JP3437539B2 - Method for producing dry powder of kale - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a dry powder of kale.

[0002]

2. Description of the Related Art Recently, various health foods have been devised and put on the market along with the enhancement of health consciousness. Among them, kale has been drawing attention as a so-called "green juice" as a health food that allows easy ingestion of vegetable ingredients.

There are various products of green juice of kale. For example, dry powder of kale, according to consumer preference,
There are products on the market that can be drunk by dissolving in water, hot water, milk, etc.

The dried powder of kale is generally produced by a process of drying and crushing the kale. In the drying process, freeze drying, spray drying, drum drying and hot air drying methods are used. Of these, hot air drying is often used because it is lower in cost than other drying methods, but if the temperature and time for drying are adjusted incorrectly, black kale will be produced and it will not be a product.

The color of the fresh leaves of kale is originally bright green. Due to the characteristics of healthy foods, it is preferred by general consumers that the product retains a green color comparable to that of fresh leaves of kale.

[0006]

Therefore, there is a demand for a method for efficiently producing a dry powder of kale retaining a green color in a short time.

[0007]

Means for Solving the Problems As a result of extensive studies on a method for drying kale, the present inventors have found a method for efficiently producing a dried powder of kale retaining a green color in a short time, and have made the present invention It came to completion.

That is, the present invention provides the following steps: (a) a step of crushing the kale into a width of 1 to 5 cm; and (b) 5 to 15 k of crushed kale per 1 m ^{2 of the} dry surface.
g (converted to raw leaf weight before treatment) is placed in a dryer, and
And a step of drying the kale diced with hot air having a wind speed of 0.1 to 5.0 m / s at 60 ° C .; and a method for producing a dried powder of kale.

The present invention also includes the following steps: (a) a step of cutting the kale into pieces having a width of 1 to 5 cm; and (b1) 5 to 15 pieces of cut pieces per 1 m ^{2 of the} dried surface.
Approximately 3 kg (kg of raw leaf before treatment) is placed in the dryer.
A step of drying the water content of the kale diced with hot air at 0 to 60 ° C. and a wind speed of 0.1 to 5.0 m / s to about 30 to 15% to obtain a semi-dried kale; (b2) per 1 m ^{2 of} dried surface , 50 to 150 kg of semi-dried kale (converted to untreated fresh leaf weight) obtained in (b1) is placed in a dryer, and the temperature is about 30 to 60 ° C. and the wind speed is 0.1 to 3.0.
a step of drying the kale fragmented with m / s hot air; and a method for producing a dried powder of kale.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing a dry powder of kale according to the present invention will be described. As the raw material kale used in the present invention, any kale belonging to the family Cruciferae can be used without particular limitation. For example, various kale such as siberian kale, scotch kale and collard can be used. The term kale also includes leaves, stems and parts thereof.

In general, a method for producing a dry powder includes steps of washing with water, drying and crushing. In the present invention, however, a step of dividing the kale into pieces (fragmentation treatment) may be included. There are two characteristics. The kale is cut into pieces by the drying process,
In other processes, it is an important process from the viewpoint of product drying and production efficiency. The kale may be fragmented before or after washing with water, but is preferably after washing with water.

In the present invention, in the drying step, one of the features is that a specific method is adopted in order to maintain the green color and flavor and efficiently dry in a short time.

Further, from the viewpoint of maintaining the green color, a step of blanching the kale is incorporated as necessary before or after the fragmentation treatment. The blanching treatment is preferably performed after the fragmentation treatment.

As described above, the method for producing a dry powder of kale according to the present invention is characterized in that the kale is cut into pieces and specific drying conditions are included. Hereinafter, the description will be made in the order of water washing-fragmentation-branching treatment-drying under specific conditions-pulverization, but it goes without saying that the present invention is not limited to this order.

Washing step First, the raw material kale is washed with water. The washing operation is not particularly limited, and the purpose is to wash away the dirt and dust adhering to the raw material kale with tap water, distilled water (preferably cold water (25 ° C. or lower)) and the like.

Shredding step Shredding is preferably performed with shreds having a width of about 1 to 5 cm. If it is cut into large pieces, the treatment efficiency in the subsequent steps is poor, while if it is cut into too small pieces, the components contained in the kale tend to be lost. Conventionally, the raw material kale was slurried into green juice, whereas the method of the present invention is to provide each treatment step in this fragmented state (shredded state) until the drying described later. . Hereinafter, the shredded kale may be referred to as shredded material. In addition, in the present specification, "sliced pieces having a width of 1 to 5 cm" include strip-shaped pieces and square-shaped pieces.

Blanching Treatment and Quenching Treatment Step In the method of the present invention, it is preferable to subject the fragmented material treated as described above to blanching treatment. Hot water, steam or the like is used for the blanching treatment. To hot water,
Sodium hydrogen carbonate, sodium carbonate, sodium chloride alone, in combination of two, or in combination of three,
It may be contained.

The blanching treatment with hot water is 80 to 1
It is carried out by immersing the fragment into hot water at 00 ° C for 1 to 5 minutes. When sodium hydrogen carbonate, sodium carbonate, and sodium chloride are contained, they are each 0.05 to 5.
It is preferable that the content be 0% by weight. When blanching is performed by adding sodium hydrogen carbonate, sodium carbonate, and sodium chloride to hot water as compared with blanching using only hot water, the green color of kale shines and a pleasant flavor comes to be exhibited.

After the blanching treatment, the shredded kale is preferably cooled immediately. Cooling is performed using a method usually used by those skilled in the art (for example, immersion, water cooling, air cooling, etc.). When cooling by immersion, it is preferably performed using water at 4 to 10 ° C. The immersion time is an arbitrary time depending on the amount of the fragmented product to be treated. As cooling by air cooling, cooling by cold air or evaporative cooling using warm air that uses latent heat of vaporization is used. Evaporative cooling is preferable in order to shorten the drying time described below.

Instead of hot water blanching, steam blanching may be used.
Blanching using steam is at normal pressure or under pressure,
It is carried out by steaming the fragmented material intermittently or continuously for a suitable time (for example, 1 to 5 minutes).

The temperature of water vapor is about 100 ° C. (at the time of pressurization,
100 to 120 ° C.), the temperature of the fragmentation product is maintained at about 70 to 90 ° C. when steam-treated using such steam, and the entire fragmentation product treated with steam is uniformly heated. Therefore, lot-to-lot differences are less likely to occur in the blanching process.

The intermittent steaming treatment is a treatment in which steaming treatment with steam for a certain period of time and a cooling treatment are repeated. For example, the process of boiling the kale shredded material with steam for 30 seconds and then cooling the shredded material to a temperature of 60 ° C. or lower, preferably 40 ° C. or lower is repeated. This intermittent steaming step does not cause discoloration of the kale during blanching even if it is repeated 10 times, but is preferably repeated 2 to 5 times. If this step is performed only once, the enzymes responsible for the green fading of kale are not completely inactivated. On the other hand, when this step is repeated 6 times or more, there is a problem that the natural components of kale begin to be lost.

The intermittent steaming treatment allows a blanching treatment for a substantially long time, and the enzyme causing fading is completely inactivated.

In the case of continuous steaming treatment (continuous steaming treatment), the treatment is carried out for 1 to 5 minutes. When steam treatment is performed for 1 minute or less, inactivation of enzymes involved in bright green fading of kale is not completely performed, and when it is longer than 5 minutes, the green color of kale starts to be impaired during blanching.

As the cooling step in the blanching with steam, cold water or air cooling can be used as in the case of hot water.

Drying Step The kale after the blanching and cooling treatment is dehydrated, and then dried in the fragmented state and then powderized. When dried, the water content of the fragment is 10% by weight.
Hereafter, it is carried out so as to be preferably 5% by weight or less.
The water content in the present invention is represented by the ratio of the weight of water in the kale to the weight of the kale.

From the viewpoint of manufacturing cost, hot air drying is the most preferable, but it has been found that the dry product turns black due to incorrect setting conditions. It is considered that the sugar contained in the leaves of kale is charred and discolored by the hot air.

In the present invention, 5 to 15 kg of shredded kale (converted to untreated fresh leaf weight) is placed in a dryer per 1 m ² of the dry surface, 30 to 60 ° C., and a wind speed of 0.1 to 5.0.
Dry the cut kale with hot air of m / s. Preferably, 8 to 12 kg, and more preferably 10 kg (all are converted to fresh leaf weight) of kale are dried.

That is, in a dryer, 5 to 15 kg of shredded kale (converted to untreated fresh leaf weight) is placed per 1 m ² of the dry surface. The drying surface means a surface such as a wire net on which a target to be dried is placed in a dryer such as a ventilation dryer.

The temperature of the hot air is 30 to 60 ° C, preferably 30 to 50 ° C. When the temperature is lower than 30 ° C, the time required for drying is too long and the manufacturing cost is increased. If the temperature is higher than 60 ° C, a black-burnt portion and an undried portion are generated, and uniform drying cannot be performed. The wind speed of hot air is 0.1 to 5.0 m
/ S is preferred. If it is slower than 0.1 m / s, the time required for drying is too long and the manufacturing cost increases. 5.0 m / s
Earlier than this, the dried kale may be scattered by the hot air. A method of lowering the temperature of hot air may be adopted depending on the progress of drying.

Under these conditions, the drying is completed in about 1 to 10 hours, preferably 1 to 5 hours.

Further, in order to perform the drying efficiently, the drying
It is also one of the present invention to carry out in two steps. You
That is, first, dry surface 1m^Two5 pieces of shredded kale
~ 15 kg (converted to raw leaf weight) is placed in the dryer
With hot air of 30 to 60 ° C and air velocity of 0.1 to 5.0 m / s
Dry the water content of the shredded kale to 30-15%,
Obtain dry kale. The semi-dry case obtained in this way
1m of dry surface ^TwoThis semi-dry kale 5
Distributing 0 to 150 kg (converted to raw leaf weight) in the dryer
Placed at 30 to 60 ° C, hot air at a wind speed of 0.1 to 3.0 m / s
Dry the kale shredded in. Drying is from 0.5 to 5
Done between.

By thus drying in two stages,
The moisture management in the drying process becomes easy, and the drying is efficiently performed.

By this drying step, the shredded kale is dried to a water content of 10% or less, preferably 5% or less. By drying under the drying conditions of the present invention, the dried product retains the color and ingredients that it had in nature.

Crushing Step The dried fragment is, for example, crusher, mill,
It is pulverized by using a blender, a stone mill, etc., by a method commonly used by those skilled in the art. The powdered pulverized product is screened if necessary, and a powder of about 30 to 250 mesh is usually used as a food material. If the particle size is small, for example, handling is poor, while if the particle size is too large, for example, uniform mixing with other food materials is hindered.

The dry powder thus obtained is sterilized, if necessary, by a method commonly used by those skilled in the art, such as microwave treatment.

The obtained dry powder can be used as it is for food and drink, but it may be used as an excipient, a filler, a binder, a thickener,
It may be mixed with an emulsifier, a colorant, a flavor, a food additive, a seasoning, etc., and molded into a form such as granules or tablets depending on the application. Furthermore, it can be mixed with various foods and drinks and used for eating and drinking. For example, royal jelly, vitamins,
Protein, calcium, chitosan, lecithin, etc. are added, and sugar solution and seasonings are added to adjust the taste. If necessary, they are formed into capsules such as hard capsules and soft capsules, tablets or pills, or formed into powder, granules, teas, tea bags, or candy. Depending on their shape or taste, they may be eaten as they are, or may be dissolved in water, hot water, milk or the like and drunk. In the case of tea bags, the ingredients may be infused before drinking.

[0038]

EXAMPLES Examples will be described below to further clarify the characteristics of the present invention, but the present invention is not limited to these examples.

Example 1: Production of dried kale powder (hot water blanching) Approximately 100 kg of fresh leaves of kale were thoroughly washed with tap water and then cut into pieces of about 3 cm width by transverse cutting (circular slice).
Then, at about 95 ° C., the mixture was poured into hot water containing 0.75% sodium carbonate and 0.75% sodium chloride, and 3
Processed for a minute. Fragments treated with hot water are immediately 2-7 ℃
It was transferred to the cold water, and immersed in the water for about 5 minutes to be cooled. After cooling, the attached water was removed. This was placed in a hot air dryer having a drying surface of 10 m ² and dried by applying hot air of 1 m / s and 40 ° C. for 4 hours. The water content of the obtained dried fragment is 5
%Met. Next, the dried shredded material was crushed to produce a dry powder of kale. The dry powder of kale obtained retained a bright green color.

Example 2 100 kg of kale which had been cut into pieces and subjected to a blanching treatment in the same manner as in Example 1 was dried in the same dryer as in Example 1 for 50 kg.
Approximately 25% water content by applying 2m / s hot air for 1 hour at ℃
Dried up. This was repeated for 10 batches. 10 batches of semi-dried shredded product having a water content of about 25% (that is, 1000 kg of kale shredded product in terms of untreated raw leaf weight) were collected and further dried at 55 ° C. for 2 hours in the same dryer as in Example 1. , 2.5 m / s of hot air was applied to dry the product to a water content of 3%, and the product was pulverized in the same manner as in Example 1 to produce a dry powder of kale. The dry powder of kale obtained retained a bright green color.

Comparative Example 1 Comparative Example 1 was carried out in the same manner as in Example 1 except that the drying step was carried out at 80 ° C. for 2 hours by applying hot air of 1 m / s.
A dry powder of kale was obtained. The dried powder of kale obtained was dark brown.

Evaluation of dried kale powder Production method of the present invention (Examples 1 and 2) and Comparative Example 1
With respect to the dried powder of kale obtained in 1., 30 subjects evaluated the color and taste. Regarding the color, the bright green color of the kale as the raw material was set to be very good, and the impression observed by the naked eye of the subject was evaluated in 5 levels.
Regarding the evaluation of taste, the impression of taste when the subject actually drank was evaluated in 5 levels. The test was carried out by allowing a subject to drink green juice in which each dry powder was dissolved in water so as to be 3 g / 100 ml. The test results are shown in Table 1.

[0043]

[Table 1]

The results show that the kale dry powder obtained by the method of the present invention has an excellent color tone, and the evaluation of tastes such as flavor, bitterness, and sweetness, which greatly depend on individual tastes, is also overall. It shows that it was evaluated as good. There were many opinions that the green juice produced by the comparative method had a dark smell.

[0045]

According to the method of the present invention, in a short time, efficiently,
A dry powder of kale retaining a green color is obtained.

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Claims (2)

(57) [Claims] 1. The following steps: (a) a step of crushing the kale into a width of 1 to 5 cm; and (b) 5 to 15 k of crushed kale per 1 m ^{2 of the} dry surface.
g (converted to raw leaf weight before treatment) is placed in a dryer, and
A process for producing a dried powder of kale, which comprises a step of drying the kale fragmented with hot air having a wind speed of 0.1 to 5.0 m / s at 60 ° C. 2. The following steps: (a) a step of shredding the kale into a width of 1 to 5 cm; and (b1) 5 to 15 shredded kale per 1 m ^{2 of the} dried surface.
30 kg (converted to fresh leaf weight before treatment) is placed in the dryer,
A step of drying the water content of the kale diced with hot air having a wind speed of 0.1 to 5.0 m / s at -60 ° C to 30 to 15% to obtain a semi-dried kale; (b2) per 1 m ^{2 of} dry surface, ( b1)
50-150 kg of semi-dried kale (converted to untreated fresh leaf weight) obtained in Step 1 is placed in a dryer, and the kale cut into pieces is dried with hot air having a wind speed of 0.1 to 3.0 m / s at 30 to 60 ° C. A process for producing a dry powder of kale.