KR101877959B1 - A method of drying tomato by using super heated steam - Google Patents

Abstract

The present invention relates to a tomato drying method using super-heated steam. The tomato drying method is as follows: peeling tomatoes; using steam having 230 to 260°C in a heater at 160 to 200°C to dry the tomatoes during 20 to 30 minutes by means of super-heated steam; and hot air drying the tomatoes during 1 to 2 hours at 70-95°C. The tomato drying method using super-heated steam and hot air drying technology of the present invention reduces moisture content of tomatoes to increase storage properties, minimizes a shape change and losses of nutrition, and can quickly restore to an original shape when water is added in a porous state.

Description

 [0001] The present invention relates to a method for drying tomatoes using superheated steam,

This study is the result of the research carried out by the Ministry of Food, Agriculture, Forestry and Livestock (Administration Department: Agriculture and Food Technology Planning and Evaluation Institute).

The present invention relates to a method of drying a tomato using super heated steam, more specifically, by drying a tomato using superheated steam and hot air drying to extend the shelf life of a tomato processed product, And a method of drying a tomato which can quickly restore to a circular shape when water is added in a porous state.

Tomatoes (Lycopersiconesculeulentum Mill.) Is a perennial plant belonging to the genus Thunbergiella. It is a vegetable known as the best food of the 21st century by American Times. It is a vegetable that must be eaten for health and longevity.

The tomato contains a large amount of lycopene ingredient. The lycopene ingredient inhibits active oxygen, which is the cause of aging, and has a strong anticancer effect. Especially, it is excellent for breast cancer, prostate cancer, digestive system cancer prevention It is effective. In addition, it is rich in vitamin C, so you can take all the daily necessities even if you eat only two times a day. It is rich in vitamin E that promotes hormone production in the body, and it is rich in glutamic acid which is good for fatigue recovery. It also has the effect of preventing the cardiovascular disease, reducing the cholesterol level and strengthening the capillary blood vessels by containing the rutin which is effective for the treatment of hypertension.

These tomatoes are consumed in a natural state such as raw tomatoes or tomato juices, or in the form of processed foods such as tomato ketchup and tomato sauce, but a variety of processed foods must be developed.

On the other hand, food drying technology is one of the longest history of food processing technology, but it is still a technology that continues to require new technology development. The most important factors in the application of drying technology are 'economics' and 'quality implementation', which are conflicting with each other. Efforts are being made to secure the best technology to satisfy the two attributes.

Various types of drying techniques such as natural drying, hot air drying, cold air drying, vacuum drying, and freeze drying are known as drying methods of basic agricultural and marine products. These techniques are classified into convection, conduction, .

Natural drying is a method of drying without the use of an artificial heat source in the open air, and is applied to a case where a small amount of agricultural products are dried. However, there is a problem that it is difficult to control the quality with a great influence on the climate.

Hot-air drying is the most common type of drying method used in many farms due to the artificial high-temperature heat drying by the drying facility. However, large-scale drying facilities are being introduced at local bases due to the economic advantages of the facilities. However, Surface hardening, browning, shrinkage, and the like. Currently, over 70% of convection-type hot-air dryers using energy-consuming and high-quality convection-type hot-air dryers are being used.

The cold air drying method is a method of removing moisture of the dried material by using the dehumidified cold air, and it has an advantage that the taste, aroma, and quality that are difficult to realize in the hot air drying can be realized. Cold air drying is applied to drying pepper, dried persimmon, jerky, and Chinese medicines, but it has a limit of productivity that requires a long drying period due to low drying temperature.

Vacuum drying and freeze drying using pressure are applied to heat-sensitive products for higher production efficiency and higher quality. Vacuum drying and freeze drying can provide a dried material having excellent quality in terms of color, flavor and stability, but it is limited in wide industrial application due to high facility and production cost.

The drying method using microwave is also known as an efficient drying technique using radiant heat, but due to the permeation / reflection characteristic of the microwave, uniform drying is difficult and the drying quality is difficult to predict, which positively does not apply to the industry.

Drying technology is difficult to uniformly optimize the drying method to achieve high efficiency and high quality because the drying condition varies depending on the characteristics of each product and the product target. In addition, since the drying heating equipment is complexly linked with the front and back processes, there are many problems that can cause many variables. Therefore, it is essential to establish a complex process that maximizes the drying efficiency and optimizes the quality.

Super heated steam refers to steam which has been heated to a saturation temperature or higher by heating the dry saturated steam to its saturated pressure. Specifically, when the liquid is heated under a certain pressure, the temperature rises, and when it reaches a certain temperature, the liquid starts to evaporate. In this case, the temperature does not change until the whole is evaporated even if it is heated again, and the liquid and vapor coexist. This is referred to as wet saturated steam (steam saturated steam), and all of which has become steam, is referred to as dry saturated steam. When the dry saturated steam is heated again, the temperature of the steam rises, which is called superheated steam.

Unlike conventional heat treatment methods, the drying method using superheated steam minimizes destruction of nutritional components of fruit and vegetables, and can rapidly cook or process various food materials such as various kinds of cereals, aquatic products or meat with high quality.

Accordingly, the present inventors have conducted studies to develop a tomato drying method capable of increasing the shelf life of a tomato, minimizing loss of shape and nutritive value, and restoring it to a circular shape at the time of syringe, The present invention has been accomplished by finding that it is possible to reduce the moisture content of the water-in-oil emulsion, thereby increasing the storage stability, minimizing the loss of shape and nutritive value,

The present invention provides a tomato drying method capable of increasing the shelf life of tomatoes, minimizing the loss of shape and nutritive value, and restoring it to a round shape upon hydrolysis.

In order to solve the above technical problem, in the present invention, after removing tomato, it is dried in superheated steam at 230 to 260 ° C for 20 to 30 minutes in a heater at 160 to 200 ° C, Lt; 0 > C for 1 to 2 hours.

According to one embodiment of the present invention, in order to reduce the drying efficiency and the deterioration of the taste of the tomato, the tomato may be pickled before the drying step or the tomato surface may be coated with the sugar powder to perform a drying process have. At this time, sugar cane can be pickled with various fruits or sugar solutions.

According to one embodiment of the present invention, in the present invention, the process for peeling off the tomato may be carried out according to the method of Korean Patent Application No. 10-2017-0050189 filed by the present inventor, And the tomato is peeled off after being sprayed on the tomato for 10 seconds to 80 seconds using superheated steam at 150 to 200 캜.

According to the present invention, by using the superheated steam and the combined drying, the water content of the tomato is reduced, thereby increasing the shelf life, minimizing the loss of shape and nutritive value, and rapidly restoring the tomato to a circular state in the porous state.

If the temperature of the heater is less than 160 ° C, the moisture content of the tomato is not decreased as desired. If the temperature of the heater exceeds 200 ° C, the nutritional content of the tomato may be destroyed or the physical properties may be deteriorated.

If the temperature of the superheated steam is less than 230 캜, the moisture content of the tomato may not be reduced as much as desired. If the temperature exceeds 260 캜, the nutrients of the tomato may be destroyed or the quality thereof may deteriorate.

If the treatment time of the superheated steam is less than 20 minutes, the moisture content of the tomato is not reduced as desired, and if it exceeds 30 minutes, the nutritional component of the tomato may be destroyed or the quality may be deteriorated.

If the hot air drying temperature is less than 70 ° C, the moisture content of the tomatoes is not reduced as desired. If the drying temperature exceeds 95 ° C, the nutritional components of tomatoes may be destroyed or the quality thereof may deteriorate.

If the hot air drying time is less than 1 hour, the moisture content of the tomato is not reduced as desired. If the drying time exceeds 2 hours, the nutritional content of the tomato may be destroyed or the quality thereof may deteriorate.

Tomatoes which can be used according to the present invention are not particularly limited in their kinds such as drop tomatoes, jujube tomatoes, and tomatoes.

As described above, the method of drying tomato using the superheated steam and the hot air drying technique of the present invention reduces the moisture content of the tomato to increase the shelf life, minimize the loss of shape change and nutritive value, It can be rapidly restored to a circular shape.

Fig. 1 is a photograph of the jujube tomato after superheated steam drying and hot air drying.
FIG. 2 is a graph showing the appearance characteristics and moisture content of the drop tomato before and after superheated steam drying and hot air drying.
FIG. 3 shows the appearance and moisture content of the jujube tomato before and after the superheated steam drying and hot air drying.
FIG. 4 shows the appearance characteristics, moisture content, pH and sugar content of dried tomatoes (24 hours) after superheated steam drying and hot air drying.
FIG. 5 shows the appearance characteristics, moisture content, pH and sugar content of dried tomatoes (36 hours) of sugar beet after superheated steam drying and hot air drying.
6 is a photograph showing the microstructure of the drop tomato according to the drying method.
FIG. 7 is a graph showing the restoration upon hydrolysis according to the drying method of the drop tomato. FIG.
8 is a photograph showing appearance characteristics of the jujube tomato before and after drying by superheated steam and hot air drying.
FIG. 9 is a graph showing the appearance characteristics, moisture content and water activity of the jujubes of sugar-pickled jujubes after superheated steam drying and hot air drying.
FIG. 10 shows the appearance characteristics, moisture content and water activity of the jujube tomatoes coated with sugar powder after superheated steam drying and hot air drying.

Hereinafter, embodiments of the present invention will be described in detail to facilitate understanding of the present invention. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the following embodiments. Embodiments of the invention are provided to more fully describe the present invention to those skilled in the art.

≪ Experimental Method and Pretreatment Process >

In order to set the optimum drying conditions of tomato using superheated steam and complex drying, the tomato dropping was carried out in accordance with the patent application 10-2017-0050189, in which the superheated steam was sprayed to the drop tomato at 150 ° C for 15 seconds at the upper and lower heater temperature 100 ° C The shell was removed by cooling.

(One) Moisture content

In the general composition analysis method, the moisture content was expressed as a mean value after three repeated measurements under the conditions of 105 ° C atmospheric pressure heating and drying according to the AOAC method.

(2) Water activity

The water activity of the samples was analyzed using a water activity meter (Aqualab water activity meter model series 3, Decagon Devices, Inc, Pullman, USA). All analyzes were repeated three times.

(3) pH

10 ml of the sample was diluted with 90 ml of secondary distilled water and filtered through a filter paper (Whatman ™ cellulose filter paper grade 1, GE Healthcare companies, UK). Using a pH meter (Orion Research Inc., USA) And the mean value after repeated measurement.

<Example 1> Evaluation of appearance characteristics after drying of jujube tomato

The jujube tomatoes were pretreated with 4 seeds containing seeds or without seeds.

After the pretreatment, the jujube tomatoes were dried in a heater at 180 ° C with steam at 220 ° C for 15 minutes, and then dried with hot air at 70 ° C.

The results are shown in Fig. Fig. 1 is a photograph of the jujube tomato after superheated steam drying and hot air drying. As you can see here, the jujube tomatoes that did not peel off were not good in appearance due to peeling in 10 minutes of superheated steam drying. The jujube tomatoes which did not remove the seeds were cracked in the superheated steam drying and the moisture of the tomato parts remained even after 5 hours of hot air drying.

Example 2 Preparation of Semi-Dry Products by Mixed Drying Method of Tomato Tomato and Jujube Tomato

The moisture content of the tomatoes and jujubes was measured by drying the superheated steam and the hot air as shown in Table 1 below. The results are shown in FIG. 2 and FIG.

Superheated steam drying Second post-drying (70 ° C Dry oven) H (占 폚) -S (占 폚) -T (m) Drying time 180-180-20 1 hour 30 minutes 180-220-15 1 hour 30 minutes 180-250-12 1 hour 30 minutes

FIG. 2 is a graph showing the appearance characteristics and moisture content before and after the drying of the over-heated steam and the hot air drying of the drop tomato, and FIG. 3 is a graph showing the appearance and moisture content of the tomato jujube before and after drying.

As shown here, the moisture content of the tomatoes was lowest in the superheated steam dried H (℃) -S (℃) -T (m): 180-180-20, -S (℃) -T (m): The moisture content was the lowest at 180-180-10.

&Lt; Example 3 > Manufacture of semi-dried product of pickled tomatoes

The berry with less flesh and the jujube tomatoes were hard to dry in a semi-dry state, and were semi-dried by dipping them with Omija Zheng + sugar under the conditions shown in Table 2 below.

FIG. 4 shows the appearance characteristics, moisture content, pH and sugar content of dried tomatoes (24 hours) after superheated steam drying and hot air drying. As shown in the figure, the moisture content of the 10% sucrose solution of omiza was 50.43% after drying with superheated steam. The proportion of sucrose increased to 61.06% for the 30% solution of omiza and 61.67% for the solution of 50% The water content of the dipping solution was high, and the pH of the dipping solution was 10.3%, 30%, 30%, and 50%, respectively. °, 50%, and 33.9 °, respectively.

In the second drying, the water content of the sample after treating for 4 hours at 85 ℃ was 10%, 30%, 13.00% and 17.5%, respectively.

FIG. 5 shows the appearance characteristics, moisture content, pH and sugar content of dried tomatoes (36 hours) of sugar beet after superheated steam drying and hot air drying. As shown here, the water content of the drop tomato was 68.93%, 30%, 66.49% and 50.87%, respectively, after the superheated steam drying of the omelet 10% shrimp. In the pH of the salting solution of Omiza, the higher the ratio of Omiza was, the lower the ratio of Omiza 10%, 30%, 30%, 3.5%, 50% % Glomeruli and 42.6 °, respectively.

The water content of the samples treated with the second hot air drying at 85 ° C for 2 hours 30 minutes was 34.15%, 30%, 33.45%, and 29.64%, respectively.

<Example 4> Evaluation of water content and water activity according to the drying method

Dried tomatoes were dried by hot air drying (HA), superheated steam drying + hot air drying (SHS + HA), superheated steam drying + infrared drying (SHS + FIR) and superheated steam (SHS) according to the conditions shown in Table 3 Moisture content, water activity and hydrolysis activity were evaluated. 6 is a photograph showing the microstructure of the drop tomato according to the drying method. FIG. 7 is a graph showing the restoration under hydrolysis according to the drying method of the drop tomato. FIG.

hot air dry Superheated steam + hot wind Superheated steam + infrared Superheated steam 85 ° C, 5 hours H (占 폚) -S (占 폚) -T (m): 180-250-20 H (占 폚) -S (占 폚) -T (m): 180-250-20 H (占 폚) -S (占 폚) -T (m): 180-250-20 85 ° C, 5 hours 85 ° C, 5 hours

Table 4 shows the moisture content and water activity according to the drying method of the drop tomato, and the total acidity, vitamin C and lycopene content according to the drying method of the drop tomato was shown in Table 5 below.

As can be seen, conventional HA drying has a higher degree of moisture removal than SHS combined with HA or FIR due to the relatively long drying time, thereby lowering the activity of water. The total acidity of the drop tomatoes produced by the combined drying process was slightly lower than the conventional HA drying. When SHS was used in combination with FIR, it was possible to maintain a higher level of vitamin C and lyicopene in HA drying with faster restoration than conventional HA and SHS.

<Example 5> Establishment of superheated steam drying and hot air drying conditions of jujube tomato

The jujube tomatoes were dried with superheated steam for 23 minutes using steam at 250 ° C in a heater at 180 ° C without cutting them, followed by hot air drying at 85 ° C for 3 hours.

8 is a photograph showing appearance characteristics of the jujube tomato before and after drying by superheated steam and hot air drying. As shown here, the moisture content of the jujube tomatoes was moderately controlled and dried.

Example 6 Preparation of Semi-Dried Product of Sugar-pickled Jujube Tomato

The jujube tomatoes were sliced for 10 minutes at a ratio of 5%, 10%, and 15% to the sugar solution. The jujube tomatoes were subjected to superheated steam drying and hot air drying under the conditions shown in Table 6 below.

FIG. 9 is a graph showing the appearance characteristics, moisture content and water activity of the jujubes of sugar-pickled jujubes after superheated steam drying and hot air drying. As shown here, it was confirmed that the water content after the final drying was very low. On the other hand, the sample which is half dried by dipping into the sugar solution has both a sweet taste and a sour taste.

Example 7 Preparation of Semi-Dry Product of Sugar Coated Jujube Tomato

On the surface of the jujubes of jujubes, sugar powder was coated on the surface by weight, followed by superheated steam drying and hot air drying. FIG. 10 shows the appearance characteristics, moisture content and water activity of the jujube tomatoes coated with sugar powder after superheated steam drying and hot air drying. As shown here, after the final drying, the moisture content was very low, while the sweetness and sourness were adequate.

Claims (3)

A semi-drying method of tomato comprising the steps of:
(S1) spraying tomatoes in a heater at 95 to 105 ° C for 10 seconds to 80 seconds using superheated steam at 150 to 200 ° C, and then peeling the tomatoes;
(S2) drying the tomato melted in (S1) with a superheated steam in a heater at 160 to 200 DEG C for 20 to 30 minutes using steam at 230 DEG C to 260 DEG C; And
(S3) a step of hot-air drying the tomatoes dried with superheated steam at 70 to 95 ° C for 1 to 2 hours in step (S2). The method according to claim 1,
And drying the tomato in step (S2), or coating the tomato surface with sugar powder. delete

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