KR20220093800A - Manufacturing method of roasted peeled sweet potatoes of bite size distributable at room temperature - Google Patents

Abstract

The present invention provides a method for producing a bite-sized peeled sweet potato that can be distributed at room temperature. The method includes: a washing step of washing a raw sweet potato; a ripening step of ripening the sweet potato to promote saccharification of the sweet potato that has gone through the washing step; a cutting step of cooling, peeling and cutting the sweet potato saccharified through the ripening step; a blanching step of immersing and blanching the cut sweet potato through the peeling and cutting step in a citric acid solution and then dehydrating and cooling the same; a drying step of drying the sweet potato that has gone through the blanching step with a microwave; a packaging step of packing the sweet potato dried through the drying step by nitrogen-filling in a pouch; and a sterilization step of sterilizing and cooling the sweet potato packaged through the packaging step in a retort. According to the present invention, in contrast to the usual discoloration of peeled and cut sweet potato products, which are dark brown, the food of the present invention has the unique color, chewing texture, and tissue texture of a roasted sweet potato, and is peeled and cut into bite-sized pieces to be convenient to eat. In addition, the present invention has an effect of preventing discoloration and deterioration caused by microorganisms in a process of long-term distribution at room temperature by means of retort sterilization after nitrogen-filling. In addition, water separation or condensation does not occur during distribution at room temperature, and the surface of the sweet potato is smooth, so sugar or mucilage does not stick to a hand. Accordingly, the sweet potato can be eaten without discomfort.

Description

A method of manufacturing a bite-sized peeled roasted sweet potato that can be distributed at room temperature {Manufacturing method of roasted peeled sweet potatoes of bite size distributable at room temperature}

The present invention relates to a method for producing bite-sized peeled roasted sweet potatoes that can be distributed at room temperature, and more particularly, by washing sweet potatoes and then aging, cooling, peeling, cutting, blanching, drying, packaging, and sterilizing, taste and texture like roasted sweet potatoes It relates to a method for producing bite-sized peeled roasted sweet potatoes that can be cut and distributed at room temperature for convenient consumption, which can suppress discoloration and the growth of microorganisms in the long-term distribution process.

Sweet potato is an alkaline food that contains a lot of fiber and starch, and is well known as a health food beneficial to the human body.

In particular, sweet potatoes require less labor for cultivation and are highly economical because the yield per unit area is very large compared to threshing crops. It has been cultivated as an old yellow crop since ancient times because it adapts well to the harsh environment and grows quickly.

Sweet potatoes are very valuable as an energy source compared to other root vegetables such as potatoes, yam, and taro.

Sweet potatoes contain a large amount of carbohydrates, dietary fiber, vitamin C, vitamin B6, and beta-carotene, and are known to be effective in preventing dry eye syndrome and arteriosclerosis (Lim et al., 2019).

In general, it is common to eat sweet potatoes baked, steamed, or cooked in an oven or microwave at home. If raw sweet potato is stored frozen, the damaged part rots during the freezing process, which leads to poor storability. For this reason, there is an urgent need for a method that can distribute sweet potatoes for a long time while maintaining the taste and nutrition.

So, in the prior art, Korean Patent Registration No. 1642498 (July 19, 2016), Patent No. 1192703 (Oct. 12, 2012), and Patent Registration No. 2085111 (February 28, 2020) have been disclosed.

The prior art Korean Patent Registration No. 1642498 discloses a method of manufacturing dried sweet potato, which comprises: steaming sweet potatoes cut into a cylinder with a length of 8 to 15 mm at 100 to 125° C. for 10 to 60 minutes; A process of drying the steamed sweet potato obtained in the electric process until the moisture content is 30-35%; A process of baking the sweet potato obtained in the electric process at 180-220°C for 3-30 minutes until the moisture content becomes 25-30%; and heating and sterilizing the sweet potato obtained in the electric process at 100 to 120° C. for 20 to 40 minutes.

That is, it includes a process of cutting-steaming-drying-baking-heating sterilization and packaging of sweet potatoes. The above manufacturing method has the advantage that it can be distributed for a long period of time by sterilizing and sterilizing dried sweet potatoes after nitrogen packaging, but the moisture content is as low as 25-30%, so it has a texture close to that of a snack rather than that of a roasted sweet potato.

In addition, the apparatus and method for manufacturing roasted sweet potato products of Korean Patent Registration No. 1192703 relates to an apparatus and method for mass production of roasted sweet potato products. After washing the sweet potato, saccharification for 10 to 15 minutes at 50 to 120 ° C in a heating tunnel system; Preheating for 10 to 15 minutes at 120 ~ 180 ℃; Completing 20 to 40 minutes at 180 ~ 200 ℃; Evaporating water at 120 ~ 180 ℃ for 10 ~ 15 minutes; and a nitrogen-substituted packaging process and sterilization at 100-110°C for 25-35 minutes after the finishing step at 50-120° C. for 10-15 minutes.

That is, it is manufactured through the steps of screening, washing, heating tunnel system, packaging, and sterilization. The above manufacturing method has the advantage that roasted sweet potatoes can be eaten all year round by sterilizing and sterilizing after roasting raw sweet potatoes, but it is inconvenient for consumers to peel the skins of roasted sweet potatoes and eat them one by one, and it is not in a cut form. There is a disadvantage that it is inconvenient to eat because it cannot be eaten, and there is a disadvantage that the hand becomes dirty because the juice or the flesh on the skin gets on the hand when the skin is peeled.

In addition, as a method for manufacturing a roasted sweet potato from which the skin has been removed, the method of manufacturing nude ice roasted sweet potato of Republic of Korea Patent No. 2085111 includes a washing step of washing the sweet potato; Peeling step of removing the skin of the sweet potato after the washing step; A pre-treatment step of heating the sweet potato at 40-60° C. for 30-90 minutes after the peeling step; an outer film forming step of solidifying the surface of the sweet potato after the pretreatment step to form an outer film enclosing the inside; After the outer film forming step, the sweet potato is first baked at 180-200° C. for 30-50 minutes, then turned over, and secondly baked at 180-200° C. for 30-40 minutes; and a freezing step of rapidly cooling the sweet potato after the baking step.

That is, it includes washing-peeling-heating-outer film formation-baking-freezing processes. Although the skin of the sweet potato is removed, the manufacturing method has the inconvenience of having to thaw because it is frozen and distributed after baking, the disadvantages that the texture of the roasted sweet potato is not completely restored when thawing, and it is not in a cut form, so it cannot be eaten in one bite. It has the disadvantage of being uncomfortable to eat.

Republic of Korea Patent Registration No. 1642498 (2016.07.19.) Republic of Korea Patent No. 1192703 (2012.10.12.) Republic of Korea Patent No. 2085111 (2020.02.28.)

The object of the present invention is proposed to solve the problems in consideration of the existing problems. Even though it is cut and peeled to a size convenient for eating, it does not brown when stored for a long time at room temperature, and is distributed at room temperature without dew condensation due to evaporation of moisture. An object of the present invention is to provide a method for manufacturing peeled roasted sweet potatoes of bite-sized possible.

In accordance with an embodiment of the present invention for solving the above technical problem, there is provided a method for manufacturing peeled roasted sweet potato of a bite size that can be distributed at room temperature, a washing step of washing the raw sweet potato; A ripening step of ripening the sweet potato to promote saccharification of the sweet potato that has been subjected to the washing step; After cooling the sweet potato saccharified through the aging step, a cutting step of peeling and cutting; A blanching step of blanching the cut sweet potato through the peeling and cutting steps by immersing it in citric acid dissolved water, followed by dehydration and cooling; A drying step of drying the sweet potato that has undergone the blanching step in a microwave; A packaging step of packing the dried sweet potato through the drying step by filling a pouch with nitrogen; and a sterilization step of sterilizing and cooling the packaged sweet potato in a retort through the packaging step.

As another embodiment, the washing process of the washing step of the present invention, the first washing to remove the soil of the sweet potato; a second washing in which the first washed sweet potato is immersed in 40 ppm sodium chlorate solution for 1 to 2 minutes; It is characterized in that it consists of a tertiary washing of washing the secondary washed sweet potato with running water.

As another embodiment, in the aging process in the aging step of the present invention, the sweet potato is aged for 40 to 90 minutes in an oven preheated to 60° C. in order to promote saccharification of the sweet potato washed in the washing step of the washing step. do.

As another embodiment, the peeling and cutting process of the cutting step of the present invention is characterized in that the sweet potato taken out of the oven in the aging step of the aging step is cooled to 25 ℃.

As another embodiment, the sweet potato cooled out of the oven of the present invention is peeled and then the sweet potato is cut into a tetrahedral shape with a side length of 2 to 6 cm.

As another embodiment, in the blanching process of the blanching step of the present invention, the sweet potato cut in the cutting step is immersed in 0.05 to 0.2% citric acid dissolved water maintained at 100° C. for 3 to 10 minutes, blanched, and then dehydrated and cooled. do.

As another embodiment, in the drying process of the drying step of the present invention, when the moisture content reaches 46 to 54% through microwave drying of the dehydrated and cooled sweet potato after the blanching of the blanching step, the microwave drying of 0.5 to 3 W/g power It is characterized in that it is dried until

As another embodiment, the packaging process of the packaging step of the present invention is characterized in that the dried sweet potato in the drying step is filled with nitrogen so that 95% or more of the air in the pouch is replaced with nitrogen.

As another embodiment, in the sterilization step of the present invention, the pouch filled with nitrogen in the packaging step is sterilized in a retort at 121° C. for 30 minutes.

As another embodiment, the sweet potato sterilized in the retort of the present invention is cooled with cooling water of 10° C. for 15 to 25 minutes to cool the product temperature to 25° C. or less.

The method for producing peeled roasted sweet potatoes of a bite size that can be distributed at room temperature of the present invention has the same texture and texture as roasted sweet potatoes, but has the advantage of convenient eating because it is cut and peeled to a suitable size to eat.

The present invention prevents the problem of serious quality deterioration due to discoloration of sweet potatoes from being discolored to brown or blackish-brown due to enzymatic action when cutting during processing of sweet potatoes and by blanching treatment with citric acid dissolved water and nitrogen filling. This has the advantage of being able to manufacture high-quality peeled roasted sweet potatoes that maintain the original color of roasted sweet potatoes.

The present invention prevents excessive heat treatment in the blanching process, microwave drying process, and sterilization process because the cut sweet potato tetrahedron has a uniform size, and by subjecting it to a uniform heat treatment, a product having a high quality and uniform texture and texture can be supplied to consumers. there are advantages to

The present invention has the advantage that no water or dew condensation occurs even during long-term distribution at room temperature, and the sugar solution or mucilage does not stick to the hands of the roasted sweet potato, so consumers can eat it without discomfort.

1 is a flowchart of a method for manufacturing peeled roasted sweet potato of a bite size that can be distributed at room temperature according to the present invention.
2 is a photograph comparing the chromaticity of peeled and cut roasted sweet potatoes prepared by blanching with citric acid dissolved water and then packing with nitrogen.

Hereinafter, in order to fully understand the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings 1 and 2 . Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below.

Referring to Figure 1, the method for manufacturing peeled roasted sweet potato of a bite-size that can be distributed at room temperature according to an embodiment of the present invention includes a washing step (S1) of washing raw sweet potatoes; A ripening step (S2) of aging the sweet potato in an oven preheated to 60°C for 60 minutes to promote saccharification of the sweet potato that has undergone the washing step (S1); A cutting step (S3) of removing the sweet potato saccharified through the aging step (S2) and cooling it to 25°C, peeling and cutting; Blanching the cut sweet potato through the cutting step (S3) for 5 minutes by immersing it in 0.1% citric acid dissolved water maintained at 100° C. for 5 minutes, followed by dehydration and cooling (S4); A drying step (S5) of drying the sweet potato that has undergone the blanching step (S4) with a microwave until the moisture content reaches 50%; A packaging step (S6) of packing the dried sweet potato through the drying step (S5) by filling a pouch with nitrogen; and a sterilization step (S7) of sterilizing and cooling the packaged sweet potato through the packaging step (S6) at 121° C. for 30 minutes in a retort.

That is, in the washing process of the washing step (S1), after selecting a sweet potato in good condition, foreign substances such as soil attached to the surface are thoroughly washed with water.

In the aging process of the aging step (S2), the sweet potato is aged for 40 to 90 minutes in an oven preheated to 60° C. in order to promote saccharification of the sweet potato washed in the washing step of the washing step (S1), preferably 60 ripen for a minute This is because an enzyme called beta-amylase that promotes glycation of starch exists in sweet potatoes. The amount of this enzyme is abundant enough to account for about 5% of the soluble protein present in sweet potatoes, and the optimum temperature for enzyme action is known to be 55°C (Hesam et al., 2015).

Therefore, it is important to set the ripening temperature and time so that the enzyme reaction can be sufficiently performed after the temperature of the center of the sweet potato reaches the optimum temperature. If the temperature of the oven is too high, the enzyme is inactivated, so it is aged in an oven preheated to 60°C. At this time, if the aging time is too short, saccharification is not achieved sufficiently, and the sweet taste of the final product decreases. It becomes crumbly, and the product loses its value.

In the cutting step of the cutting step (S3), the sweet potato taken out of the oven in the aging step of the aging step (S2) is cooled to 25° C. and then the skin is removed. Cut the peeled sweet potato into a tetrahedral shape with a side length of 2 to 6 cm. Cutting the sweet potato into the above size promotes convenience when eating, and at the same time, the subsequent processes are blanching, dehydrating and cooling (S4), drying by microwave (S5), sterilizing by retort and cooling. By preventing excessive heat treatment in (S7) and subjecting it to uniform heat treatment, it is possible to manufacture a product having a high quality and uniform texture and texture.

In particular, in the drying step (S5) of drying by microwaves, the distance from the surface of the tetrahedron to the geometric center is the penetration distance of microwaves (referring to the depth at which the power of microwaves on the surface of food is reduced to a level of 37%, In the case of sweet potato, it is known to be about 1.5 to 3 cm), so that uniform heating by microwaves is achieved by shortening it to the level. The shape at the time of cutting is not limited to a tetrahedron, and various shapes such as a hexahedron and a cylinder are possible.

In the blanching process of the blanching step (S4), the sweet potato cut in the cutting step (S3) is immersed in 0.05 to 0.2% citric acid dissolved water maintained at 100° C. for 3 to 10 minutes and then dehydrated and cooled, preferably 0.1 Blanch it by immersing it in % citric acid solution for 5 minutes. Phenolic compounds present in plants, including sweet potatoes, are oxidized to form brown substances, and the enzyme that promotes this reaction is polyphenol oxidase. Because phenolic compounds exist in intracellular vacuoles and polyphenoloxidases exist in intracellular plastids, brown matter is not formed under normal conditions (Toivonen and Brummell, 2008).

However, when the cells of sweet potato are damaged by cutting during processing, these substances are mixed with each other, and a reaction in which a phenolic compound is combined with oxygen to form a browning substance is initiated, which is promoted by polyphenol oxidase. Citric acid interferes with the browning reaction caused by polyphenol oxidase, and polyphenol oxidase is destroyed by heat and loses its function. At this time, if the blanching time is too short, the penetration of citric acid from the surface of the sweet potato is not sufficient and the destruction of polyphenol oxidase is not sufficient, so browning occurs. Conversely, if the blanching time is too long, water-soluble substances are leached from the sweet potato, which reduces the yield, deteriorates the texture of the final product, and may transfer acidity from citric acid to sweet potato. It is also possible to use vitamin C as an antioxidant instead of citric acid.

In the drying process of the drying step (S5), the dehydrated and cooled sweet potato after blanching in the blanching step (S4) is dried through microwave drying until the moisture content reaches 46 to 54%. At this time, the power of the microwave is maintained at 0.5 to 3 W/g relative to the weight of the sweet potato, preferably 1 W/g. If the power is too low, drying takes a long time, and if the power is too high, the product may be damaged due to partial overheating. If the final moisture content of the sweet potato after drying in this step is too high, there is a problem in that the water vapor evaporated from the sweet potato in the later retort sterilization process is condensed in the pouch. Conversely, if the final moisture content is too low due to excessive drying, the product is partially burned due to local overheating, resulting in loss of quality. Preferably, it is dried until the moisture content is 50%. The drying process is not limited to drying by microwaves, and freeze drying, vacuum drying, hot air drying, infrared drying, etc. may be used.

In the packaging process of the packaging step (S6), the dried sweet potato is packed with nitrogen so that 95% or more of the air in the pouch is replaced with nitrogen. In this case, a heat-resistant film pouch for retort sterilization may be used as the packaging container, and oxygen in the air is removed due to nitrogen substitution, and thus the effect of suppressing the browning reaction in the distribution process after packaging can be expected.

In the sterilization process of the sterilization step (S7), the pouch filled with nitrogen in the packaging step (S6) was sterilized in a retort at 121°C for 30 minutes and then cooled with 10°C cooling water for 15 to 25 minutes to increase the product temperature to 25 Cool to below ℃.

At this time, the heat treatment in the retort has the advantage of extending the shelf life by promoting the gelatinization and saccharification of sweet potatoes and at the same time imparting a bactericidal effect to microorganisms.

The temperature of the retort is not limited to 121°C, and the heat treatment time may vary depending on the temperature. If the sterilization temperature is higher than 121°C (for example, 125°C), the heat treatment time is shortened (15 minutes), but since the vapor pressure increases, the amount of evaporation from the sweet potato to water vapor increases. deepens On the other hand, if the sterilization temperature is lowered (eg, 115° C.), the generation of condensed water is reduced, but the heat treatment time is long (60 minutes).

As a result of measuring the browning prevention effect by nitrogen-filled packaging of peeled and cut roasted sweet potatoes manufactured through the blanching step (S4), as shown in FIG. .

In other words, when comparing the color of roasted sweet potatoes blanched at 100°C with 0.1% citric acid dissolved water, packed with nitrogen and retort-sterilized, and roasted sweet potatoes (control) sterilized without blanching and nitrogen filling at 50°C for 1 month, the color of citric acid In the case of the nitrogen-filled product after blanching with dissolved water, there was no change in color, but it was observed that the color of the control product was browned.

On the other hand, the present invention is not limited to the above-described embodiments, but can be implemented with modifications and variations without departing from the gist of the present invention, and the technical idea to which such modifications and variations are applied also falls within the scope of the following claims. have to see

Claims (10)

A washing step of washing the raw sweet potato;
A ripening step of ripening the sweet potato to promote saccharification of the sweet potato that has undergone the washing step;
After cooling the sweet potato saccharified through the aging step, a cutting step of peeling and cutting;
Blanching the cut sweet potatoes through the peeling and cutting steps by immersing them in citric acid dissolved water, followed by dehydration and cooling;
A drying step of drying the sweet potato that has undergone the blanching step in a microwave;
A packaging step of packing the dried sweet potato through the drying step by filling a pouch with nitrogen; and
A sterilization step of sterilizing and cooling the packaged sweet potato in a retort through the packaging step; The method according to claim 1,
The washing process of the washing step is,
First washing to remove the soil of the sweet potato;
a second washing in which the first washed sweet potato is immersed in 40 ppm sodium chlorate solution for 1 to 2 minutes;
A method for manufacturing peeled roasted sweet potatoes of a bite-size that can be distributed at room temperature, characterized in that it consists of; tertiary washing of washing the secondary washed sweet potatoes with running water. The method according to claim 1,
In the aging process in the ripening step, the sweet potato is aged in an oven preheated to 60° C. for 40 to 90 minutes in order to promote saccharification of the sweet potato washed in the washing step of the washing step. A method for producing peeled roasted sweet potatoes. The method according to claim 1,
The peeling and cutting process of the cutting step is a method for producing a bite-sized peeled roasted sweet potato that can be distributed at room temperature, characterized in that the sweet potato taken out from the oven in the aging step of the aging step is cooled to 25°C. 5. The method according to claim 4,
A method of manufacturing a bite-sized peeled roasted sweet potato that can be distributed at room temperature, characterized in that the sweet potato cooled after taking out from the oven is peeled and cut into a tetrahedral shape with a side length of 2 to 6 cm. The method according to claim 1,
The blanching process of the blanching step is characterized in that the sweet potato cut in the cutting step is immersed in 0.05 to 0.2% citric acid dissolved water maintained at 100° C. for 3 to 10 minutes and then dehydrated and cooled. A method for producing peeled roasted sweet potatoes. The method according to claim 1,
The drying process of the drying step is characterized in that the dehydrated and cooled sweet potato after blanching in the blanching step is dried until the moisture content reaches 46 to 54% through microwave drying of 0.5 to 3 W/g power. A method for manufacturing peeled roasted sweet potatoes in bite-sized sizes that can be distributed at room temperature. The method according to claim 1,
The packaging process of the packaging step is a method for producing a bite-sized peeled roasted sweet potato that can be distributed at room temperature, characterized in that the dried sweet potato in the drying step is filled with nitrogen so that 95% or more of the air in the pouch is replaced with nitrogen. The method according to claim 1,
The sterilization process of the sterilization step is a method for producing a bite-size peeled roasted sweet potato that can be distributed at room temperature, characterized in that the pouch filled with nitrogen in the packaging step is sterilized at 121° C. for 30 minutes in a retort. 10. The method of claim 9,
The sweet potato sterilized in the retort is cooled with cooling water of 10°C for 15 to 25 minutes to cool the product temperature to 25°C or less.

Images