processed algae material from the Examples.

[0073] Test Example 3: Treatments were performed in the same manner as in Test Example 1, Treatment Examples 1 and 3, except that the amount of hydrogen peroxide added was changed as shown in Tables 3 and 4, to obtain hydrogen peroxide-treated samples (the pH (20°C) of the mixed composition varied depending on the hydrogen peroxide concentration: neutral at 1 wt%, 5.3 at 10 wt%, and 4.7 at 30 wt%). Furthermore, a corresponding control (Ctrl) sample was obtained by performing the same treatment, except that purified water was used instead of the aqueous hydrogen peroxide solution. The relative absorbance of the obtained hydrogen peroxide-treated sample was calculated in the same manner as in Test Example 1. The results are shown in Tables 3 and 4.

[0074]

[0075]

[0076] As shown in Tables 3 and 4, a decolorizing effect was observed in all of the samples treated with hydrogen peroxide.

[0077] [Test Example 4] The same treatment as in Example 2 of Test Example 2 was carried out, except that the amount of hydrogen peroxide added was changed as shown in Table 5 (the pH (20°C) of the mixed composition varied depending on the hydrogen peroxide concentration, being 5.3 at a hydrogen peroxide concentration of 10% by weight and 4.7 at a hydrogen peroxide concentration of 30% by weight), and a hydrogen peroxide-treated sample (processed algal material) was obtained. In addition, a similar treatment was carried out, except that purified water was used instead of the aqueous hydrogen peroxide solution, to obtain a corresponding control (Ctrl) sample. The appearance of the obtained hydrogen peroxide-treated sample (processed algal material) was observed, and the decolorization effect was evaluated. The results are shown in Table 5.

[0078]

[0079] As shown in Table 5, a decolorizing effect was observed in all of the hydrogen peroxide-treated samples (processed algal materials) in the Examples.

[0080] [Test Example 5] For each of the hydrogen peroxide-treated samples of Treatment Example 5 and Treatment Example 10, 250 U of catalase and 0.05 wt% of a silicone emulsion antifoaming agent (XIAMETER AFE-1530 Antifoam Emulsion, manufactured by Dow-Toray Co., Ltd.) were added per 1 g of hydrogen peroxide to prepare an enzyme mixture (pH about 6.5 (20 ° C.)), and the mixture was stirred at 25 ° C. for 30 minutes to obtain an enzyme-treated product. In addition, for the hydrogen peroxide-treated sample obtained in the same manner as in Example 1, except that the amount of hydrogen peroxide used was changed to 5 wt%, catalase and an antifoaming agent were added to prepare an enzyme mixture (pH about 6.5 (20 ° C.)), and the mixture was stirred at 25 ° C. for 30 minutes to obtain an enzyme-treated product (processed algae material) (Example 8).

[0081] The amount of residual hydrogen peroxide in the obtained enzyme-treated product was determined by the following method.

[0082] A hydrogen peroxide color-developing solution was prepared by diluting 1.3 mg of horseradish peroxidase (Fujifilm Wako Pure Chemical Industries, Ltd.: 190 U / mg), 1.0 mL of 4-aminoantipyrine (Fujifilm Wako Pure Chemical Industries, Ltd.: 0.4 g / dL), and 1.4 mL of phenol (Fujifilm Wako Pure Chemical Industries, Ltd.: 5 g / dL) to 100 mL with Tris phosphate buffer, pH 7.2. 190 μL of the color-developing solution was mixed with 10 μL of the appropriately diluted enzyme-treated product and allowed to stand at 37°C. The absorbance at 500 nm was then measured. The detection limit was 2 ppm.

[0083]

[0084] As shown in Table 6, the amount of residual hydrogen peroxide in the obtained enzyme-treated product was below the detection limit (ND; not detected). Furthermore, the decolorization effect observed in the hydrogen peroxide-treated samples of Treatment Examples 5 and 10 was maintained unchanged in the enzyme-treated product (no change in color). Furthermore, the enzyme-treated product of Example 8 (processed algal material) not only exhibited a decolorization effect, but also achieved an excellent dispersibility improvement effect, similar to Example 1.

[0085] Test Example 6 Examples 3, 4, 6, and 7 of Test Example 5 were retested, and the a* values ​​of the obtained hydrogen peroxide-treated samples (processed algal materials) were measured using a spectrophotometer (CM-700d, Konica Minolta Sensing, Inc.). The results are shown in Table 7. The a* value represents the color tone from green to red, and the higher the a* value, the weaker the green color, i.e., the stronger the decolorization effect.

[0086]

[0087] As shown in Table 7, the decolorization effect of the processed algal material was observed to be dependent on the concentration of hydrogen peroxide.

Claims

1. A method for producing processed algal material, including a decolorization step in which the algal material is treated with hydrogen peroxide.

2. The method of claim 1, wherein the pigment to be decolorized is selected from the group consisting of chlorophyll and phycobilin.

3. The method of claim 1, wherein the algae is selected from the group consisting of blue-green algae and green algae.

4. The method of claim 1, wherein the algae is selected from the group consisting of chlorella and spirulina.

5. The method of claim 1, wherein the algal material comprises crushed cell walls of the algae.

6. A manufacturing method as described in claim 1, wherein in the decolorization process, an algal material mixed composition containing the algal material, the hydrogen peroxide, and water is subjected to a decolorization reaction, and the content of the hydrogen peroxide in the algal material mixed composition is 0.5% by weight or more.

7. The method of claim 1, further comprising a hydrogen peroxide removal step in which a hydrogen peroxide decomposing enzyme is allowed to act.

8. The method according to claim 7, wherein the hydrogen peroxide decomposing enzyme is catalase.

9. The method of claim 7, wherein the catalase is derived from the genus Aspergillus.

10. A method for decolorizing algal pigments in algal material, comprising a decolorizing step of treating the algal material with hydrogen peroxide.

11. A method for improving the dispersibility of algal material, comprising treating algal material with hydrogen peroxide, wherein said algal material comprises crushed cell walls of said algae.

12. A food or drink comprising a processed algal material obtained by the manufacturing method according to any one of claims 1 to 9.

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