JP4616409B1 - Frozen fish production method and cooking method - Google Patents

Abstract

A method for producing frozen fish and a method for cooking frozen fish using the frozen fish, in which flavor and texture are better maintained.
A fish body is immersed in an alkaline aqueous solution containing trisodium phosphate, an organic acid salt, and a saccharide having a pH of 11.6 to 12.6 for 10 minutes or more, and then frozen. At this time, it is preferable to adjust the immersion time of the fish body in the aqueous alkali solution so that the pH of the fish body after the alkali treatment is 6.5 to 8.5. The frozen fish thus obtained is cooked without thawing.
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Description

  The present invention relates to a method for producing frozen fish by immersing a fish body in an alkaline aqueous solution and freezing, and a method for cooking frozen fish for cooking the frozen fish.

  Conventionally, with regard to frozen storage of fish, the fish body is immersed in a pretreatment solution in which an alkaline agent or the like is dissolved in order to prevent deterioration of the meat quality during frozen storage and drip suppression during thawing, and then freeze the fish. It has been broken.

  For example, Patent Document 1 listed below describes a technique for preventing freezing and metamorphosis due to decomposition of trimethylamine-N-oxide by immersing fish meat such as white fish in an alkaline seasoning liquid to pH 7 or higher and then freezing. Has been.

  Patent Document 2 listed below includes sorbitol, trehalose, or a combination of these and other sugars and / or seasonings, and a pH adjuster capable of adjusting the pH of raw massive meat to the alkali side. A meat drip inhibitor characterized by the above is disclosed, and a technique for immersing fish and shellfish in an aqueous solution containing the drip inhibitor and having a pH of more than 7.5 and less than 9.5 is described.

  Further, in Patent Document 3 below, (a) a step of immersing a fish body in an alkaline aqueous solution adjusted to pH 8.6 to 11.5 at atmospheric pressure and room temperature for 30 minutes or more, and (b) the alkali treatment was performed. And a method for producing frozen fish that can be cooked while frozen, and an alkaline aqueous solution adjusted to pH 8.6 or more and 11.5 or less at atmospheric pressure and room temperature for 30 minutes. There is disclosed a frozen fish that can be cooked while frozen, characterized in that it is made of a fish that has been frozen after being adjusted to a pH of 8.6 or more and 11.5 or less by the soaking process.

JP 2005-269960 A JP 2008-289503 A Japanese Patent No. 4282746

  As described above, various techniques for freezing fish after immersing it in a pretreatment solution in which an alkaline agent or the like is dissolved have been proposed, but the deterioration of meat quality and flavor during frozen storage is prevented. However, it was still not a satisfactory technology.

  Further, Patent Document 3 discloses a technique for allowing a fish to be cooked while frozen by immersing the fish in an aqueous alkaline solution adjusted to pH 8.6 or more and 11.5 or less and then freezing the fish. However, the texture of the fish meat after cooking has not been satisfactory yet.

  Accordingly, it is an object of the present invention to provide a method for producing frozen fish and a method for cooking frozen fish using the frozen fish so that the flavor and texture are better maintained.

  In order to achieve the above object, the method for producing frozen fish of the present invention comprises immersing a fish body in an alkaline aqueous solution having a pH of 11.6 to 12.6 containing trisodium phosphate, an organic acid salt and a saccharide for 10 minutes or more. It is characterized by freezing after alkali treatment.

  According to the present invention, by immersing the fish in a highly alkaline aqueous solution having a pH of 11.6 to 12.6, fish odor components caused by ammonia contained in the fish, amines such as trimethylamine, dimethylamine, etc. It can be effectively dissolved and scattered to reduce the odor of fish after being frozen and stored.

  In addition, the alkali treatment can suppress the occurrence of drip and carding during thawing, cooking without thawing or in a half-thawed state.

  In addition, the use of trisodium phosphate, which can be made into a high pH and has a small pH buffering capacity, suppresses a significant increase in the pH of the fish itself during immersion, and the meat quality becomes softer. Therefore, the taste and texture after cooking can be improved.

  Moreover, the taste of fish can be improved by using an organic acid salt, the meat quality of fish can be improved by using sugars, and drip can be reduced even when cooked while frozen.

  In the manufacturing method of the frozen fish of this invention, it is preferable to adjust the immersion time of the fish body in the said alkaline aqueous solution so that the pH of the fish body after the said alkali treatment may be set to 6.5-8.5. According to this, it can prevent that the food texture of the fish meat after heat cooking becomes hard, and can suppress that a flavor worsens.

  Moreover, it is preferable that the immersion time of the fish body in the said aqueous alkali solution shall be 1 to 15 hours. According to this, moderate alkali treatment can be performed while suppressing a significant increase in the pH of the fish body itself, so that the occurrence of drip and curd during thawing or cooking is reduced, and the taste after cooking, A frozen fish having an excellent texture can be provided.

  Moreover, it is preferable that the said alkaline aqueous solution contains trisodium phosphate 0.1-5 mass%, organic acid salt 0.1-10 mass%, and saccharides 0.05-10 mass%. By setting the raw material of the alkaline aqueous solution to the above blending ratio, an aqueous solution having an excellent immersion treatment effect can be provided.

  Further, the organic acid salt is preferably at least one selected from citrate, lactate, malate, gluconate, succinate, and tartrate, and the saccharide is reduced syrup or syrup. At least one selected from sucrose, maltose, and dextrin is preferable, and the alkaline aqueous solution preferably further contains sodium chloride.

  Further, it is preferable that the alkali-treated fish body is once frozen, then taken out and sprayed with an aqueous solution containing saccharides or immersed in the aqueous solution to adhere to the surface, followed by freezing. According to this, when burned while frozen, the saccharide adhering to the surface forms a good burnished eye and has a good appearance.

  On the other hand, the method for cooking frozen fish of the present invention is characterized in that the frozen fish produced by the method is cooked without thawing. In this cooking method, by using the frozen fish that has been immersed in the alkaline aqueous solution and frozen, it is possible to suppress the occurrence of drip and curd even if cooked without thawing, and the flavor of the cooked fish The texture can be improved. In the present invention, “without thawing” includes not only a completely frozen state but also a half-thawed state.

  According to the present invention, the raw odor of the fish body after being frozen and stored is reduced, the occurrence of drip and curd when cooked without thawing or without thawing is suppressed, and the texture of fish meat after cooking is reduced. It can be kept soft and free of pasm, and the flavor can be improved.

  The fish to be the subject of the present invention is not particularly limited. Examples include sword fish, black diapers, hockey, marlin. Among these, mackerel, horse mackerel, red fish, hoki and madara are particularly preferably applied. These fish are not limited to fresh fish and may be used after thawing frozen ones.

  In the present invention, the fish body to be treated may be a whole fish body, a fillet, or a fish meat from which bones have been separated. Those are preferred.

  In the present invention, the alkaline aqueous solution used as a pretreatment liquid is an aqueous solution containing trisodium phosphate, an organic acid salt, and a saccharide, and adjusted to have a pH of 11.6 to 12.6 in a state before immersion in a fish. is there. The pH of the alkaline aqueous solution is more preferably 12.0 to 12.6. When the pH of the alkaline aqueous solution is less than 11.6, the treatment effect of the alkaline aqueous solution becomes weak and the fish odor mitigating effect becomes poor. Moreover, when pH of aqueous alkali solution exceeds 12.6, fish body pH will become high and flavor will worsen.

The trisodium phosphate used in the present invention may be an anhydride (Na ₃ PO ₄ ) or a hydrate (Na ₃ PO ₄ .12H ₂ O) as long as it can be used as a food material. In the present invention, the reason why trisodium phosphate is used as the alkaline agent is that the pH can be increased and the buffer capacity is small, so that a significant increase in fish pH can be suppressed. That is, by using trisodium phosphate as an alkaline agent and using the above-described alkaline aqueous solution adjusted to a high pH, ammonia contained in fish at the initial stage of immersion, amines such as trimethylamine, dimethylamine, etc. It is possible to effectively dissolve and disperse the fish odor component caused by it, reduce the raw odor of the fish body after freezing and suppress the increase in the pH of the fish body during immersion, and the meat quality becomes too soft It is possible to improve the taste and texture after cooking.

  The content of trisodium phosphate in the alkaline aqueous solution is preferably 0.1 to 5% by mass, and more preferably 0.3 to 1% by mass. When the content of trisodium phosphate is 0.1% by mass, the effect of pretreatment of the fish is poor, and when it exceeds 5% by mass, the pH of the fish tends to be high and the flavor tends to be poor.

  Examples of the organic acid salt added to the alkaline aqueous solution include citrate, acetate, lactate, malate, gluconate, succinate, and tartrate. Among these, trisodium citrate and sodium acetate are particularly preferably employed. The organic acid has the effect of improving the quality of the fish meat after cooking and reducing the fishy odor and improving the flavor.

  The content of the organic acid salt in the alkaline aqueous solution is preferably 0.1 to 10% by mass, and more preferably 0.35 to 1.5% by mass. When the content of the organic acid salt is less than 0.1% by mass, the effect of improving the meat quality and flavor of the fish meat is poor.

  Examples of the saccharide added to the alkaline aqueous solution include reduced syrup, syrup, sucrose, maltose, and dextrin. Among the saccharides, reduced candy is particularly preferably used. The sugar improves the quality of the fish meat by its water retention, and has the effect of reducing drip when cooked while frozen.

  0.05-10 mass% is preferable and, as for the content of the saccharides in alkaline aqueous solution, 0.1-0.8 mass% is more preferable. If the saccharide content is less than 0.05% by mass, the effect of reducing drip and improving the quality of fish meat will be poor, and if it exceeds 10% by mass, the sweetness will become stronger, and it will be easier to burn when baked, resulting in a decrease in yield. Tend to.

  In addition, salt, an antioxidant, etc. can be added to the aqueous alkali solution. In particular, in order to improve the permeability of the alkaline agent to the fish body, it is preferable to add salt, and the addition amount is preferably 0.1 to 5% by mass.

  The amount of the alkaline aqueous solution with respect to the fish body when immersing the fish body in the alkaline aqueous solution is not particularly limited as long as the fish body can be sufficiently immersed, but is preferably 1/3 or more of the alkaline aqueous solution with respect to the fish body 1 by mass ratio. More preferably, 1/2 to 2.

  The temperature at which the aqueous alkaline solution is immersed is not particularly limited, and may be performed at room temperature. However, in consideration of changes in seasons and regions, it is preferably performed in a room maintained at about 0 to 20 ° C.

  The immersion time in the aqueous alkali solution may be 10 minutes or more, but the pH of the fish after the alkali treatment is preferably adjusted to 6.5 to 8.5, more preferably 6.5 to 8. Is preferred. If the pH of the fish body after the alkali treatment is less than 6.5, the effect of the alkali treatment is poor, and if the pH exceeds 8.5, the flavor of the fish tends to be poor and the meat quality tends to be too soft. Generally, it is preferable to adjust so that the immersion time is 1 to 15 hours and the pH of the fish body after the alkali treatment is in the above range.

  In the present invention, the pH of the fish body after immersion in an alkaline aqueous solution is a mixture of fish meat that has been frozen and thawed after immersion in an alkaline aqueous solution and distilled water so that the mass ratio is fish meat: water = 10: 90, It shall mean the value measured by measuring the pH of the aqueous solution after stirring with a homogenizer.

  After immersing the fish body in an alkaline aqueous solution in this way, it is frozen according to a conventional method. Freezing is preferably performed at −30 ° C. or lower using a quick freezer such as a tunnel freezer, spiral freezer or contact freezer, and storage after freezing is performed at −18 ° C. or lower using a freezer, for example. preferable.

  Alternatively, the alkali-treated fish body may be once frozen, then taken out and sprayed with an aqueous solution containing sugars or immersed in the aqueous solution to adhere to the surface, followed by freezing. By attaching an aqueous solution containing saccharides to the surface of the fish body, when burned while frozen, the saccharides form good burnt eyes and have a good appearance and flavor. Although it does not specifically limit as said saccharide, For example, xylose, glucose, sugar, maltose etc. are mentioned, For example, the density | concentration of the saccharide in the said aqueous solution has preferable 1-30 mass%.

  Furthermore, after freezing the fish body that has been subjected to alkali treatment, the fish body is taken out, cut into an appropriate size that is easy for consumers to use, and if necessary, an aqueous solution containing the saccharides attached thereto, and then packaged in a vacuum pack or the like. May be stored frozen. In this case, since it is frozen and stored in an appropriately sized package, it can be sold as it is.

  The method for cooking frozen fish according to the present invention is characterized in that the frozen fish produced by the above method is cooked without thawing. Here, “without thawing” includes a partially thawed state, that is, a half-thawed state.

  The cooking can be performed by using various heating means using electricity, gas or the like as a heat source, for example, an electric oven, a gas oven, a microwave oven, a steam convection or the like. As the heating method, for example, various means such as baking, boiling, steaming, and oil can be employed. A seasoning liquid or seasoning containing soy sauce, miso, mirin, sake or the like may be applied as needed during cooking.

  As a preferable aspect of the method for cooking frozen fish of the present invention, a method of baking using an oven or the like can be mentioned. In this case, as described above, by attaching an aqueous solution containing a saccharide to the surface of the fish body, an appropriate burn can be formed on the surface to improve the flavor.

  Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following examples.

Production Example 1 (Production of basic alkali treatment agent)
30% by mass of trisodium phosphate, 25% by mass of trisodium citrate as organic acid salt, 10% by mass of sodium acetate, 30% by mass of reduced starch syrup and 5% by mass of dextrin as saccharide, Manufactured.

Production Example 2 (Preparation of alkaline aqueous solutions of various pHs)
Sodium dihydrogen phosphate and sodium chloride were added to the basic alkali treating agent of Production Example 1 to prepare alkaline aqueous solutions having various pH values A to C below. Moreover, according to the method described in the Example of the said patent document 3, alkaline aqueous solution was prepared by the mixing | blending of following D.

A: 3% by mass of basic alkali treating agent + 0.8% by mass of sodium chloride (pH 12.0)
B: 3% by mass of basic alkali treating agent + 0.2% by mass of sodium dihydrogen phosphate + 0.8% by mass of sodium chloride (pH 11.5)
C: 3% by mass of basic alkali treating agent + 0.5% by mass of sodium dihydrogen phosphate + 0.8% by mass of sodium chloride (pH 10.5)
D: Sodium hydrogen carbonate 1.2% by mass + Sodium hydrogen carbonate 0.53% by mass + Trisodium citrate 0.24% by mass + Dextrin 0.3% by mass (pH 10.0)
Test Example 1 (Effect of immersion treatment with various pH aqueous solutions)
The frozen red fish is thawed and poured into 3 pieces to form a fillet, and the alkaline aqueous solution A to D obtained in Production Example 2 is added at a mass ratio of 1 to the fish body 2 and 3 at 5 ° C. It was immersed for a period of time and frozen at −30 ° C. using a freezer after draining. Then, it was taken out, cut into a suitable size, sprayed and attached to this cut fish meat with an aqueous sugar solution containing 4% by mass of xylose, and stored frozen at -25 ° C.

  Seven days after the frozen storage, each cut fish meat was taken out and baked at 260 ° C. for 15 minutes as it was without thawing to obtain grilled fish.

  And the weight of the fish body before immersion in aqueous alkali solution, the weight of fish body after immersion in aqueous alkali solution, and the weight of fish body after heat processing were measured, respectively, and the yield was calculated | required.

  Furthermore, the fish body pH after immersion in an alkaline aqueous solution was measured by the method described above.

  Furthermore, the volatile basic nitrogen (VBN) value of the fish meat after being frozen and thawed by the above method was measured by the micro-diffusion method shown below.

1) Mixing 15 ml of raw material with 25 ml of demineralized water + 10 ml of 20% trichloroacetic acid 2) Stirring with a homogenizer (5000 rpm for 3 minutes)
3) Add demineralized water to make up to 100 ml. 4) After filtration, use filtrate as test solution. 5) Add 1.0 ml of boric acid absorbent to inner chamber of Conway diffuser. 6) 1.0 ml of test solution to outer chamber. Addition 7) Add 1.0 ml of saturated potassium carbonate solution so that it does not mix with the test solution in the outer chamber 8) Close the lid and seal 9) Mix the two solutions in the outer chamber 10) Let stand (2-3 hours) About)
11) Titration of boric acid absorbent solution in the inner chamber with 0.02N sulfuric acid 12) Obtain volatile basic nitrogen (VBN) from the following formula (i) from the titration value 0.28 × (AB) × f × 100 / x (mg / 100g) ... (I)
(In the formula (A), A represents a titration value, B represents a blank test value, f represents a 0.02N sulfuric acid factor, and x represents a sample amount (g) corresponding to 1 ml of a test solution)
The 20% trichloroacetic acid was prepared by measuring 20 g of trichloroacetic acid to 100 ml with demineralized water. Further, the potassium carbonate saturated solution was prepared by measuring 50 g of potassium carbonate to 100 ml with demineralized water. Further, the boric acid absorbent was prepared by dissolving 1 g of boric acid in 98% ethanol, adding 1 ml of a mixed indicator, and making up to 100 ml with demineralized water. Further, the mixed indicator was prepared by measuring 0.066 g of methyl red and bromcresol green to 100 ml with 98% ethanol.

  In addition, each measurement was performed similarly to the above about the sample which performed only freezing without being immersed in alkaline aqueous solution.

The results are shown in Table 1 below. In addition, the immersion yield and heating yield in Table 1 were determined by the following formulas (b) and (c).
Immersion yield (%) = (mass after immersion / mass of raw material) × 100 (b)
Heating yield (%) = (mass after heating / mass after immersion) × 100 (C)

  From the results in Table 1, sample No. 1 was immersed in an alkaline aqueous solution adjusted to pH 12. 2 shows other sample Nos. It can be seen that the heating yield is the highest and the VBN value is the lowest compared to 1, 3, 4, and 5.

Test example 2 (sensory evaluation of the processed product of the present invention and the product according to Patent Document 3)
Using the alkaline aqueous solution of A prepared in Production Example 2, mackerel, red fish, hoki and salmon are immersed in an aqueous alkaline solution, frozen, cooked by the following steps, heated yield, taste after cooking, The raw smell, texture, few cards and appearance were evaluated by 10 panelists.

  1) The fish body was wholesaled in three pieces and made into a fillet with bone removed.

  2) Aqueous alkali solution and filleted fish were mixed at a mass ratio of 1: 2, and immersed at 10 ° C. for about 3 hours.

  3) The fish body was taken out and frozen at −30 ° C., then half-thawed and processed into a fillet of 60 g per piece.

  4) The fillet was sprayed with a xylose aqueous solution to adhere to the surface.

  5) Frozen at −30 ° C. or lower with a tunnel freezer.

  6) Moved to freezer and stored frozen at -25 ° C for about 7 days.

  7) Removed from freezer and baked at 260 ° C. for 10 minutes in a gas oven while frozen.

  Evaluation of taste, etc. is performed by 10 panelists at the time of 20 minutes after cooking, with 5 points evaluation of 5: very good, 4: good, 3: normal, 2: bad, 1: very bad, The average of 10 people was rounded off.

  The heating yield was determined by (weight before cooking−weight after cooking) / weight before cooking × 100.

  In addition, commercially available frozen mackerel, frozen red fish, frozen hoki and frozen salmon, which are said to be prepared by the method described in Patent Document 3, were also cooked under the same conditions and evaluated in the same manner as above. .

  The results are shown in Table 2 below.

  As shown in Table 2, it can be seen that the treated product according to the present invention has a higher heating yield than the product of Patent Document 3, and is superior in taste, raw odor, texture and appearance.

Test Example 3 (Comparison of heating yield between a product obtained by firing the processed product of the present invention without thawing and a product obtained by thawing and baking a normal frozen product)
Using sourdough, mackerel, red fish, and hoki, in the same manner as in Test Example 2, after being immersed in an alkaline aqueous solution, frozen, removed, cooked as it is without thawing (firing in a gas oven), and heated yield Was measured. As the alkaline aqueous solution, the alkaline aqueous solution A of Production Example 2 was used.

  On the other hand, after being thawed according to a conventional method, it is thawed according to a conventional method, such as walleye pollack, mackerel, red fish, and hoki, which are frozen as they are without being immersed in an alkaline aqueous solution, and then cooked in the same manner as in Test Example 2 (firing in a gas oven) The heating yield was measured. These results are shown in Tables 3 and 4 below.

  As shown in Tables 3 and 4, a product frozen by alkali treatment according to the method of the present invention rather than a heating yield in the case of thawing a product frozen as it is without immersing it in an alkaline aqueous solution and baking it. It can be seen that the heating yield is better by 4 to 9% when firing without thawing.

Test Example 4 (Comparison of breaking strength between a product obtained by firing the processed product of the present invention without thawing and a product obtained by thawing and firing a normal frozen product)
Using mackerel and red fish, in the same manner as in Test Example 2, after being immersed in an alkaline aqueous solution, frozen, taken out, cooked as it is without thawing (firing with a gas oven), and the breaking strength was obtained by the following method. It was measured. The following alkaline aqueous solutions were used.

Mackerel ... 2% by mass of basic alkali treating agent + 1% by mass of sodium chloride (pH 12.0)
Red fish: 3% by mass of basic alkali treating agent + 0.8% by mass of salt (pH 12.0)
Measuring method of breaking strength: The raw material was cut into approximately 2 cm square, and measured using a cylindrical plunger with a diameter of 3 cm under the conditions of measuring strain rate of 85% and measuring speed of 1.0 mm / sec. The average value was measured.

  On the other hand, mackerel and red fish, which are frozen products without being immersed in an alkaline aqueous solution, are thawed according to a conventional method, and then cooked (fired in a gas oven) in the same manner as in Test Example 2, and the same as above. The breaking strength was measured. These results are shown in Table 5 below.

  As shown in Table 5, the product frozen by alkali treatment according to the method of the present invention is thawed rather than the rupture strength when the product frozen as it is without being immersed in an alkaline aqueous solution and then baked. It can be seen that the breaking strength when baked without being reduced is significantly smaller, and the product obtained by the method of the present invention is softer after cooking.

Test Example 5 (Fish pH after alkali treatment)
Mackerel and red fish were immersed in the following alkaline aqueous solutions E and F for 1 hour, 3 hours and 5 hours, respectively, and then the pH of the fish body after alkali treatment was measured by the method described above. For comparison, the pH of the fish that was not treated with alkali was measured. These results are shown in Tables 6 and 7.
E: 2% by mass of basic alkali treating agent of Production Example 1 + 0.8% by mass of sodium chloride (pH 11.9)
F: 3% by mass of basic alkali treating agent of Production Example 1 + 0.8% by mass of sodium chloride (pH 12.0)

  As described above, according to the method of the present invention, it is found that the fish body pH after the immersion treatment hardly exceeds 8.5, and is usually pH 8 or less.

Claims (9)

A method for producing frozen fish, comprising immersing a fish body in an alkaline aqueous solution having a pH of 11.6 to 12.6 containing trisodium phosphate, an organic acid salt, and a saccharide for 10 minutes or more, and then freezing the fish. . The manufacturing method of the frozen fish of Claim 1 which adjusts the immersion time of the fish body in the said alkaline aqueous solution so that pH of the fish body after the said alkali treatment may be set to 6.5-8.5. The method for producing frozen fish according to claim 1 or 2, wherein the immersion time of the fish in the alkaline aqueous solution is 1 to 15 hours. The alkaline aqueous solution contains 0.1 to 5% by mass of trisodium phosphate, 0.1 to 10% by mass of an organic acid salt, and 0.05 to 10% by mass of a saccharide. The manufacturing method of the frozen fish as described in one. The refrigeration according to any one of claims 1 to 4, wherein the organic acid salt is at least one selected from citrate, lactate, malate, gluconate, succinate, and tartrate. Fish production method. The method for producing frozen fish according to any one of claims 1 to 5, wherein the saccharide is at least one selected from reduced syrup, syrup, sucrose, maltose, and dextrin. The method for producing frozen fish according to any one of claims 1 to 6, wherein the alkaline aqueous solution further contains sodium chloride. The frozen fish body that has been subjected to alkali treatment is taken out, and then taken out and sprayed with an aqueous solution containing sugars or immersed in the aqueous solution to adhere to the surface, followed by freezing. The manufacturing method of the frozen fish of description. A method for cooking frozen fish, wherein the frozen fish produced by the method according to any one of claims 1 to 8 is cooked without thawing.