KR100762498B1 - Preparation method of grape leaf tea and grape leaf tea prepared by the same - Google Patents

Abstract

A method of manufacturing grape leaf tea by roasting and rolling a young grape leaf is provided to reduce the sour and astringent taste of grape leaves remarkably and produce grape leaf tea having excellent palatability of taste, flavor and color without destruction of nutrients. A young grape leaf is washed, dehydrated, roasted at 150 to 250deg.C, dried to a moisture content of 10% and ground. The roasting process contains rolling and is repeated 2 to 4 times. Preferably, 0.5 to 1g grape leaf tea is infused in 1 to 2L boiling water of 70 to 100deg.C for 1 to 5min.

Description

Preparation method of grape leaf tea and grape leaf tea prepared by the same}

1 is a view showing the process of steaming (wavy-rubbing-bunching) in the manufacture of grape leaf tea according to the present invention.

Figure 2 is a view showing the color change of the grape leaf tea according to the number of times (two times, three times, four times) in the manufacture of grape leaf tea according to the present invention.

3 is a diagram showing HPLC analysis of standard resveratrol (Sigma Chem. Co. USA).

Figure 4 is a view showing a tea bag containing a tea leaf tea according to the present invention.

The present invention relates to a method for producing grape leaf tea and a grape leaf tea produced thereby.

Grapes are largely divided into European, American, and hybrid species. The most cultivated variety in our country is Campbell Early, which is purplish black, medium in size and ripens from mid-August to late August. Others include Muscat Bailey, Seri Dan, and Green Grapes (Niagara).

The annual output of grapes produced in Korea is about 400,000 tons, and the cultivation area is 29,000 ha, which is one of the largest crops among farmers. Grapes account for 17% of domestic fruit production and are the second most important fruit consumption after citrus in per capita consumption per year. As such, grapes are an important source of income for farmers, but due to the climate of Korea, grape shipments are concentrated in August and September, and most of them are consumed more than 80% for reproduction, but prices fluctuate due to temporary release.

Grapes contain a lot of sugar (glucose, fructose), which is good for fatigue recovery. Vitamins A, B, B ₂ , C, and D are rich in metabolism. Other minerals such as calcium, phosphorus, iron, sodium and magnesium are also included. In addition, the polyphenol component is excellent in antioxidant effects, antimicrobial activity, mutation suppression effect, cholesterol reduction effect, etc., there is an anti-cancer component called resveratrol is also effective in inhibiting cancer. In addition, grapes are alkaline foods to strengthen muscles and bones, diuretic action to help treat edema, live blood and hematopoietic action to anemia, inhibit viral activity to prevent tooth decay. It also helps to prevent degenerative diseases such as Alzheimer's and Parkinson's by enhancing the activity and efficacy of neurons that make nerve cells.

In general, grapes are harvested in June-August, during the grape growing season, to increase yields and sugar content. The grapes that have been subjected to this saturation cycle have the effect of increasing the yield and sugar, as well as softening the texture of the grape leaves and decreasing the sour taste of the grape leaves. If the culturing is not performed, the flesh of the grapes becomes small and only the trees of the grapes grow. Therefore, in general, the ordering cycle is given, the grapes harvested after the ordering cycle is mainly used only fruit, grape leaves are rarely used, the whole amount is discarded or used as compost.

Grape leaves are rarely used in the grape processing industry because they have a strong taste and astringent taste, and mainly used are the flesh and juice of grapes. In addition, many studies on processed products using grape seeds and grape leaves show a visible result, but there is little industrial development using grape leaves.

Recently, processed foods using grape leaves have been studied a lot, such as pickled grape leaves, grape leaf salad, grape leaf dumplings, grape leaf ssambap and various types. It is also used in Greece as a traditional Greek food called dolmas (dolmas) using grape leaves, and nowadays it is used as a healthy food in high-end restaurants.

As described above, various processed foods using grape leaves have recently been developed, but there is no development of tea using grape leaves.

Recently, in Korea, dietary lifestyle, nutritional imbalance, drinking, smoking, and stress have increased, and lifestyle diseases such as hypertension, heart disease, obesity, and chronic degenerative diseases are rapidly increasing. The burden on national health and the national economy is increasing. Therefore, it is thought that if the grape leaves having excellent physiological activity as described above are processed into tea and drink continuously, even a small part will be contributed to the improvement of national health.

Thus, the present inventors while studying the tea leaf tea using the effect of the soft texture and low sourness of the grape leaves subjected to the ordering cycle, after drinking the grape leaves subjected to the ordering cycle after drinking treatment and drinking grapes The sourness of the leaves was markedly reduced in taste, and confirmed that the taste, aroma, and color preference were excellent, and completed the present invention.

The present invention is to provide a method for producing grape leaf tea and grape leaf tea produced thereby.

The present invention

1) taking young grape leaves that have been circulated and removing eggplants, then washing them clean and removing water;

2) squeezing the drained grape leaves (swelling-rubbing-bundling),

3) repeating the sound treatment, and

4) It provides a grape leaf tea manufacturing method comprising the step of drying the grape leaves subjected to the steaming treatment.

The present invention also provides a grape leaf tea produced by the above production method.

Hereinafter, the present invention will be described in detail.

The grape leaves used in the present invention are grapes of Campbell Early, MBA (Muscat Barley A), New York-Hamburg, Seridan and Steuben varieties Leaves were used, but not limited to these.

After one or more grape varieties selected from among the grape varieties are harvested in May through September, young leaves are collected and removed, and then washed clean and dried.

The grape leaves from which the water is removed are subjected to steaming (roasting) at 150 to 250 ° C, preferably 150 to 200 ° C. This waste treatment promotes enzymes to promote the chemical reaction of cells in the grape leaves.

Transfer the steamed grape leaves to a cloth or bale and mix for 3-8 minutes. Rubbing the grape leaves breaks the tissues of the grape leaves, allowing enzymes to come out of the cells in the grape leaves and to absorb water quickly.

Aggregate the rubbing treated grape leaves and leave for 10 to 30 minutes to mature. This aging spreads the moisture evenly.

The iron-rubbing-batch process is repeated 2-4 times, preferably three times, and then dried at room temperature for 24 hours until the water content is 10%.

In the preparation of the grape leaf tea according to the present invention is shown in Figure 1 (wavy-rubbing-bunching) process.

The grape leaf tea of the present invention is manufactured through the above-mentioned abrasion treatment, the color, taste, aroma, etc. are superior to the grape leaves of the grape leaves are sunlight-dried, shade drying, hot air drying, freeze-dried.

In addition, the grape leaf tea according to the present invention changes the color of the grape leaves and grape leaf tea dark brown as the number of times repeated, the resveratrol content, polyphenol content, the antioxidant effect tends to decrease. In particular, when the number of audibles three times, the preference of color, taste, aroma, etc. is the best. If the number of times of 2 times the sour taste, astringent taste, and a lot of green tea, when the number of times more than 4 times the number of times the effective ingredient decreases, the coal tends to be strong, the consumer's preference tends to decrease.

In order to drink the grape leaf tea completed through the above manufacturing process with tea, add 0.5 to 1 g of grape leaf tea to 1-2 liters of water at 70 to 100 ° C and boil it for 1 to 5 minutes. It is possible to obtain a grape leaf tea containing excellent and bioactive ingredients. In addition, the above-mentioned grape leaf tea comes out well even with the addition of a small amount so that you can drink tea with excellent taste and nutrition in a very short time. In addition, due to the abrasion treatment of the grape leaves tissue breakdown can be well cared for at a relatively low temperature in a short time to minimize nutrient destruction and excellent taste, aroma, color. In particular, it can be brewed in a short time, so it is very suitable for enjoying by car.

In addition, there is a tea bag form containing the grape leaves as a method that can simply drink the tea leaf tea as a tea. The dried grape leaves may be made into powder and then packaged in a known tea bag packaging machine in a tea bag form. The tea bag material may be a cotton or non-woven fabric having pores in which a material contained therein is dissolved in water and easily removed to the outside while the solids do not easily escape to the outside. The content of grape leaves contained in one tea bag is preferably 1.5 ~ 2.5g.

Frequently drinking the grape leaf tea according to the present invention, it can be effective in preventing diseases by the antioxidant effect, antimicrobial activity, mutation inhibition effect, cholesterol reduction effect, anticancer effect of the physiologically active ingredients contained in grapes.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited by the examples.

Example  One  : Manufacture of Grape Leaf Tea

Young grape leaves were harvested and the branches were removed, washed thoroughly, and dried. The dried grape leaves were treated with steaming (roasting) at 200 ° C., and then transferred to the bales and mixed for 3 to 8 minutes. Then, they were put together and left to mature for 10-30 minutes. The re-treatment was repeated two to four times, followed by drying at room temperature for 24 hours until the water content reached 10%.

The shredding process is shown in FIG. 1.

Comparative example  One  : Manufacture of grape leaf tea (daylight drying)

After the grape leaves were washed thoroughly, the water was removed. The dried grape leaves were spread evenly in a place with direct sunlight, and then walked and spreaded again at night to dry up to 10% moisture content.

Comparative example  2  : Manufacture of grape leaf tea (shade drying)

After the grape leaves were washed thoroughly, the water was removed. The dried grape leaves were evenly spread and dried in a shaded place with air, and dried until the moisture content was 10%.

Comparative example  3  : Manufacture of grape leaf tea (hot air drying)

After the grape leaves were washed thoroughly, the water was removed. The dried grape leaves were dried in a hot air dryer at 65 ° C. until the water content was 10%.

Comparative example  4  : Manufacture of grape leaf tea (freeze drying)

After the grape leaves were washed thoroughly, the water was removed. After freeze-dried grape leaves at -70 ℃, it was freeze-dried for 48 hours with a freeze dryer at 10 Torr.

Experimental Example  One  : Inspection of Grape Leaf Tea by Drying Method

In order to determine the consumer's preference for the grape leaf tea according to the present invention, the following sensory test was performed.

Thirty men and women (15 males and 15 females) who were in their 20s and 30s were tested for preference of grape leaf tea. 2 g of the grape leaf teas prepared in Example 1 and Comparative Examples 1 to 4 were respectively leached in 100 ml of water at 90 ° C. for 5 minutes. The leached solution was drinkable to 30 men and women, and the degree of preference was evaluated.

The results are shown in Table 1.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Symbol 3.667 1.000 2.000 1.333 1.667

※ 5: Very good, 4: Good, 3: Normal, 2: Poor, 1: Very bad

As shown in Table 1, the palatability of the grape leaf tea according to the present invention prepared through the treatment of the appearance appeared higher than the palatability of the grape leaf tea prepared in Comparative Examples 1-4.

Experimental Example  2  : 덖  Favorability test for grape leaf tea according to the number of times

In order to determine the consumer's preference according to the number of times the tea leaf tea according to the present invention, the following sensory test was performed.

Thirty men and women (15 males and 15 females) who were in their 20s and 30s were tested for preference of grape leaf tea. 2 g of grape leaf tea prepared according to the number of times of extraction (2 times, 3 times and 4 times) in Example 1 were leached in 100 ml of water at 90 ° C. for 5 minutes. The leached solution was drinkable to 30 men and women, and the degree of preference was evaluated.

The results are shown in Table 2 and FIG.

2 times 3 times 4 times Symbol 2.000 4.333 2.667

As shown in Table 2, the preference of the grape leaf tea according to the present invention was the highest preference of the consumer when the number of times of the three times. When the number of the number of times of the two times the sour taste, astringent taste, and a lot of green soybeans, when the number of times of the number of times more than four times, the coal mine is strong, the consumer's preference is reduced.

In addition, as shown in Figure 2, it was confirmed that the color of the grape leaf tea turns dark brown as the number of times repeated.

Experimental Example  3  : 덖  Comparison of the Contents of the Active Ingredients Contained in the Tea Leaves

The extent to which resveratrol and polyphenol, which are the active ingredients contained in the grape leaf tea of the present invention, was contained according to the number of times of extraction.

One. Resveratrol  analysis

1) Sample pretreatment

2g of grape leaf tea prepared according to the number of times (2 times, 3 times, 4 times) in Example 1 was boiled in 100 ml of distilled water for 10 minutes and then cooled to room temperature. It was then filtered with Whatman No. 2 filter paper and then sized to 100 ml. 50 ml of this was taken and used as the resveratrol content analysis sample.

50 mL of diethyl ether was added to the 50 mL of the sample solution, and mixed on a separatory funnel for 1 minute, and then the diethyl ether fraction was recovered. This procedure was carried out five times, and the diethyl ether fractions were collected to completely remove the solvent using a vacuum concentrator. 5 ml of acetonitrile was added thereto to dissolve the concentrate, and centrifuged at 14,000 rpm for 20 minutes. Supernatant after centrifugation was used for HPLC analysis.

The whole process was performed by blocking the light by wrapping the container in aluminum foil to prevent oxidation of resveratrol by light.

2) HPLC  Analysis condition

The HPLC conditions of the resveratrol assay established optimum analysis conditions with excellent resveratrol peak separation by varying the solvent (acetonitrile, water) mixing ratio and flow rate.

HPLC conditions of resveratrol analysis are shown in Table 3.

HPLC analysis of standard resveratrol (Sigma Chem. Co. USA) is shown in Figure 3, the detection time was 26.6 minutes.

Running time (minutes) Flow rate (ml / min) Solvent ratio Acetonitrile (%) Water (%) 0 0.3 30 70 10 0.3 30 70 20 0.3 50 50 45 0.3 50 50 50 0.3 30 70 55 0.3 30 70

2. Analysis of Polyphenols

2g of grape leaf tea prepared according to the number of times (2 times, 3 times, 4 times) in Example 1 was boiled in 100 ml of distilled water for 10 minutes and then cooled to room temperature. Then, 50 ml of the resulting solution was filtered through Whatman No. 2 filter paper and used as a polyphenol content analysis sample.

In order to quantify the total polyphenol content contained in the grape leaf tea of the present invention it was used by modifying the Folin-Denis method. 6.5 ml of distilled water was added to 0.5 ml of the sample, and 0.5 ml of Folin-ciocalteu's phenol reagent (Sigma Chem. Co. USA) was added and left for 3 minutes. 1 ml of sodium carbonate was added thereto, followed by color development for 30 minutes, and the total polyphenol content was quantified by measuring absorbance at 725 nm with a spectrophotometer.

Table 4 shows the contents of resveratrol and polyphenols according to the number of extractions contained in the grape leaf tea of the present invention.

2 times 3 times 4 times Resveratrol (mg / kg) 6.67 6.16 5.89 Polyphenol (mg / ml) 0.132 0.112 0.106 Antioxidative effect(%) 89.38 88.12 87.5 pH 4.40 4.45 4.48

As shown in Table 4, the grape leaf tea according to the present invention showed a tendency to decrease the resveratrol content, polyphenol content, antioxidant effect as the number of times of extraction. It is determined that the active ingredient is denatured by heat.

Grape leaf tea according to the present invention is a tissue breakdown of the grape leaves due to abrasion treatment can be concerned with the tea at a relatively low temperature in a short time to minimize nutrient breakdown, even with a small amount of taste in a very short time, There is an excellent effect of flavor and color. In addition, the frequent drinking of the grape leaf tea according to the present invention may be effective in preventing diseases by the antioxidant effect, antimicrobial activity, mutation inhibition effect, cholesterol reduction effect, anticancer effect of the physiologically active ingredients contained in the grape.

Claims (7)

1) taking young grape leaves that have been circulated and removing eggplants, then washing them clean and removing water; 2) squeezing the drained grape leaves (swelling-rubbing-bundling), 3) repeating the sound treatment, and 4) A method for producing grape leaf tea comprising the step of drying the grape leaves subjected to the treatment. The method of claim 1, wherein the ironing treatment is carried out at 150 ~ 250 ℃. The method of claim 1, wherein the steaming treatment is repeated 2 to 4 times. The method of claim 3, wherein the thinning treatment is repeated three times. Grape leaf tea produced by the method of any one of claims 1 to 4. A tea bag comprising the grape leaf tea of claim 5. The tea bag according to claim 6, wherein the tea bag material is cotton or nonwoven fabric.

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