JPS5914778A - Thawing of frozen food - Google Patents

Abstract

PURPOSE:To enable the extremely economical uniform thawing of frozen food, by irradiating the food with far infrared radiation having specific wavelength. CONSTITUTION:Frozen food is thawed by irradiating with far infrared radiation of 5-50mu wavelength. Since the thawing can be carried out sufficiently by using a heat source of about 24kW power consumption, it is extremely economical compared with conventional process. The use of far infrared radiation of about 5-50mu wavelength enables the thawing from the inside of the frozen food with highest attainable uniformity keeping the taste and flavor of the food as far as possible. The thawing can be carried out hygienically, because the sundry germs attached to the frozen food can be completely exterminated by thawing.

Description

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

Conventionally, frozen foods have been thawed using either drinking water or cold water as a medium, the so-called □natural thawing method, or hot water-□
These methods, which often use frozen water, require several times as much drinking water as the frozen product and use two-way warm water as the medium. 8□i amount. 7ゎ water. 4. mm

0 At thawing factories that use natural thawing methods, a considerable amount of wastewater is generated during thawing operations, and treatment of the wastewater is often a problem, requiring art universities to invest in wastewater treatment equipment. That is the reality.

The situation is the same at the current factory, which uses the hot water thawing method. Furthermore, the high frequency thawing method currently used as another thawing method has a problem in that it requires large thawing equipment. .

The present invention has been made in order to solve the above-mentioned problems in the thawing process of frozen food. Predetermined portions on both opposing sides of the main body 2 are cut out as shown by &c21 so as not to impede the rotation of the bell) 31 of the belt conveyor 3 for feeding the frozen food 12. 4
．． 5 is a rotating body constituting the belt conveyor 3, and the main body 20
An endless belt 31 is placed over the rotating body 4.5 at a position outwardly from both opposing sides. 6 is a guide roller. Reference numeral 9 denotes an air blower that is provided through a portion of the main body 2 located above a far-infrared ray generating device 8, which will be described later, and is set to blow air to the belt portion opposite to the main body 2. Reference numeral 10 denotes a stirring propeller, which is installed near the far-infrared generator 8 and exhausts the air around the far-infrared generator 8 to the outside world through an exhaust tamper 11 installed in the upper center of the main body 2. lead to. In the middle part between the blower 9 and the bell (31) facing it, there are
A plurality of far-infrared generators 8 that irradiate far-infrared rays with a wavelength of 50 μm toward the belt are successively provided along the belt movement direction.

As the far infrared ray generator 8 used for
No. 23) can be used.

In Fig. 2 h, a hollow body 8 of a predetermined thickness made of ceramic
A resistance wire 82 such as a nichrome wire is placed in the hollow part of 1, and connected to a power source via a lead 84. Furthermore, 83
is an insulator. Therefore, as the ceramic 81, ZrO,-5ift is 60 yen, mineralizing agent valve consisting of manganese oxide and at least one of oxides of iron, cobalt, nickel and chromium is y up to 15%, and the remainder is clay. By using a mixture consisting of
For example, it is much longer than a
It has been found that a wavelength of ~50 microns can be radiated. 7 is a reflecting plate made of, for example, aluminum, which reflects a part of the far infrared rays generated from the far infrared ray generator 8 toward the belt.

In such a configuration, the driving rotary body of the belt conveyor 3, for example, the rotary body 5, is driven to rotate in the b direction, the far-infrared generator 8 is turned on, and the blower 9 and the stirring propeller are driven. For example, frozen fish or meat 12 (bell at the top right corner in Figure 1)
Send on 31. Therefore, frozen food 12 is belt 3
1 is sent in the direction of arrow a. During the feeding process, the frozen food 12 is irradiated with far infrared rays having a wavelength of 5 to 50μ from a plurality of far infrared ray generators 8, and according to the inventor's experimental results, the frozen food 12 is thawed from the inside toward the surface. The amount of far-infrared rays irradiated, that is, the irradiation time, must be adjusted appropriately according to the type, shape, and dimensions of the frozen food. Thawing is completed.

The thawed frozen food 12 is sent in the direction a by the rotation of the bell 31 and taken out from a predetermined position.

By sequentially repeating such operations, the frozen food can be continuously thawed and then taken out at a predetermined position.

During the heating period, the air inside the main body 2 is removed by a blower 9. Stirring propeller lO
1 Exhaust tamper 11 is circulated a little and constantly ventilated with fresh outside air, so uniform thawing in a positive atmosphere is possible.Thus, the same amount of frozen bigeye or tuna at -20℃ can be thawed. , and compared their effects. The results are shown in Table 1. In Table 1, the "metome conversion rate" refers to the ratio of the thawed material that changed color from red to black to the total thawed material, and the "trip rate"
In this case, it refers to the yield to uniform thawing to 4°C.

According to the present invention, since thawing is performed by irradiation with far infrared rays, it is not necessary to use large amounts of drinking water or hot water at all, unlike in conventional natural thawing methods or hot water thawing methods, and there is no need to use a large amount of drinking water or hot water at all, and there is no need to use a large amount of drinking water or hot water as in the conventional natural thawing method or hot water thawing method. There is no need for a large investment in equipment, and an electric power of about 24 kW is sufficient as a heat source, so thawing can be done extremely economically compared to conventional methods. In addition, since far infrared rays of about 5 to 50μ are used, according to the experimental results of the present inventor, thawing is done from the inside of the frozen food. It is possible to defrost as uniformly as possible with no unevenness.
, it is possible to thaw the food while preserving its unique flavor as much as possible.

Regarding this point, to explain in more detail, according to the experimental results of the present inventor, when frozen food is thawed to -8°C by far-infrared irradiation with a wavelength of 5 to 50μ and then the irradiation is stopped, It was confirmed that thawing was completed approximately 3 minutes after stopping. 4. When frozen food is irradiated with far infrared rays with a wavelength of 5 to 50μ, the molecules that make up the frozen food undergo molecular motion, which generates thermal energy, and even after the irradiation of far infrared rays has stopped, the residual heat remains It is estimated that this is due to energy promoting thawing from the inside of the frozen food.In other words, it is estimated that this is due to molecular movement caused by far-infrared irradiation. Therefore, according to the present invention, since the thermal energy generated by molecular motion is added to the thermal energy given from the outside for thawing during thawing, the consumption of thermal energy is extremely small compared to the conventional method. This makes uniform thawing extremely easy.

Claims (1)

[Claims] A method for thawing frozen food, characterized by thawing the frozen food by irradiating the frozen food with far infrared rays having a wavelength of 5 to 50#.