Method for imparting heat resistance to dried fish extracts

Abstract

To provide a method for imparting heat resistance to a dried-fish extract.SOLUTION: A supercritical extract of a dried-fish extract is allowed to coexist with an aqueous solvent extract of the dried-fish extract, and a percentage of the aqueous solvent extract of the dried-fish extract and the supercritical extract of the dried-fish extract which are allowed to coexist is preferably 0.25 to 1.6 pts.wt. of an extraction raw material of the supercritical extract of the dried-fish extract to 1 pt.wt. of the aqueous solvent extract of the dried-fish extract in terms of pt.wt. of each extraction raw material.EFFECT: This makes it possible to inhibit reduction in effects of the dried-fish extract and production of unpleasant odor not only by general heating at 100°C or lower in coking and sterilizing but also by heating in heat sterilization at 100°C or higher such as retort sterilization.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for imparting heat resistance to a fish cake extract and a method for producing a fish cake extract composition having heat resistance.

Background Art

[0002] In recent years, due to the increasing preference for food, there is a demand for fish cake extracts with a strong smoked flavor and meaty texture.

[0003] Fish cakes refer to raw cakes obtained by boiling fish and then drying them, as well as naked cakes, rough cakes, and main cakes, dried cakes, and completely dried cakes that have undergone multiple processes such as mold formation and sun drying. As a typical example, dried bonito flakes have been known for a long time. Fish cake extracts are generally widely used as sauces and stocks by thinly slicing fish cakes.

[0004] In the food industry, the most common method is to heat the extraction solvent under normal pressure to extract flavor substances and aroma components from fish cakes. However, it is difficult to say that the components contained in fish cakes are sufficiently extracted, and there is a demand for fish cake extracts with a strong aroma and taste.

[0005] In addition, in the production of general liquid seasonings, a heat sterilization process is required. However, when the fish cake extract is heat sterilized, such as retort sterilization after hot filling or filling into a container, excessive heat is applied to the product, and the aroma components of the fish cakes are significantly damaged or dissipated, which has become a problem, and various studies have been conducted to solve this problem.

[0006] For example, a method using alcohol as an extraction solvent is known to extract a large amount of smoked aroma components from fish cakes. However, the alcohol extract of fish cakes has a problem of a chemical odor derived from phenols, such as phenol, cresol, and guaiacol, which are components involved in the smoked aroma. Furthermore, it is known that the extraction efficiency of water-soluble components decreases, resulting in a weakened taste.

[0007] Patent Document 1 discloses a fish broth flavor consisting of flavor components of fish flakes obtained by extracting them in a liquefied state or with subcritical or supercritical carbon dioxide in the presence of aqueous alcohol. However, a problem with the method described in Patent Document 1 is that supercritical extraction of fish flakes extracts components that cause a fishy smell.

[0008] Patent Document 2 discloses a method of incorporating a steam distillate obtained by steam distillation of dried fish into an aqueous extract of dried fish, and Patent Document 3 discloses a method for producing an extract of dried fish using a general apparatus, which includes a step of extraction under pressurized heating conditions with an aqueous organic acid solution as the extraction solvent. However, both methods aim to suppress heat degradation during extraction and improve the efficiency of extraction, and neither aims to impart heat resistance.

[0009] Patent Document 4 discloses a sauce-like oil-in-water emulsion characterized by containing oils and fats, proteins, starches, gelling agents and / or thickeners, and emulsifiers. However, the heat resistance referred to in that document refers to the stability of the emulsion, that is, the fluid state of the emulsion after heating, and not to the aroma of the extract.

[0010] As described above, none of the literature has examined a method for conferring heat resistance to dried fish extracts using supercritical extracts of dried fish. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 10-057008 [Patent Document 2] Japanese Patent Publication No. 2010-088308 [Patent Document 3] Japanese Patent Publication No. 2008-170979 [Patent Document 4] Japanese Patent Publication No. 2016-189763 [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] The present invention aims to provide a method for imparting heat resistance to fish extracts. [Means for solving the problem]

[0013] As a result of diligent research to solve the above problems, the present inventors have found that by combining a supercritical extract of dried fish with an aqueous solvent extract of dried fish, heat resistance can be imparted to the aqueous solvent extract of dried fish, thus completing the present invention.

[0014] In other words, the solutions of the present invention are as follows: Firstly, a method for imparting heat resistance to an aqueous solvent extract of dried fish products, characterized by coexisting the aqueous solvent extract of dried fish products with a supercritical extract of dried fish products. Secondly, the method according to the first, wherein the supercritical extract of dried fish products is a supercritical extract using carbon dioxide as the extraction solvent. Thirdly, the method according to either the first or second, wherein the aqueous solvent extract of dried fish products is an extract using water or ethanol as the extraction solvent. Fourthly, the method according to any one of the first to third, characterized by emulsifying the coexistence of the aqueous solvent extract of dried fish products and the supercritical extract of dried fish products. Fifthly, the method according to any one of the first to fourth, wherein the ratio of the coexistence of the aqueous solvent extract of dried fish products and the supercritical extract of dried fish products is 0.25 to 1.6 parts by weight of the supercritical extract of dried fish products to 1 part by weight of the extraction material of the aqueous solvent extract of dried fish products. Sixth, a method for producing an aqueous solvent extract of dried fish, characterized by including a step of coexisting an aqueous solvent extract of dried fish and a supercritical extract of dried fish. Seventh, a food or beverage containing the aqueous solvent extract of dried fish produced by the method described in sixth above. [Effects of the Invention]

[0015] According to the present invention, which involves coexisting a supercritical extract of fish cakes with an aqueous solvent extract of fish cakes, heat resistance can be imparted to the extract composition of fish cakes. The heat resistance of fish cakes in the present invention means that not only general heating at 100°C or lower in cooking, sterilization, etc., but also heating in heat sterilization at 100°C or higher such as retort sterilization can suppress the reduction in the effect of the fish cake extract and the generation of unpleasant odors. Further, the extract composition of fish cakes to which heat resistance is imparted by the present invention not only has heat resistance itself, but also has the effect of masking the heat deterioration odor caused by seasonings such as soy sauce and miso, which are likely to generate heat deterioration odor when heated under heat sterilization conditions and are included in food and drink products together with the extract composition of fish cakes in the present invention.

Brief Description of the Drawings

[0016] [Figure 1] Figure 1 is a graph showing the effects of Example 1, Comparative Example 1, and Comparative Example 2 on the intensity of incense, meaty aroma, and overall flavor. [Figure 2] Figure 2 is a graph showing the effects of Example 2, Comparative Example 3, and Comparative Example 4 on the intensity of incense, meaty aroma, and overall flavor. [Figure 3] Figure 3 is a graph showing the effects of Example 3, Comparative Example 5, and Comparative Example 6 on the intensity of incense, meaty aroma, and overall flavor. [Figure 4] Figure 4 shows the intensity of incense before and after retort heating in Examples 4 - 6 and Comparative Examples 7 - 12. [Figure 5] Figure 5 shows the intensity of meaty aroma before and after retort heating in Examples 4 - 6 and Comparative Examples 7 - 12. [Figure 6] Figure 6 shows the intensity of heat deterioration odor before and after retort heating in Examples 4 - 6 and Comparative Examples 7 - 12. [Figure 7] Figure 7 shows the reduction rate of the evaluation points of incense and meaty aroma before and after retort heating in Examples 4 - 6 and Comparative Examples 7 - 12.

Modes for Carrying Out the Invention

[0017] The fish cakes used as the extraction raw material of the present invention are not particularly limited in their origin and properties as long as they are generally available. Examples include bonito flakes, mackerel flakes, Sotohata flakes, tuna flakes, sea bass flakes, urume flakes, and saury flakes. Also, it may contain by-products, fragments, and shavings generated during the production of fish cakes.

[0018] The size and shape of the fish cakes are not particularly limited as long as extraction can be achieved during extraction. However, considering the size of the extraction machine and extraction efficiency, etc., those crushed to an appropriate size or shaved ones may be used.

[0019] The supercritical extraction in the present invention refers to an extraction method in which a solvent in a supercritical state is brought into contact with an extraction raw material for extraction. In the supercritical state, since the extraction solvent has both the diffusibility of a gas and the solubility of a liquid, efficient extraction can be achieved. The extraction solvent is not particularly limited as long as it can be in a supercritical state. Examples include ethanol, water, and carbon dioxide, and carbon dioxide is particularly preferred. Also, a solvent in which about 10 w / w% of ethanol is added as an extraction aid to carbon dioxide may be used for extraction.

[0020] The temperature and pressure during supercritical extraction may be any conditions under which the extraction solvent becomes a supercritical state. For example, when the extraction solvent is carbon dioxide, since it becomes a supercritical state at a temperature of 31°C or higher and a pressure of 7.38 MPa or higher, the preferred temperature when using carbon dioxide as the extraction solvent is 31°C to 55°C, and 35 to 45°C is mentioned as a more preferred temperature.

[0021] Supercritical extraction in this invention can be achieved by continuously contacting the extraction material with a supercritical extraction solvent. The amount of solvent used for extraction is not particularly limited as long as extraction is achieved, but is typically 10 to 30 parts by weight, and preferably 20 to 25 parts by weight, per 1 part by weight of the extraction material. The supply rate of the supercritical extraction solvent and the extraction time are not particularly limited as long as extraction is achieved, and may be increased or decreased as appropriate depending on the raw materials and equipment used for supercritical extraction, but the supply rate of the extraction solvent is preferably 3 mL / min to 150 mL / min, and the extraction time is preferably 30 minutes to 120 minutes.

[0022] The aqueous solvent extract of dried fish in this invention is obtained by extracting dried fish with an aqueous solvent. The aqueous solvent used for extraction is not particularly limited as long as it is water or a solvent that mixes with water in any ratio, but water, ethanol, or a mixture of water and ethanol in any ratio is preferred.

[0023] The extraction method using an aqueous solvent is not particularly limited as long as it follows a general method, and heating may or may not be performed during extraction as long as extraction is achieved. If heating is performed, the extraction temperature is preferably 50°C to 70°C, and the extraction time is preferably 1 hour or more. The extraction time may be increased or decreased as appropriate depending on the raw materials and equipment used for extraction.

[0024] Heat resistance to the dried fish extract composition can be achieved by coexisting a supercritical extract of the dried fish with an aqueous solvent extract. One method of coexistence is to mix the two. The mixing ratio when coexisting the supercritical extract and the aqueous solvent extract can be expressed as the weight ratio of the extracting materials of each extract, and it is preferable that the lower limit of the extracting material of the supercritical extract is 0.25 parts by weight per 1 part by weight of the extracting material of the aqueous solvent extract. Furthermore, it is preferable that the upper limit of the extracting material of the supercritical extract is 1.6 parts by weight, more preferably 1.5 parts by weight, even more preferably 1.4 parts by weight, and particularly preferably 1.2 parts by weight per 1 part by weight of the extracting material of the aqueous solvent extract.

[0025] The mixture obtained by mixing the two can be used as is as the heat-resistant fish extract composition of the present invention, but it may also be emulsified and used as an emulsion. The emulsification method is not particularly limited as long as it is a general method, but examples of emulsification methods include a high-speed stirrer, a high-pressure homogenizer, and an ultrasonic homogenizer, with a high-pressure homogenizer being preferred.

[0026] During emulsification, emulsifiers may be added, and there are no particular restrictions on their origin or properties as long as they are usable in food and beverages; commercially available products can be used. Examples include monoglycerol fatty acid esters, polyglycerol fatty acid esters, lecithin, and saponins, with decaglycerol monostearate, decaglycerol monooleate, and quillaja saponin being preferred.

[0027] Furthermore, a thickening agent may be added to improve the stability of the emulsion. As long as the thickening agent is suitable for use in food and beverages, there are no restrictions on its origin or properties, and commercially available products can be used. Examples include polysaccharides, and a preferred example is xanthan gum.

[0028] The average particle size of the emulsion is preferably 0.5 to 100 μm, more preferably 1 to 80 μm, and even more preferably 10 to 60 μm, as measured by laser diffraction.

[0029] The fish extract composition of the present invention can be used in any food or beverage, as long as it is a normal food or beverage. However, it is preferably used in food or beverages that use seasonings such as soy sauce or miso. Examples include dashi, noodle soup base, hot pot soup base, oden soup base, and general dishes that use fish extracts, such as prepared foods. There are no particular restrictions on the method of use. It can be used in cooking in the same way as seasonings made from dried fish flakes. [Examples]

[0030] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0031] In the examples and comparative examples, the aqueous solvent extracts of dried fish products used were a hot water extract of bonito flakes (hereinafter referred to as aqueous solvent extract A) and a 30 w / w% ethanol extract of bonito flakes (hereinafter referred to as aqueous solvent extract B), both manufactured by Mitsubishi Corporation Life Sciences Co., Ltd.

[0032] [Preparation of Fish Extract Compositions] To 1 part by weight of bonito flakes, the raw material for extraction, 20 parts by weight of supercritical carbon dioxide was continuously supplied at a flow rate of 4 mL per minute. The mixture was brought into contact with the raw material at 40°C and 30 MPa, and the extraction operation was carried out for 90 minutes to obtain a supercritical extract of bonito flakes. Next, aqueous solvent extracts A and B were mixed in a weight ratio of 4:25 with respect to the raw material to prepare an aqueous solvent extract mixture of bonito flakes. The supercritical extract and the aqueous solvent extract mixture were mixed with 1 part by weight of the raw material used to prepare the aqueous solvent extract mixture, with the raw material used for supercritical extraction in the weight ratio shown in Table 1. The mixture was then emulsified in a high-pressure homogenizer to prepare bonito flake extract compositions C to E.

[0033] [Table 1]

[0034] [Comparative Test of the Potency of Fish Extract Compositions] Aqueous solvent extracts A and B and the prepared extract compositions C to E were added to water to prepare samples for sensory evaluation, ensuring that the amount of raw material used for extraction was equal (see Table 2). Specifically, extract composition C was prepared by adding 0.001 parts by weight to 1 part by weight of water (Example 1). For comparison with Example 1, aqueous solvent extract A was prepared by adding 0.0005 parts by weight to 1 part by weight of water (Comparative Example 1), and aqueous solvent extract B was prepared by adding 0.0007 parts by weight to 1 part by weight of water (Comparative Example 2), thus equalizing the amount of raw material used in Example 1, Comparative Examples 1 and 2. In addition, extract composition D was prepared by adding 0.001 parts by weight to 1 part by weight of water (Example 2). As a comparison to Example 2, Comparative Example 3 was prepared by adding 0.0007 parts by weight of aqueous solvent extract A to 1 part by weight of water, and Comparative Example 4 was prepared by adding 0.0009 parts by weight of aqueous solvent extract B to 1 part by weight of water, thus equalizing the amounts of extraction raw materials in Examples 2, Comparative Examples 3 and 4. Furthermore, Extract Composition E was prepared by adding 0.001 parts by weight to 1 part by weight of water (Example 3). As a comparison to Example 3, Comparative Example 5 was prepared by adding 0.0009 parts by weight of aqueous solvent extract A to 1 part by weight of water, and Comparative Example 6 was prepared by adding 0.0011 parts by weight of aqueous solvent extract B to 1 part by weight of water, thus equalizing the amounts of extraction raw materials in Examples 3, Comparative Examples 5 and 6.

[0035] [Table 2]

[0036] [Evaluation Method] The fish extract was evaluated based on three items: "smoky aroma," "meaty aroma," and "overall flavor intensity." Specifically, for each amount of raw material used for extraction, a panel of nine people assigned scores on a 7-point scale (1: very weak, 2: weak, 3: slightly weak, 4: equivalent, 5: slightly strong, 6: strong, 7: very strong) to the groups with extraction composition C to E (Examples 1 to 3) and aqueous solvent extract B (Comparative Examples 2, 4, and 6), using the group with extraction composition A (Comparative Examples 1, 3, and 5) as the baseline (4 points). The average of these scores was then calculated. The standard error was also calculated for the mean values, and statistical significance was determined by a two-tailed t-test. Items showing a significant difference between the Examples and Comparative Examples were marked with "*" and "$".

[0037] [Results] The results are shown in Figures 1-3. In each figure, the bar graph represents the average sensory evaluation score, and the error bars represent the standard error of the sensory evaluation score. The test groups using extract compositions C-E (Examples 1-3) showed significantly higher values ​​in all items compared to the test groups using aqueous solvent extract A (Comparative Examples 1, 3, and 5), demonstrating superiority in smoky aroma, meaty aroma, and overall flavor intensity. Furthermore, the meaty aroma showed significantly higher values ​​compared to the test groups using aqueous solvent extract B (Examples 2, 4, and 6). In addition, the smoky aroma and overall flavor intensity showed significantly higher values ​​in Figures 2 and 3. From the above, it was shown that even with the same amount of raw materials used for extraction, it is possible to provide extract compositions that are superior in smoky aroma, meaty aroma, and overall flavor intensity.

[0038] [Comparative Test of Heat Resistance of Fish Extract Compositions] Aqueous solvent extracts A and B and extract compositions C to E were added to commercially available hot pot soup base so that the amount of raw material used for extraction was equal, and samples for sensory evaluation were prepared. Specifically, a sample for sensory evaluation was prepared by adding 0.005 parts by weight of extract composition C to 1 part by weight of water (Example 4). As a comparison to Example 4, a sample was prepared by adding 0.0026 parts by weight of aqueous solvent extract A to 1 part by weight of water (Comparative Example 7) and a sample was prepared by adding 0.0033 parts by weight of aqueous solvent extract B to 1 part by weight of water (Comparative Example 8), and these were used as samples for sensory evaluation. In addition, a sample for sensory evaluation was prepared by adding 0.005 parts by weight of extract composition D to 1 part by weight of water (Example 5). As a comparison to Example 5, comparative examples 9 and 10 were prepared by adding 0.0035 parts by weight of aqueous solvent extract A to 1 part by weight of water and 0.0044 parts by weight of aqueous solvent extract B to 1 part by weight of water, respectively, and these were used as samples for sensory evaluation. A sample for sensory evaluation was prepared by adding 0.005 parts by weight of extract composition E to 1 part by weight of water (Example 6). As a comparison to Example 6, comparative examples 11 and 12 were prepared by adding 0.0043 parts by weight of aqueous solvent extract A to 1 part by weight of water and 0.0054 parts by weight of aqueous solvent extract B to 1 part by weight of water, respectively, and these were used as samples for sensory evaluation. Furthermore, each test group was retort heated (120°C, 5 minutes) to prepare samples for evaluation after heating.

[0039] [Evaluation Method] Heat resistance was evaluated for three items: "smoky aroma," "meat aroma," and "soy sauce heating deterioration odor." Specifically, a panel of nine people assigned scores on a 7-point scale (1: very weak, 2: weak, 3: slightly weak, 4: equivalent, 5: slightly strong, 6: strong, 7: very strong) to test groups with bonito extract compositions C to E added (Examples 4 to 6) and bonito extract B added (Comparative Examples 8, 10, and 12), using the pre-retort heating score (4 points) as the baseline. The average of these scores was then calculated. The standard error was also calculated for the average value of the evaluation.

[0040] [Results] Figures 4-7 show the results. In Figures 4-6, the graphs represent the average sensory evaluation scores, and the error bars represent the standard error of the sensory evaluation scores. Figure 7 shows the rate of decrease in sensory evaluation scores before and after retorting, as shown in the results of Figures 4 and 5. Examples 4-6 showed a high additive effect in the smoky aroma and meaty aroma categories, both before and after heating, compared to the test group using the same extraction raw materials. In particular, for meaty aroma, it was clear that the decrease in evaluation scores before and after retorting heating was significantly suppressed in Example 6. Furthermore, from the sensory evaluation results of the intensity of heat-degraded odor, it was clear that each test group in the Examples tended to have suppressed heat-degraded odor, and that the heat-degraded odor was suppressed as the amount of extraction raw materials used increased. On the other hand, in each test group of the Comparative Examples, no clear correlation was found between the amount of extraction raw materials used and the sensory evaluation score for heat-degraded odor, indicating that the heat-degraded odor was not suppressed. Furthermore, regarding the rate of decrease in sensory evaluation scores before and after retort heating, each test group in the Examples tended to show a lower rate compared to each test group in the Comparative Examples, and in particular, the decrease in sensory evaluation scores was significantly suppressed in the meat aroma of Example 6. From the above, it became clear that even when added to ordinary food and beverages, it shows excellent effects in terms of smoky aroma, meat aroma, and overall flavor. In addition, since unpleasant odors such as heat degradation odors generated by retort heating were suppressed, it is considered that heat resistance was imparted to the dried fish extract.

[0041] The present invention makes it possible to impart heat resistance to fish extract compositions, and to provide fish extract compositions with high levels of smoky and meaty aroma.

Claims

[Claim 1] A method for imparting heat resistance to an aqueous solvent extract of dried fish, characterized by emulsifying a mixture of an aqueous solvent extract of dried fish and a supercritical extract of dried fish, The ratio of the aqueous solvent extract of dried fish and the supercritical extract of dried fish to be coexisting is such that, in terms of parts by weight of each extracting material, there are 0.25 to 1.6 parts by weight of the supercritical extract of dried fish for every 1 part by weight of the aqueous solvent extract of dried fish. The supercritical extract of the fish flakes is a supercritical extract using carbon dioxide as the extraction solvent. The aqueous solvent extract of the dried fish is an extract obtained using hot water or aqueous ethanol as the extraction solvent. A method for conferring heat resistance to an aqueous solvent extract of the dried fish products.

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