阅读说明：本技术 腌制水产品的方法、腌制的水产品和腌制溶液 (Method for pickling aquatic product, pickled aquatic product and pickling solution ) 是由 森隆史 井野原康太 高桥明子 杉山公教 于 2020-02-03 设计创作，主要内容包括：目的：提供一种对水产品的原味和质地影响小,且在冷冻和加热期间抑制滴水的腌制方法。解决方案：一种在满足以下a)至c)的条件下腌制水产品的方法：a)处理期间总离子强度为0.2至0.8mol/kg；b)总氯化钠浓度小于1.5重量％；和c)腌制的虾肉的pH为6.5至8.6,其中总离子强度和总氯化钠浓度是指相对于水产品的重量和腌制溶液的水的重量之和的离子强度和氯化钠浓度,其中将水产品的重量视为水的重量。(The purpose is as follows: to provide a method for salting a marine product which has little influence on the original taste and texture of the marine product and in which dripping water is suppressed during freezing and heating. The solution is as follows: a method for curing a seafood under conditions which satisfy the following a) to c): a) the total ionic strength during the treatment is 0.2 to 0.8 mol/kg; b) a total sodium chloride concentration of less than 1.5 wt%; and c) the pH of the salted shrimp meat is 6.5 to 8.6, wherein the total ionic strength and the total sodium chloride concentration refer to the ionic strength and the sodium chloride concentration relative to the sum of the weight of the water product and the weight of the water of the salting solution, wherein the weight of the water product is taken as the weight of the water.)

1. A method for curing a seafood under conditions which satisfy the following a) to c):

a) the total ionic strength during the treatment is from 0.2 to 0.8 mol/kg;

b) a total sodium chloride concentration of less than 1.5 wt%; and

c) the pH of the marinated water product is from 6.5 to 8.6, wherein the total ionic strength and the total sodium chloride concentration refer to the ionic strength and the sodium chloride concentration relative to the sum of the weight of the water product and the weight of the water of the marinating solution, wherein the weight of the water product is taken as the weight of the water.

2. The method of claim 1, wherein

d) The total concentration of trisodium citrate is 1% by weight or more.

3. The method of claim 1 or 2, wherein the pH of the salted seafood of c) is 6.5 to 8.3.

4. The method according to any one of claims 1 to 3, wherein the salt for pickling is an organic acid salt and/or an inorganic acid salt that can be used for food.

5. The method of claim 4, wherein the salt for pickling is any one of a sodium salt, a potassium salt, a calcium salt, a magnesium salt, or a combination thereof.

6. The method according to claim 4 or 5, wherein the salt for pickling is any one of citrate, carbonate, bicarbonate, ascorbic acid, erythorbate, lactate, succinate, acetate, malate, fumarate, gluconate, polyphosphate, hydrochloride, or a combination thereof.

7. The method of any one of claims 1 to 6, wherein the curing time is 1 to 48 hours.

8. The method according to any one of claims 1 to 7, wherein the seafood is sprinkled with powdered salt and water is added to satisfy the conditions a) to c) or a) to d), and then the seafood is salted therein.

9. The method of claim 8, wherein the sprinkling with the powdered salt is followed by holding for 0.5 to 2 hours, adding water, and salting for a total of 1 to 48 hours.

10. A salted seafood satisfying the following a) to c):

a) the ionic strength is 0.2 to 0.8 mol/kg;

b) the sodium chloride concentration is less than 1.5 wt%; and

c) the pH is 6.5 to 8.6.

11. The aquatic product of claim 10, further satisfying d) below:

d) the concentration of trisodium citrate is 1% by weight or more.

12. A salted seafood as claimed in claim 10 or claim 11, wherein the pH of c) is from 6.5 to 8.3.

13. A seafood product according to any one of claims 10 to 12, which is marinated with an organic acid salt and/or an inorganic acid salt useful for food.

14. The aquatic product of claim 13, wherein the organic acid salt and/or inorganic acid salt is any one of a sodium salt, a potassium salt, a calcium salt, a magnesium salt, or a combination thereof.

15. The seafood of claims 13 or 14, wherein the organic and/or inorganic acid salt is any of citrate, carbonate, bicarbonate, ascorbic acid, erythorbate, lactate, succinate, acetate, malate, fumarate, gluconate, polyphosphate, hydrochloride, or a combination thereof.

16. A pickling solution in which a marine product is pickled, which satisfies the following a) to c):

a) the total ionic strength is 0.2 to 0.8 mol/kg;

b) a total sodium chloride concentration of less than 1.5 wt%; and

c) the pH is 7.0 to 9.5.

17. The curing solution of claim 16 wherein a seafood product is cured, further satisfying the following d):

d) the total concentration of trisodium citrate is 1% by weight or more.

18. The pickling solution according to claim 16 or 17, wherein the salt used is an organic acid salt and/or an inorganic acid salt that can be used for food.

19. The salting solution of claim 18, wherein the organic acid salt and/or the inorganic acid salt is any one of a sodium salt, a potassium salt, a calcium salt, a magnesium salt, or a combination thereof.

20. The pickling solution of claim 18 or 19, wherein the organic acid salt and/or inorganic acid salt is any one of citrate, carbonate, bicarbonate, ascorbic acid, erythorbate, lactate, succinate, acetate, malate, fumarate, gluconate, polyphosphate, hydrochloride, or a combination thereof.

Technical Field

The invention relates to a method for pickling aquatic products. In particular, it relates to a pickling method capable of suppressing the occurrence of dripping water due to freezing or heating and maintaining the original taste and texture of a marine product.

Background

Many water products are refrigerated for distribution to remain fresh. Raw seafood is a food with a unique texture of fibrous texture and elasticity. However, the freezing and thawing process and the heat treatment tend to cause dripping, thereby drying the texture. As a result, the yield is also reduced. To solve this problem, techniques for salting aquatic products have long been devised.

The main methods for retaining moisture are a method of adding sodium chloride and a method of using alkali. However, sodium chloride makes water very salty and therefore its use is limited. Therefore, the aquatic product is mainly salted in the alkaline salting solution. In the case of salted shrimp, alkali has an effect of making shrimp red, and is therefore preferable from the viewpoint of appearance.

However, the drawback of pickling with alkali leads to an unnatural transparency of the seafood and is surprising in that the meat properties, which would otherwise become opaque when heated, remain transparent. In addition, the texture tends to be a jelly-like texture rather than a fibrous texture.

Patent document 1 describes "a method for producing shrimps having improved texture, taste and surface color, comprising the step (a): raw shrimp or thawed shrimp is brought into contact with a surface color improving solution for shrimp, which contains potassium carbonate, calcium oxide, tripotassium citrate, trisodium citrate, salt, sodium glutamate and water, for 30 minutes to 24 hours, the content of sodium glutamate in the surface color improving solution for shrimp being 0.01 to 2.0 mass%, and the pH being 11.0 to 13.0 ".

Patent document 2 describes "a treatment agent for aquatic products that satisfies the following requirements:

(1) it contains sodium gluconate and/or potassium gluconate;

(2) it also contains one or more selected from sodium chloride, trisodium citrate, sodium bicarbonate, sodium carbonate, trisodium phosphate, sodium glutamate, potassium carbonate, tripotassium citrate, and tripotassium phosphate;

(3) sodium in weight ratio of ions: the mixing ratio of potassium is 1:0 to 1: 1.4; and

(4) the pH of a 1% aqueous solution of the treatment agent for aquatic products is in the range of 9.0 or more but less than 10.5 ".

Patent document 3 describes "a method for producing shrimps with improved texture and transparency, comprising the step (a): contacting raw shrimp or thawed shrimp with an alkaline solution having a pH of 10.25 to 10.96, the alkaline solution containing at least one selected from the group consisting of: sodium carbonate, sodium and potassium carbonates, trisodium citrate, one or more divalent alkaline earth metal salts selected from calcium lactate, calcium chloride and magnesium chloride, and water, and the contact time with the alkaline solution is 10 to 24 hours ".

In the examples of these prior art documents, the pH and/or sodium chloride concentration of all methods is high, which inevitably affects the taste and texture of the seafood.

Reference list

Patent document

Patent document 1: JP 3590615B

Patent document 2: JP 3798391B

Patent document 3: JP 4109819B

Disclosure of Invention

Technical problem

The invention aims to provide a pickling method which has little influence on the original taste and mouthfeel of an aquatic product and inhibits dripping during freezing and heating.

Technical scheme

For the salting of aquatic products, salting solutions and salting methods having various formulations have been designed. However, an effective method of suppressing dripping during freezing and heating, more specifically suppressing loss of umami taste and maintaining texture, while maintaining the taste and texture characteristics of raw seafood, has not been established. Therefore, in the present invention, an overview of what is essential to suppress dripping water and maintain yield without affecting mouthfeel and texture is made on the pickling solution.

It was found that not the type or concentration of salt but the ionic strength is important. The discovery that ionic strength is important led to the discovery of a process that maintains productivity with little impact on mouthfeel and texture, wherein the amount of components that impact mouthfeel and texture is reduced and the amount of components that increase ionic strength is increased.

The gist of the present invention is the method for salting a marine product according to (1) to (20).

(1) A method for curing a seafood under conditions which satisfy the following a) to c):

a) the total ionic strength during the treatment is from 0.2 to 0.8 mol/kg;

b) a total sodium chloride concentration of less than 1.5 wt%; and

c) the pH of the marinated water product is from 6.5 to 8.6, wherein the total ionic strength and total sodium chloride concentration refer to the ionic strength and sodium chloride concentration relative to the sum of the weight of the water product and the weight of the water of the marinating solution, wherein the weight of the water product is taken as the weight of the water.

(2) The method according to (1), wherein

d) The total concentration of trisodium citrate is 1% by weight or more.

(3) The method according to (1) or (2), wherein the pH of the salted seafood of c) is 6.5 to 8.3.

(4) The method according to any one of (1) to (3), wherein the salt for pickling is an organic acid salt and/or an inorganic acid salt usable for foods.

(5) The method according to (4), wherein the salt for pickling is any one of a sodium salt, a potassium salt, a calcium salt, a magnesium salt, or a combination thereof.

(6) The method according to (4) or (5), wherein the salt for pickling is any one of: citrate, carbonate, bicarbonate, ascorbic acid, erythorbate, lactate, succinate, acetate, malate, fumarate, gluconate, polyphosphate, hydrochloride, or combinations thereof.

(7) The method according to any one of (1) to (6), wherein the salting time is 1 to 48 hours.

(8) The method according to any one of (1) to (7), wherein the seafood is sprinkled with powdered salt and water is added to satisfy the conditions a) to c) or a) to d), and then the seafood is salted therein.

(9) The method according to (8), wherein the sprinkling with powdery salt is followed by holding for 0.5 to 2 hours, adding water, and pickling for a total of 1 to 48 hours.

(10) A salted seafood satisfying the following a) to c):

a) the ionic strength is 0.2 to 0.8 mol/kg;

b) the sodium chloride concentration is less than 1.5 wt%; and

c) the pH is 6.5 to 8.6.

(11) A water product according to (10), which further satisfies the following d):

d) the concentration of trisodium citrate is 1% by weight or more.

(12) The salted marine product of (10) or (11), wherein the pH of c) is from 6.5 to 8.3.

(13) The aquatic product according to any one of (10) to (12), which is salted with an organic acid salt and/or an inorganic acid salt that can be used for food.

(14) The aquatic product according to (13), wherein the organic acid salt and/or the inorganic acid salt is any one of a sodium salt, a potassium salt, a calcium salt, a magnesium salt, or a combination thereof.

(15) The aquatic product according to (13) or (14), wherein the organic acid salt and/or the inorganic acid salt is any one of: citrate, carbonate, bicarbonate, ascorbic acid, erythorbate, lactate, succinate, acetate, malate, fumarate, gluconate, polyphosphate, hydrochloride, or combinations thereof.

(16) A pickling solution in which a marine product is pickled, which satisfies the following a) to c):

a) the total ionic strength is 0.2 to 0.8 mol/kg;

b) a total sodium chloride concentration of less than 1.5 wt%; and

c) the pH is 7.0 to 9.5.

(17) The pickling solution according to (16), in which a marine product is pickled, further satisfying the following d):

d) the total concentration of trisodium citrate is 1% by weight or more.

(18) The pickling solution according to (16) or (17) in which a marine product is pickled, wherein the salt used is an organic acid salt and/or an inorganic acid salt which can be used for food.

(19) The pickling solution in which a seafood product is pickled according to (18), wherein the organic acid salt and/or the inorganic acid salt is any one of a sodium salt, a potassium salt, a calcium salt, a magnesium salt, or a combination thereof.

(20) The pickling solution in which a marine product is pickled according to (18) or (19), wherein the organic acid salt and/or the inorganic acid salt is any one of: citrate, carbonate, bicarbonate, ascorbic acid, erythorbate, lactate, succinate, acetate, malate, fumarate, gluconate, polyphosphate, hydrochloride, or combinations thereof.

Advantageous effects of the invention

With the salting method of the present invention, dripping during freezing and heating is suppressed, loss of umami taste is suppressed, and productivity is maintained while preventing influence on taste, appearance and texture of the seafood, particularly salty taste due to salt, transparency due to alkali, jelly-like texture due to alkali.

Drawings

FIG. 1 is a graph showing the salting yield of shrimps salted in the salting solution using various salts of example 1, with the concentration (wt%) of the salt in the salting solution on the horizontal axis.

FIG. 2 is a graph showing the salting yield of shrimps salted in the salting solution using various salts of example 1, with the total ion intensity (mol/kg) on the horizontal axis.

FIG. 3 is a graph showing the salting yield of shrimps salted by the sprinkling method of example 5 with the total ion intensity on the horizontal axis.

Fig. 4 is a graph showing sensory evaluation results (mouthfeel and flavor) of example 6. In the figure, denotes a significant difference in probability that the risk rate is 1% or less, denotes a significant difference in probability that the risk rate is 5% or less, andrepresenting a significant difference in the probability of a risk rate of 10% or less.

Fig. 5 is a graph showing the results of sensory evaluation (texture) of example 6. In the figure, a significant difference indicates a probability of a risk rate of 1% or less, and a significant difference indicates a probability of a risk rate of 5% or less.

Fig. 6 is a graph showing the results (appearance) of sensory evaluation of example 6. In the figure, a indicates a significant difference in probability that the risk rate is 1% or less, and a indicates a significant difference in probability that the risk rate is 5% or less.

FIG. 7 is a photograph showing the appearance of the heated shrimps in comparative example 1, formula 2 and comparative example 2 of example 6.

Figure 8 is a photomicrograph (40 x magnification) of a muscle fiber cross section of a shrimp of example 6.

FIG. 9 is a graph plotting the pH of the salting solution and the pH of salted shrimp meat in example 7.

Detailed Description

The invention relates to a method for pickling aquatic products.

The aquatic products to be targeted by the present invention are not particularly limited as long as they are edible aquatic products among fishes, crustaceans, mollusks. Specifically, examples of crustaceans include shrimp, and examples of mollusks include adductor muscles of squid, octopus, and shellfish.

The shrimps which are the object of the present invention are those which are used as food in organisms belonging to the phylum Arthropoda, crustaceans (Crustacea), Proteus (Malacostraca), Decapa (Decapoda, Order Decapoda). Specific examples include short-spotted Pacific shrimps (Alpheus brevicristatus), Pacific shrimps (Marsupenaus japonica), Penaeus monodon (Penaeus monodon, Tiger shrimp), Litopenaeus vannamei (Litopenaeus vannamei), Neocaridinus vannamei (Metapenaeus joyneri), Penaeus armatus (Trachyramus curvirosis), Pandalus flabellatus (Ibacuc ciratus), Cervus cervi (Acropora shrimaps), Penaeus merus (Stenopus hispidus), Penaeus japonicus (Panulirus japonica), Panulirus scholaris (Scylis squamosus), Lobster (lobster), eastern red cherry shrimps (Lucensis cerasus), Japanese glass shrimps (Pasiphaea japonica), Red-sea old northern China (Pandalus eous, sweet shrimp), Japanese crayfish (Metahydroprophus japonica), Palaemon macrobrachium (Palaemon pacificus), Pandalus megalosus (Pandalus latirostris), Padalus curus pallidus (Heptacarpus genius), Heptaculus giganteus (Heptacarpus recitrosis), freshwater shrimps, striped macrobrachium (Palaemon pacificus), Pandalus platyphylla (Paralyx compnsa), Lobster clayformis (clafiyssh), and Red swamp crayfish (red swamp crayfish).

The shrimp may be raw or frozen and thawed.

Squids which are the object of the present invention are those used as food in organisms belonging to the molluscs (molusk), cephalopods (Cephalopod), Coleoidea (Coleoidea), brachiocarpium order (decapodiformaes). Specific examples include pacific squid (Todarodes pacifics), squid (hetrologo bleekeri), squid (utrotis edulis, brachiocarpus), squid (Ommastrephes bardemii, squid (purplespid)), squid (sepoteothyris leistrisonia), squid (thysanotis rhamsus), squid (cuttlefish), squid (ocellular cuttlefish), squid (Sepiella japonica), squid (tetrapanar morsei), squid (recutlefish), dwarfs squids (decollefish), squid (cuttlefish), squid (wished squid (Sepiella japonica), squid (tetrapanar morsei), squid (recutlefish), dwarf squids (wastagia intesci), and squid (piscijuga gigas). The squid may be unprocessed or frozen and thawed.

Octopus, which is the object of the present invention, are those used as food in organisms belonging to the phylum Mollusca (molllusca), cephalopods, class coleoidea, order octacarpa (octopus eyes). Specific examples include Octopus vulgaris (Octopus sinensis), Octopus dofleini, Octopus ocellatus (Octopus ocellatus), Octopus membranaceus (Octopus membranaceus), Octopus cyanea Octopus (Octopus cyanea Gray), Octopus esculentus (Octopus conspidius), Octopus longipes (Octopus minor), and Octopus canadensis (Benthotopus profundorum Robson). The octopus may be raw or frozen and thawed.

The adductor muscles of shellfish which are the object of the present invention are those used as food in adductor muscles of organisms belonging to the Order molluscs, Bivalves (Bivalves), pehnoda (Pectinoida) or mytilus (Order Mytiloida). Specifically, examples of organisms belonging to the order of a scallop include scallops, noble scallops (noble scallops) and Japanese fillet scallops (Japanese bay scallops), and examples belonging to the order of a mussel include Atrina pectinata (Atrina pectinata) and blue mussels (blue mussels). The adductor muscles of the shellfish may be raw or frozen and thawed.

The ionic strength is obtained by adding the product of the molar concentration of each ion in solution and the square of the charge of all the ionic species, and then halving it, as shown in the equation below.

[ equation 1]

The ionic strength of the aqueous solution of the pickling solution can be calculated according to this equation. However, even if the ionic strength of the aqueous solution of the salting solution is determined, if the amount of the salting solution relative to the water product is changed, the effect thereof is changed.

The "total ionic strength", "total sodium chloride concentration" and "total trisodium citrate concentration" in the present invention are not the ionic strength or salt concentration of the salting solution, but the ionic strength, sodium chloride concentration and trisodium citrate concentration of the sum of the weight of the aquatic product and the weight of water in the salting solution, wherein the weight of the aquatic product is also taken as the weight of water.

The present inventors found that the ionic strength at the stage where salt permeates into a water product salted in a salting solution and becomes constant is important. The weight of the water product was regarded as the amount of water, and "(aqueous solution ionic strength × amount of aqueous solution)/(amount of aqueous solution + weight of shrimp)" was defined as the total ionic strength.

Also, regarding the concentration of a salt such as sodium chloride, "(concentration in an aqueous solution × amount of an aqueous solution)/(amount of an aqueous solution + weight of a water product)" is taken as the total concentration.

This definition of total ion concentration and total concentration allows for the production of a water product that is salted as designed without differences in the effect of the amount of salting solution and the amount of water product.

In the case of using shrimp with shell, the penetration of the salting solution is slightly deteriorated due to the presence of the shrimp shell. However, since the shells are lightweight and have no significant effect, the weight of the shrimp can be calculated as the weight of water for peeled shrimp and shrimp with shells.

To determine the formulation of the pickling according to the invention, the following conditions a) to c) are necessary:

a) the total ionic strength during the treatment is from 0.2 to 0.8 mol/kg;

b) a total sodium chloride concentration of less than 1.5 wt.%, and

c) the pH of the salted seafood is between 6.5 and 8.6.

The salted aquatic product satisfying the following conditions a) to c) of the present invention refers to an aquatic product salted by the salting method satisfying the above conditions a) to c):

a) the ionic strength is 0.2 to 0.8 mol/kg;

b) a sodium chloride concentration of less than 1.5% by weight, and

c) the pH is 6.5 to 8.6.

Similarly, the salted aquatic product satisfying the condition d) that the concentration of trisodium citrate is 1% by weight or more in the present invention means an aquatic product salted by the salting method satisfying the following condition d):

d) the total concentration of trisodium citrate is 1% by weight or more.

The total ionic strength during the salting according to the present invention is 0.2 to 0.8mol/kg, preferably 0.3 to 0.7mol/kg, more preferably 0.4 to 0.7 mol/kg. The total sodium chloride concentration is less than 1.5 wt%, preferably 1.2 wt% or less, more preferably 1.0 wt% or less, 0.8 wt% or less and 0.75 wt% or less. The concentration of sodium chloride has no lower limit and may be zero, but the total concentration is preferably at least 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.05 wt% or more, because salty taste also has the effect of enhancing the umami taste of the seafood. This is not the case when the salty taste may be enhanced by other flavors. Salting the aquatic product so that the pH of the salted aquatic product is 6.5 to 8.6. Preferably, it is salted to have a pH of 6.6 to 8.3, more preferably 7.0 to 8.2, 7.0 to 8.1 and 7.0 to 8.0. Since the pH of the marinated seafood is highly correlated with the marinating solution, the pH of the seafood can be easily adjusted by adjusting the pH of the marinating solution. The pH of the pickling solution is 7.0 to 9.5, preferably 7.0 to 9.3, 7.0 to 9.0, more preferably 7.0 or more, but less than 9.0, 7.0 to 8.8, and 7.0 to 8.5. The pH of the pickled aquatic product is the pH of the liquid after the pickled aquatic product is cut up and is added with 10 times of water and fully stirred.

By setting the total ionic strength in the range of 0.2 to 0.8mol/kg, the water retention capacity of the aquatic product can be improved, the yield can be improved, and thus, dripping water can be reduced. In the related art, the concentrations of sodium chloride and alkali metal salt in the pickling solution are defined as weight%, molar concentration, etc. of the aqueous solution. However, as shown in example 1 (fig. 1 and 2), the effect of reducing dripping water was found to be closely related to the ionic strength. By calculating the ionic strength, even when the molecular weight, properties, etc. of the salt are changed, the mixing of a plurality of salts is easy, and the formulation of a desired pickling solution can be determined.

In addition, by using the total ionic strength including the weight of the aquatic product, not the ionic strength of the aqueous solution, it is possible to design in consideration of the influence of the change in the ratio of the amount of the salting solution to the amount of the aquatic product.

Furthermore, the finding of the importance of total ionic strength reveals which ingredients should be selected to reduce the impact on the strong salty taste caused by sodium chloride and the texture caused by alkali. Since the ionic strength is obtained by multiplying the molar concentration by the square of the charge, the lower the molecular weight of the salt and the higher the charge, the greater the ionic strength becomes even at the same concentration.

For example, when sodium chloride having monovalent sodium ions and chloride ions is compared with trisodium citrate having three monovalent sodium ions and trivalent citrate ions, there is a 6-fold difference in ionic strength even at the same molar concentration. When considering molecular weight, the molecular weight of sodium chloride is 58.44g/mol and the molecular weight of trisodium citrate is 258.06g/mol, differing by a factor of about 4.4. Therefore, in the case of using sodium chloride and trisodium citrate at the same ionic strength, 1.4 times as much sodium chloride must be used in terms of concentration by weight%.

In order to increase the ionic strength at a low concentration, a salt containing an ion having a low molecular weight and a high charge is preferable. Among the salts used in food products, trisodium citrate and the like have been found suitable. As shown in example 3, the preparation was made possible at an ionic strength in a range that does not affect the salty taste by adjusting the ionic strength using trisodium citrate so that the total concentration is at least 1% by weight or more.

Specific examples of the organic acid salt and/or inorganic acid salt that can be used for food in addition to sodium chloride and trisodium citrate include any of the following: sodium, potassium, calcium, magnesium, combinations thereof, and citrate, carbonate, bicarbonate, ascorbic acid, erythorbate, lactate, succinate, acetate, malate, fumarate, gluconate, polyphosphate, hydrochloride, and combinations thereof.

Specific examples include sodium chloride, trisodium citrate, potassium chloride, tripotassium citrate, calcium citrate, sodium lactate, sodium succinate, sodium acetate, sodium malate, sodium fumarate, sodium gluconate, potassium gluconate, calcium lactate, magnesium chloride, calcium chloride, sodium erythorbate, and polyphosphate.

Examples of preferred curing methods of the present invention include the following embodiments.

One embodiment is where the total ionic strength is adjusted to 0.2 to 0.8mol/kg by adding 1 to 4 wt% trisodium citrate and no sodium chloride or 1 wt% or less salt as total concentration, or another embodiment is where the total ionic strength is adjusted to 0.2 to 0.8mol/kg by further adding one or more salts selected from the following as further salts: potassium chloride, tripotassium citrate, calcium citrate, sodium lactate, sodium succinate, sodium acetate, sodium malate, sodium fumarate, sodium gluconate, potassium gluconate, calcium lactate, magnesium chloride, calcium chloride, sodium erythorbate, sodium polyphosphate, and the like.

The pickling of the present invention is carried out at a temperature (usually 0 to 20 ℃) which does not affect the quality of the aquatic product for 1 to 48 hours, preferably 3 to 36 hours, 4 to 24 hours, more preferably 5 to 24 hours, 5 to 18 hours. According to the size of the aquatic product, the aquatic product can be pickled relatively uniformly in one hour. Three hours are sufficient. There is no upper limit to the salting time, but it is not necessary to unnecessarily increase the salting time so as not to affect the quality of the aquatic product, and an appropriate time is set in conjunction with other works. It is preferable to cure the seafood until the curing solution penetrates into the center of the seafood to a uniform concentration, thereby eliminating the unevenness in taste and texture.

The pickling of the present invention may be carried out by a method of pickling a marine product in a pickling solution in which a pickling formula is dissolved, a method of sprinkling a marine product with powder of a pickling formula and then pickling the marine product with water, or a method of sprinkling only powder without adding water.

In the case of sprinkling powder, sprinkling the seafood with salt in powder form, adding water, and pickling the seafood under conditions satisfying a) to c). Specifically, after sprinkling with salt in powder form, the seafood is kept for 0.5 to 2 hours, water is added, and the seafood is salted at 0 to 20 ℃ for a total of 1 to 48 hours, preferably 3 to 36 hours, 4 to 24 hours, more preferably 5 to 24 hours, and 5 to 18 hours. The sprinkling of the powder can greatly reduce the consumption of water and salt and prevent the delicate flavor from flowing into the pickling solution. In the case of sprinkling powder, the water product is sprinkled with salt in powder form, water is added to satisfy the conditions a) to c), and further the condition d) is satisfied. The curing effect after addition of water can be considered in the same way as in the curing solution.

In the case of sprinkling only the powder, the water product is pickled with only the moisture contained in the water product. Since the yield is better in the case of adding water, water is preferably added, but only powder may be used.

The aquatic products pickled by the method have excellent quality and are better to eat.

The present invention will now be described in more detail by way of examples, but is by no means limited thereto.

Example 1

Ionic strength of curing agent

In order to maintain shrimp yield, salting with sodium chloride or alkaline agents was performed in various combinations of different components. In order to find out the most important components and how to use it, pickling was performed with various components.

Different concentrations of pickling solutions were prepared using sodium chloride, trisodium citrate, potassium chloride + trisodium citrate, sodium ascorbate, magnesium chloride as the pickling components. Frozen white shrimp (peeled shrimp) was thawed and salted with 100 wt% of a salting solution with respect to the weight of the shrimp for 18 hours.

The results are shown in FIG. 1. The results generally show that yield increases with increasing salt concentration in the pickling solution. However, no indication is obtained as to which ingredients should be used in what proportion when these components are used in combination.

FIG. 1 is a graph with the salt concentration in wt% in the pickling solution plotted on the horizontal axis, and FIG. 2 is a graph with the ionic strength plotted on the horizontal axis. The horizontal axis in fig. 2 represents the total ion intensity.

"Total ionic strength" refers to the ionic strength in the total amount of the salting solution and the weight of shrimp. When the ionic strength of the salting solution is "aqueous solution ionic strength", it is expressed by "(aqueous solution ionic strength × amount of aqueous solution)/(amount of aqueous solution + amount of shrimp)". Thus, when the weight ratio of the salting solution to the shrimp is 100%, the total ionic strength is 1/2 of the ionic strength of the aqueous solution.

As shown in fig. 2, when considering the yield as an index of total ionic strength, an approximate curve is drawn regardless of the type of salt. Thus, using an index of total ionic strength allows designing a salting solution irrespective of the type of salt, and further allows designing taking into account the amount of salting solution and shrimp.

[ example 2]

The pickling solutions were prepared using 12 formulations shown in tables 1-1 and 1-2. Frozen white leg shrimps (peeled shrimps) were thawed and salted in a salting solution at 100% by weight relative to the weight of the shrimps for 18 hours. Comparative example 1 had no salting and comparative example 2 used a high pH salting solution. The heat treatment after pickling was carried out by boiling the mixture in hot water at 100 ℃ for 90 seconds and then cooling the mixture in ice water for 1 minute.

The "ionic strength of aqueous solution" and "total ionic strength" in tables 1-1 and 1-2 are as defined in example 1.

The curing yield, i.e., the ratio of the weight after curing to the weight before curing, and the heating yield, i.e., the ratio of the weight after heating to the weight before heating, were measured, and sensory evaluation was performed using the texture of the heated sample prawns. The texture of the prawns was evaluated in 0.5 (n-3) increments based on an evaluation criterion of 0 to 2 points as follows: "texture with feeling of shrimp fiber (score 2)", "texture with slight jelly shape (score 1)", and "texture with whole jelly shape (score 0). Scores below 1 were judged as unpleasant because the texture was not shrimp-like.

The results are plotted as a mixture (white circles) in fig. 1 and 2. Even for the pickling solutions prepared by mixing various salts, it was confirmed that values similar to those obtained when the various salts were used alone were obtained by plotting the total ionic strength. From these results, it was confirmed that it is preferable to design a salting solution based on the total ion intensity of each salt.

From the results of FIG. 2, it is necessary to set the total ionic strength to at least 0.2mol/kg or more, preferably 0.3mol/kg or more. In particular, it was found that when the concentration was set to 0.4mol/kg or more, a stable yield could be obtained with any salt.

Further, it was found that when the pH of the pickling solution exceeds 10, the shrimp-like texture is impaired even if the ionic strength is appropriate.

[ tables 1-1]

[ tables 1-2]

[ example 3]

Effect of Total Ionic Strength and pH of aqueous solution on yield

To investigate the pH affecting the shrimp-like texture, 6 formulations shown in table 2 were used to prepare the pickling solutions. Frozen white leg shrimps (peeled shrimps) were thawed and salted with a salting solution at 100% by weight relative to the weight of the shrimps for 18 hours.

The definitions of the measurement items in table 1 were the same as in example 1, and sensory evaluation was performed on the heated samples in the same manner as in example 2.

The results are shown in Table 2. It was confirmed that when the pH of each pickling solution was 9.5 or more, the shrimp-like texture was impaired.

[ Table 2]

[ example 4]

Salty taste when sodium chloride is replaced by trisodium citrate

An increase in the ionic strength of the pickling solution naturally requires an increase in the salt concentration.

The curing solutions were prepared with 7 formulations shown in table 3. Frozen white leg shrimps (peeled shrimps) were thawed and salted with a salting solution in an amount of 100% by weight relative to the weight of the shrimps for 18 hours.

The definitions of the measurement items in table 3 were the same as in example 1, and sensory evaluation was performed on the heated samples in the same manner as in example 2. In this example, sensory evaluation of salty taste was also performed. The texture of shrimp was evaluated in the same manner as in example 1, and the salty taste was evaluated in increments of 0.5 (n-3) based on an evaluation criterion of 0 to 2 points as follows: "extremely salty: 2.0 point "," salty taste heavy: 1.5 points of the taste, moderate salty taste: 1.0 point "," slightly salty taste: 0.5 point "," no salty taste: 0 point ". Scores of 1.5 or more were judged as unpleasant because of the salty taste.

The results are shown in Table 3. In all cases, ionic strength and yield were similar, but there was a significant difference in salty taste. The ionic strength is obtained by adding the product of the molar concentration of each ion in solution and the square of the charge of all the ionic species, and then halving it. Thus, when comparing sodium chloride with monovalent sodium ions and chloride ions to trisodium citrate with three monovalent sodium ions and trivalent citrate ions, there is a 6-fold difference in ionic strength at the same molar concentration. In view of the molecular weight, the molecular weight of sodium chloride is 58.44g/mol and the molecular weight of trisodium citrate is 258.06g/mol, differing by a factor of about 4.4. Therefore, in the case of using sodium chloride and trisodium citrate at the same ionic strength, 1.4 times as much sodium chloride must be used in terms of concentration by weight%.

In order to increase the ionic strength at a low concentration, a salt containing an ion having a low molecular weight and a high charge is preferable. Trisodium citrate is found to be suitable among the salts used in food products.

As shown in table 3, the ionic strength can be adjusted to a preferable strength within a range that does not affect the salty taste by adjusting the ionic strength using a sodium chloride concentration of less than 3.0 wt% (total sodium chloride concentration is less than 1.5 wt%) and trisodium citrate of 2 wt% or more (total concentration of trisodium citrate is 1 wt% or more).

[ Table 3]

[ example 5]

Pickling by sprinkling powder

To confirm that the total ionic strength, including shrimp weight, is more important than the ionic concentration in the aqueous solution, attempts were made to cure the shrimp with powdered salt instead of the aqueous solution to reduce the amount of water.

Sodium chloride, potassium chloride + trisodium citrate are used as salting components in powder form. Frozen white leg shrimps were thawed and mixed with different amounts of the powder to be sprinkled, and after 1 hour, 20% by weight of water relative to the weight of the shrimps was added to pickle the shrimps for 18 hours.

For the total ionic strength in the case of sprinkling the powder, the weight of the shrimp was treated as the weight of water, and the ionic strength of the added powder was calculated from the sum of the weight of the shrimp and the amount of added water.

The results are shown in FIG. 3. It was found that even in pickling using a sprinkled powder with a reduced amount of water, a stable yield can be obtained by setting the total ion intensity to at least 0.2mol/kg or more, preferably 0.3mol/kg or more, particularly preferably 0.4mol/kg or more. From this result, it was confirmed that it is appropriate to use the total ionic strength including the weight of shrimp rather than the ionic strength of the aqueous solution.

[ example 6]

Evaluation of shrimp

In the formulation shown in Table 1-1 of example 2, the curing solutions of formulation 2 and comparative example 2 were used for curing, and the cured and heated shrimp were subjected to sensory tests. The taste/flavor, texture and appearance were evaluated organoleptically by 10 panelists. The evaluation items are independent evaluations of the items shown in fig. 4 to 6. Each evaluation item was evaluated based on 7-level evaluation criteria: "-3: very weak, -2: weak, -1: slightly weaker, 0: similarly, + 1: slightly stronger, + 2: strong, + 3: very strong ".

The results are shown in FIGS. 4 to 6. For any item, the product of the invention was judged to be preferred (plotting "water taste" and "jelly-like texture" in positive and negative directions).

Further, FIG. 7 shows photographs of the shrimps of comparative example 1 and the shrimps pickled in the pickling solutions of formula 2 and comparative example 2 in Table 1-1 after heating. It was found that the shrimps pickled in the pickling solution of the present invention did not contract in the body like the non-pickled shrimps (comparative example 1), did not have jelly-like transparency like the shrimps pickled in the prior art alkaline pickling solution (comparative example 2), and maintained good appearance.

In addition, the myofiber tissue sections of the cross sections of the shrimps pickled in the pickling solutions of formulation 2 and comparative example 2 were observed using an optical microscope (40 times). The photograph is shown in FIG. 8. It can be seen that the curing solution of this example has less effect on the muscle fibers than the known alkaline curing solutions.

[ example 7]

pH of pickling solution and pH of pickled shrimp

In order to determine the relationship between the pH of the salting solution and the pH of the salted shrimp meat, 20-component salting solutions shown in Table 4 were prepared, and frozen white shrimp were thawed and salted with the salting solutions for 20 hours. In table 4, the salt concentration is expressed as a total concentration. The weight ratio of the curing solution to the shrimps is 1:1.

The pH of the salting solution before salting and the pH of the salted shrimp meat were measured. The pH of the shrimp meat was measured as follows: cutting shrimp abdominal muscle, adding 10 times of water, stirring thoroughly, and taking pH of liquid as pH of shrimp meat. The pH of the shrimp meat before salting was 7.0.

The results are shown in Table 4 and FIG. 9. As shown in fig. 9, the pH of the salting solution and the pH of the shrimp meat have a good correlation. It was found that the pH for salting shrimp meat in a salting solution having a pH of 7.0 to 9.5 is 7.0 to 8.6, and the pH for salting shrimp meat in a salting solution having a pH of 7.0 to 9.0 is 7.0 to 8.3.

[ Table 4]

[ example 8]

Influence of pickling on squid

To examine the effect of pickling on squid, pickling solutions were prepared according to the formulation shown in table 5. Frozen squid (Todarodes pacificus) is thawed, cut into 5 to 10g, and marinated with a marinating solution of 100 wt% with respect to the weight of the squid for 18 hours. The heat treatment after pickling is boiling in hot water at 100 ℃ for 2 minutes, followed by cooling with ice water for 1 minute.

The definitions of the measurement items in table 5 were the same as in example 1, and sensory evaluation was performed on the heated samples in the same manner as in example 2. Based on the evaluation criteria of 0 to 2 points, the texture of squid was evaluated in increments of 0.5(n ═ 3) as follows; "texture with squid elasticity (score 2)", "texture with slight jelly shape (score 1)", and "texture with whole jelly shape (score 0)". Scores below 1 were judged as unpleasant because the texture was not squid-like.

The results are shown in Table 5. Also in the squid, the yield after pickling was found to be high, and the squid-like texture was maintained by satisfying the conditions that the total ionic strength was 0.2 to 0.8mol/kg, the total sodium chloride concentration was less than 1.5% by weight, and the pH of the pickled squid was 6.5 to 8.6.

[ Table 5]

[ example 9]

Effect of Pickling on Octopus

To examine the effect of pickling on octopus, pickling solutions were prepared according to the formulations shown in table 6. Frozen Octopus (Octopus ocellatus) was thawed and cut into 5 to 10g, and salted with a salting solution of 100 wt% with respect to the weight of Octopus for 18 hours. The heat treatment after pickling is boiling in hot water at 100 ℃ for 5 minutes, followed by cooling with ice water for 1 minute.

The definitions of the measurement items in table 6 were the same as in example 1, and sensory evaluation was performed on the heated samples in the same manner as in example 2. The texture of octopus was evaluated in increments of 0.5 (n-3) based on an evaluation criterion of 0 to 2 points as follows; "texture with octopus springiness (score 2)", "texture with a slight jelly-like texture (score 1)", and "texture with a whole jelly-like texture (score 0)". Scores below 1 were judged as unpleasant because the texture was not octopus-like.

The results are shown in Table 6. Also for octopus, the yield after salting was found to be high, and the texture of the octopus was maintained by satisfying the conditions that the total ionic strength was 0.2 to 0.8mol/kg, the total sodium chloride concentration was less than 1.5% by weight, and the pH of the salted octopus was 6.5 to 8.6.

[ Table 6]

[ example 10]

Influence of salting on scallop

To examine the effect of pickling on scallops, pickling solutions were prepared according to the formulations shown in table 7. Frozen scallop adductor muscle (Wakkanai scallop adductor muscle) was thawed and salted with 100 wt% of a salting solution with respect to the weight of scallop for 18 hours. The heat treatment after curing is baking in an oven at 270 ℃ for 5 minutes and 30 seconds.

The definitions of the measurement items in table 7 were the same as in example 1, and sensory evaluation was performed on the heated samples in the same manner as in example 2. The texture of the scallop was evaluated in increments of 0.5 (n-3) based on an evaluation criterion of 0 to 2 points as follows; "texture with scallop elastic feeling (score 2)", "texture with slight jelly shape (score 1)", and "texture with whole jelly shape (score 0)". Scores below 1 were judged as unpleasant because the texture was not scallop-like.

The results are shown in Table 7. Also for scallops, it was found that the yield after curing is high and the scallop-like texture is maintained by satisfying the conditions that the total ion intensity is 0.2 to 0.8mol/kg, the total sodium chloride concentration is less than 1.5 wt%, and the pH of the cured scallops is 6.5 to 8.6.

[ Table 7]

Industrial applicability

The present invention suppresses dripping during freezing and heating, and thus can provide a salted seafood in which the loss of umami taste is reduced and the taste and texture of the seafood are retained.