JP2533584B2 - Non-freezing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a non-freezing preservation method, and more particularly to a non-freezing preservation method in which foods or non-foods are preserved at low temperature without being frozen.

[Conventional technology]

Conventionally, as a method of preserving non-food such as foods, medicines and reagents, addition of a preservative to these preserved objects, sterilization by heating or irradiation, vacuum packaging or gas-filled packaging, low-temperature storage or freezing, etc. Are known, and in practice, one or more of the above methods are used together.

In the above storage method, there are various restrictions on the addition of a preservative, heat sterilization cannot be applied to things that cannot be heated such as perishables, and radiation sterilization cannot be carried out easily due to strict regulations, Further, the vacuum packaging and the gas-filled packaging have a problem that the storage performance is not always sufficient. Therefore, simple and safe storage methods such as low temperature storage and freezing are most commonly used.

The above-mentioned method of keeping at a low temperature is a method in which the water contained in the preserved product is not frozen, for example, the preserved product is preserved in the range of 5 ° C to -3 ° C, but the preservation period is not long in this method. Therefore, preservation by frozen is generally performed for the preserved object that requires long-term preservation.

[Problems to be solved by the invention]

However, the preservation method by freezing has a problem that when the preservative is frozen or thawed, the preservative undergoes denaturation and quality deterioration occurs.

Therefore, an object of the present invention is to provide a non-freezing preservation method capable of preserving food or non-food preserved objects for a long period of time without degrading the quality.

[Means for solving problems]

The present inventors, as a result of various studies, food or non-food items to be preserved, under a predetermined pressure condition, in a predetermined temperature range,
It was found that the above object can be achieved by storing without freezing.

The present invention has been made based on the above findings, non-food or solid food exhibiting quality deterioration in the process of freezing or thawing, under a pressure of 500 to 10,000 atm, under a temperature of 5 to -50 ° C, The present invention provides a non-freezing preservation method, characterized by preserving the food or non-food without freezing.

 Next, the non-cryopreservation method of the present invention will be described in detail.

In the present invention, as the food to be preserved, vegetables such as cucumber, fruits such as melon, marine products such as sea urchin, meat such as fish meat or beef such as tuna, and other solids containing water Any food may be used.

Further, the non-food item to be preserved is not particularly limited, and examples thereof include reagents such as enzymes and strains such as microorganisms.

In the present invention, the pressure applied to the preserved object is 500
It should be in the range of up to 10,000 barometric pressure.
500 to 6,500 atm is more preferable, 500 to 5,000 atm is further preferable, and 500 to 3,500 atm is particularly preferable. Needless to say, specifically, an appropriate pressure is selected according to the type of the object to be stored, the storage temperature, and the like.

The operations of pressurizing and cooling are preferably carried out gradually after avoiding freezing after placing the object to be preserved in a container capable of pressurizing and cooling. Specifically, an appropriate operation method is adopted in consideration of various conditions.

In the present invention, the temperature for storing the preserved object is 5 to −
The temperature is in the range of 50 ° C., more preferably −3 ° C. or lower, further preferably −10 ° C. or lower, particularly preferably −15 ° C. or lower. It should be noted that, specifically, an appropriate temperature is selected in a range in which the objects to be preserved are not connected, depending on the type of the objects to be preserved, the pressure applied, and the like.

〔Example〕

Hereinafter, the non-freezing preservation method of the present invention will be specifically described in detail based on Examples.

Example 1 Sea urchin (100 g) was placed in a nylon laminated film (thickness: 200 μm) bag, air inside was removed, and its inlet was heat-sealed and sealed (hereinafter referred to as a test sample). . Put this test sample in a pressure vessel that can be installed in a coolable high-pressure pressurizer, and fill the surrounding area with a pressure medium (water + glycol) to continuously pressurize and cool while preventing the sample from freezing. Perform and pressure
The temperature was set to 1,800 atm and temperature was -18 ° C. Then, this state was maintained for 7 days, and the sample was stored. Then, the temperature rising and depressurizing operations were continuously performed until the temperature became 5 ° C. and the pressure became normal pressure, and then the sample was taken out from the container (sample of the present invention).

Similarly, two test samples were prepared and one of them was frozen in −35 ° C. brine freezing and then −18 ° C.
Stored in a normal freezer for 7 days, then left at 5 ° C for thawing (cryopreserved sample), the other one is stored in a normal refrigerator at 5 ° C for 7 days (5 ° C stored sample), These two control samples were used.

With respect to each of the sample according to the method of the invention and the control sample, the drip amount, the color, the flexibility, and the cell destruction degree were observed under a microscope, and the flavor test was further conducted. The results are shown in Table 1.

In Table 1, the drip amount (A), the hue (B),
The numerical values shown in the columns of the degree of softness (C), the degree of cell destruction (D), and the flavor (E) have the following meanings, respectively. Also,
The numerical values shown in the columns (B) to (E) above are values obtained by averaging five times.

A: The drip amount is shown as a percentage of the original weight.

B: The color tone is 5 points when it is untreated, 4 points when it is slightly discolored, 3 points when the color value is slightly discolored, and 2 points and 1 point when it is not worth the product.

C: The degree of softness is 5 when untreated, 4 when slightly softened and water is removed, and 3 when slightly watered and product value limit is reached.
Points and items with no commercial value are given 2 points and 1 point.

D: The degree of cell destruction was 1 point that was partially destroyed, 2 points when it was slightly destroyed, 3 points when it was considerably destroyed, and 4 points when it was strongly destroyed compared to when it was untreated. Points, 5
It is a point.

E: The unflavor is 5 points, slightly reduced flavor is 4 points, slightly degraded flavor is 3 points, product value limit is 2 points, and no commercial value is 1 point.

As is clear from Table 1 above, the method of the present invention showed a superior preservation effect as compared with the other two preservation methods, and did not deteriorate much in quality compared to the untreated method.

Example 2 Melon was cut into four pieces (size enough to fit in a pressure vessel) and placed in a bag made of nylon laminate film (thickness: 200 μm), air inside was removed, and its inlet was heat-sealed to seal it. (This is referred to as a test sample hereinafter). After placing this test sample in a pressure vessel, the test of Example 1 was performed.
A pressure of 1,800 atm and a temperature of −18 ° C. were formed in the same manner as in the above, and this state was maintained for 7 days, and the sample was stored. Then, similarly, the temperature was returned to 5 ° C. and the pressure was returned to normal pressure, and the sample was taken out (sample of the present invention).

Similarly, two test samples were prepared, and frozen and stored at 5 ° C. under the same conditions as in Example 1 above.
The samples were stored and used as a control sample, that is, a frozen sample and a sample stored at 5 ° C. The same observations, tests, etc. as in Example 1 were carried out for each of the sample of the present invention and the both control samples, and the results are shown in Table 2.
In Table 2, the meanings of A to E are the same as those in the first embodiment.

As can be seen from Table 2, the samples according to the method of the present invention showed an excellent preservation effect as compared with the other two preservation methods, and did not show much deterioration in quality as compared with the untreated ones.

Example 3 1 kg of frozen frozen krill meat was homogenized in 2 0.1M potassium phosphate buffer solution (pH 7.0) at 7,500 × g.
Centrifuge for 20 minutes. The centrifugation supernatant was dialyzed against the same buffer. After dialysis, ammonium sulfate fractionation was performed. A 30-70% saturated precipitate fraction was taken, dissolved in 0.1 M potassium phosphate buffer (pH 7.0), and dialyzed against the same buffer to remove ammonium sulfate. The solution subjected to the above operations was used as a krill extract protease solution (hereinafter referred to as an enzyme solution).

Put 10 ml of the above enzyme solution in a bag of nylon laminate film (thickness 200 μm), remove the air inside,
The inlet was heat-sealed and hermetically sealed (hereinafter referred to as a test sample). After putting this test sample in a pressure vessel, a state of a pressure of 1,500 atm and a temperature of -18 ° C was formed in the same manner as in the case of Example 1, and this state was maintained for 7 days and the sample was stored. It was Then, similarly, the temperature was returned to 5 ° C. and the pressure was returned to normal pressure, and the sample was taken out (sample of the present invention).

Similarly, two test samples were prepared, and frozen and stored at 5 ° C. under the same conditions as in Example 1 above.
The samples were stored and used as a frozen sample of the control sample and a sample stored at 5 ° C., respectively. Foli for each of the above inventive sample, both control samples and untreated sample
The protease activity was measured by the n method, and the measurement results are shown in Table 3.

In the method for measuring protease activity in an enzyme solution by the Folin method, the activity unit is 1 μmole in 1 minute at the initial stage of reaction when dairy casein is used as a substrate at 50 ° C.
The amount of enzyme that causes an increase in the non-protein Folin reagent coloring substance corresponding to tyrosine was set to 1 PU.

As is clear from Table 3, the frozen sample showed a decrease in activity by about 1/2 and the sample stored at 5 ° C. by about 2/3 as compared with the untreated sample, but the sample of the present invention had a large activity like the control sample. No deactivation was seen. Thus, the method of the present invention showed an excellent preservation effect.

Example 4 A block of tuna (thickness 4 cm x width 4 cm x length 10 cm) was placed in a bag of nylon laminate film (thickness 200 μm), air inside was removed, and its inlet was heat-sealed and sealed. (This is referred to as a test sample hereinafter). After putting this test sample in a pressure vessel, a state of pressure of 1,800 atm and temperature of -18 ° C was formed in the same manner as in the case of Example 1, and this state was maintained for 10 days and the sample was stored. It was Then, similarly, the temperature was returned to 5 ° C. and the pressure was returned to the normal pressure, and the sample was taken out (sample of the present invention).

Similarly, three test samples were prepared, and after freezing each of the test samples by the freezing methods of air blast freezing, contact freezing and brine freezing at −35 ° C., a normal temperature of −18 ° C. was used. Each sample was stored in a freezer for 10 days, then left at 5 ° C. and thawed to give a control sample.

For each of the sample of the present invention and the above three control samples, the drip amount,
The color, softness, and cell destruction degree were observed under a microscope, and sashimi was further subjected to a flavor test. The results are shown in Table 4.
In Table 4, the meanings of A to E are the same as those in the first embodiment.

As is clear from Table 4, the quality of the sample obtained by the method of the present invention (the sample of the present invention) was not significantly deteriorated as compared with the untreated meat pieces, and it was confirmed that the method of the present invention has an excellent preservation effect. .

Example 5 A block of beef (thickness 4 cm x width 4 cm x length 10 cm) was placed in a bag of nylon laminate film (thickness 200 µm), air inside was removed, and its inlet was heat-sealed and sealed. (This is referred to as a test sample hereinafter). After placing this test sample in a pressure vessel, a pressure of 1,800 atm and a temperature of -18 ° C were formed in the same manner as in Example 1, and this state was maintained for 10 days, and the sample was stored. It was Then, similarly, the temperature was returned to 5 ° C. and the pressure was returned to normal pressure, and the sample was taken out (sample of the present invention).

Similarly, three test samples were prepared, and after freezing each of the test samples by the freezing methods of air blast freezing, contact freezing and brine freezing at −35 ° C., a normal temperature of −18 ° C. was used. Each sample was stored in a freezer for 10 days, then left at 5 ° C. and thawed to give a control sample.

For each of the sample of the present invention and the above three control samples, the drip amount,
The color, flexibility, and cell destruction degree were observed under a microscope, sliced to a thickness of 1.5 cm, baked in a frying pan, and subjected to a flavor test. The results are shown in Table 5. In addition, in Table 5,
The meanings of A to E are the same as in Example 1.

As is clear from Table 5, the sample according to the method of the present invention (the sample of the present invention) hardly deteriorates in quality as compared with untreated meat pieces, and it is recognized that the method of the present invention has an excellent preservation effect. It was

Although the present invention has been specifically described above based on the examples, it goes without saying that the non-cryopreservation method of the present invention is not limited to those shown in the examples.

〔The invention's effect〕

According to the non-freezing preservation method of the present invention, foods or non-foods can be preserved for a long period of time without deterioration of quality.
Therefore, the freshness and fresh flavor of food can be preserved for a long period of time, and for non-foods, the function impaired in the process of freezing and thawing can be retained for a long period of time.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Masakazu Hoshi Masakazu Hoshi 3-9 Tsukishima Chuo-ku, Tokyo Taiyo Fisheries Co., Ltd. Ocean Research Institute (72) Inventor Atsushi Wakameda 3-29 Tsukishima Chuo-ku, Tokyo Taiyo Fisheries Co., Ltd., Taiyo Research Center (56) References JP-A-62-122551 (JP, A)

Claims (1)

(57) [Claims] 1. A non-food product or a solid food product that exhibits quality deterioration during the process of freezing or thawing under a pressure of 500 to 10,000 atm.
A non-freezing preservation method, characterized in that the food or non-food is stored at a temperature of 5 to -50 ° C without being frozen.