Method for reducing fishy odor, and processed marine product food with reduced fishy odor

Abstract

The present invention addresses the problem of providing a processed marine product food that has reduced fishy odor, maintains good fishy flavor, and has a good overall flavor. It has been found that, by including, in a processed marine product food, an oil / fat composition in which aqueous phases each having a sweetener dissolved therein are dispersed in an oily phase, it becomes possible to reduce fishy odor contained in the processed marine product food, and to obtain a processed marine product food in which fishy odor is reduced, good fishy flavor is maintained, and the overall flavor is good.

Description

A method for reducing fishy odor, and a processed seafood product with reduced fishy odor

[0001] Related Application This application claims the benefit of priority from Japanese Patent Application No. 2025-055834 filed on March 28, 2025. The entire content of the priority application is incorporated herein by reference.

[0002] The present invention relates to a method for reducing fishy odor, and a processed seafood product with reduced fishy odor.

[0003] When producing processed foods using fish and shellfish, it is important that the fish and shellfish are fresh. If the freshness of fish and shellfish is not in a favorable state, the processed food produced through each processing step may have a fishy odor. Although this problem can be solved by methods for maintaining the freshness of fish and shellfish themselves, the management and other controls are complicated, and it is not necessarily easy to implement. Another solution is a method for reducing fishy odor. For example, Patent Document 1 discloses a fishy odor reducing composition containing, as active ingredients, reduced starch syrup having a sugar composition of 35 mass% or more monosaccharides and 25 mass% or more disaccharides, and a sugarcane-derived extract.

[0004] Japanese Unexamined Patent Publication No. 2020-014420

[0005] Patent Document 1 describes that the combined use of specific reduced starch syrup and sugarcane-derived extract reduces fishy odor and imparts fish flavor. However, depending on the type of processed food containing seafood, even if the fishy odor reducing effect is obtained, the fish flavor is also reduced. In addition, from the examples of Patent Document 1, to reduce fishy odor, the specific reduced starch syrup is blended in an amount of 2.45% by weight or more based on the weight of fish. This is a situation where the flavor of saccharides may remain strongly in the processed food. From these, it can be said that achieving both reduction of fishy odor and maintenance of rich fish flavor is a difficult problem. In addition, a method that can solve the problem of fishy odor reduction by adding a smaller amount of saccharides has been desired.

[0006] An object of the present invention is to obtain a processed seafood product in which fishy odor is reduced, good fish flavor is maintained, and the overall flavor of the food is favorable.

[0007] The inventors of this invention conducted intensive research to solve the above problems and discovered that by including an oil and fat composition in which a sweetener dissolved in an aqueous phase is dispersed in an oil phase in processed seafood products, the fishy odor contained in the processed seafood products can be reduced, and that processed seafood products with a reduced fishy odor and a good fishy flavor can be obtained, resulting in a processed seafood product with a good overall flavor. Thus, the present invention was completed.

[0008] In other words, the present invention relates to: [1] a method for reducing fish odor using an oil and fat composition in which a sweetener is dissolved in an aqueous phase dispersed in an oil phase; [2] the method for reducing fish odor according to [1], wherein the solid content concentration of the sweetener (sucrose equivalent) in the oil and fat composition is 0.01 to 6% by mass, where sucrose equivalent refers to the value obtained when the sweetness of the sweetener is converted to the sweetness of sucrose, with the sweetness of sucrose being set to 1; [3] the method for reducing fish odor according to [1] or [2], wherein the sweetener is one or more selected from the group consisting of maltose, glucose, sucrose, and monk fruit extract; [4] a processed seafood product containing an oil and fat composition in which a sweetener is dissolved in an aqueous phase dispersed in an oil phase; and [5] the processed seafood product according to [4], wherein the amount of sweetener (sucrose equivalent) brought into the processed seafood product from the aqueous phase of the oil and fat composition is 1 to 2000 ppm in the processed seafood product. [6] A method for producing processed seafood products, comprising all of the following steps (A) and (B): (A) a step of dispersing an aqueous phase in which a sweetener is dissolved in an oil phase to produce an oil and fat composition; (B) a step of producing processed seafood products by incorporating the oil and fat composition obtained in step (A) as a raw material for processed seafood products.

[0009] According to the present invention, it is possible to provide processed seafood products that have reduced fishy odor, maintain a good fishy flavor, and have a good overall flavor.

[0010] The present invention will be described in detail below. The fishy odor according to the present invention refers to an off-flavor derived from marine products, as described later, and is an off-flavor that can be felt when consuming processed marine products made using marine products. A fishy or muddy taste is also considered a fishy odor according to the present invention. Fishy odor is generally generated by a decline in the freshness of marine products or by processing, and its components are known to include low-molecular-weight volatile molecules such as volatile nitrogen-containing compounds, volatile fatty acids, volatile carbonyls, and volatile sulfur-containing compounds (organic amines such as trimethylamine and dimethylamine).

[0011] This invention relates to a method for reducing fishy odor, maintaining a good fish flavor, and obtaining a good overall flavor in processed foods by using an oil composition in which an aqueous phase containing the following sweeteners is dispersed in an oil phase. There are various methods for controlling the flavor of food, for example, sometimes enhancing a specific flavor, and sometimes reducing an undesirable flavor. Moreover, the flavors being targeted are often different. It is difficult to lump all of these different flavors and different control methods together as simply "flavor control." This invention focuses solely on reducing fishy odor.

[0012] The processed seafood products according to the present invention refer to all processed foods that use seafood as the main ingredient. Seafood here refers to items caught in bodies of water such as the sea, lakes, and clear streams, and examples include fish, shellfish, shrimp, crabs, octopus, squid, sea urchins, sea cucumbers, etc. As long as the seafood is edible, it can be used in any state, such as raw, pre-processed, or frozen.

[0013] The form of the processed seafood product according to the present invention is not particularly limited as long as it contains seafood. Examples include boiled fish, boiled fish, teriyaki fish, tsukudani (fish simmered in soy sauce), oil-packed fish, fried fish, dried fish such as salted and dried fish, dried products, smoked products, processed fish products (kamaboko, chikuwa, hanpen, fish ham, crab sticks, fish sausage, fish hamburger, fish balls, etc.), delicacies, fish sauce, etc. Processed fish products are more preferred. Furthermore, the processed seafood product can be in various forms for distribution, such as refrigerated, frozen, chilled, retort, or canned.

[0014] The processed seafood product according to the present invention may contain plant protein materials in addition to seafood. Examples of such plant protein materials include those produced from oilseeds such as soybeans, peas, mung beans, chickpeas, broad beans, rapeseed, cottonseed, peanuts, sesame, safflower, sunflower, corn, and other safflower seeds, or from grain seeds such as rice, barley, and wheat. The plant protein material can be used in any form, such as powder, granules, or textured form. Oil-in-water emulsions such as emulsion curds, which are used to improve the binding properties between doughs, can also be used. In this context, emulsion curd refers to a homogenized emulsion containing powdered plant protein material, water, and oil. The protein content in the plant protein material is preferably at least 30% by mass by dry weight, more preferably 40% by mass or more, and even more preferably 50% by mass. It is preferable that the processed seafood product according to the present invention contains 1% by mass or more of the plant protein material by dry weight. More preferably, the amount is 3% by mass or more, even more preferably 5% by mass or more, and even more preferably 7% by mass or more. The effects of the present invention can be more favorably obtained even if plant protein material is included.

[0015] The oil and fat composition of the present invention must include an oil phase. The oil phase of the present invention consists of oils and fats and components that dissolve in oils and fats. There are no particular restrictions on the oils and fats that can be used in the present invention as long as they are edible. More preferably, the oils and fats are vegetable oils. Specific examples of vegetable oils include soybean oil, cottonseed oil, corn oil, safflower oil, olive oil, palm oil, rapeseed oil, rice oil, rice bran oil, sesame oil, kapok oil, coconut oil, palm kernel oil, cocoa butter, and hydrogenated oils, fractionated oils, and transesterified oils of these. Oils and fats mixed from two or more of these can also be used. More preferably, the melting point of the vegetable oil is 40°C or lower. Even more preferably, it is 35°C or lower. Note that the melting point referred to here is the rising melting point. Appropriate vegetable oils can be selected according to the properties and physical characteristics of the processed seafood product. In addition to the vegetable oil, animal fats such as lard can also be used in combination in the oil phase. The amount of oil phase in the oil composition is preferably 99.95% by mass or less. More preferably 70 to 99.9% by mass, and even more preferably 80 to 99.9% by mass. By using an appropriate amount of oil phase, the fishy odor in the processed seafood product can be reduced.

[0016] The oil and fat composition of the present invention requires that the aqueous phase in which the sweetener is dissolved is dispersed in the oil phase. The sweetener referred to here can be a monosaccharide such as glucose and fructose, a disaccharide such as maltose and sucrose, sugar alcohols such as maltitol, sucralose, monk fruit extract, stevia, and other high-intensity sweeteners. Molasses and high-fructose corn syrup containing these can also be used. The sweetener may be extracted from natural products or artificially synthesized. More preferably, maltose, monk fruit extract, glucose, sucrose, even more preferably maltose, monk fruit extract, and most preferably maltose. Furthermore, a sweetener derived from natural products is even more preferable. By using an appropriate sweetener, the fishy odor in the processed seafood product can be reduced.

[0017] The solid content concentration of the sweetener (sucrose equivalent) in the oil and fat composition of the present invention is preferably 0.01 to 6% by mass. More preferably, it is 0.03 to 5% by mass, and even more preferably, 0.03 to 4.5% by mass. By including a suitable concentration of sweetener in the oil and fat composition, the fishy odor in the processed seafood product can be reduced. The sucrose equivalent value refers to the value obtained by converting the sweetness of the sweetener to the sweetness of sucrose, with the sweetness of sucrose being set to 1. Specifically, the sweetness of maltose is approximately 0.375. When using maltose in the oil and fat composition, an oil and fat composition having the above-mentioned solid content concentration can be obtained by incorporating 2.7 times the amount of maltose as sucrose (1 / 0.375 = 2.7). The sweetness of sucralose is 600. When sucralose is used in the oil and fat composition, an oil and fat composition having the above-mentioned solid content concentration can be obtained by incorporating sucralose in an amount equal to 0.002 times that of sucrose.

[0018] In the oil and fat composition of the present invention, it is necessary that the aqueous phase in which the sweetener is dissolved is dispersed in the oil phase, and the particle size of the aqueous phase is preferably 50 to 2000 nm. More preferably, this value is 60 to 1200 nm, even more preferably 70 to 800 nm, and even more preferably 70 to 700 nm. If the particle size of the aqueous phase in the oil phase is appropriate, the fishy odor in the processed seafood product can be reduced. The particle size of the aqueous phase can be obtained by the following measurement method: Dilute 10 μL of the oil and fat composition in 2 mL of hexane and measure it with a Zetasizer Nano S (manufactured by Malvern) (temperature 20°C, equilibrium time 240 seconds, using a glass cell).

[0019] In the oil phase of the oil and fat composition of the present invention, oil-soluble components can be dissolved to the extent that they do not hinder the effects of the present invention. Specifically, examples include oil-soluble emulsifiers, colorants, and fragrances. In particular, since the present invention adopts a so-called water-in-oil emulsion structure in which the aqueous phase is finely dispersed in the oil phase, it is preferable to use an oil-soluble emulsifier that has the function of stabilizing the emulsion structure. The oil-soluble emulsifier referred to here is an emulsifier that dissolves in oils and fats and has an HLB of 7 or less. Specifically, one or more selected from polyglycerin esters, sugar esters, sorbitan esters, and monoglycerin fatty acid esters are preferred. More preferably, polyglycerin esters, sugar esters, and distilled monoglycerides are preferred, and even more preferably, polyglycerin esters are preferred. Of these, polyglycerin condensed ricinoleic acid ester is the most preferred. Polyglycerin condensed ricinoleic acid ester is sometimes abbreviated as PGPR.

[0020] An example of a method for producing the oil and fat composition of the present invention is shown below. An aqueous phase is prepared by dissolving a sweetener in water. The type of sweetener used and the concentration of the sweetener in the aqueous phase are as described in this application. Oils and fats are then dissolved, and if necessary, an oil-soluble emulsifier is dissolved in the oil phase to prepare the oil phase. Next, the obtained aqueous phase is dispersed in the oil phase to obtain the oil and fat composition. Various methods can be used for dispersion, and specifically, a high-pressure homogenizer, an ultrasonic emulsifier, or a two-liquid impact type emulsifier, also known as a wet jet mill, can be used. By using an appropriate emulsifier, a predetermined oil and fat composition can be obtained. When using a high-pressure homogenizer, the general emulsification conditions are 10 to 30 passes at 30 to 40 MPa. This makes it possible to set the particle size of the aqueous phase in the oil phase to 50 to 2000 nm.

[0021] The amount of sweetener (sucrose equivalent) introduced from the aqueous phase of the oil and fat composition of the present invention into the processed seafood product of the present invention is preferably 1 to 2000 ppm in the processed seafood product. More preferably 2 to 1500 ppm, even more preferably 3 to 1000 ppm, and even more preferably 5 to 800 ppm. If the amount of sweetener introduced by the aqueous phase of the oil and fat composition is appropriate, the fishy odor in the processed seafood product can be reduced. Monosaccharides and disaccharides are more effective than high-intensity sweeteners, with 5 to 200 ppm being even more preferable, and 5 to 150 ppm being the most preferable.

[0022] The oil and fat composition of the present invention is preferably present in the processed seafood product at an amount of 0.5 to 20% by mass. More preferably at an amount of 2 to 15% by mass. When the amount of the oil and fat composition contained in the processed seafood product is appropriate, the fishy odor in the processed seafood product can be reduced.

[0023] ■Method for Manufacturing Processed Seafood Products An example of a method for manufacturing processed seafood products is given. Raw materials including minced seafood and salt are uniformly mixed to obtain a rough dough. The oil and fat composition of the present invention is added to the rough dough as needed, along with vegetable protein material, water, oils and fats, sugar, starch, flavorings, thickening polysaccharides, vegetables, etc., and mixed (mixing step). The rough dough is molded into the desired size and shape and heated to obtain processed seafood products. Mixers, food processors, ball cutters, silent cutters, etc. can be used as mixers. Examples of molding include ball shapes and rolled shapes. Examples of heating include steaming, baking, frying, boiling, oven heating, and retort heating. Processed seafood products can be frozen after cooling. The oil and fat composition can be added at any time during the mixing step of the raw materials used in the processed seafood product.

[0024] The processed seafood products according to the present invention may use known materials and food additives as appropriate, as long as they do not interfere with the effects of the present invention. Specifically, examples include phosphates, eggs, salt, colorants, seasonings, preservatives, antioxidants, spices, and the like.

[0025] Furthermore, this invention can also be considered as an invention of a processed seafood food containing vegetable oil with reduced fishy odor. Specifically, it is characterized by the dispersion of the aqueous phase in which the sweetener is dissolved within the oil phase.

[0026] Furthermore, the present invention can also be considered a method for producing processed seafood products containing vegetable oils, in which the fishy odor is reduced. Specifically, it is characterized by dispersing an aqueous phase in which a sweetener is dissolved in an oil phase.

[0027] The present invention will be described in more detail below. Unless otherwise specified, "parts" and "%" in this text refer to mass.

[0028] ■Method for measuring particle size in the aqueous phase: 10 μL of the oil composition was diluted in 2 mL of hexane and measured using a Zetasizer Nano S (manufactured by Malvern Corporation). The measurement conditions were: temperature 20°C, equilibrium time 240 seconds, glass cell used, measurement angle 173°, positioning method: optimal position selection, with automatic decay option enabled.

[0029] Each oil and fat composition was prepared according to the formulations shown in Table 1. The preparation method was as follows: Raw materials classified as an aqueous phase and raw materials classified as an oil phase were mixed to obtain an aqueous phase and an oil phase. The oil phase was stirred, and the aqueous phase was gradually added thereto to prepare the approximate composition. The approximate composition was subjected to a high-pressure homogenizer (10 passes at 30-40 MPa) to obtain each oil and fat composition. Each oil and fat composition was stored in a freezer overnight. The particle sizes of each oil and fat composition are shown in Table 1.

[0030] The raw materials used in the production of the oil and fat composition are as follows. Note that the sweetness level of the sweeteners is a relative value with sucrose set to 1. • Vegetable oil 1: "Unishort MJ" manufactured by Fuji Oil Co., Ltd. (melting point 26℃) • Vegetable oil 2: "Rapeseed oil" manufactured by Fuji Oil Co., Ltd. (melting point below 0℃) • Vegetable oil 3: "Nutromaster S" manufactured by Fuji Oil Co., Ltd. (melting point 32℃) • Maltose: "G2 Syrup MS-720 [N]" manufactured by Sanwa Starch Industry Co., Ltd. (maltose syrup, sweetness 0.375, solids 75%) • Glucose: sweetness 0.65, solids 98% • Sucralose: "Sucralose" manufactured by San-Ei Gen F.F.I. Co., Ltd. (sweetness 600, solids 99%) • Monk fruit extract: "Sun Nature M50" manufactured by San-Ei Gen F.F.I. Co., Ltd. (sweetness 300, solids 97%) • Emulsifier: "Poem PR-100" manufactured by Riken Vitamin Co., Ltd. (Polyglycerin condensed ricinoleate ester, HLB: 1)

[0031] ■Table 1

[0032] ■Study 1: Manufacturing of fried fish cakes Fried fish cakes were manufactured according to the formulation in Table 2. The manufacturing method for fried fish cakes was as follows: Frozen Alaska pollock surimi (Alaska pollock land-based grade 2 surimi) was thawed to approximately -5°C using a cutter mixer (Robot Coupe, model: R-3D), and then coarsely ground. When the temperature of the surimi rose to 0°C to 4°C, salt was added and the mixture was ground with salt for 2 minutes. Sugar, seasonings, and various oil and fat compositions were then added and mixed for 2 minutes. After that, starch and water were added to obtain the dough for each type of fried fish cake. The obtained dough was shaped into hemispherical shapes with a diameter of 30 mm and a thickness of 15 to 20 mm using an ice cream scoop. The shaped dough was fried at 160 to 175°C for 5 minutes. Furthermore, the term "sweeteners in processed foods" refers to sweeteners other than sugar, excluding sugar which was added in the same proportion in each test group.

[0033] The raw materials used in Study 1 were as follows: • Monosodium glutamate: Ajinomoto Co., Inc.'s umami seasoning "Ajinomoto" • Starch: Nippon Denko Chemical Co., Ltd.'s tapioca starch "PB-108"

[0034] ■Evaluation Method: The evaluation was conducted by nine experienced panelists, and the decision was made by consensus. The evaluation items and criteria were the following two items, and a relative comparison was made with reference examples. For the overall evaluation, a score of "3 points or higher" in both items was considered a passing grade.

[0035] - Presence or absence of fishy smell 1 point: More fishy smell than in Reference Example 1. 2 points: Similar fishy smell to Reference Example 1. 3 points: Weaker fishy smell than in Reference Example 1. 4 points: Significantly weaker fishy smell than in Reference Example 1. 5 points: Almost no fishy smell compared to Reference Example 1. - Overall flavor 1 point: Less fishy flavor than in Reference Example 1. 2 points: Slightly more fishy flavor than in Reference Example 1. 3 points: Similar fishy flavor to Reference Example 1, but also a taste of sweetener. 4 points: Similar fishy flavor to Reference Example 1, but also a slight taste of sweetener. 5 points: Similar fishy flavor to Reference Example 1, and the overall flavor of the processed seafood product was good.

[0036] ■Table 2

[0037] In Comparative Example 1, which directly incorporated maltose, the fishy odor was equivalent to that of Reference Example 1. In Comparative Example 2, which increased the amount of maltose, the fishy odor was reduced compared to Reference Example 1, but the sweetness was too strong, resulting in an overall poor flavor. On the other hand, in Examples 1 to 6, where the sweetener was dissolved in the aqueous phase and then dispersed in the oil phase, the fishy odor was reduced compared to Reference Example 1, and the overall flavor tended to be better, despite the smaller amount of sweetener compared to when the sweetener was directly incorporated. In particular, the processed seafood products in Examples 1 to 3 showed reduced fishy odor and a good overall flavor.

[0038] ■ Study 2: Manufacturing of fried fish cakes Fried fish cakes containing plant-based protein material were manufactured according to the formulation in Table 3. The manufacturing method for fried fish cakes containing plant-based protein material was as follows: Frozen Alaska pollock surimi was thawed to approximately -5°C using a cutter mixer, and then coarsely ground. Midway through, plant-based protein material, water, and rapeseed oil were added and mixed further. When the temperature of the surimi rose to 0°C to 4°C, salt was added and salt grinding was performed for 2 minutes. Next, sugar, seasonings, and each oil composition were added and mixed for 2 minutes. After that, starch and water were added to obtain the dough for each fried fish cake. The obtained dough was shaped into hemispherical shapes with a diameter of 30 mm and a thickness of 15 to 20 mm using an ice cream scoop. The shaped dough was fried at 160 to 175°C for 5 minutes. The evaluation of the fried fish cakes containing each of the obtained plant protein materials was performed using the same method as in Study 1, and was conducted as a relative evaluation against Reference Example 2.

[0039] The raw materials used in Study 2 were as follows: • Powdered isolated soy protein: "Fuji Pro FM" manufactured by Fuji Oil Co., Ltd.

[0040] ■Table 3

[0041] Compared to Reference Example 2, Examples 7-9 showed a reduction in fishy odor and a tendency towards improved overall flavor in the processed seafood products. In particular, Example 8 yielded the processed seafood product with the best flavor.

[0042] ■Study 3: Production of sardine balls Sardine balls were produced according to the formulation shown in Table 4. The method for producing sardine balls was as follows. Specifically, frozen Alaska pollock surimi was thawed to approximately -5°C using a cutter mixer, then coarsely ground. Thereafter, deboned sardine meat was added and further mixed. When the temperature of the sardine ball dough rose to 0°C to 4°C, salt was added, and salt grinding was performed for 2 minutes. Next, sugar, seasonings, and the oil or fat composition of Example 1 were added and mixed for 2 minutes. Thereafter, starch and water were added to obtain each sardine ball dough. The dough temperature at this time was 15°C to 20°C. The obtained dough was molded into a hemispherical shape with a diameter of 30 mm and a thickness of 15 to 20 mm using a disher. The molded dough was steamed at 90°C for 20 minutes in an oven (convection oven "SCC-WE101" manufactured by Rational Co., Ltd.). Evaluation of each obtained sardine ball was performed as a relative evaluation with respect to Reference Example 3, using the same method as in Study 1.

[0043] ■Table 4

[0044] Compared with Reference Example 3, Examples 10 and 11 had reduced fishy odor, and a tendency that the overall flavor of the processed seafood food was favorable was observed. In particular, the processed seafood food with the most favorable flavor was obtained in Example 11.

Claims

1. A method for reducing fishy odor using an oil composition in which a sweetener dissolved in an aqueous phase is dispersed in an oil phase.

2. The method for reducing fishy odor according to claim 1, wherein the solid content concentration of the sweetener (sucrose equivalent) in the oil and fat composition is 0.01 to 6% by mass. Sucrose equivalent refers to the value obtained by converting the sweetness of the sweetener to the sweetness of sucrose, with the sweetness of sucrose being set to 1.

3. The method for reducing fishy odor according to claim 1 or 2, wherein the sweetener is one or more selected from the group consisting of maltose, glucose, sucrose, and monk fruit extract.

4. A processed seafood product containing an oil and fat composition in which a sweetener is dissolved in an aqueous phase and dispersed in an oil phase.

5. The processed seafood product according to claim 4, wherein the amount of sweetener (sucrose equivalent) introduced from the aqueous phase of the oil and fat composition into the processed seafood product is 1 to 2000 ppm in the processed seafood product.

6. A method for producing processed seafood products, comprising all of the following steps (A) and (B): (A) A step of dispersing an aqueous phase in which a sweetener is dissolved in an oil phase to produce an oil and fat composition. (B) A step of producing processed seafood products by incorporating the oil and fat composition obtained in step (A) as a raw material for processed seafood products.

7. A method for producing a processed seafood product, wherein in step (B), the oil and fat composition is included such that the amount of sweetener (sucrose equivalent) introduced from the aqueous phase of the oil and fat composition into the processed seafood product is 1 to 2000 ppm in the processed seafood product.

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