JPS6053576B2 - Freshness preservation material for fruits and vegetables - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to the storage, transportation, etc. of fruit vegetables such as eggplants, tomatoes, cucumbers, and kidney beans, as well as vegetables such as spinach and Chinese cabbage, and fruits such as green bananas, apples, and European bean. Humidity,
In addition to regulating environmental gases, etc., simple temperature control is performed to maintain the freshness of fruits and vegetables over a long period of time during storage or transportation by adjusting these conditions such as temperature, humidity, and environmental gases. There is something about ingredients to keep vegetables fresh.

Corrugated pole cases are now indispensable packaging containers for the transportation of fruits and vegetables, and protect the contents from mechanical damage.
It is useful as an outer box for gas storage (also called CA storage) and plastic packaging storage.

Currently, the most commonly used transportation methods for fruits and vegetables are simply packing them bare in ordinary cardboard boxes or laminated cardboard boxes, or wrapping them in a handkerchief with plastic film such as polyethylene and then placing them in cardboard boxes. It is packed and transported. However, when transporting fruits and vegetables using this method, the humidity cannot be controlled, so the fruits and vegetables become dry or, conversely, induce an optimum temperature condition, resulting in a significant decrease in the freshness of the fruits and vegetables in a relatively short period of time. This will damage the product value. Therefore, it is possible to use a moisture-absorbing material to improve the appropriate temperature condition during gas storage, but if a normal moisture-absorbing material is used, the inside of the package becomes overly dry, which has a negative effect on fruits and vegetables. Therefore, as a material for controlling the carbon dioxide concentration in the film packaging system and at the same time controlling the humidity in the packaging system, pulp from plants in the Carnata family, such as bagasse pulp, which is squeezed gas from sugar cane, is used. Alternatively, it has been found that a sheet made of straw pulp or the like gives good results, and its usefulness has already been proven.

In addition, in order to reduce the temperature, which has a significant impact on the freshness of fruits and vegetables, other than taking large-scale measures to make warehouses or transport vehicles themselves into refrigerators, most of the packaging containers themselves rely on filling with ice or dry ice to keep the temperature low. is the current situation.
However, all of these methods are inconvenient to handle, lower the temperature unnecessarily, especially for preserving fruits and vegetables, cause low temperature damage, are not desirable at all, and lead to abnormally high costs, making them impractical. Not. The present invention solves the above-mentioned drawbacks and relates to a freshness-preserving material that provides a gas atmosphere suitable for maintaining the freshness of fruits and vegetables, which controls humidity and slowly lowers temperature, and which is suitable for maintaining the freshness of fruits and vegetables. It can be used in the form of a sheet with a cryogen made of an inorganic compound housed between a water-absorbing sheet material and a water-impermeable film such as a polyethylene film. It is.

Cryogens usually have the property of lowering the temperature of water using the heat of dissolution when inorganic salts such as ammonium chloride are dissolved in water, and I have yet to hear of any examples of them being used to maintain the freshness of fruits and vegetables. be. The cryogen referred to here is a cryogen made of water and inorganic salts that dissolves in water and lowers the water temperature.
A general term for anything that lowers the temperature within the packaging system by its heat of dissolution.

As the cryogen consisting of water and salts, any conventionally known cryogen can be freely selected, and the salts can be used alone or as a mixture of two or more types, and are preferably non-toxic and do not cause chemical damage. Examples include - single use of ammonium chloride, ammonium nitrate, calcium chloride, magnesium sulfate, a mixed system of ammonium chloride and sodium carbonate, a mixed system of ammonium chloride and potassium nitrate,
Mixture of sodium nitrate and ammonium nitrate. system, etc. As for the specific freshness-preserving material and packaging form, the first
This is shown in the cross-sectional views of FIGS. 4 and 7.

In the example shown in Figure 1, there is a freshness-preserving material at the bottom of cardboard box 1! The freshness preservation material I is about 3Tn made of bagasse pulp! A water-absorbent sheet 3 with a thickness of It has a structure in which the edges are wrapped and only the back side of the water absorbent sheet 3 is left open.

Then, Kikucumbers 6 were packed as fruit vegetables, handkerchief wrapped 7 with polyethylene film, and a freshness retention test to be described later was conducted. The example shown in Fig. 2 was also used for the cucumber storage test as in Fig. 1. In this case, a water-absorbing sheet 3 was placed on the bottom of the cardboard box 11 as in the past, and cucumbers 6 were filled. Turn the same freshness-preserving material as shown in Figure 1 upside down, so that the water-impermeable film 5 is on the bottom, the water-absorbent sheet 3 is on top, and the cold agent 4 is placed in the middle in a sandwich-like manner. The entire package is wrapped in a handkerchief package 7 made of a flexible polystyrene foam sheet.

Examples 1 and 2 demonstrate the excellence of the packaging configuration of cucumbers shown in Figs. The results are shown in Table 1 in comparison with the method of using the anti-freezing film 5. The effect of the cryogen 3 is clearly seen in the reduction of temperature, and the difference in freshness of the kiuri 6 can be seen even by naked eye observation. It appeared so clearly that it could be confirmed.

In other words, the outside temperature of the packaging container is kept at the same temperature as in summer by heating equipment.
After raising the temperature to 4℃ or higher and leaving it for about 5 days, the temperature inside the cardboard box just before opening showed a maximum difference of about 2 to 2.5℃ depending on the presence or absence of a cryogen. There are extremely few thorns, and the thorns of cucumbers remain strongly throughout.
There is no visible discoloration, softening, or wilting, and the odor is almost odorless. However, packaging without cryogens already reduces the product value, and using only cardboard boxes causes significant discoloration, softening, and The gourds had deteriorated to the point where they had no choice but to be discarded. In addition, (4), (B), (C
) indicates the temperature measurement position within the cardboard box shown in FIG.
Next, the results of the spinach preservation test are shown in Figure 3.
It is shown in FIG. 4 and Table 2.

As is well known, spinach 8 is a vegetable that is extremely difficult to maintain freshness, but the effect of the cooling agent is remarkable.
The result was that the freshness pigment was not affected and even no wilting was observed. The cryogen 4 used was one prepared by adding 75 y of sodium carbonate to 50 q of ammonium chloride and mixing them uniformly (Examples 11 and 12), and one prepared by adding 150 q of ammonium nitrate (Example 13). In addition, the soft polystyrene*Tyrole sheet used for the handkerchief packaging 7 has good insulation properties and is a suitable packaging material to fully demonstrate the temperature-lowering effect of the cryogen. A difference of more than °C was obtained. Figure 5 is a graph of the test results in Table 1, and Figure 6 is a graph of the test results in Table 1.
The test results in the table are graphed, and these graphs show that the effect of the cryogen described above can be compared with the conventional packaging form as a clearer difference in internal temperature reduction and weight loss.

The shape of the freshness preserving material 1 is as shown in FIGS. 1 and 2.
In addition to the one held in a layer between the water-impermeable film 5 and the water-absorbing sheet 3, the water-absorbing sheet 3 is used both above and below the cryogen as shown in FIG. Covering with a water-impermeable film 5 consisting of a film also gives good results.

As shown in Fig. 4, the freshness preservation material 2 is used only on a part of the bottom of the cardboard case 1, and the water absorbent sheet 3 is used on the other parts to maintain freshness as shown in Table 2. We are seeing excellent results. Another method for placing the cryogen in a corrugated hole box is to mix the cryogen with valve scraps, sawdust, etc., and use a polyethylene film with many pinholes on one side and a regular polyethylene film on the other side. It is proposed that the pinhole film be placed in a bag with the pinhole film surface facing down on top of a water-absorbing sheet-like material.

A specific example is shown in FIG. 7. A water-absorbing sheet 3 made of bagasse pulp with a thickness of about 3 TW is spread on the bottom of a flat cardboard box 1, and a cryogen (sulfuric acid) is placed on top of it as the freshness preserving material 1. A mixture of 4,100 y of magnesium) and 1,050 y of sawdust was mixed into a 150×2 polyethylene film 5 with a thickness of 30 μm and a polyethylene film with pinholes 9.
A bag of 50 TnI 1 L in size was sealed and formed into a bag, and tomatoes 11 were put in it, wrapped in a handkerchief 7 with polyethylene film, and the same test as for Kiuri was carried out. Good results were obtained, with an average decrease in internal temperature of 2.8°C and a delay in ripening of tomatoes by about 2 days. The effect of the cryogen as a freshness-keeping material for fruits and vegetables can also be obtained simply by storing the cryogen in a container and covering the top surface with a water-absorbing sheet. In this case, by using calcium chloride, which has strong water absorption, as a cooling agent alone or in combination with other inorganic compounds, the dry state inside the cardboard box can be appropriately controlled. As detailed above, by incorporating a cryogen into a packaging container such as a cardboard box by an appropriate means, and passing through a water-absorbent sheet, the cryogen is absorbed into the moisture transpired by the respiration of the cane vegetables held on the water-absorbent sheet. Contact and gradually lower the temperature of the atmosphere by just 2~3
Due to the temperature difference of 2 to 3 degrees Celsius, appropriate moisture content, and gas atmosphere, the fruits and vegetables in the packaging container are placed in favorable conditions, and as a result, the fruits and vegetables are prevented from wilting. , deterioration is suppressed and the product is kept fresh for a long period of time.

Therefore, the material of the present invention is an extremely useful freshness-preserving material for fruits and vegetables in that it suppresses a decrease in commercial value and enables long-distance transportation.

[Brief explanation of drawings]

FIGS. 1 to 4 and 7 are cross-sectional views of cardboard boxes using the freshness-preserving material according to the present invention, and FIGS. 5 to 6 are graphs showing freshness-preserving properties. 1...Cardboard box, I...Freshness preservation material, 3...Water absorbent sheet, 4...Cryogen, 5...
...Water-impermeable film, 6...Cucumber, 7
...Handkerchief packaging, 8...Spinach, 9...Pinhole in water-impermeable film, 10.
...Sawdust, 11...Tomato.

Claims (1)

[Claims] 1. A material provided in a packaging container such as a cardboard box,
A freshness-preserving material for fruits and vegetables whose main ingredient is a cryogen made of an inorganic compound that causes an endothermic reaction when absorbed or dissolved in water. 2. The freshness-keeping material for fruits and vegetables according to claim 1, which is made by sandwiching a cryogen in layers between a water-absorbing sheet material and a water-impermeable film such as polyethylene. 3. The freshness-keeping material for fruits and vegetables according to claim 1, which is obtained by storing a mixture of a cold agent, pulp waste, sawdust, etc. in a bag made of a porous material. 4. A freshness-keeping material for fruits and vegetables according to claim 1, which comprises a container containing a cryogen and covering the upper surface with a water-absorbing sheet-like material.