JP2011206040A - Method for storing farm crop - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for storing farm crops, capable of keeping the crops fresh for a long period, through inactivating oxygen without degenerating the crops such as harvested leaf vegetables and fruit vegetables.SOLUTION: The method for storing farm crops comprises the following process: a harvested farm crop 1B is washed and then soaked in water; and then the soaked farm crop is subjected to blanching 3 by magnetron radiation 3A to excite and heat the inner temperature of the farm crops to 70-80°C to effect low-temperature storage.

Description

  The present invention resides in a method for preserving agricultural crops, which can be preserved for a long period of time by inactivating enzymes without changing the external shape, substrate and components after harvesting agricultural crops such as leaf vegetables and fruit vegetables.

Agricultural crops are harvested approximately at the same time depending on the variety, cultivation method, cultivation location, and climatic conditions, and are usually delivered to the neighboring vegetable market. The price of the harvested agricultural products is Since it is determined by the supply and demand relationship in the market, if a large amount is carried in, the production price will endlessly drop.
For this reason, although distribution methods and contract cultivation have been improved, it is necessary to adjust the amount of harvest carried in and balance the supply and demand after the price of agricultural products in the market is determined by the supply and demand relationship. Has proposed a method for storing the harvested crops in high quality for a long period of time, such as forcing cultivation or restraint cultivation.

  However, forcing and restraint cultivation not only keeps and cools but also allows ventilation, etc., so that the cost of the cultivation facility is high and the maintenance cost is also high. If you don't expect it, you won't be able to find a balance. On the other hand, attempts have been made to maintain the producer's price by adjusting the supply and demand relationship by providing preservation by low-temperature storage for crops harvested in large quantities, but vegetables and fruits etc. depend on the variety and the cold storage conditions. The storage period is also remarkably different, and the storage period of vegetables and fruits generally disclosed is as shown in Table 1.

However, although the shape retainability is maintained on the outer shape, although the respiratory action and the enzyme action are suppressed to some extent under such cold conditions, the gloss and color are particularly affected by the action of the synthetic degradation substitution by the enzyme in the living body. In addition, the deterioration of the substrate due to moisture transpiration and the like is promoted along with the deterioration of the fragrance and the like, and the quality is deteriorated.
For this purpose, effective deactivation of the enzyme is desired. However, the deactivation of the enzyme is usually performed by immersing the food in hot water having a large heat capacity such as blanching prior to processing of the processed food. Heating is performed at 70 to 80 ° C.

  For this purpose, it is desirable to inactivate the enzymes of leaf vegetables and fruit vegetables. However, in order to deactivate the enzymes, the food is usually immersed in hot water having a large heat capacity such as blanching prior to processing of processed foods. The means for heating at 70 to 80 ° C. cannot be used for fresh leaf vegetables and fruit vegetables.

By the way, leaf vegetables, fruit vegetables, etc. contain extremely large amounts of moisture and nutrients in addition to meristems and permanent tissues, so their thermal conductivity is extremely poor. In order to impart the enzyme and inactivate the enzyme, it is necessary to cut it into a fine thin wall to increase the heat permeability or to blanch at a considerably higher temperature than the substantial blanching temperature.
Processed foods are cut, ground, kneaded, molded, etc. immediately after blanching, so they can be used for weakening the substrate in addition to deterioration of luster, color, fragrance, etc. due to high temperature blanching. Yeah.

On the other hand, in order to preserve harvested leafy vegetables and fruit vegetables for a long period of time and adjust the supply and demand relationship, it is necessary to inactivate the enzyme without degrading and weakening the outline and substrate as much as possible and to preserve it for a long period of time. .
For this reason, the inventors have conducted numerous studies and found that the harvested leafy vegetables and fruit vegetables contain at least about 93 to 95% by weight of water, and the electromagnetic waves radiated by the magnetron are organic, even to the inside. It can easily permeate, can cause internal heat generation by causing resonance of water molecules contained in water, and can easily adjust the internal heat generation by electromagnetic radiation due to the capacity of leaf vegetables and fruit vegetables, and Since about 93 to 95% by weight of water is contained in the substrate of leaf vegetables and fruit vegetables to be radiated, the radiation of the magnetron in a state where the outer surface is dry like normal leaf vegetables and fruit vegetables. In this case, since the skin surface is overheated, it was found that evenly blanching is performed throughout by submerging in water and radiating electromagnetic waves. It was.

  In the present invention, an enzyme contained in harvested leaf vegetables, fruit vegetables, and other agricultural crops can be easily and evenly deactivated without denaturing the scent, color and substrate of the crops, and can maintain the freshness for a long time. It is to provide a storage method.

  The technical means adopted by the present invention in order to solve the above-mentioned problem is that the crops such as harvested leaf vegetables and fruit vegetables are once washed to remove contaminants, and at least the moisture content of the outer surface of the crops is 93% or more. Weaked and soaked so that the inside of the magnetron electromagnetic wave was transferred and heated, and the inside and outside surfaces of the crops were heated to 70 to 80 ° C for a short time and evenly to deactivate the enzyme. It exists in the preservation method of the crop which preserve | saves and keeps freshness over a long period of time.

  The present invention has the above-described configuration, and is hygienic because the harvested leafy vegetables and fruit vegetables are once washed to remove the contaminants, and the electromagnetic waves of the magnetron are easily transmitted. Then, the inner surface and outer surface are permeated and heated to 70-80 ° C in a short time by wetting the outer surface with moisture content close to the moisture content of the crop and making magnetron radiation, so that gloss, fragrance, pigment Alternatively, the enzyme is evenly deactivated without denaturing the substrate, respiration, synthesis, decomposition, and substitution in the substrate are almost suppressed, and it is stored at a low temperature, so there is no growth of attached bacteria and microorganisms for a very long time. The freshness is maintained over a long period of time, and shipment is possible while taking into consideration the market price.

  After harvesting relatively thin-walled leafy vegetables such as Japanese mustard spinach and spinach, washing them with water to remove the contaminants, submerging them, moistening the moisture content of the outer surface to 93% or more, and transporting them inside the magnetron radiation The inner and outer surfaces are heated to 70 to 80 ° C. to inactivate the enzyme, and stored at a low temperature.

  The embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a flow chart of the method for preserving agricultural products of the present invention. FIG. 2 is an explanatory view of the washing 1. The washing 1 has a required storage capacity. In the washing tank 1A, which is desirable and can rotate as a whole, a crop 1B such as leafy vegetables and fruit vegetables to be washed is stored, and washing water 1C for washing is supplied from one side thereof. In general, tap water is used as the washing water 1C. However, from the viewpoint of water use, well water, river water, etc. can be used. Of course, when using such well water or river water, an appropriate disinfectant is used. Mixed use is made.

  In addition, a drainage hole 1D is provided at an appropriate water level of the rotatable washing tub 1A to discharge the sewage from which the contaminants attached to the crop 1B are removed by the rotational flow of the washing water in the washing tub 1A. During the cleaning operation, the supply of cleaning water 1C and the sewage from which the contaminants have been removed first overflow from the drainage hole 1D and the external drainage is performed. 1B is immersed in water 2.

  This water immersion 2 is intended for long-term storage by deactivating the enzyme of the crop 1B according to the present invention. For this purpose, the radiated electromagnetic waves of the magnetron 3A are uniformly and efficiently transmitted within and outside the crop 1B. The water in the agricultural product is excited and heated so that the water is permeated well and substantially reaches 70 to 80 ° C. On the other hand, when the magnetron 3A is radiated, the crop 1B such as leafy vegetables and fruit vegetables has different thicknesses, size shapes, bulks, and the like depending on the types, and the water content varies depending on the types. Or about 95% by weight.

By the way, in general, the crop 1B is washed 1 with the washing water 1C, and the water on the outer surface of the washed crop 1B is evaporated and dried, so that the inside and the outer surface of the crop 1B are large. Moisture content difference occurs.
Therefore, when the agricultural product 1B having a large difference in moisture content between the inside and the outer surface is radiated by the magnetron 3A having the same radiant energy, many water molecules are excited and heated up to the deactivation temperature in the portion where the moisture content inside the crop 1B is high. However, overheat failure due to radiant energy occurs at the portion of the outer surface where the moisture content is low, and a problem of damage to the crop 1B before maintaining freshness occurs.

For this purpose, in order to inactivate the enzyme by the radiation of the magnetron 3B, that is, to perform the blanching 3 in the crop 1B from which the contaminants have been washed away by the washing 1, the water content is close to the internal moisture content of the crop 1B. The water immersion 2 is performed in order to wet the outer surface with a certain rate.
As long as the submerged crop 1B from which the contaminants have been washed away by the cleaning 1 is substantially submerged 2, the submerged tank 2 has a required internal volume as shown in FIG. What is necessary is just to make 2A store the crop 1B and supply the water 2B so that the whole crop 1B is submerged.

  The crop 1B thus immersed in water 2 is subjected to blanching 3 for inactivating the enzyme mixed therein. This blanching 3 radiates and transmits electromagnetic waves of the magnetron 3A in a short time evenly and efficiently into the crop 1B having different varieties, thickness, size, shape, bulk, etc. The enzyme is deactivated by causing the generated moisture and the water molecules of the moisture adhering to the outer surface as wets to generate heat, and the enzyme is deactivated by heating at 70 to 80 ° C. substantially. However, if the excitation exothermic temperature is 70 ° C. or lower, the enzyme is not sufficiently deactivated. On the other hand, if the excitation exothermic temperature is 80 ° C. or higher, the internal moisture As a result, rapid external transpiration and softening of the substrate are caused, and the luster and tension are lost and the freshness is significantly reduced.

Accordingly, it is desirable that the radiation capacity, radiation intensity, and radiation time of the magnetron 3A during the branching 3 are appropriately adjusted depending on the type, thickness, shape, bulk, etc. of the crop 1B to be branched 3.
A concrete method of this blanching 3 is illustrated in FIG. 4. In the method of FIG. 4, the crop 1 </ b> B washed and submerged 2 is fed from one side of the belt conveyor 3 </ b> B to the belt conveyor 3 </ b> B. After being unfolded and placed on top, it is sequentially transferred at the transfer speed of the belt conveyor 3B.

The crop 1B transferred by the belt conveyor 3B is radiated by a magnetron 3A provided on the upper surface of the crop 1B so as to be able to radiate electromagnetic waves in a required radiation capacity, radiation intensity and radiation range. 3 is applied.
In this case, when the radiation capacity of the magnetron 3A is 500 to 600 W in terms of electric energy, the radiation intensity, that is, the radiation distance between the electromagnetic wave radiated from the magnetron 3A and the transferred crop 1B is about 50 to 80 cm. Radiation is desirable to prevent overheating damage due to excessive radiation.
In addition, since the radiated crops 1 have different moisture content, thickness, size, shape, or bulk depending on their varieties, the radiation conditions differ depending on each specific crop 1B. In the case of thin leaves and stems such as Komatsuna, the magnetron 3A may be transferred at a transfer rate such that the magnetron 3A emits in about 20 to 25 seconds at a radiation capacity of 500 W and a radiation distance of 50 cm.

Naturally, the magnetron 3A is arranged so that the ability of the blanching 3 is determined by the width and transfer speed of the belt conveyor 3B for transferring the crop 1B. The width and transfer speed of the belt conveyor 3B are determined, and the number of magnetrons 3A disposed is also determined.
When using the magnetron 3A, it is also important to provide a blocking wall 3C that prevents the radiated electromagnetic waves from diverging outside.

Thus, the crop 1B that is unfolded and transferred on the belt conveyor 3B and is subjected to the required blanching 3 is stored in the storage / storage tool 4B and is normally kept in the cold storage 4 in a low-temperature warehouse. In such a case, the cold insulation temperature varies depending on the variety, but usually 0.6 to 10 ° C. is preferable.
However, even in the crop 1B to which the blanching 3 is applied, since the respiratory action and the enzyme action are not prevented at all, ethylene gas and the like are still discharged during long-term storage. Examples include materials that can adsorb the exhausted ethylene gas or the like during storage, such as wood, corrugated cardboard material, or molded plate material such as wood powder or bamboo powder.
In addition, even in the crop 1B to which the branching 3 such as leafy vegetables and fruit vegetables is applied, the moisture content of the varieties is different in the thickness, size, shape, bulk, etc. However, there are many cases in which sufficient blanching 3 treatment is not performed, and there is a risk of promoting overheating due to ethylene gas or the like discharged by the breathing action during the storage period.
For this purpose, as shown in FIG. 5, it is desired that the gas is stored in a storage storage box 4 </ b> B having a sealing lid 4 </ b> A that can be opened and closed using the gas adsorbing material and then stored in a cold storage 4.

The results of the preservation test according to the present invention will be described below. As a sample used for the test, Komatsuna grown and harvested by house cultivation in Edogawa-ku, Tokyo, was used, and the original average moisture content was 94. 2% Komatsuna was washed with running water for 15 minutes and then placed in a state of being soaked for 10 minutes.
Next, when the radiation capacity of the magnetron is 500 W, the radiation intensity is 50 cm, the radiation distance is 20 cm, and the radiation time is 20 seconds. Sample 1 is the radiation, 30 seconds radiation is Sample 2, and the non-radiation is the control. did.
The storage test method is to store in an aluminum open storage box 60cm in length 90cm in width 15cm in depth, and place it on a storage shelf in a cold storage warehouse where the temperature is stored at 0.6 ° C. The results are as shown in Table 1.

  For a large amount of continuous processing, it is desirable to dispose a magnetron on a belt conveyor. However, as a batch system, a single magnetron can perform a branching process.

  It is a flowchart of this invention.   It is explanatory drawing of washing | cleaning.   It is explanatory drawing of immersion.   It is explanatory drawing of the branching method.   It is explanatory drawing of the storage preservation box which has a sealing lid.

DESCRIPTION OF SYMBOLS 1 Washing 1A Washing tank 1B Crop 1C Washing water 1D Drain hole 2 Submerged 2A Submerged tank 2B Submerged water 3 Branching 3A Magnetron 3B Belt conveyor 3C Insulation wall 4 Cold storage 4A Sealing lid 4B Storage storage box

Claims (3)

  Wash the harvested crops such as leaf vegetables and fruit vegetables with running water, submerge them so that the moisture content of the outer surface of the crops is at least 93%, and then transport the radiation inside the magnetron electromagnetic wave. A method for preserving agricultural crops, characterized in that water molecules are excited to generate heat so as to be heated to 70 to 80 ° C. to inactivate the whole enzyme uniformly and then stored at a low temperature.   The method for preserving agricultural products according to claim 1, wherein the radiation distance to the agricultural products, which is a measure of the magnetron electromagnetic radiation intensity when the radiation capacity of one magnetron is 500 to 600 W, is 50 to 80 cm.   The method for preserving agricultural products according to claim 1 or 2, wherein the low temperature storage temperature is 0.6 to 10 ° C.

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