JPS6156038A - Maintenance of fish freshness - Google Patents

Abstract

PURPOSE:Fishes just after killed are wrapped with an absorbing sheet each and they are kept in an oxygen gas at a specific temperature to enable long-term maintenance of high fresheness of fishes. CONSTITUTION:Fish bodies just after killed 7 are wrapped with an absorbing sheet containing physiological salne solution, artificial sea water or the like 6, respectively, then they are stored in an oxygen gas at 6-8 deg.C. The ion composition of te physiological saline solution is 160mM of NaCl, 3mM of KCl, 2mM of MgSO4, and 2mM of CaCl. Further, the ion composition of the artificial sea water contains 470mM of NaCl, 10mM of KCl, 26mM of MgCl, 28mM of MgSo4 and 10mM of CaCl2. The above-stated absorbing sheets are allowed to absorb the above-stated ion composition and ajusted in their pH to about 8 by adding a small amount of NaOH or HCl. Thus, high freshness of fish bodies can be maintained for a long period of tme without troublesome processings such as blood drawing and gutting, further by no use of an agent for removing carbon dioxide.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a fish body that is capable of keeping fish bodies, such as sea bream, in a fresh state for a long period of time, such as sea bream, whose freshness tends to decrease rapidly after slaughter. Regarding freshness preservation methods. .

Fish bodies generally become hard within six hours after being slaughtered, making them unsuitable for sashimi, and their market value is halved. It has been said that the fresh fish distribution industry would benefit greatly if the time until rigor was extended to 12 to 24 hours.

[Prior art]

As a method for maintaining the freshness of fish meat, a method is known in which the fish meat is brought into contact with 100% oxygen gas and the carbon dioxide concentration is maintained at 0% (Japanese Patent Application No. 149131/1983).However, in this method, To do this, the fish had to be dissected and the fish flesh processed into a certain size.

(Problems to be Solved by the Invention) The present inventors have maintained the fish body as it is for a long time after slaughter without dissecting the fish body, in other words, without draining the blood or removing the internal organs from the fish body. As a result of intensive research into ways to preserve the freshness of fish, we succeeded in developing a freshness preservation method that can maintain fish freshness for a long period of time.

The purpose of the present invention is to maintain fish freshness for a long time without requiring any complicated processing such as blood removal or visceral processing, and without using carbon dioxide removal agents, thereby increasing commercial value. This is a method for preserving the freshness of fish that can increase the quality of fish.

(Means for Solving the Problems) The technical means of the present invention to achieve the above object is to wrap the fish body immediately after slaughter with a water-absorbing sheet and keep it in oxygen gas at 6-8°C. This keeps the fish fresh for a long time.

(Configuration of Examples) Examples of the present invention will be specifically described below, but the present invention is not limited thereby.

In FIG. 1, reference numeral 1 denotes a net support frame, and this support frame 1 is generally formed in the shape of a rectangular parallelepiped. At the top opening of the support frame 1, the net 4 is arranged to form an rUJ-shaped fish storage area 5.5.5 for the rods 2.2 and the rods 3.3 on both sides of the top of the support frame 1. It is suspended. A fish body 7 wrapped with an absorbent sheet 6 is stored in each of these fish body storage parts 5, 5, 5 (see FIG. 2). The above-mentioned support frame 1 is neatly housed in a styrofoam box 8, and is packed and transported with an M9 fitted thereon. The lid 9 is provided with holes 10, 10 for gas exchange at appropriate openings.

In the above embodiment, three fish body storage sections 5 are illustrated, but the number can be selected as appropriate. Needless to say, the dimensions of the fish storage section 5, the support frame 1, and the box 8 are selected according to the size of the fish 7.

Since the fish storage section 5.5.5 is suspended within the support frame 1, when oxygen gas is introduced from one hole IO for gas exchange and discharged from the other hole IO, the fish body 7 The gas will be in contact with the entire surface of the

The ionic composition of the red sea bream physiological saline to be hydrated in the water-absorbing sheet is, for example, NaCl1EiO1KCI3,
Examples of the ionic composition of artificial seawater include Mg50,2 and CaC1z 2 (mM).
l470, KCll01MgC126, Mg50,28
, CaC1z 10 (mM), and after each sheet absorbs water, NaOH was added so that the pH was around 8.
, add a small amount of MCI and adjust II.

(Function) Wrap the fish body 7 immediately after slaughter with the water-absorbing sheet 6, store this in each fish body storage section 5 (see Fig. 2), and place the support frame 1 in a styrofoam box 8 and fit M9. . Then, this is placed in a refrigerated riL (not shown) at 8° C., and the air in the box 8 is replaced with cold oxygen through the gas exchange holes 10.10.

(Effects of the invention) As shown in Figure 3, the method for determining the freshness of fish using a melon pulling plate is based on the angle indicated by the caudal fin ( θ°).

For the fish showing various freshness states after undergoing the various treatments mentioned above, industry veterans determined the fish price per 1 kg (blind test). Figure 4 shows the correlation between the two (each point is the average value of 16 to 32 fish).From this figure, we can conclude that there is a close correlation between the two.In other words, freshness can be expressed numerically by the degree of curvature. In the figure below, all freshness is expressed by this degree of curvature.

Cultured red sea bream (approximately 950 g) was layered and subjected to the following eight treatments, and freshness was measured 6, 12, 18, and 24 hours later. The number of fish used for each treatment was 16-32.

■ Place the fish directly in the holding container without replacing the gas.
Maintain at 8°C in the usual way (abbreviation A, Figures 5, 6,
) in Figures 7 and 8).

■ Place the fish directly in a holding container, and add Ca (OH)2 2 Hz O(
After coexisting with a paper package containing 50g/1 fish), the air inside the container was replaced with oxygen and kept at 8°C (abbreviated as 0).
2, 0-0 in Figure 6).

■ The fish body was placed on a water-absorbing sheet (water-absorbing polymer, Kao Corporation) containing 400 ml of distilled water.

Wrap it in a paper bag (300 x 400 x about 5 mm) containing 1.10 g of KP620, place it in a holding container, and keep it at 8°C without gas replacement (abbreviation AW, marma in Figure 5).

■ Perform the same treatment as ■ using physiological saline with the same ionic composition as the body fluid of the red sea bream (abbreviation: APS, III in Figure 5).
).

■ Perform the same procedure as in ■, except that the air inside the container is replaced with oxygen gas (abbreviation OW, in Figure 6).

■ Perform the same process as in ■, except that the air inside the container is replaced with oxygen gas (abbreviations o, ps, openings in Figures 6 and 7).

■ Perform the same procedure as ■ except for adding zeolite powder (10 g/1 fish) to the body fluid sheet (abbreviation 02 psz, No. 6
O-(!9) in the figure and FIG.

■ Perform the same procedure as in ■, except that artificial seawater is used instead of body fluid (abbreviation 02SWZ, 0-O in Figure 7).

Figures 5, 6, and 7 show the results of measuring the freshness of the fish treated in steps Φ to ■ after 6, 12, 18, and 24 hours.
are shown respectively.

Figure 5 shows that wrapping the container in a water-absorbing sheet is effective in keeping it fresh regardless of whether it contains distilled water (W) or physiological saline (PS). Figure 6 shows that the air inside the container is oxygenated. This shows that replacing with 0-O is effective to some extent when a water-absorbing sheet is not used (see comparison between... and 0-O)
However, it also shows that in oxygen, there is no difference in the freshness preservation effect whether (1) or not (0-0) a water-absorbing sheet containing distilled water is used. However, what is particularly noteworthy in this figure is that the treatment method (Roro), in which the fish body is wrapped in a water-absorbing sheet containing physiological saline in oxygen, has a very high freshness preservation effect.

Figure 7 shows that when a fish body is wrapped and held in a water-absorbing sheet in oxygen, the solutions contained in the sheet include physiological saline (Roro), zeolite suspended in physiological saline (■-[phase]), Zeolite suspended in artificial seawater (0-0
), it can be seen from this figure that there is no big difference between these two champions, but both exhibit high freshness preservation effects over a long period of time. By the way, black liquor (σ-[phase]) obtained by wrapping a fish body in oxygen with a physiological saline water-absorbing sheet containing zeolite and maintaining it at 8°C, and the conventional method
When the black sake (Φ-.) of the sake held at °C is plotted against the holding time, the result is as shown in Fig. 8.

Six hours after slaughter, the fish body obtained by the conventional method has already dropped to the lowest level of black sake, but according to the retention method of the present invention, it can be seen that the value close to the highest level of black liquor is maintained until at least 24 hours later.

[Brief explanation of the drawing]

FIG. 1 shows an example of a suitable apparatus for carrying out the method of the present invention;
FIG. 2 is a cross-sectional view of a state where fish bodies are held for a long time, FIG. 3 is an explanatory diagram of a method for determining the freshness of fish bodies, and FIGS. 4 to 8 are graphs showing experimental results of freshness retention effects. Reference numeral 6 indicates a water-absorbing sheet, and 7 indicates a fish body. Procedural amendment oath July 1, 1982

Claims (5)

[Claims] (1) Wrap the fish body immediately after slaughter with an absorbent sheet, and
A method for preserving the freshness of fish, characterized in that the freshness of the fish is maintained for a long time by keeping it in oxygen gas at -8°C. (2) The method for keeping fish fresh according to claim 1, wherein the absorbent sheet is impregnated with physiological saline, artificial seawater, or similar water. (3) The ionic composition of physiological saline is NaCl160, K
The method for preserving the freshness of fish according to claims 1 and 2, wherein the ingredients are C13, MgSO_42, and CaCl_22 (mM). (4) The ionic composition of artificial seawater is NaCl470, K
Cl10, MgCl_226, MgSO_428, Ca
Cl_210 (mM) The method for keeping fish fresh according to claims 1 and 2 above. (5) The above-mentioned absorption sheet is obtained by absorbing each of the above-mentioned ionic compositions into the sheet, and then adjusting the pH to around 8 by adding a small amount of NaOH and HCl; The method for maintaining the freshness of fish as described in each of the above items.