KR102224942B1 - Manufacturing method of roast sweet potato - Google Patents

Abstract

The present invention is to provide a roasted sweet potato manufacturing method capable of maintaining the taste, aroma, and texture as if the raw sweet potato was baked just before by minimizing the moisture oozing out of the sweet potato during defrosting for ingestion. The present invention for this purpose is a pretreatment step of washing and drying sweet potatoes; A heating step of heating the pretreated sweet potato to produce a baked sweet potato; A quick freezing step of freezing the heated roasted sweet potatoes at a temperature of -35 to -45°C for 20 to 40 minutes; And a vacuum packaging step of vacuum packaging the quick-frozen baked sweet potato.

Description

Roasted sweet potato manufacturing method {MANUFACTURING METHOD OF ROAST SWEET POTATO}

The present invention relates to a method for producing a baked sweet potato, and more particularly, to a method for producing a baked sweet potato capable of maintaining the taste, aroma, and texture of the sweet potato as it is after thawing.

Sweet potato is a dicotyledonous edible crop belonging to the convolvulaceae family, originating in Central and South America, and was first introduced to Korea in 1796 and has been used as a food resource for a long time. Compared to other crops, it is less affected by the cultivation environment, is easy to cultivate, and has a yield per unit area. Many are widely cultivated throughout Korea.

These sweet potatoes are foods with a lot of carbohydrates and can be replaced with staple foods. They are rich in fiber, vitamin C, vitamin E, potassium, thiamine, and iron, and beta-carotene and ganglioside components have anticancer activity. It is also known to help lower the incidence of lung cancer by doing so. In particular, it is well-known as one of the well-being health foods along with its effectiveness in preventing diet and constipation, and its consumption is actively made in all age groups of men and women of all ages.

Sweet potatoes have the disadvantage of being sensitive to temperature because they are vulnerable to cold, and also, because they are weak to humidity and light, there is a difficulty in storing them in a well-ventilated shade at a temperature of 12 to 15°C. In addition, the conventional method of ingesting sweet potatoes is limited to raw, steamed and roasted sweet potatoes depending on the cooking type. Due to the limitations of the harvest period of the raw sweet potatoes from July to November and the storage period from October to March. There is a problem that it cannot be easily eaten except at this time.

For this reason, sweet potatoes were recognized as a food eaten only in winter. However, as described above, as various physiological effects of sweet potatoes are recently known and recognized as a weight control and health functional food, efforts have been made to develop a storage method and a processing method for sweet potatoes.

As one of the methods for producing roasted sweet potatoes, methods of rapidly cooling and freezing sweet potatoes after roasting have been recently developed, but these must be kept frozen for distribution and must be defrosted when ingested. The moisture oozes out and the quality of the appearance is degraded, such as the roasted sweet potato being crushed, and you can feel rejection due to the sense of foreign body in the process of ingestion, and the taste, texture, and nutritional status of the roasted sweet potato due to the moisture oozing out during the defrosting process. A problem of deterioration occurs.

Korean Registered Patent Publication No. 10-1548204 (Announcement on August 31, 2015)

An object of the present invention is to solve the conventional problems, the present invention is to minimize the moisture oozing out of the inside of the sweet potato when defrosting for consumption, and maintain the taste, aroma, and texture as if the raw sweet potato was baked just before. To provide a method for producing roasted sweet potatoes that can be.

In order to achieve the object of the present invention described above, the method for producing a roasted sweet potato according to the present invention includes a pretreatment step of washing and drying the sweet potato; A heating step of heating the sweet potato that has undergone the pretreatment step to produce a baked sweet potato; Quick freezing step of rapidly freezing the roasted sweet potato that has undergone the heating step for 20 to 40 minutes at a temperature of -45 to -35°C; And a vacuum packaging step of vacuum packaging the roasted sweet potato that has undergone the metal freezing step.

At this time, in the roasted sweet potato manufacturing method according to the present invention, in the heating step, the sweet potato may be prepared by heating the sweet potato at a temperature of 240 to 260° C. for 30 to 50 minutes.

In addition, in the roasted sweet potato manufacturing method according to the present invention, the processing step of cutting the roasted sweet potato in half in the thickness direction and inserting an additive into the inner space of the cut roasted sweet potato is further performed after the heating step. Can include.

In addition, in the roasted sweet potato manufacturing method according to the present invention, the pretreatment step includes: a selection step of selecting sweet potatoes within a predetermined size range; A curing step of curing the sweet potatoes that have undergone the selection step for 4 to 7 days while maintaining 85 to 100% relative humidity at a temperature of 28 to 32°C; A washing step of washing the sweet potatoes that have undergone the curing step; A drying step of drying the sweet potato that has been subjected to the washing step; And it may include a aging step of aging the sweet potatoes subjected to the drying step for 30 days at a temperature of 14 to 16 ℃.

The roasted sweet potato manufacturing method according to the present invention minimizes the bleeding of moisture generated during thawing and the amount thereof, thereby solving the problem that the thawed roasted sweet potato is sore or that the flesh and the skin are not separated well. The taste, aroma, and texture of sweet potatoes can be provided to consumers as if they were baked just before.

In addition, the roasted sweet potato manufacturing method according to the present invention can also improve long-term storage, so that the shelf life can be extended, and there is also an advantage of minimizing the change in quality even when stored for a long time.

1 is a flowchart of a method of manufacturing a baked sweet potato according to an embodiment of the present invention.
2 is a flowchart of a pre-processing step according to an embodiment of the present invention.
3 is a view showing a baked sweet potato manufactured according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention in which the above-described problem to be solved may be specifically realized will be described with reference to the accompanying drawings. In describing the present embodiments, the same names and the same reference numerals are used for the same components, and additional descriptions thereof will be omitted.

1 is a flowchart showing a method of manufacturing a roasted sweet potato according to an embodiment of the present invention, and FIG. 2 is a flow chart showing a pretreatment step according to an embodiment of the present invention.

The roasted sweet potato manufacturing method according to the present invention may include a pretreatment step (S10), a heating step (S20), a processing step (S30), a quick freezing step (S40), and a vacuum packaging step (S50).

The pretreatment step (S10) is a step of primarily treating the raw sweet potatoes harvested previously in the heating step (S20) of baking the harvested sweet potatoes into roasted sweet potatoes according to the purpose of use, and the pretreatment step (S10) according to the embodiment It may include a sorting step (S11), a curing step (S12), a washing step (S13), a drying step (S14), and a aging step (S15).

The selection step (S11) is a step of selecting the best raw sweet potatoes by condition and size for the harvested raw sweet potatoes, and may select sweet potatoes with poor quality such as appearance or select sweet potatoes within a predetermined size range with commercial availability.

For example, sweet potatoes of poor quality are not only decayed sweet potatoes, but also crushed or sprouted sweet potatoes, and sweet potatoes that are found in large quantities inside, such as tough tree trunks due to slow growth due to drought or harvested too late. Falling sweet potatoes are selected.

In addition, the predetermined size range is selected to selectively select the size of the sweet potato within the range of 3 to 10 cm, depending on the usage for children's meals, youth meals, and general home use. Sweet potatoes having a size of 3 cm or less or 10 cm or more may cause problems in that the quality of roasted sweet potatoes, such as burning or undercooked, may be deteriorated in the heating and rapid freezing steps described later.

The curing step (S12) is a step of providing a condition for the sweet potatoes to breathe in order to heal the wounds of the sweet potatoes that have occurred during the harvesting process for sweet potatoes having product value through the selection step (S11).

Curing is the original meaning of treatment. It improves storage by treating the wounds of sweet potatoes during harvesting or transporting sweet potatoes. : It is treated by the formation of a new skin on the trauma. That is, the secondary peroderm formed just under the wounded epidermis of the sweet potato develops into a new epidermal tissue and forms a cork layer to heal the wound. The cured sweet potato can suppress the weight loss rate and the occurrence of mold and sores during long-term storage.

Curing conditions according to the embodiment are suitable to be carried out for 4 to 7 days while maintaining 90 to 100% relative humidity at a temperature of 28 to 32 ℃. Such curing conditions can adjust the relative humidity and time according to the size, type (pumpkin sweet potato, golden sweet potato, etc.) of the selected sweet potato, and the temperature at the time of harvest.

Sweet potatoes cured for 4 to 7 days under conditions of 28 to 32°C temperature and 90 to 100% relative humidity as described above can suppress the weight reduction rate by about 30% and keep the skin color of the sweet potato bright, The incidence of mold and sores can be suppressed more than 10 times.

The washing step (S13) is a step of removing foreign substances such as soil from the skin of the sweet potato that has been cured through the curing step (S12). Or it can be done by sprinkling.

The drying step (S14) is a step of drying the sweet potatoes washed through the washing step (S13), which can be naturally dried at room temperature in a shade with good ventilation, and forced in a warehouse maintained at a constant temperature using a separate ventilator. It can also be dried.

The aging step (S15) is a step of aging the dried sweet potato through the drying step (S14) for a predetermined time at a temperature close to room temperature, for reference, after ripening of mango, avocado, banana, melon, pile apple, kiwi, etc. Like fruits, sweet potatoes can form the best color and taste quality by going through a predetermined aging period at room temperature rather than refrigerating after harvesting.

The aging conditions according to the embodiment are recommended to be aged for 30 days in a shady warehouse maintained at 15°C.

For example, in the season when the temperature is higher than 15℃, the maturation period of 30 days can be maintained in a low-temperature warehouse maintained at 15℃, and in certain seasons when the temperature close to 15℃, which is the time of harvesting sweet potatoes, is maintained, 15℃ is maintained. It can be naturally aged for 30 days in a well-ventilated shade.

Unlike these aging conditions, if sweet potatoes are stored for a long time at a temperature of 15° C. or lower, ethanol and acetaldehyde components increase inside the sweet potatoes, destroying the cell walls inside the sweet potatoes, causing them to be easily decayed.

The heating step (S20) is a step of heating the sweet potato matured through the aging step (S15) to produce a baked sweet potato, and the heating condition according to the embodiment may be performed at a temperature of 240 to 260°C for 30 to 50 minutes.

The heating conditions for 30 to 50 minutes at a temperature of 240 to 260° C. may be adjusted within the above range according to the size of the sweet potato, and at this time, in the case of a sweet potato selected in a size of 3 to 5 cm, at a temperature of 250° C. for 40 minutes It can be cooked deep inside by heating it while it is being heated.

If the heating temperature is less than 240°C, it takes more than 50 minutes to cook to the inner depth, and as the internal temperature of the sweet potato gradually increases over a long period of time, cells and cell walls exposed to high temperatures for a long time are destroyed, resulting in a large amount of The internal liquid of is discharged and evaporated. Eventually, after going through the freezing process described later, when thawing for ingestion, a large amount of water was discharged from the destroyed cells and tissues, resulting in deterioration of the taste and nutrition of the roasted sweet potato.

In addition, when the heating temperature exceeds 260° C., the skin part burns excessively before the sweet potato is fully cooked to the inner depth of the sweet potato, resulting in deterioration of the taste and quality of the roasted sweet potato.

Eventually, baked sweet potatoes produced while passing through heating conditions at a temperature of at least 240 to 260°C for 30 to 50 minutes are heated with high-temperature heat in a relatively short period of time to destroy cells and cell walls, thereby hardening the cell tissues before water evaporates. As a result, the moisture retained by the cellular tissue is maintained as it is. Eventually, after passing through the freezing process described later, when thawing for consumption, the taste, texture, aroma, and nutritional status of a baked sweet potato such as a raw sweet potato as if baked immediately before can be improved.

The apparatus for heating includes a heater, and a heating member may be further provided so that the heat source of the heater is effectively transmitted to the sweet potato and supports the sweet potato being heated.

The heater may be an electric heater or a heater using wood or charcoal as a heating source, and the heating member may be a member having excellent thermal conductivity such as a grill, wire mesh, plate-shaped elvan stone, or ceramic. Eventually, as the heater is heated, the heating member is also heated, and the sweet potatoes are arranged on the heating member, so that the whole sweet potato can be uniformly heated and cooked. In addition, even if you do not keep the heat in the heater continuously, you can learn it efficiently because it keeps the heat it has.

The processing step (S30) is a step of increasing the taste quality of roasted sweet potatoes and adding a separate additive in consideration of the taste of the consumer, and this processing step (S30) includes a cutting processing step (S30) and a part inserting step can do.

The cutting and processing step (S30) is a step of forming an inner space by cutting the made roasted sweet potato in half in the thickness direction, and the whole can be cut in the length direction of the roasted sweet potato, and only the central part is cut to reduce the inner space. Can be formed.

The additive inserting step is a step by inserting an additive into the inner space of the roasted sweet potato cut through the cutting and processing step (S30), and the additives are baked sweet potatoes such as cheese, butter, mustard, various sauces, and seasoning. It can be a ready-to-eat food that can be consumed with it. These additives can increase the taste when consumed with roasted sweet potatoes, and any additives capable of maintaining a frozen state for a long time can be used. However, an additive having a defrosting condition similar to that of defrosting baked sweet potatoes for consumption by consumers (within a microwave oven with a power consumption of 1000W) is preferable.

This processing step (S30) is preferably performed before the temperature of the roasted sweet potato that has been subjected to the heating step (S20) previously performed falls below a certain temperature, preferably cutting processing and inserting additives before falling below the 80°C temperature. It is good that the process is completed.

For example, the temperature of the hot roasted sweet potato begins to cool slowly at room temperature, and if it falls below 80℃, the internal liquid remaining inside the roasted sweet potato begins to ooze out. If the quick-freezing process described later is performed, the roasted sweet potato is sore when defrosted for subsequent consumption, the peeling of the flesh and the skin is not easy, and the original taste is also degraded.

The rapid freezing step (S40) is a step of rapidly freezing the roasted sweet potato that has been subjected to the processing step (S30), and the rapid freezing conditions according to the embodiment are 20 to 40 at a temperature of -45 to -35°C using a rapid cooling air. Can be quick frozen for minutes.

The conditions of rapid freezing for 20 to 40 minutes at the temperature of -45 to -35°C can be adjusted within the above range according to the size of the roasted sweet potato, and in the case of sweet potatoes selected in the size of 3 to 5 cm, the temperature is -40°C. Quick freezing for 30 minutes is preferable at.

Depending on the size of the sweet potato, sweet potatoes selected within the range of 3 to 10 cm can be completely frozen within 20 to 40 minutes at -45 to -35°C temperature conditions.

In addition, quick freezing is possible even at temperatures lower than -45°C, but the time taken until the sweet potato is completely frozen is not much different from the quick freezing process at -40°C, and a lot of power consumption is caused compared to the effect.

On the other hand, when quick freezing is performed at a temperature higher than -35°C, that is, the conventional freezing process performs gentle freezing at a temperature of -35 to -25°C. Such slow freezing is different for foods with low moisture. However, in the case of foods that have a lot of moisture, such as baked sweet potatoes, the moisture remaining inside the cell tissue when frozen makes ice crystals in the cell tissue, and the volume increases as the moisture freezes, destroying the cell wall or destroying the cell wall. It will make ice crystals.

In this way, ice crystals formed between the cells and the cells cause a wound on the cell wall surrounding the cells, and when thawing, a drip occurs in the wounded cell tissue, which results in the taste and quality of the product, It results in poor nutrition as well as color and shape.

In addition, even when the sweet potato containing moisture is frozen, the moisture evaporates and becomes water vapor, the temperature of the water vapor decreases, causing frost in the food, and the frozen sweet potato generates a large amount of moisture during subsequent thawing, making it easier to crush. Deterioration of quality is caused, such as the inability to peel off the skin and skin.

In addition, when the baked sweet potato is freeze-dried and the surface becomes porous, the connection space with the air increases, causing problems such as oxidation of fat, denaturation of protein, discoloration, and deterioration of taste and aroma.

Eventually, the baked sweet potato that is rapidly frozen for 20 to 40 minutes at the temperature of -45 to -35°C according to the embodiment is rapidly frozen through the temperature band of the maximum ice crystal generation zone (-1°C to -5°C). By performing, the cell and cell wall are prevented from being destroyed, and the moisture retained by the cell tissue during the freezing process is maintained as it is, so that when thawing for ingestion, it is not crushed, and the peeling of the skin from the inside can be performed uniformly throughout. , As it can reduce the amount of dripping water generated during thawing, it can provide the taste, texture, and aroma of baked sweet potatoes as if they were baked just before frozen sweet potatoes.

The vacuum packaging step (S50) is a step of vacuum-packing the fast-frozen baked sweet potatoes through the rapid freezing step (S40).By vacuum packaging, the baked sweet potatoes containing additives are prevented from coming into contact with oxygen and By blocking it, quality maintenance and corruption can be prevented. For example, as shown in FIG. 3, in the packaging step, individual or a plurality of roasted sweet potatoes may be vacuum-packed with a vacuum pack or wrap.

After the vacuum packaging step (S50) is performed, a freezing storage step may be further included. The second freezing step according to the embodiment may be stored in a freezer maintaining a temperature of -30 to -20°C for baked sweet potatoes including vacuum-packed additives. The expiration date of baked sweet potatoes can be further extended by continuously maintaining the frozen storage stage for these quick-frozen baked sweet potatoes.

In this way, baked sweet potatoes stored in a freezer maintained at a temperature of -30 to -20°C can be shipped in accordance with the request for shipment from the client.

Experimental Examples 1 to 4 below are comparative examples of roasted sweet potatoes prepared according to the examples of the present invention, and prepared roasted sweet potatoes by different heating conditions for producing roasted sweet potatoes and freezing conditions of the prepared roasted sweet potatoes, and thus Comprehensive results such as appearance, taste, texture, peeling and palatability of the prepared roasted sweet potatoes are shown in [Table. 1].

<Example 1>

Selecting step (S11): Selecting fresh sweet potatoes of 3 to 5 cm in size.

Curing step (S12): Curing treatment for 5 days at 100% relative humidity at 30°C.

Washing step (S13) and drying step (S14): After washing, dry naturally.

Aging step (S15): aged for 30 days in a low temperature warehouse at 15℃.

Heating step (S20): arranging the aged sweet potatoes on a grill and heating them at 250°C for 40 minutes using an electric heater to prepare baked sweet potatoes.

Quick freezing step (S40): Rapid freezing proceeds at -40℃ for 30 minutes.

<Example 2>

Prepared in the same manner as in Example 1, but prepared by arranging the sweet potatoes matured in the heating step (S20) on a grill and heating them at 180° C. for 50 minutes using an electric heater.

<Example 3>

Prepared in the same manner as in Example 1, but in the quick freezing step (S40), freezing proceeds for 60 minutes at a temperature of -25 degrees Celsius.

<Example 4>

Prepared in the same manner as in Example 1, but arranging the sweet potatoes aged in the heating step (S20) on a grill and heating them at 180° C. for 50 minutes using an electric heater to prepare baked sweet potatoes, and the quick freezing step (S40 ) At -25 degrees Celsius for 60 minutes.

division Exterior flavor Texture Peeling Preference Example 1 9 9 8 8 8 Example 2 8 7 7 7 8 Example 3 9 7 7 6 7 Example 4 7 6 6 5 6

[Table. 1] was written based on the opinions after tasting of 30 tasting groups randomly selected from men and women of all ages who sampled the roasted sweet potatoes prepared in Examples 1 to 4, and within the range of the lowest score of 1 to the highest score of 10 Was written.

In addition, in Examples 1 to 4, all of the roasted sweet potatoes that had undergone a frozen storage process for 10 days in a low temperature warehouse at 18° C. were thawed and then tasted.

First, when comparing Example 1 and Example 2, the difference in temperature during heating can be seen to have subtle differences in appearance, texture, peeling, and preference, and in particular, it can be seen that it affects the difference in taste. In addition, considering the fact that the age group of the tasting group is not considered, it can be seen that only minor differences in appearance, texture, peeling and preference can be considered to have an effect.

In addition, when comparing Example 1 and Example 3, it was confirmed that the temperature difference during rapid freezing did not show any difference in the appearance, but the taste, texture, peeling and taste were also significantly different overall.

In addition, when comparing Example 1 and Example 4, when the temperatures during heating and rapid freezing were all set differently, remarkable differences were found as a whole in appearance, taste, texture, peeling and taste.

As described above, preferred embodiments of the present invention have been described with reference to the drawings, but those skilled in the art will variously modify the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. Can be modified or changed.

Claims (4)

Select sweet potatoes 3cm to 5cm in size, curing the selected sweet potatoes at 30°C at 100% relative humidity for 5 days, washing the cured sweet potatoes, and naturally drying the washed sweet potatoes And, a pre-treatment step of aging the dried sweet potatoes in a low-temperature warehouse at a temperature of 15 ℃ for 30 days;
A heating step of heating the sweet potato that has undergone the pretreatment step at 250° C. for 40 minutes to produce a baked sweet potato;
A processing step of performing the heating step before the temperature of the roasted sweet potato falls below 80°C, cutting the roasted sweet potato in a thickness direction, and inserting an additive into the inner space of the cut roasted sweet potato;
A quick freezing step of rapidly freezing the roasted sweet potato that has undergone the processing step at -40°C for 30 minutes; And
A method for producing baked sweet potatoes comprising: a vacuum packaging step of vacuum-packing the baked sweet potatoes that have undergone the quick freezing step. delete delete delete

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