Method for maintaining freshness of fresh food, fresh food, and composition for maintaining freshness of fresh food

Abstract

A method for maintaining freshness of fresh food is provided that includes coating fresh food with a seaweed-containing composition including seaweed. The seaweed-containing composition includes an insoluble dietary fiber derived from the seaweed.

Description

[DESCRIPTION][Title of Invention]METHOD FOR MAINTAINING FRESHNESS OF FRESH FOOD, FRESH FOOD, AND COMPOSITION FOR MAINTAINING FRESHNESS OF FRESH FOOD[Technical Field]

[0001] The present disclosure relates to a method for maintaining the freshness of fresh food, fresh food, and a composition for maintaining the freshness of fresh food.[Background Art]

[0002] In recent years, food waste has become a serious social issue worldwide. The food waste refers to food that is discarded even though it is still edible. According to a 2019 report by the Food and Agriculture Organization (FAO) of the United Nations, approximately one-third of the food produced in the world is discarded. This not only means a waste of resources involved in the production, but also an increased burden on the environment, and reducing food waste is an urgent task in order to build a sustainable society.

[0003] One of the major causes of food waste is food spoilage and deterioration in quality. In particular, fruits and vegetables after harvest are easily damaged during transportation and storage, and as a result they are often discarded. Preservation technologies such as packaging technologies and freezing technologies have been developed to reduce the food waste, but most of them have a limited range of application due to the use of chemicals, the need for special equipment, or the like.

[0004] As one of the technologies that expand the application range, a technology of coating food with edible materials has been attracting attention. For example, a method has been proposed in which a plant extract composition is applied to agricultural products or the like to form protective coating on the agricultural products (see, e.g., PTE 1).

[0005] In addition, a method has been proposed for forming edible coating on the surface of an ingredient. Specifically, a first agent including a high molecular weight polysaccharide derived from seaweed that forms gel through a reaction with a metal ion and an edible vegetable fiber derived from pulp is brought into contact with the surface of the ingredient, and then a second agent including the metal ion is brought into contact to form the coating (see, e.g., PTL 2).[Citation List][Patent Literature][PTL 1]Japanese Translation of PCT International Application Publication No. JP-T-2018-529627 [PTL 2]Japanese Unexamined Patent Application Publication No. 2006-296319 [Summary of Invention] [Technical Problem]

[0006] An object of the present invention is to provide a method for maintaining the freshness of fresh food, which can maintain the freshness of fresh food, ensure high safety, and reduce consumer reluctance.[Solution to Problem]

[0007] Embodiments of the present invention provides a method for maintaining freshness of fresh food. The method includes coating a fresh food with a seaweed-containing composition including a seaweed, in which the seaweed-containing composition includes an insoluble dietary fiber derived from the seaweed.[Advantageous Effects of Invention]

[0008] According to embodiments of the present invention, a method for maintaining the freshness of fresh food is provided, which can maintain the freshness of fresh food, ensure high safety, and reduce consumer reluctance.[Brief Description of Drawings]

[0009] A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings.FIG. 1 is a flow chart illustrating a method for maintaining the freshness of fresh food.FIG. 2 is a diagram illustrating the appearance of a banana of Example 1 and a banana of Comparative example 1, after storage at room temperature for 5 days.FIG. 3 is a diagram illustrating the appearance of an avocado of Example 2 and an avocado of Comparative example 2, after storage at room temperature for 4 days.FIG. 4 is a graph showing the change in weight of the avocado of Example 2 and the avocado of Comparative example 2, during storage at room temperature for 4 days.FIG. 5 is a diagram illustrating the appearance of a cucumber of Example 3 and a cucumber of Comparative example 3, after storage at room temperature for 5 days.FIG. 6 is a diagram illustrating the appearance of a tuna fillet having been frozen of Example 4 and a tuna fillet having been frozen of Comparative example 4 after thawing at room temperature for 3 hours.The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views. [Description of Embodiments]

[0010] In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.Referring now to the drawings, embodiments of the present disclosure are described below.As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.Hereinafter, embodiments of the present invention are described in detail. In the specification, unless otherwise specified, a numerical range “x to y” indicates that the range includes numeric values x and y as the lower and upper limit values, respectively.

[0011] (Method for maintaining freshness of fresh food)A method for maintaining the freshness of fresh food according to one embodiment of the present invention includes at least coating fresh food with a seaweed-containing composition that includes seaweed (hereinafter, sometimes referred to as “coating step”), and further includes other steps as necessary.The other steps are not particularly limited and can be appropriately selected depending on the purpose, as long as they do not impair the effects of the present invention.

[0012] Fresh food in the method for maintaining the freshness of fresh food according to one embodiment of the present invention includes fruits and vegetables, fresh fish, meat, and the like, requiring freshness in the market. Food that is classified as processed food and that has been subjected to heat treatment or drying are not included in the fresh food.

[0013] The fruits and vegetables are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include, but are not limited to, climacteric fruits, non-climacteric fruits, fruits and vegetables with thin skin, and fruits and vegetables with thick and / or hard skin.Examples of the climacteric fruits include, but are not limited to, a banana, a melon, a peach, an apple, a pear, a mango, an avocado, and a tomato.Examples of the non-climacteric fruits include, but are not limited to, citrus fruits, berries, and a grape.Examples of the fruits and vegetables with thin skin include, but are not limited to, a cucumber, a strawberry, and an eggplant. The fruits and vegetables with thin skin include fruits and vegetables which contain a large amount of moisture inside the thin skin and are eaten with the skin.Examples of the fruits and vegetables with thick and / or hard skin include, but are not limited to, a pumpkin, a melon, and a pineapple.

[0014] The fresh fish is not particularly limited and can be appropriately selected depending on the purpose. Examples of the fresh fish include, but are not limited to, tuna, sardine, bonito, greater amberjack, mackerel, pacific saury, young yellowtail, yellowtail amberjack, and yellowtail.

[0015] The meat is not particularly limited and can be appropriately selected depending on the purpose. Examples of the meat include, but are not limited to, beef, pork, and chicken.

[0016] The fresh food may be a fresh food having been frozen. In the present disclosure, “fresh food having been frozen” refers to both “fresh food in a frozen state” and “fresh food once in a frozen state and thawed from the frozen state”. The frozen state refers to a state in which the surface temperature is -5 °C or lower.In a case where the fresh food is a fresh food having been frozen, coating can absorb and / or retain drips (sometimes called “cell fluids”) that are released from the fresh food upon thawing, thereby preventing the occurrence of dripping.

[0017] In the present specification, maintaining the freshness of fresh food means preventing the loss of freshness. Example thereof include, but are not limited to, preventing discoloration, delaying spoilage or softening of fruits, reducing weight and / or moisture loss during storage, and reducing the amount of dripping that occurs upon thawing.

[0018] FIG. 1 is a flow chart illustrating an example of the method for maintaining the freshness of fresh food according to one embodiment of the present invention. The method for maintaining the freshness of fresh food in FIG. 1 includes a seaweed-containing composition preparation step (SI), a fresh food cleaning step (S2), a coating step (S3), a drying step (S4), a quality inspection step (S5), and a wrapping and / or packaging step (S6). Note that FIG. 1 includes the seaweed-containing composition preparation step (SI), the fresh food cleaning step (S2), the drying step (S4), the quality inspection step (S5), and the wrapping and / or packaging step (S6), which correspond to the above-mentioned “other steps” in the method for maintaining the freshness of fresh food. However, implementation of the other steps is optional in the method for maintaining the freshness of fresh food according to one embodiment of the present invention.

[0019] < Seaweed-containing composition preparation step>The seaweed-containing composition preparation step (SI) is a step for preparing a seaweedcontaining composition that includes seaweed (hereinafter sometimes referred to as “seaweedcontaining composition”).

[0020] < <Seaweed-containing composition> >The seaweed-containing composition includes at least seaweed and, if necessary, further includes other components.

[0021] In conventional techniques for coating food with edible materials, water-soluble substances are extracted from seaweed using water, hot water, or the like, and insoluble substances are removed as impurities. However, the extraction process itself incurs costs, and by removing insoluble substances as impurities, the weight is reduced by 5% to 44% (according to Table 2 in R. Penalver, Seaweeds as a Functional Ingredient for a Healthy Diet, Mar. Drugs 2020, 18(6), 301), leading to an increase in the cost of the materials used. Thus, in terms of costs, the conventional technologies have not yet reached a level where they can replace plastic packaging.

[0022] -Seaweed-The seaweed-containing composition of the present embodiment includes all the components constituting seaweed. The seaweed-containing composition of the present embodiment includes water-soluble substances such as alginic acid, fucoidan, and carrageenan, and insoluble substances such as insoluble dietary fibers including cellulose, lignin, and the like, derived from the seaweed.Further, in addition to polysaccharides such as alginic acid and cellulose, the seaweed generally includes: fucoidan, which has antibacterial properties; proteins; lipids; minerals such as iron, magnesium, and calcium; salts derived from seawater; and the like. That is, the seaweed includes many beneficial substances that contribute to maintaining the health of the human body.

[0023] The type of seaweed is not particularly limited and can be appropriately selected depending on the purpose, as long as the seaweed can be used in food. Examples of the type of seaweed include, but are not limited to, seaweed belonging to the genus Eucheuma, seaweed belonging to the genus Sargassum, seaweed belonging to the genus Turbinaria, and seaweed belonging to the genus Gracilaria. These may be used alone or in combination of two or more.

[0024] The seaweed-containing composition includes all the components constituting seaweed, and thus includes an insoluble dietary fiber derived from seaweed. The content of the insoluble dietary fiber derived from seaweed in the seaweed-containing composition is not particularly limited and can be appropriately selected depending on the purpose. However, the content is preferably 3% to 50% by mass, more preferably 5% to 44% by mass, of solid contents.A method for measuring the content of the insoluble dietary fiber derived from seaweed is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include, but are not limited to, the modified Prosky method.

[0025] The insoluble dietary fiber derived from seaweed is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include, but are not limited to, cellulose and lignin. These may be used alone or in combination of two or more.

[0026] The salt content of the seaweed-containing composition is not particularly limited and can be appropriately selected depending on the purpose. However, the salt content is preferably 1% by mass or less of solid contents.Seaweed generally has the salt content close to the salt concentration of seawater, which is about 3.5% by mass. Further, if a large amount of seawater is mixed in during the preparation of the seaweed-containing composition, the salt concentration further increases after drying. Thus, the seaweed-containing composition may have the salt content similar to that of seawater.When the fresh food is coated with the seaweed-containing composition with a high salt content, the skin of the fresh food, especially fruits and vegetables, may dry out. However, by setting the salt content within a preferable range, the dryness of the skin of the fresh food can be further reduced. For example, in a case of the fresh food, such as a cucumber or a strawberry, which has a large amount of moisture inside the thin skin, it is preferable to set the salt content within the preferable range.

[0027] A method for measuring the salt content is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include, but are not limited to, a conductivity measurement method.

[0028] -Other components -Other components in the seaweed-containing composition are not particularly limited and can be appropriately selected depending on the purpose, as long as they do not impair the effects of the present invention. Examples of the other components include, but are not limited to, a synthetic polymer, a lipid, an antibacterial agent, an antioxidant, an emulsifier, a preservative, and a pigment. These may be used alone or in combination of two or more. The other components can provide more effective freshness preservation in various fresh foods depending on the purpose or function of coating.

[0029] For example, the use of an antioxidant can prevent oxidation and discoloration of the skin of fruits and vegetables.As the antioxidant, a known antioxidant can be appropriately selected, and examples thereof include, but are not limited to, ascorbic acid.

[0030] Further, for example, the use of a pigment that absorbs light of a specific wavelength has the effect of mitigating photolysis and preventing color change. The pigment can be used, forexample, to change the color in appearance or to create a natural color that makes discoloration less noticeable.

[0031] The content of the other components in the seaweed-containing composition is not particularly limited and can be appropriately selected, taking into consideration costs, consumer acceptability, and the like. However, it is preferable that the content does not exceed the weight of seaweed as a main component.

[0032] It is preferable that the seaweed-containing composition does not include any chemically synthesized component.

[0033] The form of the seaweed-containing composition is not particularly limited and can be appropriately selected depending on the purpose. Examples of the form include, but are not limited to, a powder form, a fdm form (also referred to as “sheet form”), a gel form, and a liquid form.

[0034] The form of the seaweed-containing composition may be changed as appropriate. For example, the seaweed-containing composition prepared in the powder form may be transported and / or stored, and then the seaweed-containing composition may be made into other forms such as a liquid form, a gel form, and a film form before the coating step is performed.

[0035] A method for preparing the seaweed-containing composition is not particularly limited and can be appropriately selected depending on the form of the seaweed-containing composition and the like. For example, the seaweed-containing composition in the liquid form can be prepared by adding dried and crushed seaweed and other components as necessary to a solvent such as water or ethanol, which can be used in food. The preparation conditions are not particularly limited and can be appropriately selected depending on the purpose. For example, a homogeneous solution can be obtained by controlling the dissolution temperature and pH.The content of seaweed in the seaweed-containing composition is not particularly limited and can be adjusted to a concentration suitable for the coating thickness and the method used in the coating step.

[0036] Further, the seaweed-containing composition in the liquid form can be made into a powder form, a film form, or a gel form by known methods to prepare the seaweed-containing composition in other forms, such as a powder form, a film form, and a gel form.

[0037] Further, the salt content of the seaweed-containing composition can be adjusted by a method such as diluting the seaweed-containing composition in the liquid form and filtering it througha filter, or selectively removing ions (salts) using an ion exchange membrane or ion exchange resin.

[0038] The seaweed-containing composition uses a natural component, seaweed, as a raw material, which ensures safety and enables cost reduction by shortening the production process.

[0039] <Fresh food cleaning step>The fresh food cleaning step (S2) is a step for cleaning the surface of fresh food.The fresh food cleaning step removes foreign matters such as soil, wax, and impurities from the surface of fresh food. By cleaning and sanitizing the surface of fresh food, the adhesion of the seaweed-containing composition is improved, and the number of microorganisms is reduced, improving the shelf life.

[0040] A cleaning method is not particularly limited and can be appropriately selected depending on the type of fresh food and the like. Examples of the cleaning method include, but are not limited to, a method in which a brush or a washing tank is used to wash the fresh food with water at an appropriate temperature and a suitable detergent. For example, in many cases, fruits and vegetables are washed in a sorting facility after harvesting, so that existing washing equipment can be used as is as the cleaning method.

[0041] Further, during the fresh food cleaning step, drying can be performed, if necessary, to remove unnecessary moisture.

[0042] <Coating step>The coating step (S3) is a step for coating fresh food with the seaweed-containing composition that includes seaweed. By coating the fresh food, maintain the freshness can be maintained.The coating may be performed in a manner in which a film of the seaweed-containing composition is formed on the surface of fresh food, or in a manner in which the seaweedcontaining composition is attached to the surface of fresh food.

[0043] A coating method is not particularly limited and can be appropriately selected depending on the form of the seaweed-containing composition, the characteristics of fresh food, the form of coating, and the like.For example, in the case of the seaweed-containing composition in the liquid form, coating, immersion, spraying, and the like can be mentioned. More specifically, a method using a brush, an immersion tank, a spray, or inkjet technology, or the like can be mentioned.

[0044] In the case of the seaweed-containing composition in the powder or gel form, for example, a method of sprinkling the seaweed-containing composition onto the surface of fresh food tomake it adhere to the fresh food, a method of placing the fresh food on the seaweedcontaining composition in the powder or gel form, thereby making the seaweed-containing composition adhere to the surface of fresh food, and the like can be mentioned.

[0045] In the case of the seaweed-containing composition in the film form, for example, a method of wrapping the seaweed-containing composition around the fresh food for coating, and the like can be mentioned.

[0046] In the case of the fresh food having been frozen, it is preferable to use one or more seaweedcontaining compositions selected from the group consisting of seaweed-containing compositions in a powder form, a film form, and a gel form, as the seaweed-containing composition, and to attach the one or more seaweed-containing compositions to the surface of the fresh food having been frozen.

[0047] The degree (i.e., thickness and amount) of coating is not particularly limited and can be appropriately selected depending on the form of the seaweed-containing composition, the characteristics of fresh food, the form of coating, and the like. However, it is preferable to apply the seaweed-containing composition uniformly to the surface of fresh food. By forming a uniform coating, it becomes possible, for example, to adjust the respiration rate of fresh food and thereby extend the freshness maintenance period, further improving the freshness maintenance effects.

[0048] When the fresh food having been frozen is coated, the timing of coating is not particularly limited and can be appropriately selected depending on the purpose. For example, if the seaweed-containing composition is in the powder or gel form, the coating can be performed when the surface of the fresh food having been frozen is in an unfrozen state. Further, if the seaweed-containing composition is in the film form, the fresh food having been frozen can be coated at any time from before freezing to thawing.

[0049] When the fresh food is coated with the seaweed-containing composition in the powder form, it is preferred to use the seaweed-containing composition having a uniform particle size to avoid clumping and provide optimal appearance and texture.

[0050] < Drying step>The drying step (S4) is a step for drying the coated fresh food.By performing the drying step, it is possible to form a film on the surface of fresh food, to remove excess moisture from the surface of the coated fresh food, and the like.

[0051] A drying method is not particularly limited and can be appropriately selected depending on the form of the seaweed-containing composition and the characteristics of fresh food.Examples of the drying method include, but are not limited to, natural drying, hot air drying, and freeze drying. These methods may be used alone or in combination of two or more. Proper drying maximizes the adhesion and effectiveness of the coating.

[0052] < Quality inspection step>The quality inspection step (S5) is a step for inspecting whether the fresh food is properly coated.

[0053] A quality inspection method is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include, but are not limited to, a visual inspection method and an image-based method using a camera. These methods may be used alone or in combination of two or more.

[0054] The quality inspection can inspect, for example, the uniformity of coating on fresh food, the presence of damage, the presence of foreign matter, and the like. The quality inspection can ensure a consistent quality of product and increase consumer confidence.

[0055] If the product fails the quality inspection, it is possible to choose actions such as reinspection, disposal, and repeating the fresh food cleaning step.

[0056] < Wrapping and / or packaging step>The wrapping and / or packaging step (S6) is a step for wrapping and / or packaging the coated fresh food.

[0057] In the wrapping and / or packaging step, the coated fresh food can be wrapped and / or packaged, for example, in a manner suitable for transportation.

[0058] A type of packaging material is not particularly limited and can be appropriately selected depending on the impact on the quality of the coated fresh food, the transport conditions, and the like. By selecting a packaging material that does not adversely affect the quality of the coated fresh food and transporting the coated fresh food under appropriate temperature and humidity conditions, it is possible to prevent damage and deterioration of the quality of the coated fresh food during transportation, thereby reducing food waste.

[0059] Compared to the traditional post-harvest processing technologies such as wax coating and anti-fungal agents, the technology described in PTL 1, which employs a plant-based and sustainable production process, has the potential to improve preservation effects and expand the range of applicable crops through the precise coating technology. However, conventional technologies for coating food with edible materials use compounds that are chemically synthesized or extracted and / or purified from raw materials, and there are still issues withtheir safety and consumer acceptability. Further, the compounds are regulated under laws and safety standards that vary from region to region as additives to the food to which the compounds are applied. The complexity of these regulations is not only a factor that determines whether or not the technology can be adopted, but also a problem in deepening the understanding of consumers.

[0060] In the method for maintaining the freshness of fresh food according to one embodiment of the present invention, the fresh food is coated with the seaweed-containing composition using seaweed which can be eaten directly without chemical synthesis or purification process. Thus, compared to related art using compounds, the present method achieves a significant improvement in terms of safety and environmental impact. Further, the seaweed can maintain the freshness of fresh food for a long period of time due to its natural gas barrier properties, moisture retention properties, and antibacterial properties. Further, consumers accept seaweed as food, so that there is little reluctance to the coating using the seaweed.

[0061] Further, the seaweed-based coating is biodegradable in soil and ocean, so that it does not consume petroleum resources compared to currently widely used plastic packaging, and there is no risk of contamination spreading through runoff of the seaweed-based coating into the soil or ocean. This makes the seaweed-based coating an option for the sustainable food preservation technology.

[0062] Discoloration of fruits and vegetables due to spoilage, softening, damage, and the like is one of the indicators of deterioration of the freshness of food. This reduces consumer purchasing motivation, resulting in a significant drop in commercial value. In particular, fruits and vegetables that are discolored are rejected by quality inspection before shipping, are left unsold in stores, or end up spoiling after being purchased by final consumers. As a result, such fruits and vegetables are mostly discarded without being recycled in the end.It is known that important factors in the deterioration of the freshness of fruits and vegetables include moisture loss, oxidation, mechanical damage, photolysis, and spoilage caused by microorganisms. In particular, in climacteric fruits, an increase in ethylene associated with respiration, along with the spoilage and softening, accelerates the aging of fruits and vegetables.The method for maintaining the freshness of fresh food according to one embodiment of the present invention, which has gas barrier properties, moisture retention properties, and antibacterial properties, effectively prevents these factors. However, it is expected that the effects can be further enhanced by adding other functional substances as necessary.

[0063] Further, when the fresh food having been frozen is thawed, dripping occurs. However, the method for maintaining the freshness of fresh food according to one embodiment of the present invention contributes to maintaining the quality of the thawed fresh food bypreventing the occurrence of dripping, thereby enhancing consumer purchase motivation while also achieving the preservation of flavor and texture.

[0064] By maintaining the freshness of food using the method for maintaining the freshness of fresh food according to one embodiment of the present invention, it is possible to reduce food waste throughout the entire supply chain.

[0065] (Fresh Food)Fresh food according to one embodiment of the present invention is fresh food in which the surface is coated with a seaweed-containing composition that includes seaweed.

[0066] < Seaweed-containing composition including seaweed>The seaweed-containing composition including seaweed is the same as the seaweedcontaining composition including seaweed in the method for maintaining the freshness of fresh food according to one embodiment of the present invention.

[0067] Coating of the fresh food with the seaweed-containing composition including seaweed can be performed in the same manner as the coating step in the method for maintaining the freshness of fresh food according to one embodiment of the present invention.

[0068] The fresh food according to one embodiment of the present invention is the same as the fresh food in the method for maintaining the freshness of fresh food according to one embodiment of the present invention. Preferable examples of the fresh food according to one embodiment of the present invention include fresh food having been frozen.

[0069] (Composition for maintaining freshness of fresh food)A composition for maintaining the freshness of fresh food according to one embodiment of the present invention includes at least seaweed and, if necessary, further includes other components.

[0070] The composition for maintaining the freshness of fresh food is the same as the seaweedcontaining composition including seaweed in the method for maintaining the freshness of fresh food according to one embodiment of the present invention.

[0071] Fresh food coated by the composition for maintaining the freshness of fresh food is the same as the fresh food in the method for maintaining the freshness of fresh food according to one embodiment of the present invention. The composition for maintaining the freshness of fresh food can be suitably used for fresh food having been frozen.[Examples]

[0072] The following examples and comparative examples are provided to describe the embodiments of the present invention in more detail. However, the present invention is not limited by these examples and comparative examples.

[0073] (Example 1)Preparation of composition for maintaining freshness of fresh food>As an example of seaweed, seaweed belonging to the genus Eucheuma was used. The seaweed to be used was dried and then crushed.Water was added so that the content of the crushed seaweed was 5.0% by mass, thereby preparing a composition for maintaining the freshness of fresh food in a liquid form.The content of an insoluble dietary fiber derived from the seaweed in the composition for maintaining the freshness of fresh food in the liquid form was 2.0% by mass (40% by mass of solid contents).Further, the salt content in the composition for maintaining the freshness of fresh food in the liquid form was 3.4% by mass of solid contents.

[0074] <Coating fresh food>A banana was used as an example of fresh food. The banana with the surface washed was used.The composition for maintaining the freshness of fresh food in the liquid form was evenly applied to the entire surface of the banana and dried in an indoor environment to coat the banana with the composition. The thickness of the coating was approximately 1 pm.

[0075] (Comparative example 1)In Comparative example 1, a banana was not coated with the composition for maintaining the freshness of fresh food in the liquid form in Example 1.

[0076] <Evaluation>The bananas of Example 1 and Comparative example 1 were stored at room temperature for 5 days. FIG. 2 illustrates the appearance of the bananas after 5 days of storage at room temperature.

[0077] As illustrated in FIG. 2, in the banana of Comparative example 1, which was not coated with the composition for maintaining the freshness of fresh food, the typical black speckled pattern (sugar spots) was observed after five days of storage. On the other hand, in the banana in example 1, which was coated with the composition for maintaining the freshness of fresh food, the sugar spots were prevented even after five days of storage, demonstrating the freshness maintaining effects.

[0078] (Example 2)Preparation of composition for maintaining freshness of fresh food>A composition for maintaining the freshness of fresh food in a liquid form was prepared in the same manner as in Example 1, except that seaweed belonging to the genus Sargassum was used as an example of seaweed, and water was added so that the content of the crushed seaweed was 10.0% by mass.The content of an insoluble dietary fiber derived from the seaweed in the composition for maintaining the freshness of fresh food in the liquid form was 4.0% by mass (40% by mass of solid contents).Further, the salt content in the composition for maintaining the freshness of fresh food in the liquid form was 3.4% by mass of solid contents.

[0079] <Coating fresh food>An avocado was used as an example of fresh food. The avocado with the surface washed was used.The composition for maintaining the freshness of fresh food in the liquid form was evenly applied to the entire surface of the avocado with the surface washed, and dried in an indoor environment to coat the avocado with the composition. The thickness of the coating was approximately 2 pm.

[0080] (Comparative example 2)In Comparative example 2, an avocado was not coated with the composition for maintaining the freshness of fresh food in the liquid form in Example 2.

[0081] <Evaluation>The avocados of Example 2 and Comparative example 2 were stored at room temperature for 4 days. FIG. 3 illustrates the appearance of the avocados after storage at room temperature for 4 days. Further, FIG. 4 illustrates a graph showing the change in weight of the avocados during storage at room temperature for 4 days. FIG. 4 illustrates the weight percentage of the avocados on each measurement day, with the weight of the avocados at the start of storage being taken as 100%. In FIG. 4, white the square represents the results of Example 2, and the black triangle represents the results of Comparative example 2.

[0082] As illustrated in FIG. 3 and FIG. 4, the avocado of Example 2, which was coated with the composition for maintaining the freshness of fresh food, had slower spoilage and softening after 4 days than the avocado of Comparative example 2, which was not coated with the composition for maintaining the freshness of fresh food. The avocado of Example 2 also exhibited less weight loss and better retention of its initial condition at the start of storage. It was confirmed that the avocado of Comparative example 2, which was not coated with the composition for maintaining the freshness of fresh food, had progressed in spoilage and softening including softening of the fruit and discoloration of the skin.

[0083] The results of Example 2 and Comparative example 2 suggest that coating with the composition for maintaining the freshness of fresh food prevents the respiratory activity of avocado, delays spoilage and softening, and also reduces moisture loss, thereby maintaining the freshness. These results show that the coating with the composition for maintaining the freshness of fresh food is effective in maintaining the freshness and market value of avocado, and also show that it is important to deliver the fresh food to consumers at the optimal ripeness. This approach is effective for all climacteric fruits, such as a banana, an avocado, and a melon.

[0084] (Example 3)Preparation of composition for maintaining freshness of fresh food>As an example of seaweed, seaweed belonging to the genus Turbinaria was used.The seaweed was dried and then crushed. Next, water was added to the crushed seaweed, and then the salt content was reduced by filtration through a filter. Then, the seaweed was dried to obtain a seaweed powder with the salt content of 0.7% by mass of solid contents.Water was added so that the content of the seaweed powder was 5.0% by mass to prepare a composition for maintaining the freshness of fresh food in a liquid form.The content of an insoluble dietary fiber derived from the seaweed in the composition for maintaining the freshness of fresh food in the liquid form was 2.0% by mass (40% by mass of solid contents).

[0085] <Coating fresh food>A cucumber was used as an example of fresh food. The cucumber to be used was washed with running water and then lightly wiped to remove moisture from the surface.The composition for maintaining the freshness of fresh food in the liquid form was evenly applied to the entire surface of the cucumber and dried in an indoor environment to coat the cucumber with the composition. The thickness of the coating was approximately 1 pm.

[0086] (Comparative example 3)In Comparative example 3, the cucumber was not coated with the composition for maintaining the freshness of fresh food in the liquid form in Example 3.

[0087] <Evaluation>The cucumbers of Example 3 and Comparative example 3 were stored at room temperature for 5 days. FIG. 5 illustrates the appearance of the cucumbers after storage at room temperature for 5 days.

[0088] As illustrated in FIG. 5, compared to the cucumber of Comparative example 3, which was not coated with the composition for maintaining the freshness of fresh food, the cucumber ofExample 3, which was coated with the composition for maintaining the freshness of fresh food, showed reduced moisture loss, demonstrating the freshness maintaining effects.

[0089] A cucumber has a high-water content and requires a coating suitable for its characteristics. Because the composition for maintaining the freshness of fresh food uses seaweed, the salt content from seawater may cause the surface of the cucumber to dry out. Thus, it is important to minimize the salt amount, taking into account the effect of osmotic pressure. The present example is merely one example, but by keeping the salt content in the composition for maintaining the freshness of fresh food to 1% by mass or less of solid contents and setting the coating thickness to approximately 1 pm, it was confirmed that moisture loss was prevented, resulting in the effect of contributing to maintaining the freshness of cucumber. Note that it is also effective to add a lipid as an auxiliary component to improve the moisture retention. This approach is particularly effective for the fresh food, such as a cucumber, a strawberry, or an eggplant, which has a high-water content and is eaten with the skin.

[0090] (Example 4)Preparation of composition for maintaining freshness of fresh food>As an example of seaweed, seaweed belonging to the genus Gracilaria was used.The seaweed was dried and then crushed. The seaweed was dried and then crushed. Next, water was added to the crushed seaweed, and then the salt content was reduced by filtration through a filter. Then, the seaweed was dried to obtain a composition for maintaining the freshness of fresh food in a powder form (salt content: 0.7% by mass of solid contents). The content of an insoluble dietary fiber derived from the seaweed in the composition for maintaining the freshness of fresh food in the powder form was 40% by mass of solid contents.

[0091] <Coating fresh food>A tuna fillet having been frozen was used as an example of fresh food. The tuna fillet having been frozen to be used was confirmed to have no impurities on the surface.The composition for maintaining the freshness of fresh food in the powder form was evenly sprinkled over the entire surface of the tuna fillet having been frozen, and made to adhere, thereby coating the tuna fillet having been frozen with the composition. Note that when the composition for maintaining the freshness of fresh food in the powder form was sprinkled, the tuna fillet having been frozen had a non-frozen surface, with only the surface being thawed.

[0092] (Comparative example 4)In Comparative example 4, the tuna fillet having been frozen was not coated with the composition for maintaining the freshness of fresh food in the powder form in Example 4.

[0093] <Evaluation>The tuna fillets having been frozen of Example 4 and Comparative example 4 were thawed at room temperature for 3 hours. FIG. 6 illustrates the appearance of the tuna fillets after thawing at room temperature for 3 hours.

[0094] As illustrated in FIG. 6, in the tuna fillet having been frozen of Example 4, which was coated with the composition for maintaining the freshness of fresh food in the powder form, drips (cell fluids) were prevented from releasing, confirming that the freshness was maintained. Preventing the occurrence of dripping contributes to maintaining the quality of the thawed tuna, thereby enhancing consumer purchase motivation while also achieving the preservation of flavor and texture.

[0095] In Example 4, the composition for maintaining the freshness of fresh food in the powder form was applied to effectively absorb moisture. The composition for maintaining the freshness of fresh food in the powder form having uniform granular shape was evenly sprinkled over the tuna fillet having been frozen to avoid clumping and provide optimal appearance and texture.

[0096] The coating with the composition for maintaining the freshness of fresh food in the powder form effectively reduces dripping that occurs on the surface during thawing, thereby maintaining the flavor and texture of tuna and improving the freshness after thawing. Additionally, by reducing weight the loss due to dripping, it is expected that a value of product at the time of sale can be increased, leading to higher profits.

[0097] By using seaweed, which is widely accepted by consumers, in the composition for maintaining the freshness of fresh food, it is possible to reduce potential reluctance toward the coated fresh food and provide a sense of safety. This approach is particularly effective not only for fresh fish having been frozen but also for other raw foods that tend to release cell fluids upon thawing, such as meats having been frozen, vegetables having been frozen, and fruits having been frozen.

[0098] Further, the form of the composition for maintaining the freshness of fresh food may be something other than the powder form. For example, the composition for maintaining the freshness of fresh food in a film form may be wrapped around and coated on the fresh food having been frozen, or the composition for maintaining the freshness of fresh food in a gel form may be applied to and coated on the fresh food having been frozen. In these cases, the same effects as those of the composition for maintaining the freshness of fresh food in the powder form can be obtained.

[0099] Aspects of the present invention are, for example, as follows.[Aspect 1] A method for maintaining the freshness of fresh food, including coating a fresh food with a seaweed-containing composition including a seaweed, in which the seaweedcontaining composition includes an insoluble dietary fiber derived from the seaweed.[Aspect 2] The method in the Aspect 1, in which a content of the insoluble dietary fiber derived from the seaweed in the seaweed-containing composition is 5% to 44% by mass of solid contents.[Aspect 3] The method in the Aspect 1 or Aspect 2, in which a salt content in the seaweedcontaining composition is 1% by mass or less of solid contents.[Aspect 4] The method in any of the Aspect 1 to Aspect 3, in which the fresh food is a fresh food having been frozen.[Aspect 5] The method in the Aspect 4, in which: the seaweed-containing composition includes at least one selected from the group consisting of seaweed-containing compositions in a powder form, seaweed-containing compositions in a film form, and seaweed-containing compositions in a gel form; and the coating includes attaching the seaweed-containing composition to a surface of the fresh food having been frozen.[Aspect 6] The method in the Aspect 5, in which: the seaweed-containing composition includes a seaweed-containing composition in a powder form; and the attaching includes attaching the seaweed-containing composition in the powder form to the surface of the fresh food having been frozen when the surface of the fresh food having been frozen is in an unfrozen state.[Aspect 7] A fresh food having a surface coated with a seaweed-containing composition including a seaweed, in which the seaweed-containing composition includes an insoluble dietary fiber derived from the seaweed.[Aspect 8] The fresh food in the Aspect 7, in which a content of the insoluble dietary fiber derived from the seaweed in the seaweed-containing composition is 5% to 44% by mass of solid contents.[Aspect 9] The fresh food in the Aspect 7 or Aspect 8, in which a salt content in the seaweedcontaining composition is 1% by mass or less of solid contents.[Aspect 10] The fresh food in any of the Aspect 7 to Aspect 9, in which the fresh food is a fresh food having been frozen.[Aspect 11] A composition for maintaining the freshness of fresh food, including a seaweed, in which the composition includes an insoluble dietary fiber derived from the seaweed. [Aspect 12] The composition in the Aspect 11, in which a content of the insoluble dietary fiber derived from the seaweed is 5% to 44% by mass of solid contents.[Aspect 13] The composition in the Aspect 11 or Aspect 12, in which a salt content is 1% by mass or less of solid contents.[Aspect 14] The composition in any one of the Aspect 11 to Aspect 13, in which the composition is used for a fresh food having been frozen.[Aspect 15] The composition in any one of the Aspect 11 to Aspect 14, in which the composition is in a powder form, a film form, a gel form, or a liquid form.

[0100] The method for maintaining the freshness of fresh food in any of the Aspect 1 to Aspect 6, the fresh food in any of the Aspect 7 to Aspect 10, or the composition for maintaining the freshness of fresh food in any of the Aspect 11 to Aspect 15 can solve the various conventional problems and achieve the object of the present invention.

[0101] The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and / or features of different illustrative embodiments may be combined with each other and / or substituted for each other within the scope of the present invention. Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.

[0102] This patent application is based on and claims priority to Japanese Patent Application No. 2024-120951, filed on July 26, 2024, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

Claims

[CLAIMS]1. A method for maintaining freshness of fresh food, the method comprising: coating a fresh food with a seaweed-containing composition including a seaweed, wherein the seaweed-containing composition includes an insoluble dietary fiber derived from the seaweed.

2. The method according to claim 1, wherein a content of the insoluble dietary fiber derived from the seaweed in the seaweed-containing composition is 5% to 44% by mass of solid contents.

3. The method according to claim 1, wherein a salt content in the seaweedcontaining composition is 1% by mass or less of solid contents.

4. The method according to any one of claims 1 to 3, wherein the fresh food is a fresh food having been frozen.

5. The method according to claim 4, wherein: the seaweed-containing composition includes at least one selected from the group consisting of seaweed-containing compositions in a powder form, seaweed-containing compositions in a film form, and seaweed-containing compositions in a gel form; and the coating includes attaching the seaweed-containing composition to a surface of the fresh food having been frozen.

6. The method according to claim 5, wherein: the seaweed-containing composition includes a seaweed-containing composition in a powder form; and the attaching includes attaching the seaweed-containing composition in the powder form to the surface of the fresh food having been frozen when the surface of the fresh food having been frozen is in an unfrozen state.

7. A fresh food having a surface coated with a seaweed-containing composition including a seaweed, wherein the seaweed-containing composition includes an insoluble dietary fiber derived from the seaweed.

8. The fresh food according to claim 7, wherein a content of the insoluble dietary fiber derived from the seaweed in the seaweed-containing composition is 5% to 44% by mass of solid contents.

9. The fresh food according to claim 7, wherein a salt content in the seaweedcontaining composition is 1% by mass or less of solid contents.

10. The fresh food according to any one of claims 7 to 9, wherein the fresh food is a fresh food having been frozen.

11. A composition for maintaining freshness of fresh food, the composition comprising a seaweed, wherein the composition includes an insoluble dietary fiber derived from the seaweed.

12. The composition according to claim 11, wherein a content of the insoluble dietary fiber derived from the seaweed is 5% to 44% by mass of solid contents.

13. The composition according to claim 11, wherein a salt content is 1% by mass or less of solid contents.

14. The composition according to any one of claims 11 to 13, wherein the composition is used for a fresh food having been frozen.

15. The composition according to any one of claims 11 to 14, wherein the composition is in a powder form, a film form, a gel form, or a liquid form.

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