JPS5834920B2 - Kaitohouhou - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for thawing frozen foods.

Today, advances in freezing technology have made it possible to preserve seafood, meat, and even soups for long periods of time, and with the spread of cold chains, the quantity of frozen foods has increased significantly.

However, the taste of these frozen foods primarily depends on the thawing method.

Currently known thawing methods include air thawing, ice thawing, crushed ice thawing, electric thawing, and boiling thawing. For example, the thawing time for approximately 500 g of frozen food varies depending on the method. It takes about 10 minutes to 3 days, and a common phenomenon during thawing is the occurrence of drips, which affects the flavor of frozen foods.

Foods are approximately 60-90% water; for example, meat (high-fat) is 50% water, and meat (low-fat) is 70-90% water.
76%, fish meat (high fat) about 60%, and fish meat (low fat) 75-80%.

In order to restore frozen food to its fresh state, it is necessary that the thawing time is short, the amount of dripping is small, the color does not change, there is little loss of flavor, and the freshness is on the same level as fresh meat. .

In order to achieve such an objective, in the present invention, the material to be thawed is stored in an airtight container whose pressure is reduced to a maximum of 100 torr and a minimum of 10-2 torr, and the material is placed between a pair of electrodes provided in the container. The structure is such that a high-frequency power source generates a gas discharge, and thawing is performed by the action of ions, electrons, etc. generated during the discharge.

The reason for limiting the pressure inside the sealed container from 100 Torr to 10-2 Torr is based on Paschen's law, which is based on <Pd curve (P:
This is because the atmospheric pressure in the sealed container (d: distance between electrodes) was controlled within the range of the lowest flat part.

By doing so, a stable suspended discharge occurs at a relatively low voltage, and ions and electrons are activated.

Therefore, thawing is performed by hitting the object to be thawed with such ions and electrons.

Hereinafter, the method of the present invention will be explained with reference to the drawings regarding one embodiment of the apparatus.

In the figure, reference numeral 1 denotes a closed container, and the gas in the closed container 1 is pulled out using a pipe 2 and an exhaust device 3 to exhaust the gas.

As described above, the level of exhaust is within the range of a maximum of 100 torr and a minimum of 10-2 torr based on Paschen's law.

Reference numeral 4 denotes a mounting table on which the object to be thawed 6 is placed and serves as one electrode when applying a high frequency voltage, and the lid 1a of the closed container 1 or a part thereof serves as the other electrode.

When the inner cover 1a is used as an electrode, an insulating material such as synthetic resin is used for the side wall 1b to prevent leakage.

Thus, when a high frequency is applied between the electrodes 1a and 4 using the high frequency power source 5, a glow discharge is generated in the container 1, and the object to be thawed 6 is thawed by hitting the object 6 with ions and electrons.

According to an embodiment of the method of the present invention, 500 g of beef frozen at -18°C was depressurized to about 0.2 torr in a sealed container and then glow discharged using a high frequency of 3 KV and 550 KHz. I was able to defrost it in 3 minutes.

This is approximately 1
/3 time.

Further, the drip amount is as small as 0.7%, which is about 1/2 compared to the case of natural thawing.

The method for generating electrical discharge in a closed container is as follows:
For example, one electrode is inserted into one end of a horizontally long insulating container, and the other electrode is wrapped around the container from the other end, and a high-frequency power source is connected between the two electrodes. Although a glow discharge device can be used, it is desirable that the generated ions and electrons hit the food to be thawed inserted into the container to some extent, so the net-like shelves on which the food is placed should be made of conductive material such as metal. The other electrode is a rod-shaped electrode and is opposed to it at a distance, and a DC high voltage or high voltage pulse is applied with the one electrode as the negative electrode to generate ions and It is desirable to give electrons a direction of movement.

When the other electrode is a rod-shaped electrode as described above, it is desirable to move the position of the rod-shaped electrode facing the mesh-shaped electrode sequentially or even continuously over a certain range in order to avoid partial thawing.

In addition, the glow discharge current should be limited or the atmospheric pressure should be adjusted so that the food to be thawed, the mesh electrode, or the container, etc., are not overheated or etched locally or globally (especially on the surface) due to the impact of ions and electrons. Alternatively, it is necessary to change and adjust the interval of the discharge as a pulsed discharge.

According to the method of the present invention, the pressure inside the closed container is controlled based on Paschen's law, so
It is excellent in that it can efficiently generate glow discharge with a small power supply and does not require a large-capacity power supply like a so-called microwave oven that uses electromagnetic waves.

[Brief explanation of the drawing]

The figure is a sectional view of an apparatus according to an embodiment of the method of the present invention. In the figure, 1 is a sealed container, 3 is an exhaust system, 5 is a high frequency power supply, and 6
is the item to be thawed.

Claims (1)

[Claims] 1. Storing the material to be thawed in a sealed container, reducing the pressure of the gas in the sealed container to a range of a maximum of 10 Torr and a minimum of 10-2 Torr, and placing one electrode in the sealed container at a distance from the electrode. A thawing method characterized in that a glow discharge is caused between the object and the other electrode arranged, and the object to be thawed is thawed by being bombarded with ions and electrons caused by the glow discharge.