JPWO2020045406A1 - An oyster flavor reduction inhibitor, an aqueous solution for holding live oysters, and a method for producing oysters with suppressed flavor deterioration. - Google Patents

Abstract

An oyster flavor reduction inhibitor containing at least one extract selected from the group consisting of enokitake extract, yeast extract and barley extract. It is preferable that the extract is contained in an amount of 50 to 100% by weight based on the dry weight of the oyster flavor reduction inhibitor. An aqueous solution for holding live oysters can be provided by using the oyster flavor reduction inhibitor.

Description

The present invention relates to an oyster flavor reduction inhibitor, an aqueous solution for holding live oysters, and a method for producing oysters in which flavor deterioration is suppressed.

Oysters are said to be sea milk and are popular because they have a milky, rich flavor and high nutritional value. However, if raw oysters after landing are refrigerated and then transported or stored, there is a problem that the flavor of the oysters gradually deteriorates during the transportation or storage, and the area where the oysters can be transported while maintaining the flavor is limited. There is also a method of transporting seafood alive at a constant temperature by putting seawater in a water tank and supplying oxygen, but this method requires a large device for temperature control and oxygen control, which is desirable in terms of economic efficiency. It wasn't. Furthermore, a method of freezing raw oysters immediately after landing and then transporting or storing them is also common, but according to this method, the flavor of oysters is significantly impaired due to sublimation of water during freezing and drip during thawing. There was a problem that so-called freezing failure occurred.

Patent Document 1 discloses a freshness-preserving agent for seafood containing an organic acid such as α, α-trehalose, citric acid, and / or a polyphenol as an active ingredient for the purpose of maintaining the freshness of fresh seafood. Has been done. However, when this freshness preserving agent is applied to oysters, there is a problem that the flavor and color of the components contained in the freshness preserving agent adhere to the oysters and the original flavor and color tone of the oysters are impaired. Further, Patent Document 2 discloses a method in which a quality improving agent containing an alkaline substance and sodium lactate or potassium lactate is brought into contact with the shellfish in order to soften the shellfish in a short time and improve the texture and taste. There is. However, the method is intended to soften shellfish, and is not intended to suppress the deterioration of oyster flavor that may progress after landing of oysters.

Japanese Unexamined Patent Publication No. 2003-225847 JP-A-2010-154799

An object of the present invention is an oyster flavor reduction inhibitor used to suppress the deterioration of oyster flavor that may progress after landing of oysters and to provide raw oysters that retain the original milky and rich flavor. , An aqueous solution for holding live oysters, and a method for producing oysters in which deterioration of flavor is suppressed.

As a result of diligent research to solve the above problems, the present inventors held live oysters in an aqueous solution containing a specific amount of a specific extract and a specific sodium chloride concentration for a specific time, thereby transporting the live oysters thereafter. Alternatively, they have found that the deterioration of the flavor of oysters that may occur during storage can be suppressed, and have completed the present invention.

That is, the first aspect of the present invention relates to an oyster flavor reduction inhibitor containing at least one extract selected from the group consisting of enokitake mushroom extract, yeast extract and barley extract. The oyster flavor reduction inhibitor preferably contains the extract in an amount of 50 to 100% by weight based on the dry weight of the oyster flavor reduction inhibitor.
The second aspect of the present invention is to contain at least one extract selected from the group consisting of an enokitake extract, a yeast extract and a barley extract in a solid content of 0.1 to 800 ppm and a sodium chloride concentration of 2 to 3. It relates to an aqueous solution for holding live barley, which is 5% by weight. The aqueous solution for holding the live oyster may be one using the agent for suppressing the flavor deterioration of the oyster.
A third aspect of the present invention relates to live oysters that are kept in the aqueous solution having a temperature in the range of 1 to 25 ° C. for 10 to 15,000 minutes while being supplied with oxygen.
The fourth aspect of the present invention relates to raw oysters in which the live oysters are refrigerated or frozen.
Fifth of the present invention contains at least one extract selected from the group consisting of enokitake extract, yeast extract and barley extract in terms of solid content of 0.1 to 800 ppm and a sodium chloride concentration of 2 to 3. A method for producing an oyster with suppressed flavor deterioration, which comprises holding a live oyster for 10 to 15,000 minutes in a state where oxygen is supplied in an aqueous solution having a temperature in the range of 5% by weight and a temperature of 1 to 25 ° C. Regarding.

According to the present invention, an oyster flavor reduction inhibitor used to suppress the deterioration of oyster flavor that may progress after landing of oysters and to provide raw oysters that retain the original milky and rich flavor. , An aqueous solution for holding live oysters, and a method for producing oysters in which flavor deterioration is suppressed can be provided. According to the present invention, it is possible to suppress a decrease in the flavor of oysters when the raw oysters are refrigerated or frozen, and it is also possible to suppress a freezing disorder even when the raw oysters are frozen. In addition, it is possible to prevent the flavor and color derived from the flavor reduction inhibitor from adhering to the raw oysters. According to the present invention, since the deterioration of the flavor of oysters is suppressed, it is possible to expand the transportable area of raw oysters that retain the original milky and rich flavor.

Hereinafter, the present invention will be described in more detail. The oyster flavor reduction inhibitor of the present invention is for suppressing the milky and rich flavor reduction of oysters that may occur after landing of oysters, especially during refrigeration or freezing of raw oysters, and contains a specific extract. To do. The oyster flavor reduction inhibitor of the present invention is used by blending with salt water, and the live oyster is treated with salt water containing the oyster flavor reduction inhibitor of the present invention before refrigerating or freezing the raw oyster. This makes it possible to achieve the object of the present invention.

The extract used in the oyster flavor reduction inhibitor of the present invention is at least one extract selected from the group consisting of enokitake mushroom extract, yeast extract and barley extract.

The enokitake extract is not particularly limited, but for example, an extract obtained by extracting the offspring of enokitake with an extraction solvent such as hot water and / or alcohol, or after decomposing the offspring of enokitake with an enzyme or an alkaline solvent, heat is applied. Examples thereof include an extract extracted with an extraction solvent such as water or alcohol, a concentrated solution obtained by concentrating these extracts, the extract or a powder obtained by drying the concentrated solution, and the like. These extracts are preferably extracts that do not use a solvent other than water or naturally-derived ethanol from the viewpoint of consumers' safety and security. However, considering the cost, water is more preferable.

The temperature of the extraction solvent at the time of extraction may vary in a suitable temperature range depending on the type of the extraction solvent, but generally, the boiling point (° C.) of the extraction solvent under atmospheric pressure is -20 ° C to that of the extraction solvent under atmospheric pressure. Boiling point (° C.) is preferred. If the temperature of the extraction solvent at the time of extraction is lower than the boiling point (° C.) -20 ° C of the extraction solvent under atmospheric pressure, the effect of suppressing the flavor deterioration of oysters may be weakened, and the boiling point (° C.) under atmospheric pressure may be weakened. ), The extraction method may be complicated because special pressurizing equipment is required.

The enokitake refers to a species of Flameluina velutipes, which is a kind of mushroom of the family Physalacriaceae. Although not particularly limited, artificially cultivated white and bean sprout-like commercially available enokitake mushrooms can be used. Such commercially available enokitake mushrooms are generally edible and easily available.

The yeast extract is not particularly limited, but for example, an extract obtained by extracting yeast with an extraction solvent such as hot water or alcohol, or an extract obtained by decomposing yeast with an enzyme or an alkaline solvent and then using an extraction solvent such as hot water or alcohol. Examples thereof include the extracted extract, a concentrated solution obtained by concentrating these extracts, the extract or a powder obtained by drying the concentrated solution, and the like. These extracts are preferably extracts that do not use a solvent other than water or naturally-derived ethanol from the viewpoint of consumers' safety and security. However, considering the cost, water is more preferable.

The temperature of the extraction solvent at the time of extraction may vary in a suitable temperature range depending on the type of the extraction solvent, but is generally from the boiling point (° C.) of the extraction solvent under atmospheric pressure (° C.) to -20 ° C to the atmospheric pressure of the extraction solvent. Boiling point (° C.) is preferred. If the temperature of the extraction solvent at the time of extraction is lower than the boiling point (° C.) -20 ° C of the extraction solvent under atmospheric pressure, the effect of suppressing the flavor deterioration of oysters may be weakened, and the boiling point (° C.) under atmospheric pressure may be weakened. ), The extraction method may be complicated because special pressurizing equipment is required.

The yeast refers to a microorganism that assimilate sugar to produce alcohol when fermented in an anaerobic environment. Specific examples include yeasts belonging to the genus Saccharomyces, yeasts belonging to the genus Candida, and the like, but are not particularly limited. From the viewpoint of having abundant eating experience, the yeast may be Saccharomyces cerevisiae, and from the viewpoint of much knowledge in research and the like, the yeast is Candida utilis. You may.

The barley extract is not particularly limited, but for example, an extract obtained by extracting barley with an extraction solvent such as hot water or alcohol, or decomposing barley with an enzyme or an alkaline solvent and then using an extraction solvent such as hot water or alcohol. Examples thereof include the extracted extract, a concentrated solution obtained by concentrating these extracts, the extract or a powder obtained by drying the concentrated solution, and the like. These extracts are preferably extracts that do not use a solvent other than water or naturally-derived ethanol from the viewpoint of consumers' safety and security. However, considering the cost, water is more preferable.

The temperature of the extraction solvent at the time of extraction may vary in a suitable temperature range depending on the type of the extraction solvent, but generally, the boiling point (° C.) of the extraction solvent under atmospheric pressure is -20 ° C to that of the extraction solvent under atmospheric pressure. Boiling point (° C.) is preferred. If the temperature of the extraction solvent at the time of extraction is lower than the boiling point (° C.) -20 ° C of the extraction solvent under atmospheric pressure, the effect of suppressing the flavor deterioration of oysters may be weakened, and the boiling point (° C.) under atmospheric pressure may be weakened. ), The extraction method may be complicated because special pressurizing equipment is required.

The barley is a plant of the Gramineae family native to Central Asia, and its scientific name is Hordeum vulgare, and it is classified into two-row barley and six-row barley, skin barley and hordeum, and glutinous and mochi.

The oyster flavor reduction inhibitor of the present invention is obtained by adding at least one extract selected from the group consisting of enokitake extract, yeast extract and barley extract by dry weight to the total dry weight of the flavor reduction inhibitor. It is preferably contained in an amount of 50 to 100% by weight. It is more preferably 70 to 100% by weight, still more preferably 90 to 100% by weight. If it is less than 50% by weight, the effect of suppressing the deterioration of oyster flavor may not be exhibited. The solid content other than the extract that can be contained in the oyster flavor reduction inhibitor of the present invention is not particularly limited, and any naturally derived solid content may be contained, for example, dextrin, starch, lactose. And so on.

The shape of the oyster flavor reduction inhibitor of the present invention is not particularly limited, and may be a liquid shape such as an aqueous solution, or a solid shape such as powder, granule, or block.

By adding the oyster flavor reduction inhibitor of the present invention to fresh water, seawater, or salt water, it can be used as an aqueous solution for holding live oysters of the present invention, which will be described below. Further, by adding the oyster flavor reduction inhibitor of the present invention to the cage in which the harvested live oysters are temporarily bred, the oyster flavor reduction suppression effect can be obtained.

The aqueous solution for holding live oysters of the present invention contains the extract. It is used by immersing live oysters in the aqueous solution, which can prevent the original milky and rich flavor of oysters from deteriorating when the live oysters are refrigerated or frozen after this use.

The aqueous solution for holding live oysters of the present invention preferably contains the extract in a solid content of 0.1 to 800 ppm. The content is more preferably 0.1 to 240 ppm, further preferably 0.2 to 240 ppm, and particularly preferably 0.2 to 60 ppm. If it is less than 0.1 ppm, the effect of suppressing the deterioration of oyster flavor may not be exhibited. If it exceeds 800 ppm, the pigment component derived from the extract may adhere to the oyster or the flavor of the oyster may be impaired.

The sodium chloride concentration of the aqueous solution for holding live oysters of the present invention is preferably 2 to 3.5% by weight, more preferably 2.3 to 3.5% by weight, still more preferably 2.3 to 3.2% by weight. , 2.5 to 3% by weight is particularly preferable. If the sodium chloride concentration is less than 2% by weight or more than 3.5% by weight, oysters cannot grow in the holding aqueous solution of the present invention, and the flavor of oysters may be impaired.

The aqueous solution for holding live oysters of the present invention may contain salts other than sodium chloride as long as the above-mentioned sodium chloride concentration is satisfied. However, the content of salts other than sodium chloride is preferably limited to 1/3 by weight with respect to the weight of sodium chloride. The type of salts other than sodium chloride is not particularly limited as long as it is a salt that can be used as a food additive.

The holding aqueous solution may be produced by adding salt to fresh water as long as the sodium chloride concentration is satisfied, or using seawater or adjusting the sodium chloride concentration of seawater. It may be manufactured by using.

The aqueous solution for holding live oysters of the present invention is preferably sterilized. Specifically, based on the processing standards for raw oysters defined by the Food Sanitation Law, the most probable number of coliform bacteria per 100 ml of the aqueous solution is preferably 100 or less, and more preferably 70 or less.

By treating the live oysters with the aqueous solution for holding the live oysters of the present invention, particularly before refrigerating or freezing the raw oysters, it is possible to produce oysters in which the deterioration of flavor is suppressed. An example of a specific mode of the process is as follows. After sterilizing the aqueous solution to the most probable number of coliform bacteria, the temperature of the aqueous solution is preferably set in the range of 1 to 25 ° C., and live oysters are immersed while supplying oxygen to the aqueous solution. Holds for 10 to 15,000 minutes. Then, by taking out the live oysters from the aqueous solution, it is possible to obtain oysters in which the deterioration of flavor is suppressed. The method for sterilizing the aqueous solution is not particularly limited, and for example, sterilization by ultraviolet irradiation, ozone sterilization, chlorine sterilization, or the like may be performed.

The temperature of the aqueous solution is preferably controlled in the range of 1 to 25 ° C, more preferably 1 to 17 ° C, still more preferably 3 to 17 ° C. If the temperature is lower than 1 ° C. or higher than 25 ° C., the activity of live oysters may be reduced in the aqueous solution, and the effect of suppressing the deterioration of oyster flavor may not be exhibited.

The method for supplying oxygen to the aqueous solution may be any method as long as the dissolved oxygen concentration required for the growth of oysters can be secured.

The time for holding the live oyster in the aqueous solution is preferably 10 to 15000 minutes, more preferably 15 to 9000 minutes, further preferably 20 to 7200 minutes, particularly preferably 30 to 6000 minutes, and extremely preferably 150 to 6000 minutes. .. If the retention time is shorter than 10 minutes, the retention time of the flavor reduction inhibitor for live oysters may be insufficient, and the oyster flavor reduction suppression effect may not be exhibited. If it is longer than 15,000 minutes, the flavor of oysters may be impaired.

The treatment of live oysters using the aqueous solution for holding live oysters of the present invention described above may be carried out in a stationary water tank or may be carried out while being transported together with the water tank. Even when the treatment is carried out while being transported, according to the method of the present invention, if the temperature of the aqueous solution is within the above-mentioned range, it is not necessary to perform strict temperature control, so that the conventional seafood remains alive. The transportation cost can be suppressed as compared with the transportation method.

The oysters obtained according to the method for producing oysters of the present invention may be kept in the aqueous solution for a specific time as described above, then landed and then peeled, or stored in a refrigerator with shells for 1 to 5 days. , Maintains the original milky and rich flavor of oysters. Further, the oysters obtained according to the method for producing oysters of the present invention are kept in the aqueous solution for a specific period of time as described above, and then landed and then frozen and stored for one month or more. Maintains flavor.

Examples will be shown below and the present invention will be described in more detail, but the present invention is not limited to these examples. In the examples, "part" and "%" are based on weight.

(Production Example 1) Preparation of Enokitake Mushroom Extract 200 ml of hot water heated to 100 ° C. was added to 100 g of commercially available enokitake mushroom (fruiting body), and the mixture was kept for 2 hours. Then, the solid content was filtered off to obtain an enokitake extract having a solid content of 0.6% by weight. The viscosity of the obtained aqueous solution having a solid content concentration of 0.5% by weight (W / W) of the enokitake extract was 17 mPa · s.

(Production Example 2) Preparation of yeast extract 200 ml of hot water heated to 100 ° C. was added to 100 g of baker's yeast (“Kaneka East GA” manufactured by Kaneka Corporation), and the mixture was kept for 2 hours. Then, the solid content was filtered off to obtain a yeast extract having a solid content of 1.0% by weight. The viscosity of the aqueous solution of the obtained yeast extract having a solid content concentration of 0.5% by weight (W / W) was 8 mPa · s.

(Production Example 3) Preparation of barley extract 200 ml of hot water heated to 100 ° C. was added to 100 g of barley flour (“barley flour” manufactured by Ishibashi Kogyo Co., Ltd.) and kept for 2 hours. Then, the solid content was filtered off to obtain a barley extract having a solid content of 0.5% by weight. The viscosity of the aqueous solution of the obtained barley extract having a solid content concentration of 0.5% by weight (W / W) was 5 mPa · s.

(Production Example 4) Preparation of kelp extract 200 ml of hot water heated to 100 ° C. was added to 100 g of kelp (“Makombu” manufactured by Kurakon Co., Ltd.) and kept for 2 hours. Then, the solid content was filtered off to obtain a kelp extract having a solid content of 2.0% by weight. The viscosity of the aqueous solution having a solid content concentration of 0.5% by weight (W / W) of the obtained kelp extract was 120 mPa · s.

<Evaluation of milky flavor of oysters>
The milky flavor of the peeled oysters obtained in the examples and comparative examples was evaluated by 10 trained panelists (5 males and 5 females) based on the following criteria, and the average value was used as the evaluation value. did.
5 points: Very better than the oysters of Example 15 and very strong milky flavor 4 points: Better than the oysters of Example 15 and strongly felt the milky flavor 3 points: Equivalent to the oysters of Example 15 And you can feel the milky flavor 2 points: It is worse than the oysters of Example 15 and it is hard to feel the milky flavor 1 point: It is much worse than the oysters of Example 15 and you can not feel the milky flavor

<Evaluation of rich flavor of oysters>
The rich flavor of the peeled oysters obtained in the examples and comparative examples was evaluated by 10 trained panelists (5 males and 5 females) based on the following criteria, and the average value was used as the evaluation value. did.
5 points: Very better than the oysters of Example 15 and very strong flavor 4 points: Better than the oysters of Example 15 and strongly felt the rich flavor 3 points: Equivalent to the oysters of Example 15 And you can feel the rich flavor 2 points: worse than the oysters of Example 15 and slightly lighter and harder to feel the rich flavor 1 point: much worse than the oysters of Example 15 and light and rich I can't feel the flavor

<Comprehensive evaluation>
A comprehensive evaluation was performed based on the evaluation results of the milky flavor of oysters and the rich flavor of oysters. The evaluation criteria at that time are as follows.
A: The milky flavor of oysters and the rich flavor of oysters all satisfy 4.0 points or more and 5.0 points or less.
B: The milky flavor of oysters and the rich flavor of oysters are all 3.5 points or more and 5.0 points or less, and at least one of 3.5 points or more and less than 4.0 points.
C: The milky flavor of oysters and the rich flavor of oysters are all 3.0 points or more and 5.0 points or less, and at least one of 3.0 points or more and less than 3.5 points.
D: The milky flavor of oysters and the rich flavor of oysters are all 2.0 points or more and 5.0 points or less, and at least one of 2.0 or more and less than 3.0 points.
E: At least one of less than 2.0 in the evaluation of the milky flavor of oysters and the rich flavor of oysters.

(Example 1)
According to the formulation shown in Table 1, 200 liters of an aqueous solution containing 1% by weight of the enokitake extract obtained in Production Example 1 and 3% by weight of salt was filled in a water tank, and the water temperature was controlled to 15 ° C. Forty live oysters were immersed in the water tank, held for 180 minutes while supplying oxygen, and then the oysters were landed. Immediately after landing, the shells of the oysters were peeled and the shells were taken out to obtain the peeled oysters. The obtained peeled oysters were drained, vacuum-packed, stored in a refrigerator at 4 ° C. for 24 hours, and then the milky flavor and rich flavor of the oysters were evaluated, and the results are shown in Table 1. ..

(Example 2)
Peeled oysters were obtained in the same manner as in Example 1 except that the yeast extract obtained in Production Example 2 was blended in place of the enokitake extract according to the formulation shown in Table 1. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 1.

(Example 3)
Peeled oysters were obtained in the same manner as in Example 1 except that the barley extract obtained in Production Example 3 was blended in place of the enokitake extract according to the formulation shown in Table 1. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 1.

(Comparative Example 1)
Peeled oysters were obtained in the same manner as in Example 1 except that the kelp extract obtained in Production Example 4 was blended in place of the enokitake extract according to the formulation shown in Table 1. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 1.

(Comparative Example 2)
This comparative example is based on the freshness-preserving agent described in Example B-6 of Patent Document 1 (Japanese Unexamined Patent Publication No. 2003-225847). According to the formulation shown in Table 1, oyster peeled meat was obtained in the same manner as in Example 1 except that the enokitake extract was not blended and trehalose, citric acid, and polyphenol were blended. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 1.

As is clear from Table 1, the enokitake extract (Production Example 1) and the yeast extract (Production Example 1) in which the viscosity of the aqueous solution having a solid content concentration of 0.5% (W / W) of the extract is in the range of 3 to 50 mPa · s. The peeled oysters (Examples 1 to 3) obtained by treating with a saline solution containing a barley extract (Production Example 3) or Production Example 2) have a milky and rich flavor, and in particular. The flavor of the product obtained by treating with a saline solution containing the Enokitake extract (Example 1) was extremely good. On the other hand, peeled oysters obtained by treating with a saline solution containing a kelp extract (Production Example 4) having a viscosity of an aqueous solution having a solid content of 0.5% (W / W) of the extract of 120 mPa · s (comparison). In Example 1), both the milky flavor and the rich flavor were felt weak. In addition, the oyster peeled meat (Comparative Example 2) obtained by treating with a saline solution containing trehalose, citric acid, and polyphenols had a slightly rich flavor, but a weak milky flavor, and was due to polyphenols. Coloring was seen.

(Examples 4 to 7, Comparative Example 3)
According to the formulation in Table 2, the blending amount of the Enokitake extract was changed from 1.0% by weight to 0.002% by weight (Example 4), 0.1% by weight (Example 5), 4.0% by weight (Example). 6) Peeled oysters were obtained in the same manner as in Example 1 except that the content was changed to 13.0% by weight (Example 7) or 15.0% by weight (Comparative Example 3). The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 2.

(Comparative Example 4)
Peeled oysters were obtained in the same manner as in Example 1 except that an aqueous solution prepared without adding the enokitake extract was used according to the formulation shown in Table 2. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 2.

As is clear from Table 2, the peeled oysters (Examples 1, 4 to 7) obtained by treating with a saline solution in which the solid content of the enokitake extract in the aqueous solution is in the range of 0.1 to 800 ppm are obtained. In each case, a milky and rich flavor was felt, and in particular, the flavor obtained by treating with a saline solution having a solid content of 60 ppm (Example 1) was extremely good. On the other hand, the peeled oysters (Comparative Example 3) obtained by treating the enokitake extract with a saline solution having a solid content of 900 ppm had a slightly rich flavor, but a weak milky flavor. In addition, the peeled oysters (Comparative Example 4) obtained by treating with a saline solution containing no enokitake extract had a weak milky flavor and a rich flavor.

(Examples 8 to 10)
According to the conditions in Table 3, the amount of salt blended was changed from 3.0% by weight to 2.0% by weight (Example 8), 2.3% by weight (Example 9), or 3.5% by weight (Example). Oysters were obtained in the same manner as in Example 1 except that they were changed to 10). The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 3.
(Example 11)
Oysters were obtained in the same manner as in Example 1 except that the type of the aqueous solution containing salt was changed from saline solution to seawater according to the conditions shown in Table 3. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 3.

(Comparative Example 5)
This comparative example is based on the shellfish quality improving agent described in Example 1-1 of Patent Document 2 (Japanese Unexamined Patent Publication No. 2010-154799). Oysters were obtained in the same manner as in Example 1 except that the type of salt in the aqueous solution was changed from sodium lactate to sodium hydrogen carbonate according to the formulation shown in Table 3.

As is clear from Table 3, the peeled oysters (Examples 1, 8 to 11) obtained by treating with an aqueous solution containing an enokitake extract and having a sodium chloride concentration in the range of 2 to 3.5% by weight were obtained. All of them had a strong milky and rich flavor. On the other hand, live oysters (Comparative Example 5) containing an enokitake extract but immersed in an aqueous solution containing 3.5% by weight of sodium lactate and sodium hydrogen carbonate instead of sodium chloride were killed by immersion for 180 minutes. However, both the milky flavor and the rich flavor became less noticeable.

(Examples 12 to 14)
Examples except that the water temperature of the aqueous solution was changed from 15 ° C. to 2 ° C. (Example 12), 10 ° C. (Example 13), or 22 ° C. (Example 14) according to the conditions shown in Table 4. The peeled oysters were obtained in the same manner as in 1. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 4.

As is clear from Table 4, the peeled oysters (Examples 1, 12 to 14) obtained by treating with a saline solution containing the enokitake extract and having a water temperature of 1 to 25 ° C. are all milky and have a rich flavor. In particular, the flavors of those obtained by treating with a saline solution containing an enokitake extract and having a water temperature of 15 ° C. or 10 ° C. (Examples 1 and 13) were extremely good.

(Examples 15 to 17, Comparative Examples 6 and 7)
According to the conditions in Table 5, the retention time of oysters in the aqueous solution was changed from 180 minutes to 15 minutes (Example 15), 8000 minutes (Example 16), 14800 minutes (Example 17), 5 minutes (Comparative Example 6). Or, the peeled oysters were obtained in the same manner as in Example 1 except that the time was changed to 17280 minutes (Comparative Example 7). The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 5.

As is clear from Table 5, the peeled oysters (Examples 1, 15 to 17) obtained by holding the oysters in a saline solution containing the enokitake extract for 10 to 15,000 minutes all had a milky and rich flavor. In particular, the flavor of the peeled oyster meat (Example 1) having a holding time of 180 minutes was extremely good. On the other hand, the peeled oyster meat (Comparative Example 6) having a holding time of 5 minutes was felt to have a weak milky flavor and a rich flavor. In addition, the peeled oyster meat (Comparative Example 7) having a holding time of 17280 minutes had a slightly rich flavor, but a weak milky flavor.

(Examples 18 and 19)
Oysters were stored in the refrigerator in the same manner as in Example 1 except that the storage time of the peeled meat in the refrigerator was changed from 24 hours to 96 hours (Example 18) or 120 hours (Example 19). I got a peeled meat. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 6.

(Example 20)
According to the conditions of Table 6, after holding the live oysters in the aquarium in the same manner as in Example 1, the oysters with shells were prepared in the same manner as in Example 18 except that the oysters were stored in the refrigerator with shells for 96 hours without being peeled. Obtained. Then, the oysters were peeled and the shellfish was taken out to evaluate the milky flavor and the rich flavor, and the results are shown in Table 6.

(Example 21)
According to the conditions in Table 6, after obtaining the peeled oysters in the same manner as in Example 1, drain the oysters, vacuum-pack them, store them in a freezer at -20 ° C for 1 month, and then store them in a refrigerator at 4 ° C for 24 hours. And thawed to get the peeled oysters. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 6.

(Example 22)
According to the conditions of Table 6, the peeled oysters were obtained in the same manner as in Example 1 except that the storage time of the peeled meat in the refrigerator was changed from 24 hours to 0 hours (that is, the refrigerated storage was not performed). The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 6.

(Comparative Example 8)
Peeled oysters were obtained in the same manner as in Example 19 except that an aqueous solution prepared without adding the enokitake extract was used according to the conditions shown in Table 6. The milky flavor and rich flavor of the obtained peeled oysters were evaluated, and the results are shown in Table 6.

(Reference example)
Without retaining the live oysters in the aqueous solution, the shells of the live oysters are peeled off to obtain the peeled oysters, and then the peeled oysters have a milky flavor and richness without refrigeration. The flavor was evaluated and the results are shown in Table 6.

As is clear from Table 6, oysters obtained by treating with a saline solution containing an enokitake extract and then refrigerating the oysters with peeled meat or with shells for 0 to 120 hours (Examples 1, 18, 19, 20). In both cases and 22), a milky and rich flavor was felt. The peeled oysters (Example 21) obtained by freezing for one month after treatment with a saline solution containing the enokitake extract also had a milky and rich flavor. In particular, the peeled oysters obtained by immediately peeling the shells from the aqueous solution without refrigerating (Example 22) and the peeled oysters obtained by refrigerating the shells after landing from the aqueous solution for 24 hours. The flavor of (Example 1) was extremely good, at the same level as the peeled oysters (reference example) that were neither retained in an aqueous solution nor refrigerated. On the other hand, the oyster peels obtained by treating with a saline solution containing no enokitake extract and refrigerated for 120 hours (Comparative Example 8) are the same as those obtained by refrigerating for 24 hours (Comparative Example 4). Both the milky flavor and the rich flavor were felt weak.

Claims (7)

An oyster flavor reduction inhibitor containing at least one extract selected from the group consisting of enokitake extract, yeast extract and barley extract. The oyster flavor reduction inhibitor according to claim 1, wherein the extract is contained in an amount of 50 to 100% by weight based on the dry weight of the oyster flavor reduction inhibitor. At least one extract selected from the group consisting of enokitake extract, yeast extract and barley extract is contained in a solid content of 0.1 to 800 ppm and has a sodium chloride concentration of 2 to 3.5% by weight. An aqueous solution for holding oysters. The aqueous solution according to claim 3, which uses the oyster flavor reduction inhibitor according to claim 1 or 2. Live oysters kept in an aqueous solution according to claim 3 or 4 having a temperature in the range of 1 to 25 ° C. for 10 to 15,000 minutes while being supplied with oxygen. Raw oysters in which the live oysters according to claim 5 are refrigerated or frozen. At least one extract selected from the group consisting of Enokitake extract, yeast extract and barley extract is contained in a solid content of 0.1 to 800 ppm, a sodium chloride concentration of 2 to 3.5% by weight, and a temperature of 1. A method for producing an oyster with suppressed flavor deterioration, which comprises holding a live oyster for 10 to 15,000 minutes in a state where oxygen is supplied in an aqueous solution in the range of ~ 25 ° C.