JP2003116488A - Frozen fish meat fillet and method for improving quality thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frozen fish meat fillet and a method for improving the quality thereof in which freezing deterioration of the fish meat fillet caused by freezing and the occurrence of drips during thawing are suppressed and deterioration of a taste and touch of the fish meat fillet due to freezing preservation is suppressed by being uniformly permeated with a sugar and/or a sugar alcohol into the fish meat fillet. SOLUTION: This frozen fish meta fillet is obtained by successively passing the fish meat filet through three steps of a first step of immesing the fish meat fillet in an aqueous solution of the sugar and/or sugar alcohol a second step of taking out the fish meat fillet from the dipping solution and storing the taken out fish meat fillet in cold, and a third step of freezing the fish meat fillet. The average concentration of the sugar and/or the sugar alcohol contained in the fish meta fillet is 1-15 wt.%.

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

The present invention relates to a frozen fish meat fillet and a method for improving the quality thereof. More specifically, the fish meat fillet is dipped in an aqueous solution of sugar and / or sugar alcohol, and then the fish meat fillet dipped in the aqueous solution is immersed in a dipping solution. By removing from the fish and refrigerating for a certain period of time, the freezing denaturation of the fish meat fillet that occurs during freezing is suppressed, long-term frozen storage in the form of fish meat fillet is possible, the occurrence of drip during thawing is suppressed, and further frozen storage Even after thawing the fish meat fillet, good taste and texture can be obtained.

[0003]

[Problems to be Solved by the Invention]

[0004] Fish meat is one of the important food ingredients that support the Japanese diet, and is distributed in various forms depending on its use. However, since the taste and freshness of the meat deteriorate significantly over time,
The preservation method according to the form of fish meat is introduced.

On the other hand, fish meat fillets, which are used in various fields because of easy secondary processing,
It is one of the processing forms of fish meat that is mainly found in white fish, but when freeze preservation, which is a classic preservation method for this fish meat fillet, is adopted, the water content in the fish meat forms ice crystals during freeze preservation, Then, the ice crystals that formed gradually grow, so that the tissue of fish meat is finally destroyed and the meat quality deteriorates, the surface of the fish meat is dried and frozen, and a discoloration called oil burning occurs. Since it appeared, even if it was thawed after that, it was not an edible product.

Further, when the fish meat fillet is stored in a frozen state, there is a problem that drip is generated at the time of thawing and the meat quality, texture, appearance are deteriorated, and the yield is lowered.

[0007] For these reasons, fish fillets are distributed by refrigeration for a relatively short storage period, and the distribution of frozen fish fillets in the frozen form, which is required for storage stability, is realized. The current situation is not.

[0008] Japanese Patent Application Laid-Open No. 8-308484 introduces a method of immersing fish meat in question in an aqueous solution of a mixture of sugar alcohol and sodium chloride and keeping it refrigerated for the purpose of maintaining the freshness of raw fish. ing. However, the freshness retention period by this method is about 2 weeks at the longest, and the penetration of sugar alcohol stops at the surface layer of the fish meat, resulting in a strong sweetness depending on the part of the fish meat, and sodium chloride permeating the fish meat. Therefore, intake of sodium chloride tends to increase,
Etc. is a concern.

[0009] Japanese Patent Laid-Open No. 9-299062 discloses that fish meat is frozen and preserved by spraying a treatment agent in which trehalose and salt are mixed in a powder state or immersing the treatment agent in an aqueous solution of the treatment agent. A method for suppressing freezing disorders due to is introduced. However, even in this method, it is necessary to use salt, so that salt penetrates into the livestock meat,
There is a concern that salt intake tends to increase.

[0010]

[Means for Solving the Problems]

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, immersed in an aqueous solution of sugar and / or sugar alcohol having a specific composition without using salts, and then immersed in the aqueous solution. By removing the prepared fish meat fillet from the immersion liquid and refrigerating for a predetermined time, sugar and / or sugar alcohol diffuses uniformly inside the fish meat fillet, and sugar and / or sugar alcohol inside the fish meat fillet and the whole fish meat fillet. Since the difference in the content concentration of the fish meat becomes small, the freezing denaturation of the fish meat fillet due to frozen storage can be suppressed, the fish meat fillet can be stored frozen for a long period of time, the occurrence of drip during thawing is suppressed, and after the frozen fish meat fillet is thawed. Furthermore, they found that a good taste and texture were retained, and completed the present invention.

Means for solving the problems of the present invention are as follows.

First, the fish fillet is sequentially immersed in an aqueous solution of sugar and / or sugar alcohol, a first step, a second step of taking out from the immersion liquid and refrigerating, and a third step of freezing. It is a method for improving the quality of frozen fish meat fillet, wherein the average concentration of sugar and / or sugar alcohol contained in the fish meat fillet is 1 to 15% by weight.

Secondly, the method for improving the quality of frozen fish meat fillet according to the first aspect, which comprises immersing in a water solution of sugar and / or sugar alcohol having a solid content concentration of 5 to 50% and a temperature of -5 to 20 ° C. Is.

Thirdly, there is provided a method for improving the quality of frozen fish meat fillet according to the first or second method, which comprises refrigerating at a temperature of -5 ° C to 15 ° C for 6 hours or longer.

Fourthly, the sugar and / or sugar alcohol is fructose, glucose, maltose, xylose, mannose, sucrose, xylobiose, lactose,
Trehalose, starch hydrolyzate containing saccharides with a degree of polymerization of 2 or less as the main component, xylooligosaccharides with saccharides with a degree of polymerization of 2 or less as the main component, sorbitol, erythritol, xylitol, mannitol, maltitol, lactitol, xylobiitol, polymerization One or more selected from the group consisting of a reduced starch hydrolyzate containing a hydride of a saccharide having a degree of polymerization of 2 or less as a main component and a reduced xylooligosaccharide containing a hydride of a saccharide having a polymerization of 2 or less as a main component. The method for improving the quality of a frozen fish meat fillet according to any one of the first to third aspects, which is a mixture.

Fifth, at the end of the first step, the average concentration of sugar and / or sugar alcohol contained in the fish meat fillet is 3 to.
The method for improving the quality of frozen fish meat fillet according to any one of the first to fourth aspects, wherein the quality is adjusted to 15% by weight.

Sixth, at the end of the second step, the concentration of sugar and / or sugar alcohol in the center of the fish meat fillet is adjusted to 3 to.
The quality of the frozen fish meat fillet according to any one of the first to fifth aspects, wherein the quality is adjusted to 15% by weight and the average concentration of sugar and / or sugar alcohol in the entire fish meat fillet is adjusted to 3 to 15% by weight. It is an improved method.

Seventh, by sequentially passing through the three steps of the first step of immersing the fish meat fillet in an aqueous solution of sugar and / or sugar alcohol, the second step of taking out from the immersion liquid and refrigerating, and the third step of freezing, The concentration of sugar and / or sugar alcohol in the center of the fish meat fillet is 3 to 15% by weight, and the average concentration of sugar and / or sugar alcohol in the whole fish meat fillet is 3 to 15% by weight, which is improved in quality. Frozen fish fillet.

The fish meat fillet referred to in the present invention refers to a state in which gills, internal organs and head are removed from the fish body, and the fish meat is dropped into three pieces to remove the mid-bone portion.

The present invention is mainly intended for fish which have a low freezing tolerance and are not suitable for long-term storage by freezing. For example, perch, salmon, scorpion, flatfish,
Examples include fishes belonging to the orders Medaka, Cod, and blowfish.
Further, specifically, horse mackerel, yellowtail, barracuda, croaker, sawara, Thailand, shiragisu, sweetfish, salmon, swordfish, flounder, flounder, saury, cod, kawahagi, puffer fish and the like can be mentioned.

It is needless to say that the fish meat fillet used in the present invention preferably has a high degree of freshness, but it can be used without any problem as long as it is on the market.

The type and quality of the sugar and / or the sugar alcohol used in the immersion treatment step of the present invention may be such that they are commercially available as pharmaceuticals, foods or food additives, and fructose, glucose and maltose are sufficient. , Xylose, mannose, sucrose, xylobiose, lactose, trehalose, starch hydrolyzate containing saccharides having a degree of polymerization of 2 or less as a main component, xylooligosaccharides having saccharides having a degree of polymerization of 2 or less, sorbitol, erythritol, xylitol, mannitol , Maltitol, lactitol, xylobiitol, reduced starch hydrolyzate containing hydride of saccharide having a degree of polymerization of 2 or less as a main component, and reduced xylo-oligosaccharide having hydride of saccharide having a degree of polymerization of 2 or less as a main component. Can be used alone or in combination of two or more selected from the group It is.

Among these, those having a relatively small average molecular weight, those having a high solubility in water and hardly causing crystal precipitation, or those having a combination in which crystal precipitation does not easily occur can be more advantageously employed and have such properties. Examples of those equipped with include sorbitol and maltitol.

In order to sufficiently obtain the effects of the present invention, the solid concentration of the aqueous solution of sugar and / or sugar alcohol used in the immersion treatment step is preferably in the range of 5 to 50%.

When the solid content concentration of the aqueous solution of sugar and / or sugar alcohol exceeds 50%, the viscosity of the aqueous solution to be dipped becomes high and the handling tends to be difficult, and the surface of the fish fillet may become sticky and the commercial value may be impaired. The amount of sugar and / or sugar alcohol penetrating into the fish meat is increased, so that the taste of the fish meat becomes less likely to be affected.

When the solid content concentration of the aqueous solution of sugar and / or sugar alcohol is less than 5%, the time required for the dipping process is prolonged until the sugar and / or sugar alcohol sufficiently penetrates into the fish meat fillet. Become.

The aqueous solution of sugar and / or sugar alcohol prepared to the above-mentioned concentration has various sweeteners, nucleic acid-based seasonings such as amino acids, mirin, for the purpose of seasoning and flavoring.
Various seasonings such as soy sauce, spices, phosphates, and various additives may be appropriately added and mixed.

The temperature of the immersion liquid when the fish meat fillet is immersed in an aqueous solution of sugar and / or sugar alcohol is -5 ° C to 20 ° C.
The temperature is preferably in the range of 0 ° C, more preferably 0 ° C to 10 ° C.

When the temperature of the sugar and / or sugar alcohol aqueous solution during the immersion treatment is lower than -5 ° C, ice crystals are formed inside the immersed fish meat fillet. The sugar and / or sugar alcohol sufficiently penetrates into the fish meat fillet. It becomes susceptible to freezing before the operation.

When the temperature of the aqueous solution of sugar and / or sugar alcohol during the immersion treatment exceeds 20 ° C., the autolysis of fish meat tissue and the propagation of microorganisms become active, the discoloration of fish meat progresses, and the fish meat becomes brown or black. It becomes easy to be affected by.

The time for immersing the fish meat fillet in the aqueous solution of sugar and / or sugar alcohol needs to be appropriately changed depending on the solid content concentration and temperature of the immersion liquid, the meat quality, type, freshness, size of the fish meat fillet, and the like. Finally, the average concentration of sugar and / or sugar alcohol contained in fish fillet is 3
These conditions may be freely selected within the range of ˜15% by weight.

No special operation is required while the fish meat fillet is dipped in the aqueous solution of sugar and / or sugar alcohol, but if necessary, stir the dipping liquid or turn the fish meat fillet inside out. You may add the operation of.

According to the present invention, the fish meat fillet is immersed in an aqueous solution of sugar and / or sugar alcohol, and then the fish meat fillet is taken out from the immersion liquid and refrigerated for a certain period of time. Alternatively, since sugar alcohol permeates the whole fish meat fillet, the difference in concentration of sugar and / or sugar alcohol contained in the fish meat fillet can be reduced.

Since the fish meat fillet in which the difference in the concentration of sugar and / or sugar alcohol contained in the fish meat fillet is small is contained at a uniform concentration overall, the quality of the fish meat fillet is maintained uniform during frozen storage. It becomes possible to do. Further, the drip does not locally occur from the portion having a low content concentration, and the drip amount at the time of thawing can be reduced.

The fish meat fillet taken out from the immersion liquid may be stored as refrigerated as it is, but may be subjected to any treatment such as simple draining, wiping of the immersion liquid adhering to the surface, and washing with water.

The fish fillet taken out from the immersion liquid is preferably stored in a refrigerator at -5 ° C to 15 ° C.

When the temperature during refrigeration is lower than -5 ° C., ice crystals are formed inside the fish meat fillet during refrigeration, and freezing occurs before sugar and / or sugar alcohol uniformly penetrates the whole fish meat fillet. Are more susceptible to.

When the temperature during refrigeration exceeds 15 ° C., the autolysis of fish meat tissue and the growth of microorganisms become active, the quality of the meat portion deteriorates, and the coloring or discoloration of the meat portion progresses and becomes brown or black. , And so on.

Refrigeration time depends on the meat quality and type of fish fillet,
Although it depends on the size, it is usually 6 hours or longer, preferably 20 hours or longer, more preferably 40 hours or longer, and most preferably 60 hours or longer. If the refrigerating time is not sufficient, sugar and / or sugar alcohol may not uniformly and sufficiently permeate the entire fish meat fillet, and the effect of the present invention may not be sufficiently obtained.

According to the method of the present invention, the fish meat fillet is immersed in an aqueous solution of sugar and / or sugar alcohol, and then taken out from the immersion liquid to store the fish meat refrigerated, and then the sugar and / or sugar alcohol contained in the fish meat fillet. The concentration of
3 to 15% by weight, preferably 5 to 5% in the center of fish fillet
It is 14% by weight, more preferably 6 to 11% by weight.
The average concentration of sugar and / or sugar alcohol contained in the whole fish meat fillet is 3 to 15% by weight, preferably 5 to
It is 14% by weight, more preferably 6 to 11% by weight.

The difference in concentration of sugar and / or sugar alcohol contained in the fish meat fillet is determined by the average concentration of sugar and / or sugar alcohol contained in the whole fish meat fillet and the sugar and / or sugar alcohol contained in the center of the fish meat fillet. It can be easily obtained by comparing the difference with the concentration of.

Since the frozen fish meat fillet obtained in the present invention contains sugar and / or sugar alcohol uniformly regardless of the position of the fish meat fillet, the center of the fish meat fillet, which is a portion away from the contact surface with the immersion liquid, is obtained. Concentration of sugar and / or sugar alcohol contained in the part and sugar and / or sugar in the whole fish fillet
Alternatively, the average concentration of sugar alcohol and the difference between the two are small.

The central portion of the fish meat fillet referred to in the present invention means the remaining portion of the surface layer portion of the fish meat fillet from which the fish meat having a thickness of 5 mm is removed.

The frozen fish meat fillet obtained by the present invention has a difference in concentration of sugar and / or sugar alcohol contained in the whole fish meat fillet from the average concentration of sugar and / or sugar alcohol contained in the center of the fish meat fillet of 5% by weight. % Or less, preferably 3% by weight or less, and the difference in concentration between the two is small, so there is little drip when thawing the frozen fish meat fillet, and the quality, texture, taste, etc. of the entire fish meat fillet is maintained uniform. You can

When the difference between the average concentration of sugar and / or sugar alcohol contained in the whole fish meat fillet and the concentration of sugar and / or sugar alcohol contained in the center of the fish meat fillet exceeds 5% by weight, sugar and / or sugar alcohol is contained. Is likely to be a factor causing deterioration of quality, texture, taste and the like depending on the amount of drip when frozen fish meat fillet is thawed and the portion of the fish meat fillet.

There is no special condition for the frozen storage in the present invention, and it may be any temperature as long as the immersed fish meat fillet is frozen. Further, in order to prevent the growth of ice crystals inside the fish meat fillet, it is preferable to freeze it rapidly. For these frozen storages, a normal household freezer, a commercial freezer, and freezing with a liquefied gas typified by liquid nitrogen can be adopted, and a preferable freezing temperature is -10 ° C or lower, more preferably -2.
It is 0 ° C or lower.

By passing through the steps of the present invention, sugar and / or sugar alcohol is uniformly contained in the fish meat fillet,
It is possible to freeze-store in the form of fish fillet, which was not possible in the past, and it can be stored in a frozen state for a long time, and it is possible to obtain a fish fillet that maintains a high quality even after thawing. Specifically, it is possible to obtain effects such as less drip when thawing and good texture and taste.

The frozen fish meat fillet according to the present invention is
Although slightly different depending on the storage conditions and the type of fish meat to be stored, even if frozen and stored for 1 month or longer, preferably 3 months or longer, and more preferably 6 months or longer, for example, steamed, boiled, grilled, stir-fried, dried fish, oil It can be suitably used for various purposes such as conditioning.

The effects of the present invention will be specifically described below with reference to examples, but the technical scope of the present invention is not limited to the following examples. In the following examples,% means% by weight unless otherwise specified.

[0051]

[Example 1]

1. Preparation of Immersion Solution Sorbitol (trade name: sorbit D-powder, manufactured by Towa Kasei Kogyo Co., Ltd.) 36 parts by weight and an aqueous sorbitol solution consisting of 64 parts by weight of water were prepared. Put in a container. 2. Preparation of Alaska pollack fillet A fresh Alaska pollack fillet was prepared by removing the internal organs, head, and fins of fresh pollock, and removing it into three pieces to remove the middle bones. 3. Immersion of Alaska pollack fillet The prepared Alaska pollack fillet was immersed for 6 hours in an immersion liquid prepared at a liquid temperature of 4 ° C. Then, it was taken out from the immersion liquid and drained. 4. Cold-stored and frozen storage The Alaska pollack fillet that had been soaked was refrigerated for 48 hours in a refrigerating room adjusted to 4 ° C., and then frozen-stored at −20 ° C. for 1 month to prepare a frozen Alaska pollack fillet.

[0053]

Example 2

A frozen Alaska pollack fillet was prepared in the same manner as in Example 1 except that the Alaska pollack fillet was refrigerated at 4 ° C. for 72 hours.

[0055]

Example 3

Immersion of walleye pollack fillet at 4 ° C. for 12 hours
A frozen walleye pollack fillet was prepared in the same manner as in Example 1 except that the time was set.

[0057]

Example 4

Immersion of walleye pollack fillet at 4 ° C. for 12 hours
A frozen Alaska pollack fillet was prepared in the same manner as in Example 1 except that the time was set to 4 hours and the refrigerated storage was performed at 4 ° C. for 72 hours.

[0059]

Example 5

Immerse Alaska pollack fillet at 4 ° C. for 24 hours.
A frozen walleye pollack fillet was prepared in the same manner as in Example 1 except that the time was set.

[0061]

Example 6

Immerse Alaska pollack fillet at 4 ° C. for 24 hours.
A frozen Alaska pollack fillet was prepared in the same manner as in Example 1 except that the time was set to 4 hours and the refrigerated storage was performed at 4 ° C. for 72 hours.

[0063]

[Comparative Example 1]

Fresh Alaska pollack was used as a fillet in the same manner as in Example 1 and was immediately frozen and stored at -20 ° C for 1 month without immersion treatment and refrigerated storage to prepare a frozen Alaska pollack fillet.

[0065]

[Comparative Example 2]

Fresh walleye pollack was made into a fillet as in Example 1, and after soaking in the same dipping solution at 4 ° C. for 6 hours,
Frozen Alaska pollack fillet was prepared by freezing and storing at -20 ° C for 1 month without refrigerating.

[0067]

[Comparative Example 3]

Fresh Alaska pollack was made into a fillet as in Example 1, immersed in the same dipping solution at 4 ° C. for 12 hours, and stored frozen at −20 ° C. for 1 month without refrigeration to prepare a frozen Alaska pollack fillet. did.

[0069]

[Comparative Example 4]

Fresh Alaska pollack was used as a fillet in the same manner as in Example 1, soaked in the same dipping solution at 4 ° C. for 24 hours, and stored frozen at −20 ° C. for 1 month without refrigeration to prepare a frozen Alaska pollack fillet. did.

[0071]

[Comparative Example 5]

Fresh Alaska pollack was made into a fillet as in Example 1, immersed in the same immersion liquid at 4 ° C. for 48 hours, continuously refrigerated at 4 ° C. for 72 hours, and then frozen at −20 ° C. for 1 month. Then, a frozen walleye pollack fillet was prepared.

[0073]

[Table 1]

Measurement of Difference in Sorbitol Concentration between Central Part of Fish Meat Fillet and Whole Fish Meat Fillet Regarding the Alaska pollack fillet before being subjected to the cryopreservation process in each Example and Comparative Example, the sorbitol concentration contained in the central part of the Alaska pollack fillet and the Alaska pollack fillet The average sorbitol concentration contained in the whole was measured and the difference was calculated.

In the measurement of the sorbitol concentration in the central part of Alaska pollack fillet, the remaining portion of the walleye pollock fillet, which had been removed by 5 mm, was taken out from the surface layer of the Alaska pollack fillet before being subjected to the cryopreservation step and used as a sample for measuring the sorbitol concentration. The sample taken out was minced with a food processor and 10 g of minced meat was collected. After adding 90 g of pure water to 10 g of the minced meat thus collected, it was homogenized for 5 minutes at 10,000 rpm using a homogenizer. Next, it was centrifuged at 3,500 rpm for 20 minutes at 5 ° C., and the supernatant was subjected to membrane filtration with a 0.45 μm membrane filter and then analyzed by high performance liquid chromatography to measure the concentration of sorbitol contained in the central part of Alaska pollack fillet. The measurement results are shown in Table 2.

In the measurement of the average sorbitol concentration contained in the whole Alaska pollack fillet, the whole Alaska pollack fillet was used as a sample, minced as it was with a food processor, and the same procedure as in the measurement of the sorbitol concentration at the center of the Alaska pollack fillet was followed by a high-speed liquid. Chromatographic analysis was performed to determine the average sorbitol concentration in the whole walleye pollock fillet. The measurement results are shown in Table 2.

The products of Examples according to the present invention have a small difference in sorbitol concentration of less than 3% by weight from the center of the fish meat fillet and the average of the whole fish meat fillet, and the sorbitol is uniformly contained in the fish meat fillet. It was

In Comparative Examples 2 to 4 which were not stored in a refrigerator after being immersed in the sorbitol aqueous solution, the sorbitol concentration difference was 5 between the inside of the fish meat fillet and the average of the whole fish meat fillet.
Sorbitol was not contained in the fish meat fillet at a uniform concentration in excess of wt%.

[0079]

[Table 2]

Measurement of drip amount The Alaska pollack fillet frozen and stored was filtered with a filter paper (product number: N
o. 2. The amount of drip per 100 g of frozen fish meat fillet was determined by using the increased weight of the filter paper when placed on Toyo Paper Co., Ltd. and naturally thawed at 25 ° C. for 4 hours as the amount of drip. The measurement results are shown in Table 3.

The product of the example according to the present invention is obviously drip in comparison with the fish meat fillet of Comparative Example 1 in which no treatment was performed or Comparative Example 2 in which the sample was immersed in the immersion liquid and not stored in the refrigerator. The quantity was reduced.

[0082]

[Table 3]

Sensory test of frozen Alaska pollack fillets The frozen Alaska pollack fillets prepared in Examples 2, 4, 6 and Comparative Example 5 of the present invention were each steamed at 99 ° C. for 8 minutes, and a sensory test for sweetness of the steamed Alaska pollack was conducted. Carried out. As a target, a commercially available walleye pollack fillet was directly steamed at 99 ° C. for 8 minutes and used. A trained panel of 7 people was prepared as an evaluator.

In the sensory test, there is no difference in sweetness as compared with the target product, and those which are deliciously eaten are +1 and those which are slightly sweeter as compared with the target product, but those which are deliciously eaten ±
0 was evaluated as -1 if the product was obviously sweeter than the target product and was not delicious. The evaluation results are shown in Table 4.

The products of the examples according to the present invention were delicious as in the case of the target product, and were hardly affected by sweetness. On the other hand, since the comparative example product contained a large amount of sorbitol in the fish meat fillet, it had a strong sweetness and was not delicious.

[0086]

[Table 4]

Claims (7)

[Claims] 1. A fish meat fillet is sequentially passed through three steps of a first step of immersing the fish meat fillet in an aqueous solution of sugar and / or sugar alcohol, a second step of taking out from the immersion liquid and refrigerating, and a third step of freezing. A method for improving the quality of frozen fish meat fillet, wherein the average concentration of sugar and / or sugar alcohol contained in is 1 to 15% by weight. 2. A solid content concentration of 5 to 50% and a temperature of -5 ° C.
The method for improving quality of frozen fish meat fillet according to claim 1, wherein the method is soaked in an aqueous solution of sugar and / or sugar alcohol at -20 ° C. 3. The method for improving the quality of frozen fish meat fillet according to claim 1 or 2, which is refrigerated under the conditions of a temperature of −5 ° C. to 15 ° C. and 6 hours or more. 4. A starch hydrolyzate containing fructose, glucose, maltose, xylose, mannose, sucrose, xylobiose, lactose, trehalose, a saccharide having a degree of polymerization of 2 or less as a main component, and a degree of polymerization of 2 as the sugar and / or the sugar alcohol. Xylooligosaccharides containing the following saccharides as main components, sorbitol, erythritol, xylitol, mannitol, maltitol, lactitol, xylobiitol, reduced starch hydrolysates containing hydrides of saccharides with a degree of polymerization of 2 or less It is one kind or a mixture of two or more kinds selected from the group consisting of reduced xylo-oligosaccharides whose main component is a hydride of two or less saccharides.
5. A method for improving the quality of a frozen fish meat fillet according to any one of 1. 5. The frozen fish meat according to claim 1, wherein at the end of the first step, the average concentration of sugar and / or sugar alcohol contained in the fish meat fillet is adjusted to 3 to 15% by weight. How to improve the quality of fillets. 6. At the end of the second step, the concentration of sugar and / or sugar alcohol in the center of the fish meat fillet is adjusted to 3 to 15% by weight, and the average concentration of sugar and / or sugar alcohol in the whole fish meat fillet is adjusted. Adjust to 3-15% by weight,
The method for improving the quality of a frozen fish meat fillet according to any one of claims 1 to 5. 7. The fish meat fillet is sequentially passed through three steps of a first step of immersing the fish meat fillet in an aqueous solution of sugar and / or sugar alcohol, a second step of taking out from the immersion liquid and refrigerating, and a third step of freezing. The concentration of sugar and / or sugar alcohol in the central portion is 3 to 15% by weight, and the average concentration of sugar and / or sugar alcohol in the whole fish meat fillet is 3
Improved frozen fish fillet, ~ 15% by weight.