JPS61249375A - Processing of food - Google Patents

Abstract

PURPOSE:To enable the efficient freezing or thawing of a large-sized fish, etc., in high heat-exchange efficiency, preventing the degradation of the food, and keeping the excellent taste and flavor of the original food, by spraying a gas for a proper period at temperature, humidity, flow rate and pressure determined according to the kind of food and the purpose of the treatment. CONSTITUTION:A proper food is sprayed directly or indirectly for a proper period with a gas having a temperature, humidity, flow rate, pressure, etc., controlled to proper levels by sensors, etc., according to the kind of the food and the purpose of the treatment. The freezing or thawing treatment is targeted to the part near the surface of the food, preferably a shield-packed fish body, etc. The surface of the food is preferably coated or impregnated with an antioxidant such as alpha-tocopherol.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is capable of rapidly freezing or thawing various foods in optimal conditions by using gas whose conditions are set according to the food to be processed and the processing purpose. This relates to a method for processing food that can be processed.

[Conventional technology]

In general, leaving food at room temperature for a long time is unfavorable in terms of taste, nutrition, hygiene, etc., so various food preservation methods have been proposed for a long time, and among them, frozen preservation has excellent storage stability. Moreover, it is highly evaluated because there is little change in food quality.

Until today, many techniques have been put into practical use for freezing methods to preserve food, and various methods have also been developed for thawing frozen foods.For example, evaporators and blowers have been developed. The so-called air blast freezing method, in which the food to be frozen is placed in an atmosphere of cold air created by the air blast, is currently widely used in Japan, and the so-called air thawing method, in which the food to be thawed is exposed to air at an appropriate temperature, humidity, and flow rate, is widely used. As the method is becoming widely used, the technology of using gas such as air for freezing or thawing is already known.
These conventional freezing and thawing methods using gases have some drawbacks.

[Problem that the invention seeks to solve]

In other words, - Even though food is eaten in the mouth, its structure, contents, etc. are rarely uniform throughout the food; conversely, in the case of large to medium-sized fish,2 for example, the body of a tuna has fat on its dorsal and ventral sides. There are variations in structure, content, etc., such as markedly different degrees of distribution, and therefore, there are optimal freezing or thawing conditions depending on the part of the food.
Conventional freezing or thawing methods using gas process the entire food under the same conditions by placing the food in a gas atmosphere adjusted to an appropriate temperature, so some foods may be frozen in whole or in part. Alternatively, the decompression conditions may not be met.

Furthermore, the above-mentioned conventional methods generally have been developed recently because the food is stored and processed in a large warehouse.

Another drawback is that it is extremely difficult to implement processing methods that require detailed chondrules for the degree of freezing or thawing, such as methods in which only the surface of the food is rapidly frozen or thawed.

[Means for solving problems]

The present invention was made with the aim of solving the above-mentioned difficulties of the prior art, and its structure is such that temperature, humidity, flow rate, pressure, etc. are controlled for appropriate foods according to the type of food and the purpose of processing. This method is characterized in that the food is frozen or thawed by directly or indirectly injecting the determined gas for an appropriate period of time.

The present invention will be explained in detail below.

Although there are no particular limitations on the objects that can be processed by freezing or thawing according to the present invention, the present invention is suitable for processing foods that are currently distributed as frozen foods and whose structure, contents, etc. are not uniform throughout. This includes large to medium-sized fish.

For example, fish such as tuna can be mentioned.

Furthermore, since the method of the present invention involves injecting a gas such as air, if the food to be processed is vacuum-packed with a synthetic resin film in a shield pack, it is possible to prevent drying due to the injecting of the gas, and also to prevent external damage. Infiltration of oxygen and germs can be prevented, and if the surface of a food is coated or impregnated with an antioxidant such as α-tocopherol, the preservability can be further improved. .

The method of the present invention involves directly or indirectly injecting the above-mentioned food with a gas whose temperature, humidity, flow rate, pressure, etc. are determined depending on the type of food and the purpose of processing, for an appropriate period of time. This can be easily carried out by using air as an air supply source and controlling a plurality of nozzles whose flow rate can be adjusted using a computer.

In other words, it is sufficient to determine the conditions of the air to be sprayed onto the food by detecting the temperature, quality, direction, etc. of one food using an appropriate sensor.For example, in the case of fish such as tuna, first detect the temperature. First, determine the temperature by determining whether to freeze or thaw. Next, determine the flow rate, pressure, injection time, etc. by detecting the size and length. It is only necessary to determine the injection flow rate from each nozzle by detecting whether the nozzle is on the ventral side or the ventral side.

Note that the gas injection may be continuous or intermittent.

Also, if the computer is programmed appropriately,
Of course, it is possible to rapidly freeze only the surface of the food concerned, and to thaw a food whose surface only has been frozen in this way.

In order to carry out the above-described method of the present invention, for example, a flow-adjustable nozzle such as Transvector (trade name) is installed in a chamber having a diameter and length that allows the passage of fish such as tuna. An appropriate number of nozzles are installed around the circumference with their injection ports facing inward, and each nozzle is equipped with a sensor that detects temperature, size, degree of fat distribution, etc., and injects from each nozzle according to a predetermined program based on the output of the sensor. A processing device configured with a microcomputer that controls the flow rate of air may be used.

Incidentally, the food may be advanced while being rotated within the above-mentioned apparatus.

[Operation and effect of the invention]

The method of the present invention does not place the food in an air atmosphere set to certain conditions as in the conventional method, but instead injects gas directly or indirectly onto the food, so it has excellent heat exchange efficiency. Since the processing temperature of the food can be adjusted not only by the temperature of the gas but also by its flow rate or flow rate, the food is less likely to be damaged, and is particularly suitable for the above-mentioned rapid freezing and thawing of only the surface.

In addition, in recent years, a technology called freezing temperature storage has been developed in which each food is stored at its own freezing point (around minus 3 degrees Celsius). It has been introduced that the taste is superior to that obtained by defrosting, but according to the method of the present invention, defrosting can be easily performed within such a narrow temperature range.

Furthermore, according to the method of the present invention, the temperature of the gas injected onto the food varies depending on the type of food and the purpose of processing.

Since the humidity, flow rate, pressure, injection time, etc. are determined, even large to medium-sized fish whose structure and content are not uniform throughout can be frozen under the optimal conditions for each part. Alternatively, it can be decompressed.

As described above, the present invention is extremely excellent as a food processing method.

Claims (1)

[Scope of Claims] 1. The food can be treated by directly or indirectly injecting a gas with the temperature, humidity, flow rate, pressure, etc. determined according to the type of the food and the purpose of processing the food for an appropriate time. A food processing method characterized by freezing or thawing. 2. The processing method according to claim 1, wherein the freezing or thawing is performed near the surface of the food. 3. The processing method according to claim 1, wherein the temperature, humidity, flow rate, pressure, injection time, etc. of the gas are determined by detecting the temperature, quality, directionality, etc. of the food using an appropriate sensor. 4. The processing method according to claim 1, wherein the food is vacuum-shield-packed fish bodies. 5. The processing method according to claim 1 or 2, wherein the surface of the food is coated or impregnated with an antioxidant such as α-tocopherol.