Method for producing stevia tomatoes with enhanced calcium and magnesium

Abstract

The present invention relates to a method for producing stevia tomatoes, the method comprising impregnating tomatoes immersed in an immersion solution by reducing the pressure in a vacuum state and maintaining the reduced pressure, and then raising the pressure back. The stevia tomatoes of the present invention exhibit enhanced natural sweetness and mineral content while maintaining the appearance and texture of tomatoes, thereby providing tomatoes with low calories and high nutritional value.

Description

Method for manufacturing calcium and magnesium-fortified stevia tomatoes

[0001] The present invention relates to a method for producing high-functional tomatoes with enhanced sweetness and nutritional components by uniformly infusing stevia and minerals into the tomato tissue through vacuum impregnation technology.

[0002] Tomatoes are annual plants native to Latin America belonging to the family Solanaceae, and the term generally refers to their fruit. Depending on cultivation methods or seed characteristics, tomatoes of various shapes and colors are produced, such as regular tomatoes, cherry tomatoes, date tomatoes, sticky tomatoes, and black tomatoes.

[0003] Although tomatoes can be cultivated year-round, they are characterized by being at their best in taste and nutritional value during the summer months of June to August, as they become richer in glutamic acid, which provides umami flavor, and lycopene, an excellent nutrient, the more sunlight they receive. Lycopene is a type of carotenoid that acts as an antioxidant, possessing the efficacy to prevent and treat various diseases by eliminating free radicals that cause strong toxicity in the body. In addition, it is known to be effective in inhibiting fat cells and preventing and treating bladder, prostate, and liver cancers.

[0004] Furthermore, tomatoes are rich in vitamins A and C, and also contain vitamins H and P, which are not typically found in other vegetables or fruits; the various vitamins in tomatoes can help maintain internal balance and aid in skin care. In addition, the organic acids in tomatoes function to aid digestion, while alkaline minerals neutralize acidified blood.

[0005] Although tomatoes contain sugars, the amount is small, and due to the trace amounts of solinine and other bitter-tasting components, they may have a negative effect when served raw or added during the cooking process.

[0006] In order to reduce or eliminate flavors that impair the taste of tomatoes, various sweetening ingredients are introduced during processing. However, when combined with sugar, a representative sweetening ingredient, negative phenomena are observed, such as the destruction of Vitamin B, a beneficial component in tomatoes, or inhibition of its absorption into the body. Consequently, there is a need for a tomato processing method that can enhance the flavor of tomatoes while maintaining their original nutritional value.

[0007] Stevia is a type of natural sweetener extracted from the leaves of Stevia rebaudiana, and it is gaining popularity as a sugar substitute due to its strong sweetness. When provided for consumption, it is generally offered in the form of steviol glycosides; in this case, it exhibits a sweetness up to 100 times that of ordinary refined sugar. However, it is widely known as a sweetener that replaces sugar, which causes various adult diseases, based on the observation that it provides no calories upon consumption due to the absence of a metabolic process in the body to break down glycoside bonds. Based on these characteristics of Stevia, various methods have been provided to introduce Stevia components into tomatoes to enhance their flavor.

[0008] As for prior art related to stevia tomatoes, Korean Registered Patent No. 2718431 discloses a method for manufacturing stevia tomatoes with an improved shelf life, and Korean Registered Patent No. 2562237 discloses a method for manufacturing enzyme-treated stevia tomatoes using a micro-ultrasonic bubble process, but these are different from the method for manufacturing calcium and magnesium-fortified stevia tomatoes using the vacuum impregnation technology of the present invention.

[0009] The present invention was devised in response to the above-mentioned needs, and the objective of the present invention is to provide a method for producing stevia tomatoes with enhanced sweetness and minerals and excellent palatability while maintaining the appearance and texture of the tomato, by utilizing vacuum impregnation technology to effectively inject stevia and mineral solutions into the tomato, thereby producing stevia tomatoes with enhanced sweetness and minerals simultaneously, by optimizing the type and content of the immersion solution materials, pressure, and impregnation conditions.

[0010] To solve the above problem, the present invention provides a method for producing stevia tomatoes, characterized by comprising the steps of: (1) preparing an immersion solution by adding stevia, sucralose, and calcium chloride or magnesium chloride to water; (2) immersing tomatoes in the immersion solution prepared in step (1); and (3) lowering and maintaining the pressure of the tomatoes immersed in step (2) under vacuum conditions, and then raising the pressure again to impregnate them.

[0011] In addition, the present invention provides a stevia tomato produced by the above method.

[0012] In addition, the present invention provides a processed tomato food product manufactured using the above-mentioned stevia tomato.

[0013] Mineral-fortified stevia tomatoes produced using the vacuum impregnation technology of the present invention have the effect of producing high-quality tomatoes with low calories and high nutritional value, while maintaining the appearance and texture, and allowing stevia and mineral solutions to penetrate uniformly into the tomato tissue to achieve natural sweetness and mineral fortification.

[0014] In addition, the stevia tomato of the present invention has the effect of increasing the preference for tomatoes among all consumers, including children, due to its appropriate sweetness, thereby promoting tomato consumption and helping to increase the income of tomato farming households.

[0015] FIG. 1 is a vacuum-impregnation device for uniformly penetrating the components of an immersion solution into tomato tissue. The vacuum-impregnation device consists of a device interior (1) for placing tomatoes and an infiltration solution, a pressure gauge (3) for measuring the internal pressure of the device, a regulator (2, 4) for controlling the internal pressure, and a vacuum pump (5) for creating a vacuum inside the device.

[0016] Figure 2 is a graph comparing the sugar content of the stevia tomatoes of the present invention. In Figure 2, ST in (A) represents the stevia tomato of Preparation Example 1, ST in (B) represents the stevia tomato of Preparation Example 2, and con represents an untreated tomato.

[0017] FIG. 3 is a graph comparing the calcium and magnesium content of the stevia tomatoes of the present invention. In FIG. 3, (A) after refers to the stevia tomato of Preparation Example 1, (B) after refers to the stevia tomato of Preparation Example 2, and before refers to the untreated tomato.

[0018] To achieve the above objective, the present invention

[0019] (1) A step of preparing an immersion solution by adding stevia and sucralose and calcium chloride or magnesium chloride to water;

[0020] (2) a step of immersing the tomatoes in the immersion solution prepared in step (1) above; and

[0021] (3) A method for manufacturing stevia tomatoes is provided, characterized by including the step of lowering and maintaining the pressure of the immersed tomatoes from step (2) under vacuum, and then raising the pressure again to impregnate them.

[0022] In the method for producing stevia tomatoes according to the present invention, the soaking solution of step (1) can preferably be prepared by adding 4 to 6 parts by weight of stevia and 4 to 6 parts by weight of sucralose and 8 to 12 parts by weight of calcium chloride or magnesium chloride to 100 parts by weight of water, more preferably by adding 4 to 6 g of stevia, 4 to 6 g of sucralose, and 8 to 12 g of calcium chloride or magnesium chloride to 100 mL of water, and most preferably by adding 5 g of stevia, 5 g of sucralose, and 10 g of calcium chloride or magnesium chloride to 100 mL of water. When tomatoes are soaked in the soaking solution prepared with the above types and amounts of materials, it is possible to enhance not only the natural sweetness but also the minerals simultaneously without affecting the texture of the tomatoes.

[0023] In addition, in the method for producing stevia tomatoes according to the present invention, it is preferable to immerse the tomato in the immersion solution until the entire tomato is submerged during the immersion in step (2). This is because the parts of the tomato that are not immersed in the immersion solution do not increase in sugar content and mineral content.

[0024] In addition, in the method for producing stevia tomatoes according to the present invention, the impregnation of step (3) may preferably include the step of lowering the pressure of the immersed tomato from 1 bar to 0.6 to 0.8 bar at a rate of 0.001 bar / s to 0.04 bar / s in a vacuum state, maintaining the reduced pressure state of 0.6 to 0.8 bar for 30 to 90 seconds, and then raising the pressure again to 1 bar at a rate of 0.001 bar / s to 0.04 bar / s to impregnate it, and more preferably, the step of lowering the pressure of the immersed tomato from 1 bar to 0.7 bar at a rate of 0.001 bar / s to 0.04 bar / s in a vacuum state, maintaining the reduced pressure state of 0.7 bar for 60 seconds, and then raising the pressure again to 1 bar at a rate of 0.001 bar / s to 0.04 bar / s to impregnate it. Raising the pressure back to atmospheric pressure after the tomatoes had undergone vacuum and depressurization processes under the above conditions allowed for maximum enhancement of mineral content without damaging the tomato skin (external bursting), without altering the physical properties of the tomatoes, and while allowing the components of the immersion solution to penetrate the tomatoes uniformly.

[0025] The method for producing stevia tomatoes according to the present invention, more specifically, is

[0026] (1) A step of preparing an immersion solution by adding 4 to 6 parts by weight of stevia and 4 to 6 parts by weight of sucralose and 8 to 12 parts by weight of calcium chloride or magnesium chloride to 100 parts by weight of water;

[0027] (2) a step of immersing the tomatoes in the immersion solution prepared in step (1) above; and

[0028] (3) The method may include the step of lowering the pressure of the immersed tomatoes from step (2) from 1 bar to 0.6 to 0.8 bar at a rate of 0.001 bar / s to 0.04 bar / s in a vacuum state, maintaining the reduced pressure state of 0.6 to 0.8 bar for 30 to 90 seconds, and then raising the pressure back to 1 bar at a rate of 0.001 bar / s to 0.04 bar / s to impregnate them.

[0029] More specifically,

[0030] (1) A step of preparing an immersion solution by adding 5 parts by weight of stevia and 5 parts by weight of sucralose and 10 parts by weight of calcium chloride or magnesium chloride to 100 parts by weight of water;

[0031] (2) a step of immersing the tomatoes in the immersion solution prepared in step (1) above; and

[0032] (3) The immersed tomatoes from step (2) above may be subjected to a vacuum, and the pressure is lowered from 1 bar to 0.7 bar at a rate of 0.001 bar / s to 0.04 bar / s, and when the pressure is reduced to 0.7 bar, it is maintained for 60 seconds, and then the pressure is raised again to 1 bar at a rate of 0.001 bar / s to 0.04 bar / s to impregnate them.

[0033] The present invention also provides a stevia tomato produced by the above method.

[0034] The present invention also provides a processed tomato food product prepared using the stevia tomato. Examples of foods to which the stevia tomato may be added include meat, sausage, bread, chocolate, candies, snacks, confectionery, pizza, ramen, other noodles, chewing gum, rice cakes, dairy products including ice cream, various soups, beverages, tea, drinks, alcoholic beverages, and vitamin complexes, and include all processed foods in the conventional sense.

[0035]

[0036] The present invention will be described in detail below with reference to manufacturing examples and embodiments. However, the following manufacturing examples and embodiments are merely illustrative of the present invention, and the content of the present invention is not limited to the following manufacturing examples and embodiments.

[0037]

[0038] Preparation Example 1. Calcium-fortified Stevia Tomato

[0039] (1) A soaking solution was prepared by adding 600 mL of water, 30 g of stevia, 30 g of sucralose, and 60 g of calcium chloride (CaCl2) to a beaker.

[0040] (2) Cherry tomatoes that had been washed and dried were placed inside a vacuum-impregnation device (Fig. 1), and the immersion solution prepared in step (1) was added so that the tomatoes were submerged.

[0041] (3) The vacuum-impregnation device of step (2) above was vacuumed at a rate of 0.001 bar / s to 0.04 bar / s from atmospheric pressure (1 bar) to 0.7 bar, and when the vacuum pressure was reduced to 0.7 bar, it was maintained for 1 minute, and then the pressure was raised back to atmospheric pressure (1 bar) at a rate of 0.001 bar / s to 0.04 bar / s to perform vacuum impregnation treatment.

[0042] (4) The vacuum-impregnated tomatoes from step (3) above were washed with water and then dehydrated.

[0043]

[0044] Preparation Example 2. Magnesium-fortified Stevia Tomato

[0045] (1) A soaking solution was prepared by adding 600 mL of water, 30 g of stevia, 30 g of sucralose, and 60 g of magnesium chloride (MgCl2) to a beaker.

[0046] (2) Cherry tomatoes that had been washed and dried were placed inside a vacuum-impregnation device (Fig. 1), and the immersion solution prepared in step (1) was added so that the tomatoes were submerged.

[0047] (3) The vacuum-impregnation device of step (2) above was vacuumed at a rate of 0.001 bar / s to 0.04 bar / s from atmospheric pressure (1 bar) to 0.7 bar, and when the vacuum pressure was reduced to 0.7 bar, it was maintained for 1 minute, and then the pressure was raised back to atmospheric pressure (1 bar) at a rate of 0.001 bar / s to 0.04 bar / s to perform vacuum impregnation treatment.

[0048] (4) The vacuum-impregnated tomatoes from step (3) above were washed with water and then dehydrated.

[0049]

[0050] Experimental method

[0051] 1. Sugar Content Analysis of Mineral-Fortified Stevia Tomatoes

[0052] To examine the change in sugar content of stevia tomatoes prepared with calcium and magnesium-fortified stevia solution, 10 g of tomatoes were homogenized and measured three times using an Abbe refractometer (ATAGO CO., 501-DS, Tokyo, Japan).

[0053]

[0054] 2. Analysis of Mineral Content in Mineral-Fortified Stevia Tomatoes via ICP-OES

[0055] The mineral content of mineral-fortified stevia tomatoes was analyzed using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). For sample pretreatment, an acid digestion solution prepared by mixing nitric acid (HNO3) and perchloric acid (HClO4) in a 1:1 ratio was added, followed by heating at 180°C for 2–3 hours to ensure complete acid digestion. The acid-digested solution was cooled to room temperature, filtered to remove impurities, and serially diluted with distilled water. For ICP-OES analysis, emission lines Ca at 317.933 nm and Mg at 285.213 nm, which exhibit low interference and a high signal-to-background ratio, were used; emission line selection was optimized based on previous interference studies and standard data. The prepared samples were injected into the ICP-OES system, and plasma analysis was performed; the concentration of each mineral was quantified based on standard calibration curves.

[0056]

[0057] 3. Sensory Evaluation of Mineral-Fortified Stevia Tomatoes According to Mineral Concentration

[0058] To compare the quality characteristics of mineral-fortified stevia tomatoes according to mineral concentration, graduate students from Gyeongsang National University, whose suitability as inspectors was recognized, were selected and trained for the purpose of this experiment, after which a sensory evaluation was conducted. The sensory evaluation items included the taste, appearance, aroma, texture, and overall satisfaction of the stevia tomatoes prepared according to mineral concentration, and were conducted using a 9-point Liker scale, where 9 points represent excellent quality and 1 point represents very poor quality.

[0059]

[0060] Example 1. Sugar content of stevia tomatoes

[0061] The results of measuring the sugar content (Brix) of mineral-fortified stevia tomatoes are shown in Figure 2. The Brix of the cherry tomatoes before impregnation (con) was 6.5%, but it increased to 7.2% for both Preparation Examples 1 and 2 after impregnation. This confirmed that the immersion solution had uniformly penetrated the stevia into the tomato tissue.

[0062]

[0063] Example 2. Analysis of Mineral Content in Stevia Tomatoes

[0064] The results of measuring the mineral content of mineral-fortified stevia tomatoes are shown in Figure 3. The calcium content of a regular tomato (before) was 10.45 mg per 100 g, and the magnesium content was 8.25 mg. Compared to the regular tomato, the calcium content of Preparation Example 1 increased by up to 5.3 times, and the magnesium content of Preparation Example 2 increased by up to 2.25 times. This corresponds to a maximum calcium content of 55.38 mg and a maximum magnesium content of 18.56 mg per 100 g of tomato. Therefore, the present invention established an impregnation pressure and vacuum speed that prevent changes in the physical properties of the tomato and do not cause the exterior to burst, and was able to maximize the mineral content.

[0065]

[0066] Example 3. Sensory evaluation of stevia tomatoes

[0067] The results of the sensory evaluation of calcium-fortified stevia tomatoes prepared by varying the amount of calcium chloride added to the immersion solution relative to water (0%, 1%, 3%, 5%, and 10%) are shown in Table 1 below. As a result, there was no significant difference in appearance and texture between the untreated group (regular tomato) and the stevia tomatoes. However, the untreated group showed low preference values ​​in the 2.5, 2.3, and 2.3 point ranges for aroma, taste, and overall preference, respectively. In the case of the stevia tomatoes with 1-5% added calcium, preference values ​​in the 8.0-8.3 point range were observed for taste and overall preference. In particular, the stevia tomatoes with 10% added calcium showed the highest preference values ​​in the 8.5 point range for taste and overall preference.

[0068] Sensory Evaluation Results of Calcium-Fortified Stevia Tomatoes Category (Regular Tomato) 1% Calcium 3% Calcium 5% Calcium 10% Calcium Appearance 7.5±0.01 a 7.5±0.00 a 7.5±0.00 a 7.5±0.01 a 7.5±0.01 a Scent 2.5±0.03 b 7.0±0.01 a 7.0±0.01 a 7.0±0.00 a 7.0±0.01 a Taste 2.3±0.04 d 8.0±0.01 c 8.0±0.01 c 8.3±0.02 b 8.5±0.01 a Texture (firmness) 7.5±0.00 a 7.5±0.00 a 7.5±0.01 a 7.5±0.01 a 7.5±0.01 a Overall preference 2.3±0.06 d 8.0±0.00 c 8.0±0.00 c 8.3±0.01 b 8.5±0.01a

[0069] The results of the sensory evaluation of magnesium-fortified stevia tomatoes prepared by the method of Preparation Example 2, but with varying amounts of magnesium chloride added to the immersion solution relative to water (0%, 1%, 3%, 5%, and 10%), are shown in Table 2 below. As a result, no significant difference was observed in the appearance and texture between the untreated group and the magnesium-fortified tomatoes, confirming that the immersion solution treatment did not alter the appearance and texture of the tomatoes. Additionally, while there was no significant difference in preference for aroma depending on the amount of magnesium added, the group with 10% magnesium added showed the highest score for taste and overall preference, while the untreated group showed a low score in the 2-point range.

[0070] Sensory Evaluation Results of Magnesium-Fortified Stevia Tomatoes Category con (Regular Tomato) 1% Magnesium 3% Magnesium 5% Magnesium 10% Magnesium Appearance 7.5±0.00 a 7.5±0.00 a 7.5±0.00 a 7.5±0.00 a 7.5±0.00 a Scent 2.5±0.83 b 7.0±0.01 a 7.0±0.01 a 7.0±0.00 a 7.0±0.01 a Taste 2.3±0.03 d 8.0±0.00 c 8.0±0.00 c 8.3±0.00 b 8.5±0.02 a Texture (firmness) 7.5±0.00 a 7.5±0.00 a 7.5±0.00 a 7.5±0.00 a 7.5±0.00 a Overall preference 2.3±0.05 d 8.0±0.00 c 8.0±0.00 c 8.3±0.02 b 8.5±0.01a

Claims

1. (1) A step of preparing an immersion solution by adding stevia, sucralose, calcium chloride or magnesium chloride to water; (2) a step of immersing the tomatoes in the immersion solution prepared in step (1) above; and (3) A method for manufacturing stevia tomatoes characterized by including the step of lowering and maintaining the pressure of the immersed tomatoes from step (2) under vacuum, and then raising the pressure again to impregnate them.

2. A method for producing stevia tomatoes according to claim 1, wherein the immersion solution of step (1) is prepared by adding 4 to 6 parts by weight of stevia and 4 to 6 parts by weight of sucralose and 8 to 12 parts by weight of calcium chloride or magnesium chloride to 100 parts by weight of water.

3. A method for producing stevia tomatoes according to claim 1, wherein step (3) lowers the pressure of the immersed tomatoes from 1 bar to 0.6 to 0.8 bar at a rate of 0.001 bar / s to 0.04 bar / s in a vacuum state, maintains the reduced pressure state of 0.6 to 0.8 bar for 30 to 90 seconds, and then raises the pressure back to 1 bar at a rate of 0.001 bar / s to 0.04 bar / s to impregnate them.

4. In Paragraph 1, (1) A step of preparing an immersion solution by adding 4 to 6 parts by weight of stevia and 4 to 6 parts by weight of sucralose and 8 to 12 parts by weight of calcium chloride or magnesium chloride to 100 parts by weight of water; (2) a step of immersing the tomatoes in the immersion solution prepared in step (1) above; and (3) A method for manufacturing stevia tomatoes characterized by including the step of lowering the pressure of the tomatoes immersed in step (2) from 1 bar to 0.6 to 0.8 bar at a rate of 0.001 bar / s to 0.04 bar / s in a vacuum state, maintaining the reduced pressure state of 0.6 to 0.8 bar for 30 to 90 seconds, and then raising the pressure back to 1 bar at a rate of 0.001 bar / s to 0.04 bar / s to impregnate them.

5. Stevia tomato produced by the method of any one of paragraphs 1 to 4.

6. A processed tomato food product manufactured using the stevia tomato of Paragraph 5.

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