KR101556338B1 - Preparing method of purple corn extract - Google Patents

Abstract

The present invention relates to a method for producing a purple corn extract, and more particularly, to a method for effectively producing a purple corn extract having a remarkably improved yield and functionality. Specifically, according to the purple corn extract preparation method of the present invention, it is possible to mass produce a purple corn extract or an excellent quality purple corn extract having remarkably improved contents of polyphenols and anthocyanins in the extract in a short time, and furthermore, A composition for preventing or treating diseases selected from the group consisting of cancer, hypertension, diabetes, and complications of diabetes, which contains an anthocyanin isolated therefrom as an active ingredient, and which is free from side effects or toxicity, and an antioxidative composition, There is provided a food composition comprising an antioxidant composition or an antioxidant composition.

Description

TECHNICAL FIELD The present invention relates to a purple corn extract,

The present invention relates to a method for producing a purple corn extract, and more particularly, to a method for effectively producing a purple corn extract having a remarkably improved yield and functionality.

Diabetes is a chronic disease in which glucose is released from the blood due to insulin deficiency, that is, blood glucose level is higher than that of a normal person, and is caused by abnormal abnormal insulin metabolism process or abnormal physiological activity of insulin in β-cells of Langerhans islets in the pancreas It is one of the representative adult diseases that develops. In developed countries, the number of diabetic patients is rapidly increasing, and the number of diabetic patients is gradually increasing as the living standard is improved and the lifestyle is westernized in Korea. In recent years, about 5% or at least 2.5 million people are estimated to be diabetic, and diabetes is the fourth leading cause of death among Koreans.

When the hyperglycemic environment continues for a long time in the body due to diabetes, various complications may be induced by high osmotic stress caused by hyperglycemia or by the presence of glycated products in the large and small blood vessels of the kidney, nerve, retina and whole body. Because of the greater risk of complications caused by diabetes, efforts are now being made to inhibit, prevent, or ameliorate the onset or progression of diabetic complications (diabetic complications) rather than the treatment of diabetes itself.

Recently, as incomes of diabetics and diabetic complications have increased due to the increase of national income and dietary pattern, inhibitors have been developed and prescribed for the prevention of diabetic and diabetic complications. However, prescription of diabetic and diabetic complications is limited due to side effects. Therefore, the importance of functional foods which do not cause such side effects or toxicity is strongly recognized.
Especially, interest in physiologically active ingredients contained in plants is increasing, and there is a tendency to prefer natural products having various physiological effects and proven safety and efficacy against human body. In addition, there is a demand for the development of medicines and health foods, such as drinks, in which soluble substances in natural materials are extracted and added so that the active ingredients of such natural products can be used quickly and easily.
Representative of the physiologically active ingredients contained in these plants are polyphenol components such as flavonoids, procyanidin, tannins, anthocyanins, and phenolic acids. Such polyphenols are aromatic compounds having two or more phenolic hydroxyl groups in one molecule and are antioxidative physiologically active substances having anticancer, anti-inflammatory and anti-thrombogenic action.
Purple corn (Zea mays L.) is a perennial plant belonging to the Gramineae family, which has been cultivated for thousands of years in Peru, mainly in Latin America. In addition, purple corn contains various functional materials such as dietary fiber, polyphenol, plant sterol, tocophenol derivative and carotenoid, and in particular, anthocyanin, which is one of the above-mentioned polyphenols, is a main component. These anthocyanins are a kind of water soluble flavonoid red pigment of polyphenols, and can be used as health functional foods and medicines because they have excellent anti-obesity, antidiabetic and antioxidant effects.
Therefore, the various effective ingredients including the purple corn extract and the anthocyanin isolated from the extract can be used in the fields of health functional foods and pharmaceuticals because they can have anti-cancer, anti-diabetic, antihypertensive, antioxidant and anti- , The conventional method for producing an extract has a problem that it takes a long time and a lot of manpower to produce an extract, which is not economical and is not suitable for an industrial scale.

Japanese Patent Publication No. 3978564 (September 19, 2007) Published Patent Application No. 10-2011-0092179 (Aug. 17, 2011)

Ph.D. Thesis: Antioxidative Effect of Purple Corn Pigment and Its Application to the Food Industry,.

The inventors of the present invention have found that when purple corn is extracted under specific conditions, the purple corn extract or the extract of the present invention has an excellent quality The present inventors completed the present invention by confirming that the purple corn extract of the present invention can be mass-produced in a short time.
Accordingly, the present invention provides a production method capable of mass-producing a purple corn extract having excellent effects of preventing or treating various diseases such as cancer, hypertension, diabetes, and complications of diabetes without significant adverse effects or toxicity, .

In order to achieve the above object, the present invention provides a method for preparing a purple corn extract comprising extracting purple corn with a C ₁ to C ₄ lower alcohol solvent having a concentration of 5 to 80% (v / v) .

The present invention also provides a method for producing purple corn extract comprising ultrasonically extracting purple corn with a lower alcohol solvent of C ₁ to C ₄ .

The present invention also provides a purple corn extract prepared by the above-described method.

The present invention also relates to the above purple corn extract,

A composition for preventing or treating diseases selected from the group consisting of cancer, hypertension, diabetes, and complications of diabetes, an antioxidative composition, and a composition or antioxidant composition for preventing or treating the above-mentioned diseases, ≪ / RTI >

Hereinafter, the present invention will be described in more detail.

According to one embodiment of the present invention, there is provided a method for preparing a purple corn extract comprising extracting purple corn with a C ₁ to C ₄ lower alcohol solvent having a concentration of 5 to 80% (v / v).

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The extraction is preferably a step of extracting the purple corn with a C ₁ to C ₄ lower alcohol solvent having a concentration of 20 to 40% (v / v), more preferably 30 to 35% (v / v) . ≪ / RTI > When a solvent that does not meet the above-mentioned concentration range is used, there is a problem that the yield is lowered, which is not preferable.

The lower alcohol solvent of C ₁ to C ₄ may be ethanol, methanol, propanol, or butanol, preferably 10 to 20 times, more preferably 10 to 15 times the weight of the purple corn Can be used. When the amount of the alcohol solvent is less than the above range, the yield, the polyphenol content and the anthocyanin content can be remarkably reduced, and when the amount exceeds the above range, the increase in the effect is insignificant, while the cost and the extraction unit cost Which is not preferable.

Further, preferably, the extraction may be performed using ultrasonic waves.

When extracted using ultrasonic waves, the C ₁ to C ₄ lower alcohol solvent may be used in an amount of 5 to 20 times by volume, more preferably 10 to 20 times by volume, of the purple corn.

In addition, the preparation method may further include a step of concentrating and drying the extract obtained through the extraction step to produce an extract, but the present invention is not limited thereto. As shown in FIG.

On the other hand, anthocyanin among the active ingredients contained in purple corn is chemically unstable. Specifically, anthocyanin is structurally charged with cations because of the covalent bonding of one electron to the carbon at the 2-position among unshared electron pairs of oxygen at the 1-position. Such compounds are called oxonium compounds, The chemical instability of anthocyanin is related to the oxonium structure.

Therefore, in order to solve the above-mentioned degeneration due to chemical instability of anthocyanin, inorganic acids such as hydrochloric acid, nitric acid, sulfamic acid and perchloric acid, and at least one acid selected from acetic acid, formic acid, lactic acid, and organic acids such as oxalic acid .

Preferably, the C ₁ to C ₄ lower solvent may include at least one acid selected from the group consisting of inorganic acids and organic acids in an amount of 0.1 to 20% (v / v) of the solvent. If the amount is below the above range, there are problems such as a decrease in the extraction yield and a decrease in stability, which is undesirable. When the amount exceeds the above range, there is a problem such as a weakening of stability.

The extraction time and the extraction temperature may be preferably 20 to 60 캜 for 4 to 24 hours, more preferably 4 to 12 hours. When the amount of the extract is less than the above range, there is a problem such as a decrease in the extraction yield, which is not preferable. When the extraction exceeds the above range, there is a problem such as a weak stability.

On the other hand, when the above-described extraction process is performed using ultrasonic waves, it is preferable to carry out the ultrasonic treatment at an oscillation intensity of 150 to 300 watt for 8 to 20 minutes, more preferably for an oscillation intensity of 190 to 260 watt for 9 to 16 minutes In case of extracting below the above range, there is a problem that the yield of the extract and the content of the functional substance contained in the extract are insufficient, and when extracting in excess of the above range, The increase in the effect to be caused is insignificant.

(%), Total polyphenol content (mg / g), ABTS inhibition rate (%), aldose reductase inhibition rate (%) and total anthocyanin content (mg / L) of the purple corn prepared by the above- Or the like, or a significantly improved effect.

In detail, when the ultrasonic wave is not used, the total yield of the purple corn extract and the total polyphenol content of the extract are most affected by the extraction temperature, as shown in Example 7 to be described later. Therefore, it is preferable to further increase the total yield and the polyphenol content by performing the extraction temperature at a temperature of 30-60 캜.

In addition, the total anthocyanin content of the extract is most affected by the extraction time, and preferably, the extraction time is performed for 7.5 to 9 hours to further increase the total anthocyanin content of the extract.

On the other hand, when the extraction process is carried out using ultrasound, the total polyphenol content in the purple corn extract and the ABTS inhibition rate of the extract are most influenced by the concentration ratio of the extraction solvent. Therefore, preferably, the ultrasonic extraction step is performed by ultrasonically extracting a C ₁ to C ₄ lower alcohol solvent having a concentration of 5 to 80% (v / v), more preferably 20 to 40% (v / v) The total polyphenol content and ABTS inhibition rate of the extract can be further increased.

In addition, the total yield of the extract and the inhibition rate of the aldose reductase are most affected by the extraction time, and preferably the ultrasonic extraction is performed for 9 to 16 minutes to further increase the total yield of the extract and the inhibitory rate of the aldose reductase have. Also, the major anthocyanin area value is most influenced by the vibration intensity at the time of ultrasonic extraction, and preferably, the ultrasonic extraction is performed at a vibration intensity of 190 to 260 watts, thereby further increasing the major anthocyanin area value.

Therefore, according to another embodiment of the present invention, a purple corn extract prepared by the above purple corn extract manufacturing method is provided.

The present invention also provides a composition for preventing or treating diseases selected from the group consisting of purple corn extract or cancer comprising anthocyanin isolated from the extract as an active ingredient, hypertension, diabetes, and diabetic complications.

As used herein, the term treatment refers to the reduction or amelioration of symptoms, a reduction in the extent of disease, a delay or alleviation of disease progression, an improvement, alleviation or stabilization of a disease state, partial or complete recovery, Is used to mean both.

The composition may preferably be to prevent or treat the diabetic complications by inhibiting the activity of the aldose reductase.

Among diabetic complications, diabetic retinopathy (diabetic retinopathy) or nuclear hardening cataract is known to be the main cause of the accumulation of sorbitol in the cells. In particular, in patients with non-insulin dependent diabetes mellitus, progression of diabetic retinopathy is more affected by the duration of abnormally high concentration of sorbitol than by the amount of sorbitol in the erythrocytes. Therefore, Clinical studies have shown that early use of an inhibitor of aldose reductase may be effective in the prevention and treatment of diabetic retinopathy.

Aldose reductase is one of the enzymes directly involved in the treatment of complications induced by hyperglycemia and is involved in the pathway of polyol (polyol), one of the metabolic pathways in vivo. The polyol pathway consists of two pathways, a pathway in which aldose reductase is involved and reduces glucose to sorbitol, and a pathway in which sorbitol dehydrogenase is involved and sorbitol is dehydrogenated into D-fructose. The polyol pathway is present in the brain, liver, pancreas, kidney, adrenal glands, testes, seminal vesicles, placenta, red blood cells, lens, cornea, iris, retina and peripheral nerves and is reduced to sorbitol in glucose and sorbitol produced is in dihydrogenase To be converted into fructose. However, when the intracellular glucose inflow is increased, glucose produces a large amount of intermediate metabolites and sorbitol through the polyol pathway, and sorbitol is not effectively diffused out of the cell and accumulates in the cell, resulting in increased intracellular osmotic pressure . High osmotic conditions cause mutations in various metabolic processes in the cell and reduce the stability of the cell membrane leading to complications such as neuropathy, nephropathy, retinopathy, and cataract.

Therefore, the composition can be effectively used for the prevention or treatment of diabetic complications by containing the purple corn extract or the anthocyanin isolated from the extract, which is excellent in inhibition rate of aldose reductase, as an active ingredient.

Furthermore, the purple corn extract or the anthocyanin isolated from the extract has various functions including antidiabetic, antioxidant, antimicrobial, antimutagenic and anticancer activities in addition to functions as a natural coloring agent. Accordingly, the present invention provides an antioxidative composition comprising the purple corn extract or the anthocyanin isolated from the extract as an active ingredient. Since the antioxidant composition can be used for preparing an antioxidant and the antioxidant activity also has excellent effects on wrinkles, stains, or aging prevention, the antioxidant composition can also be used for manufacturing a cosmetic composition. In addition, the anthocyanin extract inhibited the growth of cancer cells, and anthocyanin in the adenocarcinoma of the colon showed a remarkable survival prolongation effect on the development of cancer. In the treatment of various blood circulation diseases due to the weakness of capillary blood vessels, Inhibition, and maintenance of normal vascular permeability.

The term "food" as used herein means a natural product or a processed product containing one or more nutrients, preferably a food product, a food additive, a health functional ingredient Food, and beverage, each of which can be manufactured by a common manufacturing method.

(Eg, soy sauce, soybean paste, kochujang, mixed potato, etc.), sauces, confectionery (eg, snacks), and various kinds of foods such as meat products, fish products, tofu, (Eg, fruits, vegetables, beverages, beverages, fermented beverages, tea, etc.), natural foods (eg, Seasonings (e.g., ramen soup, etc.), various health supplements, health functional foods, and the like.

In the present invention, the functional food refers to a food group which is imparted with added value to function and express the function of the food by using physical, biochemical, biotechnological techniques and the like, the regulation of the biological defense rhythm of the food composition, Means a food which is processed and designed so that the body control function regarding the body is sufficiently expressed to the living body. The functional food may include a food-acceptable food-aid additive, and may further comprise suitable carriers, excipients and diluents conventionally used in the production of functional foods.

As used herein, beverage is intended to include functional beverages. The beverage is not particularly limited as long as it contains the purple corn extract or the anthocyanin isolated therefrom as an active ingredient as an essential ingredient and may contain various flavors or natural carbohydrates as an additional ingredient .

In addition, the above-mentioned food composition can be used as a flavoring agent such as a variety of nutrients, vitamins, minerals (electrolytes), synthetic flavors and natural flavors, coloring agents and thickening agents (cheese, chocolate etc.), pectic acid and its salts, Organic acids, protective colloid thickening agents, pH adjusting agents, stabilizers, preservatives, glycerin, alcohols, and carbonating agents used in carbonated beverages. These components may be used independently or in combination. The proportion of such additives can be selected, for example, in the range of 0 to 20 parts by weight per 100 parts by weight of purple corn extract of the present invention, but is not limited thereto and can be appropriately adjusted by those skilled in the art.

The pharmaceutical composition may further contain an appropriate carrier, excipient, diluent and the like conventionally used in the production thereof.

The carrier, excipient and diluent may be, for example, lactose, dextrose, sucrose, sorbitol, mannitol, xylitol, erythritol, maltitol, starch, acacia rubber, alginate, gelatin, calcium phosphate, calcium silicate, cellulose, methylcellulose, microcrystalline cellulose, Polyvinylpyrrolidone, water, methylhydroxybenzoate, propylhydroxybenzoate, talc, magnesium stearate, and the like.

The above pharmaceutical compositions may be used in oral formulations such as powders, granules, tablets, suspensions, emulsions, syrups and the like in accordance with a conventional method. The preferable dosage is not particularly limited so long as the amount suitable for treatment or prevention of the subject and / And can be determined depending on the age, sex, general health condition and weight of the subject to be treated, kind and severity of the disease, kind of formulation, kind and content of other components contained in the composition, And may be suitably selected by those skilled in the art.

According to the purple corn extract of the present invention, it is possible to mass-produce a purple corn extract or a purple corn extract of excellent quality with remarkably improved contents of active ingredients in the extract in a short period of time. Further, the purple corn extract or the purified purple corn extract A composition for preventing or treating diseases selected from the group consisting of cancer, hypertension, diabetes, and complications of diabetes mellitus including anthocyanin as an active ingredient without any side effects or toxicity, and a composition for preventing or treating the diseases, / RTI >

1 is a three-dimensional graph of the total yield (%) of purple corn according to extraction temperature (° C) and extraction time (hr) measured according to Example 5.A of the present invention.
2 is a graph showing the relationship between the concentration of ethanol solvent (% (v / v)) measured according to Example 5.A of the present invention and the total yield (%) of purple corn according to the amount of extraction solvent Dimensional graph.
3 is a three-dimensional graph of the total polyphenol content (mg / g) of purple corn according to extraction temperature (° C) and extraction time (hr) measured according to Example 5.B of the present invention.
Figure 4 shows the total polyphenol content (mg / g) of purple corn according to the concentration of ethanol solvent (% (v / v)) measured according to Example 5.B of the present invention and the amount of extraction solvent (1: ). ≪ / RTI >
5 is a three-dimensional graph of total anthocyanin content (mg / L) of purple corn according to extraction temperature (° C) and extraction time (hr) measured according to Example 5.C of the present invention.
Figure 6 shows the total anthocyanin content (mg / L) of purple corn according to the concentration of ethanol solvent (% (v / v)) measured according to Example 5.C of the present invention and the amount of extraction solvent (1: Dimensional graph.
FIG. 7 is a contour line showing the total yield (%) of purple corn according to the vibration intensity (watt), the extraction time (min) and the ratio of the extraction solvent (%).
8 is a contour line of the total polyphenol content of purple corn according to the vibration intensity (watt), the extraction time (min) and the proportion of the extraction solvent (%) upon ultrasonic extraction.
FIG. 9 is a contour line showing the ABTS + inhibition rate (%) of purple corn according to the vibration intensity (watt), the extraction time (min) and the ratio of the extraction solvent (%).
FIG. 10 is a contour line of the major anthocyanin area area of purple corn according to the vibration intensity (watt), the extraction time (min), and the proportion of the extraction solvent (%) upon ultrasonic extraction.
Fig. 11 is a contour line of aldose reductase inhibition rate (%) of purple corn depending on the vibration intensity (watt), extraction time (min) and ratio of extraction solvent (%) upon ultrasonic extraction.
FIG. 12 shows HPLC data of the component analysis of the extracts extracted from each section during ultrasonic extraction.

Hereinafter, preferred embodiments of the present invention will be described in more detail to facilitate understanding of the present invention. However, the following examples are illustrative of the present invention, and the scope of the present invention is not limited thereto.

Reference Example  1. Experimental material

The purple corn ( Zea ) used in the following Examples and Experimental Examples mays . L) To prepare the sample, purple corn was supplied from the Gangwon-do corn test site, and dried by hot air at 45 ° C. Then, it was crushed to a size of 0.5 mm or less using a crusher (Kaiser, JL-500, Joylife) Purple corn samples were prepared by varying the particle size. Ethanol (purity 94.5% (v / v)) was purchased from Daejung Co. (4020-2210) and the reagents used for the analysis were the reagents above the first grade.

Example  1. Experimental design for optimization of extraction conditions

In this experiment, the central composite design was used to design the extraction conditions and the response surface methodology (RSM) was used to optimize the extraction conditions. (2007); Optimization of Ultrasonic-assisted Extraction of Phenolic Compounds from Chinse Quince (Chaenomeles sinensis) by Response Surface Methodology, Hui Teng et al., (J. Choi, YJ et al. (Industrial Food Engineering, 2008)), and the optimization of the hot water extraction process for the beneficial component of licorice using reaction surface methodology.

In Table 1 below, purple corn ( Zea mays . L), and the results were shown. Specifically extracted with independent (criteria) variable in the central composite design temperature (℃, X _1), the extraction time (hr, X _2), extracting the concentration of ethanol (% (v / v)) , X 3), the extraction solvent (-2, -1, 0, 1, 2) of the amount of ethanol in 1 g of the sample (1: X, X ₄ ) And extracted.

The dependent variables (response) related to the quality characteristics of the extracts were total yield, total polyphenol content (TPC), and total anthocyanin content (TAC) The mean value was used for regression analysis. The statistical analysis system (SAS version 9.1) program was used to predict the optimal conditions by regression analysis.

Response surface analysis conditions of purple corn and its result No. ^One) Independent variables ^{2 )} Dependent variable ³⁾ X ₁ X ₂ X ₃ X ₄ Y ₁ Y ₂ Y ₃ One 30 (-1) 6 (-1) 25 (-1) 12 (-1) 6.00 5.91 55.16 2 50 (1) 6 (-1) 25 (-1) 12 (-1) 7.65 3.40 32.06 3 30 (-1) 10 (1) 25 (-1) 12 (-1) 6.00 6.55 65.20 4 50 (1) 10 (1) 25 (-1) 12 (-1) 6.70 5.47 47.71 5 30 (-1) 6 (-1) 35 (1) 12 (-1) 5.85 6.32 66.17 6 50 (1) 6 (-1) 35 (1) 12 (-1) 8.50 2.04 16.61 7 30 (-1) 10 (1) 35 (1) 12 (-1) 6.15 8.08 77.94 8 50 (1) 10 (1) 35 (1) 12 (-1) 7.30 3.70 34.71 9 30 (-1) 6 (-1) 25 (-1) 20 (1) 6.30 4.42 41.02 10 50 (1) 6 (-1) 25 (-1) 20 (1) 7.75 6.64 67.21 11 30 (-1) 10 (1) 25 (-1) 20 (1) 6.25 6.33 63.39 12 50 (1) 10 (1) 25 (-1) 20 (1) 8.10 6.47 65.81 13 30 (-1) 6 (-1) 35 (1) 20 (1) 6.35 5.75 58.94 14 50 (1) 6 (-1) 35 (1) 20 (1) 9.25 3.62 70.81 15 30 (-1) 10 (1) 35 (1) 20 (1) 6.35 6.30 64.96 16 50 (1) 10 (1) 35 (1) 20 (1) 9.00 4.67 69.92 17 20 (-2) 8 (0) 30 (0) 16 (0) 5.75 3.41 20.63 18 60 (2) 8 (0) 30 (0) 16 (0) 9.10 3.80 24.07 19 40 (0) 4 (-2) 30 (0) 16 (0) 5.95 4.64 40.02 20 40 (0 12 (2) 30 (0) 16 (0) 6.00 4.63 37.48 21 40 (0 8 (0)  20 (-2) 16 (0) 6.40 6.22 52.90 22 40 (0) 8 (0) 40 (2) 16 (0) 5.75 4.92 71.46 23 40 (0) 8 (0) 30 (0) 8 (-2) 2.70 6.63 60.04 24 40 (0) 8 (0) 30 (0) 24 (2) 6.35 5.72 56.32 25 40 (0) 8 (0) 30 (0) 16 (0) 5.75 4.95 45.34 26 40 (0) 8 (0) 30 (0) 16 (0) 5.78 4.34 35.13 27 40 (0) 8 (0) 30 (0) 16 (0) 5.73 4.28 40.88

1) The interval number of the experimental condition according to the central synthesis plan

2) X ₁ = extraction temperature (℃), X ₂ = Extraction time (hr), X ₃ = Ethanol concentration (% (v / v in)), X ₄ = amount of ethanol (1: X)

3) Y ₁ = total yield (%), Y ₂ = total polyphenol content (mg / g), Y ₃ = total anthocyanin content (mg /

Table 2 shows the results when expressed in response surface model equation using the results shown in Table 1. The ridge line analysis was carried out with the estimated normal points as the good points, And the extraction conditions at this time (optimum extraction conditions) are shown in Table 3 below. The total yield, total polyphenol content, and total anthocyanin content (response surface analysis results) according to each extraction condition (reaction surface analysis conditions: extraction temperature, extraction time, concentration of extracted ethanol solvent, amount of extraction solvent) (Fig. 1 to 6), and the effect on each result was examined according to each extraction condition (see Table 4) (see Example 5).

Example  2. Extraction and total yield measurement

1 g of each of the purple corn samples prepared in Reference Example 1 was placed in a 10 ml tube, ethanol was added at a concentration and an amount corresponding to the conditions shown in Table 1, and the contents of the purple corn samples were measured using a water bath (TAITEC, Japan) The extraction conditions were extracted with 27 extraction conditions according to the temperature, ethanol concentration and addition amount of each extraction time in Table 1. In order to overcome the chemical instability due to the structural characteristics of the purple corn anthocyanin, inhibition of anthocyanin modification was suppressed by adding HCl to the concentration of 0.1% (v / v) HCl for each solvent. The extract thus obtained was concentrated under reduced pressure and dried with a high-efficiency centrifugal concentration system (EZ-2 plus, Genevac, UK) after excluding 1 mL (stored for experiments in Examples 2 and 3) The total yield (%) of the extracts was determined by the solid yield (%) to be shown in Table 1, respectively.

Example  3. Total polyphenol content ( TPC ) Measure

The total polyphenol content was determined by the Folins-Denis method, widely used for the analysis (References: Folin O, Denis W. 1912, On phosphotungstic-phosphomolybdic compounds as color reagents. : 239-249). 0.5 mL of the sample obtained in Example 2 was mixed with 0.5 mL of 1 N Folin-Ciocalteu reagent (Sigma Aldrich, F9252-500 mL), allowed to stand for 3 minutes, and then 10 mL of 2% (w / v) Na ₂ CO ₃ solution Were added. The absorbance was measured at 750 nm using a spectrophotometer (Uvikon XS, secoman, USA) after the mixture was allowed to stand for 1 hour. From the standard curve prepared using gallic acid as a reference material, the total polyphenol content (Mg / g), which is shown in Table 1 above.

Example  4. Measurement of total anthocyanin content

Total anthocyanin content was measured using the pH differential method (Reference: Giusti MM, Wrolstad RE, 2001. Characterization and measurement of anthocyanins by UV-visible spectroscopy.Current Procotols in Food Analytical Chemistry p F1.2.1-F1.2.13). The pH differential method is based on the reaction that anthocyanin undergoes a reversible structural transformation in response to changes in pH, the colorless oxonium form at pH 1.0 and the colorless hemiketal form at pH 4.5 will be. Diluted with 0.025 M potassium chloride (Oriental Chemical Ind. Co., Ltd., Seoul, Korea) buffer to determine the dilution factor so that the absorbance value would be 0.7-1.0, and the sample was diluted with 0.025 M potassium chloride Were diluted with buffer (pH 1.0) and 0.4 M sodium acetate (Samchun Pure Chemical Co., Ltd., Seoul, Korea) buffer (pH 4.5) After equilibration for 15 minutes, the absorbance was measured at 700 nm using a spectrophotometer (Uvikon XS, secoman, USA) at the maximum absorption wavelength (515 nm) and the total anthocyanin content was calculated by the following equation.

[Equation 1]

_{A = (A λ vis - max} -A 700 nm) pH1 .0 - (A λ vis - max -A 700 nm) pH4 .5

A _{λ vis - max} : absorbance at maximum absorption wavelength

A _{700 nm} : Absorbance at 700 nm

MW: molecular weight of cyaniding-3-glucoside = 449.2

DF: Dilution factor

?: molar extinction coefficient = 26,900

Example 5 . Derivation of optimum extraction condition

Based on the results of the extraction results of the respective conditions shown in Table 1 above, based on the results of the total yield, the total polyphenol content (TPC), and the total anthocyanin content (TAC), superimposing Table 1 shows the range of optimal extraction conditions for each extract. After setting arbitrary points in the predicted range, we experimented with the method and compared with the predicted values.

Polynomials on the extraction conditions of purple corn through reaction surface analysis Dependent variable Secondary polynomials obtained through reaction surface analysis ^{1 )} R ² valence Total yield (%) Y _TY = 29.279167-0.538500X ₁ -0.842500X ₂ -0.823000X ₃ -0.010833X ₄ + 0.006002X ₁₂ -0.007188X ₁ X ₂ + 0.059427X ₂ ² + 0.004625X ₁ X ₃ -0.003125X ₂ X ₃ + 0.010508X ₃ ² + 0.004219X ₁ X ₄ ² + 0.014844X ₂ X ₄ + 0.003437X ₃ X ₄ -0.0077997X ₄ ² 0.8004 0.0192 Total polyphenol content (mg / g) Y _TPC = 12.967917 + 0.236917X ₁ + 0.119583X ₂ -0.184667X ₃ -1.221042X ₄ -0.001699X ₁₂ -0.000781X ₁ X ₂ + 0.021901X ₂ ² -0.013988X ₁ X ₃ + 0.003563X ₂ X ₃ + 0.012854X ₃ ² + 0.16953X ₁ X ₄ ² -0.021797X ₂ X ₄ -0.007281X ₃ X ₄ + 0.029538X ₄ ² 0.7863 0.0266 Total anthocyanin content (mg / L) Y _TAC = 412.389167 + 0.248000X ₁ + 4.349167X ₂ -14.648667X ₃ -23.737500X ₄ -0.027356X ₁₂ -0.058562X ₁ X ₂ + 0.341094X ₂ ² -0.079975X ₁ X ₃ -0.072875X ₂ X ₃ + 0.288875X ₃ ² + 0.279406X ₁ X ₄ ² -0.230156X ₂ X ₄ + 0.099687X ₃ X ₄ + 0.388867X ₄ ² 0.7768 0.0325

1) X ₁ , extraction temperature (캜); X ₂ , extraction time (hr); X ₃ , concentration of ethanol solvent (%); X ₄ , the amount of the extraction solvent (1: X)

Among the extraction conditions of purple corn, the maximum level and the extraction condition Dependent variable Independent variable Maximum value Morphology X ₁ ¹⁾ X ₂ ²⁾ X ₃ ³⁾ X ₄ ⁴⁾ Total yield (%) 58.87 7.53 32.31 17.65 10.33 Saddle point Total polyphenol content (mg / g) 29.29 8.99 33.67 10.25 7.89 Saddle point Total anthocyanin content (mg / L) 45.22 7.85 34.14 22.97 82.44 Saddle point

1) X ₁ , extraction temperature (캜); X ₂ , extraction time (hr); X ₃ , concentration of ethanol solvent (%); X ₄ , the amount of the extraction solvent (1: X)

Regression analysis of regression model according to extraction condition of purple corn Extraction condition F-ratio X ₁ ¹⁾ X ₂ ²⁾ X ₃ ³⁾ X ₄ ⁴⁾ Total yield (%) 8.09 3.34 0.40 3.44 Total polyphenol content (mg / g) 3.76 2.60 3.12 3.15 Total anthocyanin content (mg / L) 1.90 4.29 2.83 2.98

1) X ₁ , extraction temperature (캜); X ₂ , extraction time (hr); X ₃ , concentration of ethanol solvent (%); X ₄ , the amount of the extraction solvent (1: X)

A. Total yield

As shown in Table 2, the regression equation R ² of the total yield (%) was 0.8004, which was significant at the level of 5%. The optimum extraction conditions were 58.87 ℃ for extraction temperature, 7.53 hr for extraction time, and the concentration of ethanol solvent was 10.33% 32.31%, and the amount of the extraction solvent was 1: 17.65 (Table 3).

The reaction surface analysis results for the yields according to the respective extraction conditions were shown in a three-dimensional graph using Sigma plots (FIGS. 1 and 2). As shown in Table 4, the extraction temperature had the greatest influence on the extraction temperature of 8.09, and the ethanol solvent concentration had a relatively small effect on the extraction temperature. It can be seen from the three-dimensional graphs of FIGS. 1 and 2 that the extracting time is not related to the yield in detail. On the other hand, in the case of the extraction temperature, the total yield tends to increase remarkably as the temperature increases (Fig. 1). In addition, with regard to the concentration condition of the ethanol solvent, the yield was increased as the concentration was increased, but the point at which the rate of increase was decreased and the amount of the extraction solvent was relatively small (FIG.

B. Total polyphenol content

As shown in Table 2, the regression equation R2 of the total polyphenol content (mg / g) was 0.7863, which was significant at the 5% level. As a result, the maximum value of total polyphenol content was 7.89mg / g. The optimal extraction conditions were 29.29 ℃ for extraction temperature, 8.99 hr for extraction time, The concentration of the ethanol solvent was 33.67%, and the amount of the extraction solvent was 1: 10.25 (Table 3).

The reaction surface analysis results for the total polyphenol content according to each extraction condition were expressed in a three-dimensional graph using Sigma plot (FIGS. 3 and 4). As shown in Table 4, the extraction temperature had the greatest effect on the extraction temperature of 3.76, followed by the extraction solvent amount, ethanol concentration, and extraction time in that order. As can be seen from FIG. 3, the lower the extraction temperature, the higher the total polyphenol content. The longer the extraction time, the more polyphenol was increased , And the point at which the rate of growth decreased. Also, as shown in FIG. 4, the concentration of the ethanol solvent was relatively insignificant to the polyphenol content, and the amount of the extraction solvent increased as the solvent ratio increased.

C. Total anthocyanin content

As shown in Table 2, the regression equation R ² of total anthocyanin content was 0.7768, which was significant at the 5% level. The maximum value of total anthocyanin was 82.44 mg / L, and the optimal extraction conditions were 45.22 ℃ for extraction temperature, 7.85 hr for extraction time, (34.14%) and the amount of extraction solvent was 1: 22.97 (Table 3).

The contour map was plotted using a Sigma plot to determine the response surface analysis results for the yields according to each extraction condition (Figures 5 and 6). As shown in Table 4, the extraction time was 4.29, and the amount of extraction solvent, ethanol concentration, and extraction temperature were influenced in order. 5 and 6, and specifically, in FIG. 5, the extraction temperature did not significantly affect the total anthocyanin content. As the extraction time increased, the anthocyanin content increased, but at the point where the increase rate decreased . In addition, as shown in FIG. 6, the concentration of ethanol solvent showed a relatively small effect on anthocyanin content, and the amount of extraction solvent increased with an increase in solvent ratio.

D. Derivation of optimal extraction conditions

The total yield (%) and total polyphenol content (mg / g) of extracts were determined by extracting temperature, extraction time, concentration of extracted ethanol solvent and amount of extraction solvent. ) Superimposing the three-dimensional graph obtained by AC on the total anthocyanin content (mg / L), and determining the overlapping portion as an extraction condition range satisfying all the characteristics of the extract, (Table 5). In addition, we set an arbitrary point in the predicted range and substituted it into the regression equation to predict the optimal value.

Range of optimal extraction conditions of purple corn through reaction surface analysis Extraction condition Optimum extraction condition range Extraction temperature (캜) 30-60 Extraction time (hr) 7.5-9.0 Concentration of ethanol solvent (% (v / v)) 32-34 The amount of extraction solvent (1: X) 10-20

As shown in Table 5 above, the purple corn extract was extracted with an extraction temperature of about 30 to 60 DEG C, an extraction time of about 7.5 to 9.0 hours, a concentration of 32-34% ethanol solvent, and an extraction solvent amount of 10-20 times And thus can be optimized.

The reliability of the regression equation derived from the experimental results obtained under the same conditions as those predicted by the RSM method can be verified by using a similar or slightly higher or lower value to the predicted range.

Estimation of optimum extraction of purple corn and its experimental value Dependent variable Forecast range Experimental value Total yield (%) 5.78 5.76 Total polyphenol content (mg / g) 4.46 4.58 Total anthocyanin content (mg / L) 40.88 42.28

Extraction temperature: 40 캜, extraction time: 8 hr, concentration of ethanol solvent: 33%, amount of extraction solvent: 1: 15

Example  6. Experimental design for optimization of extraction condition in ultrasonic extraction

As in the case of Example 1, a central composite design was used to design the experiment, and response surface methodology (RSM) was used to optimize extraction conditions.

Table 7 below shows the reaction surface analysis conditions for the optimal extraction of purple corn (Zea mays. L) and the results thereof (positive control group is shown in Table 8). Specifically, the vibration intensity (150 ~ 300 watt, X ₁ ), extraction time (8 ~ 16 min, X ₂ ), ethanol solvent concentration (solvent ratio) of the sonication as independent (condition) (20 to 40% (v / v), X ₃ ) were encoded into -1, 0, 1, and 3 stages respectively and set to 15 intervals according to the central synthesis plan (extraction solvent ratio was set as solvent Of 1: 10 (5 g of sample: 50 ml of solvent).

In addition, the dependent (response) variables related to the quality characteristics of the extract are the total yield, the total polyphenol content (TPC), the ABTS ⁺ inhibition rate against the antioxidant capacity, the major anthocyanin area value (content) And all experiments were repeated three times and the mean value was used for regression analysis. The statistical analysis system (SAS version 9.1) program was used to predict the optimal conditions by regression analysis.

No ^{1 )} Independent variable Dependent variable Vibration intensity (watt, X ₁ ) Extraction time (min, X ₂ ) Solvent ratio (%, X ₃ ) Total yield (%) TPC (%) ABTS inhibition rate (%) Major anthocyanin area value (area) AR inhibition rate (%) One -1 (150) -1 (8) 0 (30) 1.36 3.74 71.6 7.70 9.81 2 1 (300) -1 (8) 0 (30) 1.19 1.78 49.3 5.24 19.73 3 -1 (150) 1 (16) 0 (30) 1.41 1.34 31.0 6.65 18.58 4 1 (300) 1 (16) 0 (30) 2.42 2.18 57.3 10.64 18.18 5 -1 (150) 0 (12) -1 (20) 1.03 2.37 61.5 8.77 26.91 6 1 (300) 1 (16) -1 (20) 1.38 3.42 90.2 10.16 17.57 7 -1 (150) 0 (12) 1 (40) 0.99 3.35 86.0 7.96 22.15 8 1 (300) 0 (12) 1 (40) 1.07 1.90 54.9 12.05 44.01 9 0 (200) -1 (8) -1 (20) 0.94 2.69 64.0 8.40 32.76 10 0 (200) 1 (16) -1 (20) 0.74 2.59 55.3 7.03 35.57 11 1 (300) 0 (12) -1 (20) 0.89 2.91 65.0 7.45 39.86 12 0 (200) 1 (16) 1 (40) 1.93 2.47 58.1 15.95 30.30 13 0 (200) 0 (12) 0 (30) 1.64 1.82 51.5 7.50 34.56 14 0 (200) 0 (12) 0 (30) 1.62 1.73 50.8 8.67 38.36 15 0 (200) 0 (12) 0 (30) 1.75 1.92 53.8 7.52 36.40

1) The interval number of the experimental condition according to the central synthesis plan

Positive control group ABTS inhibition rate (%)
-trolox AR inhibition rate (%)
quercetin 99.59% (1 mg / ml) 82.99% (0.01 mg / ml)

Example  7. Extraction and total yield measurement

5 g of each of the purple corn samples prepared in Reference Example 1 was put in a 50 ml tube and 30 ml of ethanol was added at a ratio according to Table 7 and sonicated using a sonicator (powersonic 420, hwashin) We extracted 15 extraction conditions according to each extraction time and vibration intensity. In order to overcome the chemical instability due to the structural characteristics of purple corn anthocyanin, inhibition of anthocyanin modification was suppressed by adding HCl to 0.01% (v / v) HCl concentration for each solvent. The extract thus obtained was concentrated under reduced pressure using a high-efficiency centrifugal concentration system (EZ-2 plus, Genevac, UK) and dried, and the total yield (%) of the extract was determined by the solid yield (%) based on the dry matter amount used in preparing the extract Are shown in Table 7, respectively.

Example  8. Total polyphenol content ( TPC ) Measure

The total polyphenol content was measured by the Folins-Denis method in the same manner as in Example 3 above. Specifically, 0.5 mL of the sample obtained in Example 7 was mixed with 0.5 mL of 1 N Folin-Ciocalteu reagent (Sigma Aldrich, F9252-500 mL), allowed to stand for 3 minutes, and then 10 mL of 2% Na ₂ CO ₃ solution was added . The absorbance was measured at 750 nm using a spectrophotometer (Uvikon XS, secoman, USA) after the mixture was allowed to stand for 1 hour. From the standard curve prepared using gallic acid as a reference material, the total polyphenol content (Mg / g), which is shown in Table 7 above.

Example  9. ABTS Using Antioxidant ability ( ABTS  Inhibition rate) measurement

The antioxidant activity of ABTS radicals was measured by the antioxidant activity of ABTS free radicals produced by the reaction of ABTS and potassium persulfate, .

The radical scavenging activity of ABTS was measured at 1 mg / mL concentration and the positive control was Trolox (6-hydroxy-2, 3-ethylbenzthiazoline-6-sulphonic acid) 5,7,8-tetramethylchroman-2-carboxylic acid) showed a 99.6% radical scavenging ability at 33.33 ug / ml (290 ul of ABTS ⁺ solution in 10 ug of sample).

(2007), Structural Identification and Antioxidant Properties of Major Anthocyanin Extracted from Omija (Schizandra chinensis) Fruit, JFS c. Food chemistry (vol.74 Nr. First, 11 ml of 2 mM ABTS was mixed with 9.5 ml of 3.5 mM potassium persulfate, dissolved in 10 ml of distilled water, and 290 ml of tertiary distilled water was added to dilute 30 times and then overnight to induce ABTS radical formation. The ABTS radical-induced ABTS radical-derived solution (290 μl) was mixed with 10 μl of each extract obtained in Example 7 at room temperature for 10 minutes. The absorbance at 750 nm was measured using a spectrophotometer (secoman, USA) Were measured. The ABTS radical scavenging ability (ABTS inhibition rate (%)) was calculated from the absorbance difference (%) of the sample added and the non-added sample obtained in Example 7, as shown in the following Equation 2,

&Quot; (2) "

ABTS radical scavenging activity (%) = (1-sample absorbance / no additive absorbance) × 100

Example  10. Major Anthocyanins Area value  Measure

1 mg of the extract of each condition extracted in Example 7 was diluted to 1 mg / ml in 1 ml of 50% (v / v) MeOH solvent, and then the area of the anthocyanin area of each extract was calculated using HPLC (Table 7). Acetonitrile (AcCN) and formic acid were purchased from Merck Inc. (USA) and Fluka Inc. (Germany) as HPLC mobile phase solvents, respectively. The analytical column was C18 column (4.6 mm × 150 mm, 10 μl) from Shiseido, Japan. The analytical wavelength was 520 nm for visible light, and the sample injection volume was the column temperature 40 ° C. The concentration gradient conditions of the HPLC mobile phase solvent were as shown in Table 9 below. Area values of major anthocyanin components (Cyaniding-3-glucoside, Pelargonidin-3-glucoside, and Peonidin-3-glucoside etc.)

HPLC extraction conditions of purple corn Classification Condition Moblie phase A - 0.1% formic acid
B - AcCN Gradient (B%) 10 minutes 10% 20 minutes 15%, 35 minutes 28%, 40 minutes 100%, 43 minutes 5 minutes 53 minutes 5%

Example  11. Aldos  Measurement of reducing enzyme inhibition rate

In relation to the treatment or prevention effect of diabetic complication, DMSO was added to the extract of each condition extracted in Example 2 to measure the inhibitory effect of aldose reductase for inhibiting the onset of diabetic complications, and the extract was prepared at a concentration of 1 mg / ml Respectively.

As a source of the enzyme, a rat lens was extracted and homogenized by adding a certain amount of sodium buffer (pH 6.2) according to the wet weight. The homogenized lens was centrifuged at 10000 rpm for 30 minutes at 4 ° C The supernatant was taken up to a concentration of 40% with ammonium sulfate and centrifuged. The supernatant was again taken, and ammonium sulfate was added thereto to 70% again. After stirring for 1 hour, the resulting pellet , And dialyzed for 1 day, which was used as an enzyme source.

The activity of the rat lens aldose reductase was determined by measuring the absorbance reduction rate of NADPH at 340 nm for 4 minutes using DL-glyceraldehyde as a substrate by spectrophotometer.

Specifically, 530 ul of 0.1 M sodium phosphate buffer (pH 6.2) was added to a 1 ml cuvette, and 160 ul of the same unit of enzyme was added thereto. 100 ul of 10 mM DL-glyceraldehyde was added (or not added) After the addition of 100 ul of 0.3 mM NADPH, the absorbance of NADPH was measured at 340 nm for 4 minutes. The results are shown in Table 7 (AR inhibition rate (%)). As a control, quercetin, a standard substance known to inhibit aldose reductase inhibition, was treated in the same manner as described above, and the rate of decrease in absorbance was measured and compared with purple corn (Table 8).

Example  12. Derivation of optimal extraction conditions

The contour map (contour map) for the total yield, total polyphenol content (TPC), ABTS inhibition rate, major anthocyanin area value and ALD inhibitory rate (AR inhibitor (%)) ) Were superimposed on each other, the range of optimum extraction conditions of each condition of Table 7 was predicted in the range of overlapping portions.

Table 10 shows the results of the response surface model equation using the results shown in Table 7 above. Table 11 shows the maximum value of each ridge and the extraction condition (optimum extraction condition) at that time.

Total yield, total polyphenol content, ABTS inhibition rate, major anthocyanin area value and inhibitory rate of aldose reductase (reaction surface analysis) according to each extraction condition (reaction surface analysis conditions: vibration intensity, extraction time, solvent ratio) plotted with contour lines (Version 10.0, Systat Software Inc, USA) (Figs. 7 to 11), and the effect of each extraction condition on each result was examined (Table 12). The statistical analysis system (SAS version 9.1) program was used to predict the optimal conditions by regression analysis.

Polynomials on the extraction conditions of purple corn through reaction surface analysis Dependent variable Secondary polynomials obtained through reaction surface analysis ^{1 )} R ² valence Total yield (%) Y _TY = -0.020804-0.004987X ₁ -0.407875X ₂ + 0.256639X ₃ -0.000013194X ₁ ² + 0.001013X ₁ X ₂ -0.001141X ₂ ² + 0.000007533X ₁ X ₃ + 0.010135X ₂ X ₃ -0.006183X ₃ ² 0.9318 0.0190 Total polyphenol content (mg / g) Y _TPC = 12.415430-0.018390X ₁ -0.834504X ₂ -0.182790X ₃ + 0.000021155X ₁ ² + 0.002009X ₁ X ₂ + 0.022933X ₂ ² -0.000631X ₁ X ₃ -0.0089442X ₂ X ₃ + 0.007394X ₃ ² 0.9522 0.0082 ABTS + inhibition rate (%) Y _ABTS = 185.307184-0.222553X ₁ -7.613813X ₂ -3.701514X ₃ + 0.000149X ₁ ² + 0.043695X ₁ X ₂ + 0.090459X ₂ ² -0.013394X ₁ X ₃ -0.206778X ₂ X ₃ + 0.159973X ₃ ² 0.9409 0.0136 Major anthocyanin area value (area) Y _AC = 51.491227-0.036947X ₁ -2.942226X ₂ -1.842043X ₃ -0.000124X ₁ ² + 0.005674X ₁ X ₂ + 0.021489X ₂ ² + 0.001109X ₁ X ₃ + 0.053284X ₂ X ₃ + 0.018438X ₃ ² 0.8863 0.0605 AR inhibition rate (%) Y _ARI = -131.950338 + 1.055848X ₁ + 18.930262X ₂ -4.566950X ₃ -0.002204X ₁ ² -0.010826X ₁ X ₂ -0.713597X ₂ ² + 0.004492X ₁ X ₃ + 0.028675X ₂ X ₃ + 0.052399X ₃ ² 0.9170 0.0299

1) X ₁ , vibration strength (in watts); X ₂ , extraction time (min); X ₃ , ratio of ethanol solvent (%)

Among the extraction conditions of purple corn, the maximum level and the extraction condition Dependent variable Vibration intensity (watt) Extraction time (min) Solvent Ratio (%) Maximum value Morphology Total yield (%) 258.77 15.45 32.31 2.24 Saddle point Polyphenol content (mg / g) 190.47 9.65 36.45 3.18 Saddle point ABTS + inhibition rate (%) 197.11 10.24 38.18 77.15 Saddle point Major anthocyanin area value (area) 244.26 14.29 37.79 12.97 Saddle point AR inhibition rate (%) 228.88 11.95 20.01 46.00 Saddle point

Regression analysis of regression model according to extraction condition of purple corn Extraction condition F-ratio Total yield (%) TPC (mg / g) ABTS inhibition rate (%) Major anthocyanin area value (area) AR inhibitor (%) Vibration intensity (watt) 6.49 2.19 0.77 5.63 0.65 Extraction time (min) 9.55 12.34 9.17 3.39 15.97 Solvent Ratio (%) 6.72 18.68 16.60 3.98 1.81

A. Total yield

As shown in Table 10, the regression equation R ² of the total yield (%) was 0.9318, which was significant at the 5% level. The maximum value of the yield was 2.24%, and the optimal extraction conditions were 258.77 watts of vibration intensity, 15.45 min of extraction time, and 32.31% of ethanol solvent, respectively. (Table 11).

A contour map was drawn using a Sigma plot to determine the reaction surface analysis results for the yields according to the respective extraction conditions (FIG. 7). As can be seen from FIG. 7, the longer the extraction time and the higher the extraction solvent ratio, the higher the total yield.

As shown in Table 12, the extraction time was 9.55, and the influence of the vibration intensity and the ethanol concentration ratio was relatively small compared to the extraction time.

B. Total polyphenol content

As shown in Table 10, the regression equation R ² of the total polyphenol content (mg / g) was 0.9522, which was significant at the 5% level. As a result, the maximum value of total polyphenol content was 3.18 mg / g. The optimal extraction conditions were 190.47 watt vibration intensity, 9.65 min extraction time, (Table 11).

The contour map was plotted using a Sigma plot to determine the response surface analysis results for the yield according to each extraction condition (FIG. 8). As shown in FIG. 8, it was confirmed that the content of polyphenol is increased as the vibration intensity is low, the extraction time is short, and the ratio of the extraction solvent is high.

As shown in Table 12, the solvent ratio was the largest at 18.68, and the extraction time was 12.34, which was influenced not only by the solvent ratio but also by the extraction time, 2.19, indicating relatively little effect on solvent ratio or extraction time.

C. ABTS  Inhibition rate

As shown in Table 10, the regression equation R ² of ABTS inhibition rate (%) was 0.9409, which was significant at the 5% level. The maximum value of ABTS inhibition rate was 77.15%, and the optimal extraction conditions were 197.11 watt of vibration intensity, 10.24 min of extraction time, 38.18% of extraction solvent, (Table 11).

A contour map was plotted using a Sigma plot to determine the reaction surface analysis results for the yield according to each extraction condition (FIG. 9). As shown in FIG. 9, it was found that the inhibition rate increases as the vibration intensity is lower, the extraction time is shorter, and the solvent ratio is higher.

As shown in Table 12, the effect of extraction conditions was most affected by the solvent ratio of 16.60, followed by extraction time of 9.17, which was also affected by the extraction time, but the vibration intensity was only 0.77 Solvent ratio or extraction time.

D. Major anthocyanins Area value

As shown in Table 10, the regression equation R ² of the major anthocyanin area area was 0.8863, which was significant at the 10% level. The optimum extraction conditions were 244.26 watts of vibration intensity, 14.29 min of extraction time, and 37.79% of extraction solvent, respectively. As a result, the maximum value of ABTS inhibition rate was 12.97 area. (Table 11).

A contour map was drawn using a Sigma plot to determine the response surface analysis results for the yields according to the respective extraction conditions (FIG. 10). As shown in FIG. 10, it was found that the anthocyanin content can be further increased by extracting with an oscillation intensity of 200 to 280 watts, and that an extract having a high anthocyanin content can be obtained as the extraction time and solvent ratio are higher.

As shown in Table 12, the influence of the extraction condition was most affected by the vibration intensity of 5.63, and the influence of the extraction time and the ethanol concentration ratio was relatively small compared with the vibration intensity.

E. Aldos  Reducing enzyme inhibition rate

As shown in Table 10, regression equation R ² of aldose reductase inhibition rate (%) was 0.9170, which was significant at the 5% level. The optimum extraction conditions were 228.88 watts of vibration intensity, extraction time of 11.95 min, extraction solvent ratio of 20.01%, and the maximum extraction rate of ABTS inhibition was 46.00% (Table 11).

A contour map was drawn using a Sigma plot to determine the reaction surface analysis results for the yields according to the respective extraction conditions (FIG. 11). 11, when the extraction time, the extraction solvent ratio, and the vibration intensity corresponded to the intermediate level, the aldose reductase inhibition rate was found to be high.

As shown in Table 12, the extraction time was 15.97, and the vibration intensity and solvent ratio had a relatively small effect on extraction time. Specifically, the longer the extraction time, the greater the AR inhibition rate.

F. Derivation of optimum extraction condition

In order to elucidate optimal extraction conditions of purple corn extracts, the total yield (%) of extracts (%), total polyphenol content (%), superimposing the contour map obtained by the AF on the ABTS inhibition rate (%), the major anthocyanin area value and the aldose reductase inhibition rate (%), (Table 13). The optimum extraction conditions were estimated based on the total extraction yield, TPC, ABTS + inhibition of antioxidant activity, major anthocyanin content, and AR inhibition.

Range of optimal extraction conditions of purple corn through reaction surface analysis Extraction condition Optimum extraction condition range Vibration intensity (watt) 190.47-258.77 Extraction time (min) 9.65-15.45 Percentage of Ethanol Solvent (%) 20.01-38.18

As shown in Table 13, it can be seen that the purple corn extract can be optimized by extraction at an oscillation intensity of about 190 to 260 watts, an extraction time of about 9 to 16 min, and a ethanol solvent ratio of about 20 to 40% there was.

That is, the extracts of purple corn extracted with the above extraction conditions showed the total yield (%), total polyphenol content (mg / g), ABTS inhibition rate (%), major anthocyanin area value, and aldose reductase inhibition rate ) Of the present invention.

Claims (10)

A C ₁ to C ₄ lower alcohol solvent having a concentration of 20 to 40% (v / v) of purple corn was used at a volume ratio of 1: 10 to 20 times the weight of the purple corn,
Lt; RTI ID = 0.0 > 30-60 C < / RTI > for 7.5-9 hours,
Wherein the solvent further comprises 0.1 to 20% (v / v) acid.
The method according to claim 1,
Wherein the C ₁ to C ₄ lower alcohol solvent has a concentration of 32 to 34% (v / v).
The method according to claim 1,
Wherein the acid is at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfamic acid, perchloric acid, acetic acid, formic acid, lactic acid, and oxalic acid.
delete delete delete delete Using a C ₁ to C ₄ lower alcohol solvent having a concentration of 20 to 40% (v / v) of purple corn,
Ultrasonic extraction for 9 to 16 minutes at an oscillating intensity of 190 to 260 watts,
Wherein the solvent further comprises 0.1 to 20% (v / v) acid.
delete delete

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