Method for producing frozen seafood food to be eaten raw and method for preventing deterioration of frozen seafood food to be eaten raw

Abstract

To provide a frozen fish and shellfish food to be eaten raw which exhibits a long shelf life after thawing.SOLUTION: A production method of a frozen fish and shellfish food to be eaten raw includes the steps of: placing fish and shellfish to be eaten raw and seasoning liquid in an amount by weight which is 0.2 to 0.5 times that of the fish and shellfish into a container and sealing the resultant, followed by vacuum-packaging; and freezing the container having the fish and shellfish after the vacuum-packaging. The seasoning liquid contains sodium acetate. Time from contact between the seasoning liquid and the fish and shellfish to freezing start is set within 130 minutes.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing frozen seafood food to be eaten raw and a method for preventing deterioration of frozen seafood food to be eaten raw. [Background technology]

[0002] In recent years, there has been an increasing demand for food shelf life. This demand is particularly strong for seafood to be eaten raw, which is easily spoiled. For example, Patent Document 1 below is an example of extending the shelf life of seafood to be eaten raw by treating it with sodium acetate, a shelf life enhancer. In Example 1 of Patent Document 1, fillets of seafood such as tuna are immersed in an immersion liquid containing 20% ​​by mass of sodium acetate for 1 minute, and after draining the liquid, a storage test is conducted for up to 72 hours, but no evaluation is conducted after freezing and thawing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-221080 A Summary of the Invention [Problem to be solved by the invention]

[0004] Seafood for eating raw is a widely popular food ingredient, and there is a strong demand for freezing seafood and preserving it for a long period after thawing so that it can be eaten raw. On the other hand, it is known that freezing and thawing seafood produces drips, which increases the water activity on the surface of the seafood and makes it easier for microorganisms to grow. For this reason, it has been difficult to make seafood edible for raw consumption after freezing and thawing, and even more so, it has been difficult to keep thawed seafood fresh for a long period of time.

[0005] An object of the present invention is to provide a technology that can provide a good shelf life effect for seafood to be eaten raw even after freezing and thawing. [Means for solving the problem]

[0006] The present invention has been found to solve the above problems, and is a method for producing a frozen seafood food to be eaten raw, comprising the steps of: sealing seafood to be eaten raw and a seasoning liquid in an amount of 0.2 to 0.5 times the weight of the seafood in a container and vacuum-packing the seafood; and freezing the container containing the vacuum-packed seafood, The present invention provides a method for producing a frozen seafood food to be eaten raw, in which the seasoning liquid contains sodium acetate, and the process from contact of the seasoning liquid with the seafood to the start of freezing is carried out within 130 minutes.

[0007] The present invention also provides a method for preventing deterioration of frozen seafood food to be eaten raw, comprising the steps of: sealing seafood to be eaten raw and a seasoning liquid in an amount of 0.2 to 0.5 times the weight of the seafood in a container and vacuum-packing the seafood; and freezing the container containing the vacuum-packaged seafood, The present invention provides a method for preventing deterioration of frozen seafood foods to be eaten raw, the method comprising the steps of: (a) providing a seasoning liquid containing sodium acetate; and (b) carrying out the process from contact of the seasoning liquid with the seafood to the initiation of freezing within 130 minutes. Effect of the Invention

[0008] According to the present invention, it is possible to provide a frozen seafood food product to be eaten raw that has a good shelf life after thawing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will now be described based on its preferred embodiments. The present invention relates to a method for producing a frozen seafood food to be eaten raw, the method comprising the steps of: sealing seafood to be eaten raw and a seasoning liquid in an amount of 0.2 to 0.5 times the weight of the seafood in a container and vacuum-packing the seafood; and freezing the container containing the vacuum-packaged seafood, This is a method for producing frozen seafood food to be eaten raw, in which the seasoning liquid contains sodium acetate, and the process from contact of the seasoning liquid with the seafood to the start of freezing is carried out within 130 minutes.

[0010] Examples of seafood for raw consumption include fish, shellfish, crustaceans, and cephalopods. Examples of fish include rockfish, red grouper, red sea bream, horse mackerel, conger eel, sweetfish, monkfish, grunt, threadfin tuna, sardine, char, eel, stingray, lizardfish, scorpionfish, scorpionfish, sculpin, bonito, black tuna, barracuda, flounder, filefish, amberjack, sillago, kinki, silver-stripe round herring, croaker, flathead, salmon (including Atlantic salmon, trout salmon, and coho salmon), mackerel, shark, pacific saury, and Japanese saury. Examples of fish include: Japanese rat, halfbeak, grass carp, silver carp, pangasius, flounder, loach, sea bass, cod, sea bream, hairtail, flying fish, loach, Nile tilapia, catfish, herring, rainbow trout, goby, grouper, conger eel, flounder, yellowtail, pufferfish, crucian carp, yellowtail (including growth and seasonal names such as yellowtail, Japanese amberjack, and Japanese white-eye), Atka mackerel, hoki, black rockfish, tuna, carp, milkfish, rockfish, mamakari, Japanese carp, and rohu. Examples of shellfish include oysters, clams, short-necked clams, scallops, and blood clams. Examples of crustaceans include shrimp, crabs, and mantis shrimp. Examples of cephalopods include squid and octopus.

[0011] Among these, in the present invention, fish that are in high demand for eating raw are preferred, and horse mackerel, sardines, bonito, flounder, salmon, mackerel, flounder, sea bream, hairtail, herring, flounder, yellowtail, tuna, and yellowtail are more preferred, with horse mackerel, bonito, salmon, mackerel, sea bream, yellowtail, yellowtail, and tuna being particularly preferred, and salmon is the most preferred because of the excellent color effect when the present invention is applied.

[0012] In the present invention, it is preferable that the fish and shellfish to be eaten raw are in a shape that is easy to eat before vacuum packaging. Examples of such shapes include sashimi, slices, dices, bite-sized pieces, and other fillets. The size of one piece is not particularly limited, but is preferably, for example, 1.0 to 20.0 g in terms of ease of eating and excellent effects of the present invention, is particularly preferably 1.0 to 15.0 g, and is even more preferably 1.0 to 10.0 g.

[0013] Seafood to be eaten raw is vacuum-packed together with a seasoning liquid containing sodium acetate. It is preferable to treat the seafood with an aqueous solution containing sodium hypochlorite before the treatment, since this further enhances the shelf life improvement effect. In this case, the concentration of sodium hypochlorite in the aqueous solution containing sodium hypochlorite is preferably 30.0 to 250.0 ppm by mass, more preferably 50.0 to 200.0 ppm. The immersion time in the aqueous solution containing sodium hypochlorite is preferably 5.0 to 60.0 seconds, more preferably 10.0 to 30.0 seconds. The immersion treatment can be suitably carried out at a temperature at which the aqueous solution of sodium hypochlorite has a water temperature of 1.0 to 15.0°C.

[0014] Seafood to be eaten raw is vacuum-packed together with a seasoning liquid containing sodium acetate. As shown in Example 3 described below, even if the concentration of sodium acetate in the seasoning liquid is, for example, about 0.9% by mass, a certain shelf life effect is exhibited. However, in terms of exhibiting an excellent shelf life effect especially after thawing, the amount of sodium acetate in the seasoning liquid is preferably 5.0% by mass or more, more preferably 6.0% by mass or more, even more preferably 7.0% by mass or more, and particularly preferably 8.0% by mass or more. In addition, in terms of reducing sourness, the amount of sodium acetate in the seasoning liquid is preferably 15.0% by mass or less, more preferably 14.0% by mass or less, even more preferably 13.0% by mass or less, particularly preferably 12.0% by mass or less, and most preferably 11.5% by mass or less.

[0015] The seasoning liquid used in the present invention preferably has a pH of 5.5 to 7.0, particularly preferably 6.0 to 7.0, at 10° C. When the seasoning liquid has a pH of 5.5 or more, particularly 6.0 or more, at 10° C., the taste is good and the quality of the meat, such as the texture, is easily maintained. In addition, when the seasoning liquid has a pH of 7.0 or less at 10° C., there is an advantage in that discoloration of seafood can be prevented.

[0016] The seasoning liquid used in the present invention contains at least one seasoning other than sodium acetate, such as table salt or the like, which are commonly used in the art. The seasoning liquid may contain an organic acid or an acid salt. These have the function of adjusting the pH to a desired range and also function as a seasoning. Examples of organic acids or acid salts include fumaric acid, monosodium fumarate, citric acid, malic acid, tartaric acid, potassium hydrogen tartrate, succinic acid, monosodium succinate, adipic acid, lactic acid, ascorbic acid, phytic acid, gluconic acid (including glucono delta lactone), acetic acid (including glacial acetic acid), and brewed vinegar. Among them, it is preferable to use monosodium fumarate, monopotassium citrate, and acetic acid in terms of versatility and seasoning. When the seasoning liquid contains an organic acid or an acid salt, the amount of the acid salt is usually preferably 5.0 to 300 parts by mass, more preferably 5.0 to 25.0 parts by mass, and even more preferably 10.0 to 20.0 parts by mass, relative to 100 parts by mass of sodium acetate.

[0017] Examples of seasonings in the seasoning liquid include the above-mentioned salts and organic acids or acid salts of organic acids, as well as normal salts of organic acids (normal salts other than sodium acetate), such as disodium succinate, trisodium citrate, sodium malate, sodium lactate, sodium gluconate, sodium glutamate, etc. Among these, in the present invention, it is preferable to contain at least one selected from disodium succinate, trisodium citrate, sodium malate, sodium lactate, sodium gluconate, sodium glutamate, etc., as they serve as a sour agent or umami seasoning, etc., in that they improve the taste of the resulting frozen seafood food for raw consumption.

[0018] In addition, in the present invention, the use of at least one selected from disodium succinate, trisodium citrate, sodium malate, and sodium lactate is preferable as a pH adjuster or buffer in terms of maintaining the quality and taste of the resulting seafood.

[0019] From these points of view, in the present invention, it is particularly preferable that the composition contains at least one selected from disodium succinate, trisodium citrate, sodium malate, and sodium lactate, and it is particularly preferable that the composition contains disodium succinate and / or trisodium citrate.

[0020] When the seasoning liquid used in the present invention contains at least one selected from disodium succinate, trisodium citrate, sodium malate, sodium lactate, sodium gluconate, and sodium glutamate, the total amount of the seasoning liquid is preferably 0.05% by mass or more, more preferably 0.08% by mass or more, even more preferably 0.5 to 3.0% by mass, and even more preferably 1.0 to 2.0% by mass, in order to further enhance the above-mentioned taste improving effect. Also, when the seasoning liquid used in the present invention contains at least one selected from disodium succinate, trisodium citrate, sodium malate, and sodium lactate, the total amount of the seasoning liquid is preferably 0.05% by mass or more, more preferably 0.08% by mass or more, even more preferably 0.5 to 3.0% by mass, and even more preferably 1.0 to 2.0% by mass. Similarly, when the seasoning liquid used in the present invention contains disodium succinate and / or trisodium citrate, the total amount thereof in the seasoning liquid is preferably 0.05 mass% or more, more preferably 0.08 mass% or more, even more preferably 0.5 to 3.0 mass%, and even more preferably 1.0 to 2.0 mass%.

[0021] In particular, when the seasoning liquid used in the present invention contains trisodium citrate, in order to further enhance the above-mentioned taste improving effect and quality preserving effect, the amount thereof in the seasoning liquid is preferably 0.5 to 3.0 mass %, and more preferably 1.0 to 2.0 mass %.

[0022] Furthermore, when the seasoning liquid used in the present invention contains disodium succinate, in order to further enhance the above-mentioned taste improving effect and quality preserving effect, the amount thereof in the seasoning liquid is preferably 0.05 to 0.3 mass %, and more preferably 0.08 to 0.2 mass %.

[0023] The seasoning liquid used in the present invention preferably contains an emulsifier in terms of shelf life. Examples of emulsifiers include glycerin fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, and lecithin. Here, the glycerin fatty acid esters include glycerin acetate esters, glycerin acetate fatty acid esters, glycerin lactate fatty acid esters, glycerin citric acid fatty acid esters, glycerin succinate fatty acid esters, glycerin diacetyl tartaric acid fatty acid esters, polyglycerin fatty acid esters, and polyglycerin condensed ricinoleic acid esters, in addition to esters of glycerin and fatty acids. Lecithins include fractionated lecithin, enzymatically decomposed lecithin, and enzymatically treated lecithin. Among these, it is preferable to use glycerin fatty acid esters in the present invention.

[0024] When the seasoning liquid used in the present invention contains an emulsifier, the amount of the emulsifier in the seasoning liquid is preferably 0.01 to 1.0 mass %, more preferably 0.1 to 0.5 mass %, and most preferably 0.1 to 0.3 mass %, in order to enhance the above-mentioned effects of using the emulsifier.

[0025] When the seasoning liquid contains salt, the amount of salt is preferably 0.5 to 3.0% by mass in terms of taste and soaking efficiency of the solution, and more preferably 1.0 to 2.0% by mass.

[0026] In the present invention, in order to more effectively exhibit the taste, texture, color and shelf life effect, the amount of components in the seasoning liquid other than water, sodium acetate, organic acid or its acid salt or normal salt, emulsifier and salt is preferably 20 mass % or less, more preferably 15 mass % or less, even more preferably 5 mass % or less, and most preferably 2 mass % or less. In particular, in order to more effectively exert the taste, texture, color and shelf life effects in the present invention, the amount of components other than water, sodium acetate, normal salts of organic acids, emulsifiers and salt in the seasoning liquid is preferably 20 mass % or less, more preferably 15 mass % or less, even more preferably 5 mass % or less, and most preferably 2 mass % or less.

[0027] In the present invention, the seasoning liquid is vacuum-packaged together with the fish and shellfish to be eaten raw. The seasoning liquid used for vacuum packaging has a weight of 0.2 times or more and 0.5 times or less relative to the fish and shellfish to be eaten raw. When the seasoning liquid used for vacuum packaging has a weight of 0.2 times or more relative to the fish and shellfish to be eaten raw, it is excellent in improving the shelf life and the seasoning is evenly in contact with the fish and shellfish. In addition, when the seasoning liquid used for vacuum packaging has a weight of 0.5 times or less relative to the fish and shellfish to be eaten raw, it has an advantage of being able to reduce the product weight. From this viewpoint, the seasoning liquid used for vacuum packaging has a weight of 0.2 times or more and 0.4 times or less relative to the fish and shellfish to be eaten raw, more preferably more than 0.2 times.

[0028] In the present invention, the time from the contact of the seasoning liquid with the raw fish and shellfish to the start of freezing during vacuum packaging is also important. The start of freezing usually refers to the time when the vacuum-packed raw fish and shellfish food is placed in a freezer. If this time is too long, dripping is likely to occur, the water activity of the surface of the resulting fish and shellfish increases, and the effect of improving the shelf life cannot be obtained. In addition, in terms of taste, if this time is too long, the taste of the seasoning liquid in the resulting fish and shellfish becomes strong, and the commercial value decreases. In terms of color, it is also desirable that this time be short. From these points of view, in the present invention, the time from the contact of the seasoning liquid with the raw fish and shellfish to the start of freezing is 130 minutes or less, preferably 70 minutes or less, and particularly preferably 40 minutes or less. In particular, the time from the contact of the seasoning liquid with the raw fish and shellfish to the start of freezing is preferably 27 minutes or less in terms of improving the color of the fish and shellfish, and is particularly preferably 22 minutes or less, and most preferably 17 minutes or less. In the present invention, it is not necessary to perform pre-freezing (for example, pre-freezing at -20°C or lower) after the liquid seasoning comes into contact with the fish and shellfish to be eaten raw and before vacuum packaging.

[0029] From the standpoint of shelf life, the temperature of the seasoning liquid when it comes into contact with seafood is preferably higher than 0°C and not higher than 15°C, and even more preferably higher than 0°C and not higher than 12°C.

[0030] From the viewpoint of improving shelf life, the time from when the seasoning liquid comes into contact with the fish and shellfish to be eaten raw until the start of freezing is preferably 30 seconds or more, and even more preferably 3 minutes or more.

[0031] The packaging material used in this embodiment is not particularly limited as long as it can package seafood meat and seasoning liquid, and has gas barrier properties that can be used for vacuum packaging. Usually, a plastic film is used, and examples of the material include synthetic resin films, such as VDC / MA (vinylidene chloride / methyl acrylate copolymer), HIPS (high impact polystyrene), PVDC (polyvinylidene chloride), PVC (polyvinyl chloride), PA (polyamide), PE (polyethylene), PP (polypropylene), EVOH (ethylene-vinyl alcohol copolymer), PET (polyethylene terephthalate resin), and composites of one or more of these. Polyvinylidene chloride, polyamide, polypropylene, or composites of these are preferred in terms of tear resistance, storage stability, etc.

[0032] In this embodiment, the seafood and the seasoning liquid are contained in a packaging material and vacuum-packaged. Regarding the order of placement, of the seafood and the seasoning liquid, if the seafood is placed first and then the seasoning liquid is placed, this has the advantage that the seasoning liquid will not splash. After the seafood and seasoning are placed inside the packaging material, the inside of the packaging material is evacuated using a vacuum pump, and the packaging material is sealed by heat sealing or the like.

[0033] In the above vacuum packaging, the degree of vacuum, when an absolute vacuum is 100% and atmospheric pressure is 0%, is preferably within the range of 85 to 99% from the standpoint of shelf life and prevention of oxidation, more preferably within the range of 90 to 99%, and most preferably within the range of 95 to 99%.

[0034] In the present invention, during vacuum packaging, the time required from when the seasoning liquid comes into contact with the seafood to be eaten raw to when the vacuum packaging is completed is usually preferably 10 minutes or less, more preferably 5 minutes or less, even more preferably 4 minutes or less, and particularly preferably 3 minutes or less.

[0035] In the present invention, it is preferable that the time from completion of vacuum packaging to the start of freezing is short in terms of the shelf life improving effect and taste and color. From this point of view, in the present invention, the time from completion of vacuum packaging to the start of freezing is preferably 2 hours or less, preferably 1 hour or less, more preferably 30 minutes or less, even more preferably 25 minutes or less, particularly preferably 20 minutes or less, and most preferably 15 minutes or less.

[0036] The temperature of the seafood from the completion of vacuum packaging to the start of freezing is usually higher than 0°C and lower than 15°C, more preferably higher than 0°C and lower than 12°C, and even more preferably higher than 0°C and lower than 10°C.

[0037] From the viewpoint of improving shelf life, the time from the completion of vacuum packaging to the start of freezing is preferably 20 seconds or more, and even more preferably 2 minutes or more.

[0038] The freezing temperature is preferably -15°C to -40°C from the viewpoint of inhibiting microbial growth. The above freezing is preferably rapid freezing. For example, rapid freezing is preferably performed at a freezing rate that reaches the above target freezing temperature in 60 to 10 minutes, more preferably in 40 to 10 minutes, from the viewpoint of inhibiting microbial growth. Therefore, a freezing rate of -0.25°C / min or more is preferable, and -0.375°C / min to -4°C / min is more preferable. EXAMPLES

[0039] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited to such examples. In addition, "%" in Table 1 means "% by mass" unless otherwise specified.

[0040] Example 1 Raw salmon (salmon trout slices, approximately 8 g per slice, approximately 160 g) was immersed in a 200 ppm aqueous sodium hypochlorite solution (15°C) at room temperature (20°C) for 10 seconds. A preparation containing 80.6% by mass of sodium acetate, 10.9% by mass of trisodium citrate, 2.2% by mass of glycerin fatty acid ester, and 0.8% by mass of disodium succinate was used as preparation 1. 13.3 parts by mass of preparation 1, 1.6 parts by mass of salt, and 85.1 parts by mass of water were combined to prepare a seasoning liquid (10°C, pH at 10°C is 6.7). As a vacuum packaging bag, a nylon poly new L type (size 180mm x 300mm) manufactured by Fukusuke Kogyo Co., Ltd. was used. Raw salmon and 30 parts by mass of seasoning liquid per 100 parts by mass of raw salmon were put into this packaging bag and vacuum-packed. As a vacuum packaging device, a vacuum packaging machine HPS-300A-HP manufactured by Hoshizaki Co., Ltd. was used, and degassing was performed so that the vacuum degree was 95.0 to 99.0%. The vacuum packaging work was performed at room temperature. The time from the start of contact of the seafood with the seasoning liquid to the completion of vacuum packaging was 120 seconds. The vacuum-packed seafood was placed in a freezer at -30°C as a freezing device 10 minutes after the completion of vacuum packaging, and frozen at a freezing rate of -30°C / 30 minutes to obtain a frozen seafood food for raw consumption. From the completion of vacuum packaging to the introduction into the freezer, it was stored in a refrigerator (over 0°C and below 10°C, the same below).

[0041] Example 2 The time from completion of vacuum packaging to freezing of the vacuum packaged body was changed to 30 minutes from 10 minutes in Example 1. Otherwise, a frozen seafood food to be eaten raw was obtained in the same manner as in Example 1.

[0042] Example 3 The time from completion of vacuum packaging to freezing of the vacuum packaged body was changed to 2 hours from 10 minutes in Example 1. Otherwise, a frozen seafood food to be eaten raw was obtained in the same manner as in Example 1.

[0043] Example 4 A frozen seafood food product for raw consumption was obtained in the same manner as in Example 1, except that Preparation 2 (composition: sodium acetate 7.2% by mass, monosodium fumarate 0.9% by mass, other pH adjusters, seasonings (organic acids)) was used instead of Preparation 1. The pH of the seasoning liquid at 10°C was 4.1.

[0044] Example 5 A frozen seafood food for raw consumption was obtained in the same manner as in Example 1, except that Preparation 3 (composition: containing 64% by mass of sodium acetate, 10% by mass of monosodium fumarate, and 1% by mass of glycerin fatty acid ester) was used instead of Preparation 1. The pH of the seasoning liquid at 10°C was 5.7.

[0045] Comparative Example 1 Raw salmon (salmon trout slices, about 8 g per slice, about 160 g) treated with sodium hypochlorite solution in the same manner as in Example 1 was immersed in a seasoning liquid (10 ° C) of the same mass as the raw salmon, which was a mixture of 4 parts by mass of Preparation 1, 0.5 parts by mass of salt, and 95.5 parts by mass of water, and stored in a refrigerator in that state for 2 hours, after which the liquid was drained and placed in a packaging bag (Fukusuke Kogyo Co., Ltd. nylon poly new L type (size 180 mm x 300 mm)), vacuum-packaged under the same vacuum packaging conditions as in Example 1, and then placed in a freezer at the same temperature as in Example 1 and frozen at the same freezing rate as in Example 1 to obtain a frozen seafood food for raw consumption. The pH of the seasoning liquid at 10 ° C was 6.7.

[0046] Comparative Example 2 This comparative example is an example in which the sample was immersed in a high-concentration aqueous sodium acetate solution for a short period of time, similar to Example 1 of Patent Document 1. Raw salmon (salmon trout slices, about 8g per slice, about 160g) treated with sodium hypochlorite solution in the same manner as in Example 1 was immersed in 160g (10°C) of the same mass of immersion liquid as the raw salmon, which was a mixture of 20 parts by mass of sodium acetate and 80 parts by mass of water, and stored in the refrigerator in that state for 1 minute, after which the liquid was drained and placed in a packaging bag (Fukusuke Kogyo Co., Ltd. nylon poly new L type (size 180mm x 300mm)), vacuum-packaged under the same vacuum packaging conditions as in Example 1, and then placed in a freezer at the same temperature as in Example 1 and frozen at the same freezing rate as in Example 1 to obtain a frozen seafood food for raw consumption. The pH of the immersion liquid at 10°C was 8.4.

[0047] The shelf life of thawed frozen seafood foods to be eaten raw was evaluated using the following method. The results are shown in Table 1. The unit of bacterial count is cfu / g.

[0048] <How to evaluate shelf life> Packaged frozen seafood foods to be eaten raw were thawed by running water through the packaging for 20 minutes, then opened and transferred to a sterilized bag and kept at 10° C. The viable bacterial counts of the foods immediately after opening and after being kept at 10° C. for 96 and 120 hours under the above conditions were examined using the following method. The general viable bacteria count of the food sample was determined by the general viable bacteria count test stipulated by the Food Sanitation Inspection Guideline. Specifically, a total of 25g was weighed out by cutting small pieces from multiple locations in the food sample and transferred to a sterilized bag for stomacher processing. Phosphate buffer was used as dilution water, and 225ml of this dilution water was added and stomached. The sample liquid after stomaching was used as the sample source liquid to prepare 10-fold serial dilutions. 1ml of the prepared sample liquid was mixed with 15-20ml of standard agar medium and incubated in an incubator at 35±1℃ for up to 48 hours, and the viable bacteria count was then performed. (Evaluation Criteria) ◎: Bacterial counts below 3000cfu / g at the time of opening, after 96 hours, and after 120 hours 〇: The highest bacterial count at the time of opening, after 96 hours, and after 120 hours is between 3000cfu / g and 6000cfu / g △: The highest bacterial count at the time of opening, after 96 hours, and after 120 hours was 6,000 cfu / g or more and less than 10,000 cfu / g ×: The highest number of bacteria at the time of opening, after 96 hours, and after 120 hours is 10,000 cfu / g or more.

[0049] Four panelists visually evaluated the color of the frozen seafood food for raw consumption thawed as described above, and also ate the food and evaluated its sourness, texture, and flavor according to the following criteria. The evaluation method selected was the one most frequently chosen. The panelists' evaluations of color, sourness, texture, and flavor were consistent. The panelists' comments on texture and flavor are shown in Table 1.

[0050] (evaluation) <Color evaluation> 4: The fish's original color is maintained. 3: There is some fading, but it does not affect the product. 2: Discoloration is observed. 1: Significant discoloration is observed.

[0051] <Evaluation of sourness> 3: Almost no sourness. 2: Slightly sour taste. 1: Tastes sour or has a strong sour taste.

[0052] <Evaluation of texture and flavor> 3: Good, no problems. 2: Generally no problems, but there are some points of concern. 1: I feel there is a problem.

[0053] [Table 1]

[0054] The Food Sanitation Act stipulates that the upper limit of the general viable bacteria count for frozen seafood foods to be eaten raw is 100,000 / g, but it is desirable that the count not exceed 10,000 regardless of the passage of time. In the present invention, the viable bacteria count remains stably low for 120 hours after opening, demonstrating superior effects compared to conventional techniques.

Claims

1. A method for producing a frozen seafood food to be eaten raw, comprising the steps of: sealing raw seafood and a seasoning liquid in an amount of more than 0.2 times and not more than 0.5 times the mass of the seafood in a container and vacuum packaging the seafood; and freezing the vacuum-packaged seafood, This method for producing a frozen seafood food to be eaten raw comprises the steps of: the seasoning liquid contains sodium acetate; the period from contact of the seasoning liquid with the seafood to the start of freezing is 130 minutes or less; and the amount of components in the seasoning liquid other than water, sodium acetate, an organic acid or its acid salt or normal salt, an emulsifier, and salt is 20 mass% or less.

2. 2. The method for producing a frozen seafood food to be eaten raw according to claim 1, wherein the period from contacting the seasoning liquid with the seafood to the start of freezing is within 40 minutes.

3. The method for producing a frozen seafood food for raw consumption according to claim 1 or 2, wherein the amount of sodium acetate in the seasoning liquid is 5.0 mass% or more and 15.0 mass% or less.

4. The method for producing a frozen seafood food for raw consumption according to claim 1 or 2, wherein the seasoning liquid has a pH of 5.5 to 7.0 at 10 ° C.

5. The method for producing a frozen seafood food to be eaten raw according to claim 1 or 2, wherein in the freezing step, the freezing rate is -0.25 ° C. / min or more and the freezing temperature is -15 ° C. to -40 ° C.

6. The method for producing a frozen seafood food for raw consumption according to claim 1 or 2, wherein the seafood is salmon.

7. A method for preventing deterioration of frozen seafood food to be eaten raw, comprising the steps of: sealing and vacuum-packing seafood to be eaten raw and a seasoning liquid in an amount of more than 0.2 times and not more than 0.5 times the mass of the seafood in a container; and freezing the seafood after the vacuum packaging, The method for preventing deterioration of frozen seafood foods to be eaten raw, wherein the seasoning liquid contains sodium acetate, the period from contact of the seasoning liquid with the seafood to the start of freezing is within 130 minutes, and the amount of components in the seasoning liquid other than water, sodium acetate, organic acid or its acid salt or normal salt, emulsifier, and salt is 20 mass% or less.

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