KR101582116B1 - Storage method for leafy vegetables using dry thermal treatment - Google Patents

Abstract

The present invention relates to a method of storing leaf vegetables using a dry heat treatment, wherein the leaf vegetables are stored at a low temperature after thermal shock is applied by a thermal heat treatment, thereby suppressing physiological disturbance during storage and reducing the amount of vaporizing action, The hardness is excellent even when stored, and the taste is not deteriorated.

Description

[0002] Storage methods for leaf vegetables using dry heat treatment [

The present invention relates to a method of storing leaf vegetables using a dry heat treatment having a high hardness even when stored for a long period of time, by suppressing a physiological disorder during storage and reducing the activity of vaporization to reduce weight loss and selectivity loss.

Cabbage is the most used vegetable among domestic vegetables. The cultivation area decreased from 52,000 hectares in 2000 to 33,000 hectares in 2010, 4% per year, but it increased again to 39,000 hectares in 2011, 656 thousand tons of Chinese cabbage, 174 thousand tons of highland Chinese cabbage, 1,897 thousand tons of autumn Chinese cabbage, and 335 thousand tons of winter cabbage, totaling about 3,062 thousand tons.

Cabbage is a relatively low respiratory rate and ethylene production rate. Respiration rate is 4.59 to 9.89 mLCO ₂ / kg / h at 20 ℃, 1.85 to 3.65 mLCO ₂ / kg / h at 5 ℃, 0.95 to 2.24 mVCO ₂ / kg / h, and the ethylene generation amount is 0.3 to 0.7 μL / kg / h at 20 ° C.

But it is detected to be less than 0.01 μL / kg / h at 0 ° C, and it is known that it hardly occurs.

In addition, the initial freezing point of Chinese cabbage is stored at -1.32 to -1.55 ° C in the leaves and -0.30 to -0.64 ° C in the stem, . At such low temperatures, wintering Chinese cabbage can be stored for about 70 to 80 days. However, loss of more than 40% is caused by weight loss and selectivity. In addition, packaging method of polyethylene film was tried to suppress weight loss during long - term storage, but there was no significant difference in loss rate through weight loss and selectivity.

In addition, most of the methods for storing the Chinese cabbage at low temperature are equipped with a humidity controller to store the cabbage under a constant humidity. When the humidity is high, the tissue is softened, and the microbes are easily reproduced. When the humidity is low, There is a problem that the product is lost because it is hardened and dried. Therefore, it is necessary to keep the humidity at a certain level. In this case, a lot of electric power is consumed, which is economically disadvantageous.

Therefore, there is a need for a cabbage storage method that can maintain freshness even when there is no humidity control device for long-term storage of Chinese cabbage, which is economical and can reduce weight loss and selectivity loss.

Korean Patent No. 0966267 Korea Patent Publication No. 2008-0102719 Korean Patent No. 1304223

It is an object of the present invention to provide a method for storing leaf vegetables using dry heat treatment, which suppresses physiological disorders during storage and reduces the activity of vaporization to reduce weight loss and selectivity loss and maintains hardness even during storage for a long period of time.

To achieve the above object, the present invention provides a method for storing leaf vegetables using dry heat treatment, wherein the leaf vegetables are stored at a low temperature after thermal shock is applied by dry heat treatment.

The dry heat treatment may be performed in a hot air drying method at 35 to 65 ° C, preferably 40 to 50 ° C for 0.5 to 10 minutes, preferably 1 to 5 minutes.

The low temperature may be -5 to 15 占 폚.

The leaf vegetables may be coated with a humid porous artificial stone having at least one selected from the group consisting of vermiculite, pumice, perlite, volcanic stone and talc after thermal shock is applied by dry heat treatment.

The water containing the antimicrobial substance dissolved in the humidified porous artificial stone may be absorbed in advance before covering the leaf vegetables with the humidified porous artificial stone.

The leaf vegetables coated with the humectant porous artificial stone can be packaged in a plastic film.

In the process of applying heat shock to the leaf vegetables, the leaf vegetables are stacked in a lateral direction in a packaging container having a plurality of holes, for example, with roots of leaf vegetables facing to the side, and the packaging container is passed through a tunnel type hot- Lt; / RTI >

The process of covering the heat-shocked leaf vegetables with the humid porous artificial stone may be to fill the remaining space of the wrapped container with the moisture absorbent porous artificial stone so that the surface of the leaf vegetable can be covered with the humid porous artificial stone.

In order to coat the leaf vegetables with humus porous artificial stone, 5 to 200 parts by weight of the humus porous artificial stone may be added to 100 parts by weight of the leaf vegetables.

The roots of the leaf vegetables may be coated with a wax or polymer that is not gas permeable.

The leafy vegetables may be cabbage, cabbage, lettuce or lettuce.

One embodiment of the method of storing leafy vegetables of the present invention comprises the steps of: laminating leaf vegetables horizontally to the packaging container after having a packaging container having a plurality of holes in a conveyor belt; Passing a packaging container in which the leaf vegetables are stacked in a tunnel type hot air dryer having an opening through which a conveyor belt is drawn in and out; Filling the empty space of the packaging container that has passed through the hot air dryer with a humid porous artificial stone; Packaging the packaging container containing the leaf vegetable and the humidified porous artificial stones into a plastic film; And conveying the packaged packaging container to a cryogenic reservoir with a conveyor belt.

In the method of storing leaf vegetables using the dry heat treatment of the present invention, heat shock protein (heat shock protein) is generated by dry heat treatment of leaf vegetables to suppress the physiological disorder that occurs during storage for a long time, and when the wax layer on the surface of the leaf vegetables is melted By penetrating into the pores and blocking it, the action of vaporization is reduced, so that the weight can be suppressed. In addition, when cabbage was stored for a long time, the amount of lobes removed due to less rancidity or decay in the outer leaves was decreased, and the luminal loss was reduced.

Fig. 1 is a photograph of a Chinese cabbage with a bacillus.

The present invention relates to a method of storing leaf vegetables using a dry heat treatment having a high hardness even when stored for a long period of time, by suppressing a physiological disorder during storage and reducing the activity of vaporization to reduce weight loss and selectivity loss.

Hereinafter, the present invention will be described in detail.

In the method for storing leafy vegetables of the present invention, the leaf vegetables are heat-shocked by a dry heat treatment while being transported using a conveyor belt, and then stored at a low temperature. In addition, leafy vegetables can be stored at low temperature after they are heat shocked by dry heat treatment and then covered with humid porous artificial stone.

The dry heat treatment is performed using a hot air drying method, for example, a hot-air drier at 35 to 65 ° C, preferably 40 to 50 ° C for 0.5 to 10 minutes, preferably 1 to 5 minutes. When heat shock is applied to the leaf vegetables by heat treatment, the heat shock protein is generated, and the leaf tissue is inhibited physiological disorder during storage for a long time, and the wax layer present on the surface of the leaf vegetables melts and permeates into the pores, .

When the temperature is lower than the lower limit of the temperature during the dry heat treatment, the effect caused by thermal shock on the leaf vegetables can not be obtained. If the temperature is higher than the upper limit, the roots may be spoiled and decayed. When the time of dry heat treatment is less than the lower limit of the above range, the effect of thermal shock on the leaf vegetables can not be obtained, and when the upper limit is exceeded, the elasticity of the leaf vegetables may be lost.

The low temperature is not particularly limited as long as it is capable of maintaining the leafy vegetables as fresh as possible for a long period of time, but is preferably -5 to 15 ° C, more preferably -3 to 3 ° C. If the temperature is lower than the lower limit, it may be corroded due to low-temperature obstruction and rash may occur. If the temperature is above the upper limit, yellowing of leaves or surface drying may occur due to breathing of leafy vegetables.

When the leaf vegetables are pretreated by the precooling treatment or the incubator treatment instead of the dry heat treatment, they can be stored for a long period of time in the low temperature storage equipped with the humidity control device. However, in the case of pretreating the leaf vegetables by the dry heat treatment, Even without a humidity controller, it can remain fresh for long periods of time in a low-temperature reservoir.

In addition, leaf vegetables coated with humus porous stones are packed. In the process of packaging the leaf vegetables coated with the humidified porous artificial stone, the leaf vegetables are put into the packaging container, and the hollow space of the packaging container is filled with the humidified porous artificial stone so that the surface of the leaf vegetables can be covered with the humidified porous artificial stone. Wrapping or wrapping leaf vegetables and porous artificial stones in a water vapor permeable plastic film bag in a packaging container.

The packaging container is a box in which a hole can be formed and ventilated, and a mixture of leaf vegetables and an impregnated porous artificial stone covering the leaf can be loaded without applying a load. The material is made of plastic, Can be used without. However, it can be put into the packaging container after putting it in the vapor permeable plastic film bag without sealing it directly into the packaging container with the leaf vegetable and the humidified porous artificial stone. The water vapor permeable plastic film bag preferably has high water vapor permeability so that the inside of the bag becomes humidified due to the divergence of the moisture contained in the leaf vegetables and the humid porous artificial stones. Biaxially oriented polypropylene film (OPP), flexible polyvinyl chloride stretch film (PVDC), biaxially oriented polystyrene film (OPS), and the like can be used.

Porous artificial stones having a relatively small particle size can be obtained by introducing leaf vegetables into the packaging container or the water vapor permeable plastic film bag first and then pouring the porosity between the leaf vegetables and the leaves of the leaf vegetables And some porous artificial stones may be put in a packaging container or a water vapor permeable plastic film bag before putting leafy vegetables and then coating the remaining porous artificial stones with a coating.

In the process of covering the leaf vegetables with the porous artificial stone, when the leaf vegetables are put in a packaging container or a water vapor permeable plastic film bag, the roots of the leaf vegetables are put side to side (in the horizontal direction), and the root portions of the leaf vegetables are pressed It is preferable from the viewpoint of being able to prevent it. In the present invention, the term 'root portion of leaf vegetables' is used to mean both the root portion when harvesting roots at the time of harvesting leaf vegetables, and the cut portion of the root portion when cutting root portions such as Chinese cabbage . It is preferable that the roots of the leaf vegetables are coated with a wax or polymer having no gas permeability, that is, water or water vapor can not permeate or the penetration amount thereof is insignificant, so that moisture evaporation through the roots can be suppressed. The gaseous non-permeable wax or polymer may be, for example, shellac, which is an animal resin made from paraffin, carnauba wax or secretory worms.

In the present invention, the humectant porous artificial stone covering the leafy vegetables can absorb the water in advance and can perform a buffering action to maintain the moisture content of the leafy vegetables. Specifically, since the leaf vegetable pretreated with a thermal shock reduces the transpiration action, the humidity can be maintained uniformly only by the humid porous artificial stone absorbing moisture without the humidity control device. In addition, the humid porous artificial stone is not only advantageous in controlling humidity but also light in weight compared to the volume. Therefore, it is possible to lighten the weight of the mixture while covering many leafy vegetables, and it is possible to easily separate leafy vegetables without leaving scars on the surface of the leafy vegetables .

The antimicrobial material can be adsorbed on the humid porous artificial stone, thereby suppressing the occurrence of wrinkles and fungi of leaf vegetables. The antimicrobial substance is not particularly limited as long as it is synthetic or natural, as long as it can be used for preserving food or agricultural products. In order to maximize the antimicrobial activity in a humid environment, a water-soluble antimicrobial substance is preferable. In order to simultaneously perform adsorption of an antimicrobial substance to a porous artificial stone and water absorption, a water-soluble antimicrobial substance is dissolved in water, It is preferable to absorb it into the stone.

The blending ratio for covering the above-described leafy plants with the humectant porous artificial stone is not particularly limited to an amount such that the leaf vegetables are sufficiently enclosed in the humid porous artificial stone, but it is preferable that 100 to 100 parts by weight of the leaf vegetables have 5 to 200 parts by weight , Preferably 10 to 150 parts by weight, and more preferably 20 to 100 parts by weight. In case of less than the lower limit value, the leaf vegetables are not sufficiently coated with the porous artificial stones, so that it is difficult to sufficiently exhibit the function as a buffer material for humidity control. When the upper limit value is exceeded, the storage space occupies a large amount and the effect as a buffer material for humidity control is no longer increased. The water absorption rate of the porous artificial stones is 10 to 150%, preferably 30 to 140%, more preferably 50 to 130%. The water uptake rate is calculated as the ratio of the weight of the dry weight to the weight of the dry weight of the 100 g dry weight. When the moisture absorption rate is low, the amount of the humidified porous artificial stone to be added to the leaf vegetables is increased to achieve the humidity control buffer effect of the present invention, so that the storage efficiency is lowered. When the upper limit is exceeded, However, as the porosity increases, the porosity decreases and the porous artificial stone can be broken. The porosity of the porous artificial stones is 30 to 80%, preferably 40 to 60%. When the porosity is lower than the lower limit, the amount of water is so small that the buffer capacity due to the humidity change is low. When the porosity exceeds the upper limit Humidity Porous artificial stones are fragile and water flows from the pores of porous artificial stones. The average particle size of the porous artificial stone of the present invention is 0.5 to 30 mm, preferably 4 to 28 mm, and more preferably 8 to 25 mm. When the particle size exceeds the upper limit, the particles are too large, The artificial stones are difficult to be mixed, and when the particle size is less than the lower limit, the porosity is relatively low and the moisture content is low.

Examples of the humid porous artificial stone include at least one selected from the group consisting of vermiculite, pumice, perlite, volcanic stone and talc.

One embodiment of the method of storing leafy vegetables of the present invention comprises the steps of: laminating leaf vegetables horizontally in the packaging container after having a packaging container having a plurality of holes in a conveyor belt; Passing a packaging container in which the leaf vegetables are stacked in a tunnel type hot air dryer having an opening through which a conveyor belt is drawn in and out; Filling the empty space of the packaging container that has passed through the hot air dryer with a humid porous artificial stone; Wrapping the packaging container containing the leaf vegetable and the humidified porous artificial stones with a plastic film; And conveying the wrapped packaging containers to a cryogenic reservoir with a conveyor belt.

Another embodiment of the method for storing leafy vegetables of the present invention comprises the steps of: placing a packaging container having a plurality of holes in a conveyor belt and then providing a plastic film bag inside the packaging container; Laminating leaf vegetables on the plastic film bag; Passing a plastic film bag in which the saline solution is laminated to a tunnel type hot air dryer having an opening through which a conveyor belt is drawn in and out; Filling the hollow space of the plastic film bag which has passed through the hot air dryer with humid porous artificial stones; And sealing the plastic film bag in which the leaf vegetable and the humid porous artificial stone are mixed; And conveying the packaging container provided with the sealed plastic film bag with a conveyor belt to the cryogenic reservoir.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

The low temperature storage pool was used for the experiment, and the Chinese cabbage was harvested from the farmhouse in Gangwon - do (Pyeongchang, Gangwon - do).

(1) Dry heat treatment experiment

Manufacturing example  One.

After wrapping the package in a box (box) so that the root cutting part of the cabbage was turned to the side (horizontal direction), the packing container was passed through a tunnel type hot air dryer using a conveyor belt and heat shock was applied. Wrapped and transported to a low-temperature reservoir at -1 ° C using a conveyor belt. At this time, the thermal shock by the hot air dryer is performed at 40 ° C for 2 minutes and 30 seconds.

Manufacturing example  2.

The procedure was the same as that of Preparation Example 1 except that the process of passing through the tunnel type hot air dryer was omitted and the Chinese cabbage was stored at a temperature of -1 ° C and a relative humidity of 96% instead of -1 ° C.

Test Example  One.

1-1. Respiratory rate _{(㎖CO 2 / kg / h)} : the sample into 1 kg at 0 ℃ the gas barrier sealed container taking the gas in the vessel 200 ㎕ was measured using a gas chromatography (GC-14A, Shinadzu, Japan ).

1-2. Gas Composition (%): 1 kg of sample was placed in a gas-tight sealed container at 0 ° C, and 200 μl of the gas in the container was taken over time and measured by gas chromatography (GC-14A, Shinadzu, Japan).

1-3. Ethylene production rate (ml C ₂ H ₄ / kg / h): 1 kg of sample was placed in a gas-tight sealed container at 0 ° C, and 200 μl of gas in the container was taken over time and analyzed by gas chromatography (GC-14A, Shinadzu, Japan).

division Production Example 1 Production Example 2 Respiratory rate (㎖CO ₂ / kg) 1.29 1.39 Gas composition
(%, O ₂₎ 0day 14.2 14.3 10day 3.6 3.7 20day 1.9 1.8 30day 1.8 1.7 40day 1.7 1.7 Gas composition
(%, CO ₂ ) 0day 0.0 0.0 10day 3.0 3.1 20day 6.2 6.2 30day 7.2 7.4 40day 10.8 10.9 Ethene incidence
(Ml C ₂ H ₄ / kg / h) 2day 0.0042 0.0048 4day 0.0063 0.0083 7day 0.0072 0.0089

As shown in Table 1 above, the Chinese cabbage stored according to Production Example 1 of the present invention is likely to have excellent storability due to a slow respiration rate as compared with Preparation Example 2, and the rate of ethylene generation is low. Therefore, Of aging and aging.

On the other hand, the oxygen concentration and the carbon dioxide concentration were found to be within the standard error range in Production Example 1 and Production Example 2.

(2) Dry heat treatment temperature confirmation experiment

Manufacturing example  3.

The same procedure as in Preparation Example 1 was carried out except that the thermal shock was carried out at 30 ° C for 2 minutes and 30 seconds by a hot air drier.

Manufacturing example  4.

The same procedure as in Preparation Example 1 was carried out except that a thermal shock by a hot air drier was performed at 45 ° C for 2 minutes and 30 seconds.

Manufacturing example  5.

The same procedure as in Preparation Example 1 was carried out except that the thermal shock by a hot air dryer was carried out at 60 ° C for 2 minutes and 30 seconds.

Manufacturing example  6.

The same procedure as in Preparation Example 1 was carried out except that the thermal shock by a hot air dryer was carried out at 70 DEG C for 2 minutes and 30 seconds.

Test Example  2.

The respiration rate, gas composition and ethylene generation rate were tested in the same manner as in Test Example 1 above.

division Production Example 3 Production Example 4 Production Example 5 Production Example 6 Respiratory rate (㎖CO ₂ / kg) 1.41 1.25 1.30 1.32 Gas composition
(%, O ₂₎ 0day 14.3 14.1 14.2 14.2 10day 3.8 3.5 3.6 3.6 20day 2.0 1.8 1.8 1.7 30day 1.9 1.7 1.7 1.6 40day 1.9 1.6 1.7 1.6 Gas composition
(%, CO ₂ ) 0day 0.1 0.0 0.0 0.0 10day 3.4 2.9 3.1 2.9 20day 6.5 6.1 6.2 6.1 30day 7.4 7.1 7.3 7.2 40day 11.3 10.9 10.9 10.8 Ethene incidence
(Ml C ₂ H ₄ / kg / h) 2day 0.0050 0.0040 0.0044 0.0045 4day 0.0086 0.0059 0.0064 0.0069 7day 0.0091 0.0068 0.0075 0.0080

As shown in the above Table 2, the stored Chinese cabbage had a low respiration rate and a low ethylene generation rate in the order of Production Example 4> Production Example 5> Production Example 6> Production Example 3, And aging are most suppressed. In particular, in Preparation Example 3, the Chinese cabbage was aged from 30 days of storage to deteriorate the merchantability. In Example 6, the Chinese cabbage began to be spoiled and decayed from about 30 days after storage, and the productability was deteriorated after about 40 days.

On the other hand, the oxygen concentration and the carbon dioxide concentration were found to be within the standard error range in Production Examples 3 to 6.

Therefore, the following test was carried out at a temperature of 45 ° C during the dry heat treatment.

(3) Dry heat treatment time confirmation experiment

Manufacturing example  7.

The same procedure as in Production Example 1 was carried out except that the thermal shock by a hot air dryer was carried out at 45 ° C for 20 seconds.

Manufacturing example  8.

The same procedure as in Preparation Example 1 was carried out except that the thermal shock was carried out at 45 캜 for 2 minutes by a hot air drier.

Manufacturing example  9.

The same procedure as in Preparation Example 1 was carried out except that the thermal shock by a hot air dryer was carried out at 45 ° C for 5 minutes.

Manufacturing example  10.

The same procedure as described in Preparation Example 1 was carried out except that the thermal shock by a hot air drier was carried out at 45 ° C for 10 minutes.

Manufacturing example  11.

The same procedure as in Preparation Example 1 was carried out except that the thermal shock by a hot air drier was carried out at 45 ° C for 20 minutes.

Test Example  3.

The respiration rate, gas composition and ethylene generation rate were tested in the same manner as in Test Example 1 above.

division Production Example 7 Production Example 8 Production Example 9 Production Example 10 Production Example 11 Respiratory rate (㎖CO ₂ / kg) 1.43 1.27 1.28 1.31 1.43 Gas composition
(%, O ₂₎ 0day 14.0 14.1 14.0 14.1 14.1 10day 3.6 3.5 3.6 3.7 3.9 20day 1.8 1.7 1.7 1.8 2.1 30day 1.7 1.6 1.7 1.7 2.0 40day 1.7 1.6 1.6 1.7 2.0 Gas composition
(%, CO ₂ ) 0day 0.0 0.0 0.0 0.0 0.0 10day 2.9 2.9 2.9 3.2 3.5 20day 6.3 6.2 6.3 6.3 6.6 30day 7.1 7.2 7.2 7.2 7.5 40day 11.0 10.9 10.8 10.9 11.4 Ethene incidence
(Ml C ₂ H ₄ / kg / h) 2day 0.0049 0.0042 0.0043 0.0045 0.0051 4day 0.089 0.0060 0.0061 0.0066 0.0090 7day 0.092 0.0069 0.0071 0.0077 0.0093

As shown in the above Table 3, the stored Chinese cabbage was excellent in the storage stability in Production Example 8 because the respiration rate was low and the rate of ethylene generation was low in the order of Production Example 8> Production Example 9> Production Example 10> Production Example 11> , The ripening and aging of Chinese cabbages are suppressed the most. In particular, in Preparation Example 11, the resilience of Chinese cabbages decreased from about 20 days after storage.

Therefore, the following test was carried out with a dry heat treatment time of 2-3 min.

Example  One.

Porous artificial stone (vermiculite), which absorbed water, was poured into an empty space (a space left after laminating the cabbage) of a packaging container which had been subjected to a thermal shock through a tunnel type hot air drier in the same manner as in Preparation Example 1, After that, the packaging container is wrapped with LDPE having a thickness of 50 탆 and transferred to a low temperature reservoir for storage. At this time, the thermal shock by the hot air dryer is performed at the temperature of 45 ° C and for 2 minutes and 30 seconds.

Comparative Example  One.

The same operation as in Example 1 was carried out except that it was stored in an incubator instead of the hot air dryer.

Comparative Example  2.

The same procedure as in Example 1 was carried out except that the pre-cooling was carried out for 8 hours instead of the hot-air dryer.

Test Example  4. Measurement of respiration rate, gas composition and ethylene generation rate

The respiration rate, gas composition and ethylene generation rate were tested in the same manner as in Test Example 1 above.

division Example 1 Comparative Example 1 Comparative Example 2 Respiratory rate (㎖CO ₂ / kg) 1.25 1.35 1.07 Gas composition
(%, O ₂₎ 0day 14.1 14.1 14.3 10day 3.6 3.5 6.1 20day 1.9 1.7 1.9 30day 1.8 1.6 1.8 40day 1.7 1.6 1.7 Gas composition
(%, CO ₂ ) 0day 0.0 0.0 0.0 10day 3.0 3.2 3.0 20day 6.1 6.3 6.1 30day 7.1 7.6 6.4 40day 10.8 11.1 10.2 Ethene incidence
(Ml C ₂ H ₄ / kg / h) 2day 0.0041 0.0047 0.0038 4day 0.0060 0.0079 0.0061 7day 0.0069 0.0085 0.0070

As shown in Table 4 above, the Chinese cabbage stored in accordance with Example 1 of the present invention is likely to have excellent storability due to a slow respiration rate as compared with Comparative Example 1, and since the rate of ethylene generation is low, Of aging and aging.

On the other hand, it was confirmed that the oxygen concentration and the carbon dioxide concentration did not differ within the standard error range in Example 1 and Comparative Example 1-2.

Test Example  5. Selection loss and weight reduction rate

5-1. Weight loss (%): The weight of Chinese cabbage after lapse of storage period and the weight of Chinese cabbage which can not be used were measured.

5-2. Weight reduction rate (%): The weight and storage period of Chinese cabbage were measured, and weight was measured.

division Example 1 Comparative Example 1 Comparative Example 2 Selective loss (%) 0day 9.80 9.81 9.80 15day 13.90 17.23 10.17 30day 14.21 28.66 16.56 45day 22.24 32.54 22.84 Weight reduction rate (%) 15day 0.26 1.56 0.73 30day 0.43 1.84 0.81 45day 0.67 1.94 0.89

As shown in Table 5, it was confirmed that the selectivity loss of the Chinese cabbage stored according to Example 1 of the present invention shows a lower loss than Comparative Examples 1 and 2.

In addition, it was confirmed that the weight reduction rate of the Chinese cabbage stored in accordance with Example 1 of the present invention was lower than that of Comparative Examples 1 and 2. Particularly, in Comparative Example 2, it was confirmed that the selectivity loss was not high but the weight decreased considerably.

Test Example  6. Electrical Conductivity Measurement

The stem portion of the Chinese cabbage stored in Examples and Comparative Examples was cut and 2 g was taken and measured with an EC meter (Cybersan.com 11, Eutech instruments, Singapore) using 0.4 M mannitol solution.

division Example 1 Comparative Example 1 Comparative Example 2 Electrical conductivity (ds / m) 0day 4.07 4.07 4.08 15day 5.12 5.61 4.92 30day 9.84 11.46 10.45 45day 11.07 13.59 12.38

As shown in Table 6, the electrical conductivity of the Chinese cabbage stored according to Example 1 of the present invention was gradually increased until the 15th day of storage as in Comparative Examples 1 and 2, then rapidly increased until 30 days of storage, It was confirmed that a difference in conductivity occurred.

The effect of suppressing the aging of the Chinese cabbage and the occurrence of a Japanese bell pepper disease (Fig. 1) in the Chinese cabbage can be suppressed.

Test Example  7. Longitudinal hardness  Measure

The cabbages stored in Examples and Comparative Examples were cut in half and then measured using a fruit hardness tester (FHM-1, Takemura, Japan).

division Example 1 Comparative Example 2 Comparative Example 3 Hardness Hardness (kg) 0day 0.909 0.910 0.909 15day 0.864 0.834 0.847 30day 0.816 0.810 0.806 45day 0.698 0.659 0.665

As shown in Table 7, the chonding hardness of the Chinese cabbage stored according to Example 1 of the present invention was gradually decreased until storage 30 as in Comparative Examples 1 and 2, Respectively.

Example 1 confirmed that the effect of suppressing the lowering of the hardness and hardness was excellent.

Test Example  8. Morphological observation

The morphological characteristics of Example 1, Comparative Example 1 and Comparative Example 2 are shown in photographs.

As shown in Table 8, it was confirmed that the Chinese cabbage stored according to Example 1 and Comparative Example 2 of the present invention did not have a rash phenomenon of the outer leaves, but was relatively shiny even after cleansing, and that the inner leaves of the cut surface had elasticity.

On the other hand, in the Chinese cabbage of Comparative Example 2, a water droplet was formed due to supersaturation in the wrapped film, and roots softening, rashing of the outer leaves and smell occurred.

The part of the Chinese cabbage was discolored for about 45 days because it was not caused by the dry heat treatment of the present invention but the cabbage used in the present test was a cabbage containing a storage disorder presumed to be a deficiency of calcium.

Test Example  9. Sensory evaluation

The average value of 20 Chinese cabbages stored in the examples and comparative examples was evaluated by evaluating the appearance, color, flavor, texture and overall acceptability of the Chinese cabbage, and then performing a sensory test with a 9-point scale method (as the degree was increased to 9 points) This is shown in Table 9 below.

- Appearance, color, fragrance, texture and comprehensive preference: 1 = very bad, 9 = very good

division Example 1 Comparative Example 1 Comparative Example 2 Exterior 30day 7.8 7.1 7.7 60day 6.3 5.3 6.0 90day 5.7 4.1 5.1 color 30day 8.0 6.9 7.3 60day 7.8 5.1 6.4 90day 7.2 3.7 5.0 incense 30day 7.9 6.5 7.0 60day 7.1 5.5 5.9 90day 6.8 4.0 4.5 Texture 30day 7.8 6.7 6.6 60day 7.1 5.0 4.8 90day 6.4 3.4 3.6 Comprehensive likelihood 30day 7.7 6.7 6.7 60day 7.0 5.3 5.5 90day 6.2 4.0 4.3

As shown in Table 9, it was confirmed that the Chinese cabbage stored according to Example 1 of the present invention is superior to Comparative Examples 1 and 2 in appearance, color, fragrance, texture and overall acceptability.

Particularly, in Comparative Example 2, it was confirmed that appearance and texture were drastically lowered when left for a while even at room temperature for distribution after storage.

Claims (18)

Apply heat shock to the leafy vegetables by dry heat treatment, cover them with humid porous artificial stone, then store at low temperature;
Wherein the moisture-absorbing porous artificial stones are water-absorbed, the water-absorbing porous artificial stones have an absorption rate of 10 to 150%, and 100 parts by weight of the leaf vegetables are coated with 5 to 200 parts by weight of humus porous artificial stones. The method of claim 1, wherein the dry heat treatment is performed for 0.5 to 10 minutes. The method of claim 1, wherein the dry heat treatment is performed for 1 to 5 minutes. 4. The method according to any one of claims 1 to 3, wherein the dry heat treatment is performed at 35 to 65 占 폚. 4. The method according to any one of claims 1 to 3, wherein the dry heat treatment is performed at 40 to 50 占 폚. The method according to claim 1, wherein the dry heat treatment is performed by a hot air drying method. The method according to claim 1, wherein the low temperature is -5 to 15 占 폚. delete The method according to claim 1, wherein the humid porous artificial stone is at least one selected from the group consisting of vermiculite, pumice, perlite, volcanic stone, and talc. The method according to claim 1, wherein the water is a water-soluble antimicrobial substance. [2] The method according to claim 1, wherein the leaf vegetables covered with the humus-permeable artificial stone are packaged in a plastic film. 2. The method according to claim 1, wherein the step of applying heat shock to the leaf vegetables comprises laminating the leaf vegetables in a lateral direction in a plurality of pores and passing the pavement through a tunnel type hot air dryer while transferring the pavement to a conveyor belt. . [14] The method of claim 12, wherein the step of applying heat shock to the leaf vegetables comprises laminating the leaf vegetables on the packaging container with the root portions of the leaf vegetables facing to the side. [2] The method according to claim 1, wherein the step of covering the heat-impregnated leaf vegetables with the humidified porous artificial stone is performed in such a manner that the surface of the leaf vegetables is covered with the humidified porous artificial stone, Of the leaf vegetables. delete [2] The method according to claim 1, wherein the roots of the leaf vegetables are coated with wax or polymer having no gas permeability. The method according to claim 1, wherein the leaf vegetables are cabbage, cabbage, lettuce or lettuce. Laminating leaf vegetables horizontally in the packaging container after having a packaging container having a plurality of holes in the conveyor belt;
Passing a packaging container in which the leaf vegetables are stacked in a tunnel type hot air dryer having an opening through which a conveyor belt is drawn in and out;
Filling the empty space of the packaging container that has passed through the hot air dryer with a humid porous artificial stone;
Packaging the packaging container containing the leaf vegetable and the humidified porous artificial stones into a plastic film; And
Transferring the packaged packaging containers to a low temperature reservoir with a conveyor belt,
Wherein the moisture-absorbing porous artificial stones are water-absorbed, the water-absorbing porous artificial stones have an absorption rate of 10 to 150%, and 100 parts by weight of the leaf vegetables are coated with 5 to 200 parts by weight of an artificial porous artificial stones.

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