JPH08126481A - Prevention of fading of tuna fish and production of canned tuna - Google Patents

Abstract

PURPOSE: To stabilize the characteristic desirable pink color tone of the tuna fish and prevent the deterioration of the color tone, even when the tuna fish is left in air, by treating the tuna fish with an arbitrary transglutaminase. CONSTITUTION: Tuna fish is treated with either of a calcium-dependent transglutaminase and a calcium-nondependent transglutaminase. The tuna fish is preferably treated with the transglutaminase for approximately 5min to 15hr at 0-60 deg.C before or after a process (e.g. boiling process) for heating the tuna fish. Either of the calcium-dependent transglutaminase and the calcium- independent transglutaminase may be used, and is added in an amount of 0.1-100 units per g of the tuna fish, when added.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for preventing fading of tuna fish meat and a method for producing canned tuna, and more specifically, a method for preventing fading of a preferred color tone peculiar to tuna fish (tuna meat) and a preferred color tone peculiar to tuna fish meat. The present invention relates to a method for manufacturing canned tuna to be held.

[0002]

2. Description of the Related Art In recent years, tuna fish meat has become a popular food in combination with the convenience of consumers' eating habits and the trend of health. In particular, canned tuna is used everywhere because it can be easily used as a topping for salad, a center for cooking bread, or a dressing food simply by opening the can.

The reason for this popularity is that, in addition to the taste of tuna fish that is delicious and that it suits any dish at a light night, the desirable pink color peculiar to tuna fish is fresh, which makes the appetite aesthetically pleasing and, in turn, gives a sense of health. You can invite them.

However, the preferable pink color tone peculiar to this tuna fish meat is unstable in the air, and the pink color tone becomes a whitish smoky color tone or a color tone which reduces appetite even after being left for about 20 minutes. , Changes quickly and fades.

Conventionally, as a method for stabilizing the color tone of tuna fish meat, a method of adding a reducing substance or a chelating agent or a method of increasing the amount of edible oil to be enclosed at the same time in the case of canned tuna has been proposed. Although some of these methods have already been carried out, it cannot be said that the effect of preventing fading is still present, and no fundamental solution has been found.

[0006]

An object of the present invention is to prevent the fading of tuna fish meat by stabilizing the preferable pink color tone peculiar to the tuna fish meat and preventing the deterioration of the color tone even when left in the air. An object of the present invention is to provide a method for producing a canned tuna that can maintain a desirable pink color tone for a long time even after opening the can.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that (1) it is preferable that transglutaminase is allowed to act on tuna fish meat. The pink tones are retained for a long time,
(2) In allowing transglutaminase to act, coexistence of sugar / polymerized phosphate in the system, that is, (a)
The coexistence of transglutaminase and saccharides, (b) the coexistence of transglutaminase and polymeric phosphates, or (c) the coexistence of transglutaminase, sugars and polymeric phosphates is the color tone of tuna fish. It has been found that it is effective for retention, and the present invention has been completed based on these findings.

That is, the present invention provides (Invention 1) a method for preventing fading of tuna fish meat, which comprises causing transglutaminase to act on the tuna fish meat, and (Invention 2) applying transglutaminase to tuna fish meat. A method for producing a canned tuna, which is characterized by sealing and sterilizing after heating, (Invention 3): applying transglutaminase to tuna fish meat in a system to which sugars and / or polymerized phosphates are added A method for preventing fading of tuna fish characterized by the following: (Invention 4) A method in which transglutaminase is allowed to act on tuna fish in a system to which sugars and / or polymerized phosphates are added, and then the mixture is sealed and heat-sterilized. It is a characteristic method of manufacturing canned tuna.

[0009]

As the transglutaminase used in the present invention, either calcium-dependent or calcium-independent transglutaminase can be used.

The origin of the transglutaminase used in the present invention is also not particularly limited. That is, microbial origin (see Japanese Patent Application Laid-Open No. 01-27471), guinea pig liver origin (see Japanese Patent Publication No. 01-50382),
Derived from fish [Nobuo Seki et al., Journal of Japan Society of Fisheries, Vol. 56, No. 1
No., pages 125-132 (1990)] and those prepared by the gene recombination method (JP-A-01-300).
Various transglutaminases can be used. Particularly, transglutaminase derived from a calcium-independent microorganism is suitable as the transglutaminase used in the present invention.

As a method of causing transglutaminase to act on tuna fish meat, a method of adding and holding transglutaminase before and after a heating step of tuna fish, for example, a steaming step is adopted. For example, a method of immersing fresh tuna fish meat or heated tuna fish meat in a solution in which transglutaminase is dissolved or dispersed at a certain temperature for a certain time, a method of adding transglutaminase to a container holding tuna fish meat, etc. are adopted. can do.

It is suitable that the action time is about 5 minutes to 15 hours. In order to prevent excessive action of transglutaminase, the activity of transglutaminase may be stopped at appropriate times by heating. In order to make transglutaminase act uniformly on tuna fish meat,
The addition of transglutaminase may be performed in several divided portions. In addition, the preferred pink color of tuna fish meat is
Although it is also present in fresh fish meat, it becomes clearer immediately after heating such as steaming. Therefore, the point of action and method of action of transglutaminase capable of retaining the clearest color tone are selected.

In the method of the invention 2 or the invention 4, the tuna fish meat on which transglutaminase is allowed to act can be filled in a can, but the transglutaminase is allowed to act on the tuna fish meat which is previously filled in the can. Method is recommended.

The temperature at which transglutaminase acts is selected from the range of 0 ° C. or higher and the deactivation temperature of the enzyme or lower. Generally, a temperature in the range of 0 to 60 ° C is selected. A temperature in the range of 20 to 40 ° C. is selected when it is necessary to act on the tuna fish meat particularly quickly.

The addition amount or contact amount of transglutaminase can be expressed by the activity unit of transglutaminase defined as described below. In the case of addition, it is 0.1 to 100 units, preferably 0.5 to 10 units per 1 g of tuna fish meat protein.

Below this range, the expected effect cannot be achieved. That is, it is not possible to expect a desirable effect of retaining the pink color tone. On the other hand, above this range, the action of transglutaminase is extremely rapidly expressed, resulting in a change in the tissue and physical properties of the tuna fish meat, which may result in an overly hard texture and a sticky texture. is there.

The activity unit of transglutaminase is measured and defined as follows. That is, the temperature is 37 ° C,
Allow transglutaminase to act in a reaction system using benzyloxycarbonyl-L-glutamylglycine and hydroxylamine as substrates in a Tris-buffer solution at pH 6.0, and form an iron complex in the presence of trichloroacetic acid from hydroxamic acid produced. The absorbance of the produced iron complex at 525 nm is measured, a calibration curve is prepared from the amount of hydroxamic acid, and the amount of the enzyme that produces 1 μmol of hydroxamic acid in 1 minute is defined as 1 unit of transglutaminase activity unit (Japanese Patent Laid-Open No. H11-24035) No. 01-27471).

The tuna fish meat used as a raw material is fresh tuna fish meat or tuna fish meat subjected to heat treatment such as steaming. Good results are obtained by selecting a raw material having a clear color tone.

Further, as a method of sealing the canned tuna and sterilizing by heating, a method of manufacturing an ordinary canned product is applied correspondingly.

In the present invention, saccharides used include sucrose, lactose, glucose, fructose, dextrin and the like. Above all, lactose has a large effect of promoting the action of transglutaminase.

The amount of sugar added and used is about 0.5 to 10 g per 100 g of tuna fish meat. Addition below this range does not show a significant difference from the case of no addition, and addition beyond this range does not show a color retention effect.
On the contrary, it has the opposite effect of changing the color of the tuna meat to a white state.

The polymerized phosphates used are meta-polymerized phosphates, ortho-polymerized phosphates or poly-polymerized phosphates, especially their sodium salts. Further, the use of the mixture has a larger effect of maintaining the color tone than the case where the mixture is used alone.

The amount of polymerized phosphate added is 100 tuna fish meat.
About 0.01 to 0.5 g per g, preferably 0.05
~ 0.3g. Addition below this range does not show a significant difference from the case of no addition, and addition above this range is not preferable because the taste of the polymerized phosphate itself is developed.

When transglutaminase is allowed to act, there is coexistence of saccharide / polymerized phosphoric acid in the system, and its mode is (1) coexistence of transglutaminase and saccharide,
(2) coexistence of transglutaminase and polymerized phosphate,
(3) Three modes of coexistence of transglutaminase, saccharides, and polymeric phosphate can be adopted.

The present invention will be described below with reference to examples. This example does not limit the invention. In the examples, “parts” means parts by weight and “%” means weight / weight% unless otherwise specified.

[0026]

【Example】

(Example 1): Manufacture of canned tuna by transglutaminase treatment before heating The head and internal organs were removed from the freshly fried fish bodies of tuna, and they were carefully washed with water. This washed fish body was raw-cut and then steamed at about 100 ° C. for 3 hours. After cooling down overnight,
Raw tuna fish meat was obtained by removing the skin, bones, fins and blood meat from the steamed fish. This tuna fish meat was filled in a pond can, and then seasoning containing umami seasoning and salt, salad oil, transglutaminase preparation [Ajinomoto Co. product, specific activity 1 unit / mg, Streptoverticillium mobaraense (Streptoverticillium mobaraense) IF
O 13819 obtained from culture], lactose [Vario Co., Ltd. product] and polymerized phosphate [Odaira Chemical Co., Ltd. product, main component is mixture of meta-polymerized sodium phosphate and ortho-polymerized sodium phosphate] were added.

The amount of transglutaminase preparation 0.1 g (corresponding to 100 units), lactose 1 g and polymerized phosphate 0.1 g per 100 g of tuna fish meat. Is. After the addition, the mixture was kept at room temperature for 1 hour, canned with a vacuum simmer, and then heat sterilized at 113 ° C. for 80 minutes.
After the heat sterilization treatment, it was cooled to room temperature by water cooling to obtain "test tuna can B". At the same time, by the same method, “test tuna can A” in which addition of lactose and polymerized phosphate was omitted was obtained. In addition, a “control tuna can” without the addition of the transglutaminase preparation was obtained.

(Example 2): Measurement of change in color tone after opening cans "Control tuna can" and "Test tuna can A" produced in Example 1
Also, the "test tuna can B" was opened, each content was transferred to a ceramic pot, the opening was covered with a wrap material, and then kept in a refrigerator kept at 0 to 5 ° C for 2 days. Immediately after opening the can or after 2 days, the color tone of each content was measured with a color difference meter [product of Nippon Denshoku Co., Ltd.]. Table 1 shows the a value which is an index of red (pink) among the values measured by the color difference meter.

[0029]

[Table 1]

As shown in Table 1, it was confirmed that the "control tuna can" had a marked decrease in a value, and the pink color tone was significantly discolored. In the “test tuna can A”, the decrease in the a value was small. Furthermore, in the "test tuna can B", the decrease in the a value was about 40% of that in the "control tuna can". The change in pink color tone and the difference in the degree of change were clearly identified by visual observation.

From these measurement results and visual results,
Transglutaminase has the effect of maintaining the favorable pink color of tuna fish, and addition of sugar and polymeric phosphate has the effect of increasing the effect of transglutaminase on maintaining the preferable pink color of tuna fish. I confirmed that there is. Among the values measured by the color difference meter, no change was observed in the L value and the b value (not shown in Table 1) due to retention for 2 days, and discoloration (fading) was selective only in the pink color system. It is presumed that it is occurring in.

(Example 3): Preservation of color tone by treatment with transglutaminase after heating "Control tuna can" was produced in the same manner as in Example 1.

(Example 4): Measurement of change in color tone after opening can The "control tuna can" prepared in Example 3 was opened, and the contents of each were transferred to a ceramic pot to form a "control section". No additives were added, and in "Test Area A", 0.1 g of transglutaminase preparation per 100 g of tuna fish meat (equivalent to 100 units)
In addition, to the “test section B”, 0.1 g of transglutaminase preparation (corresponding to 100 units), 1 g of lactose and 0.1 g of polymerized phosphate per 100 g of tuna fish meat were added.
After covering the opening with a wrap material and holding it at room temperature for 1 hour,
It was kept for 2 days in a refrigerator kept at 5 ° C. Immediately after opening the can or after 2 days, the color tone of each content was measured with a color difference meter. Table 2 shows the a value which is an index of red (pink) among the values measured by the color difference meter.

[0034]

[Table 2]

As shown in Table 2, it was confirmed that the "a" value in the "control section" was remarkably reduced, and the pink color tone was significantly discolored. In the “test area A”, the decrease in the a value was small. Furthermore, in the “test section B”, the decrease in the a value was only about 37% of that in the “control section”. In addition, the change in the pink color tone and the difference in the degree of the change can be visually observed,
Clearly identified.

From these measurement results, transglutaminase has an effect of maintaining a preferable pink color tone of tuna fish meat, and addition of sugar and polymerized phosphate has a preferable pink color tone of tuna fish meat which transglutaminase has. It was confirmed that there is an effect of increasing the action of holding the.

[0037]

As described above, the tuna fish meat treated by the method of the present invention and the canned tuna produced by the method of the present invention do not change or discolor when stored in air, There is an effect that the desirable pink color tone peculiar to tuna fish meat can be preserved for a long period of time.

Claims (4)

[Claims] 1. A method for preventing fading of tuna fish meat, which comprises causing transglutaminase to act on the tuna fish meat. 2. A method for producing a canned tuna, which comprises subjecting tuna fish meat to transglutaminase, sealing and heat sterilizing. 3. The method for preventing fading of tuna fish meat according to claim 1, wherein transglutaminase is allowed to act on the tuna fish meat in a system to which sugars and / or polymerized phosphates are added. 4. A method in which transglutaminase is allowed to act on tuna fish meat in a system to which sugars and / or polymerized phosphates are added, and then the tuna fish meat is sealed and heat-sterilized.
The method for producing canned tuna described.