• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.112-120
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• 1977

In Korea. the cultivating standard of stevia is not established yet. Because stevia is across-fertilizing plant. planting a cutting is its available propagation method. This study was made to know the effective propagation growth and adaptability of stevia in Jeju-do, according to the wintering effect and the planting density.

• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.190-196
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• 2008

This study was performed to aid the development of a reduced-calorie ssanghwa beverage, by using substitutes for high fructose com syrup(HFCS). The relative sweetness levels of HFCS, aspartame, acesulfame-K, and glucosyl stevia solutions were examined in comparison to a 10% sucrose solution in a binary solution model. And the sensory properties of ssanghwa beverages containing aspartame, acesulfame-K, and glucosyl stevia were evaluated at the equi-sweetness to HFCS. In the binary solution model, the relative sweetness of HFCS to sucrose was 0.8, while the values for aspartame, acesulfame-K, and glucosyl stevia were 140, 170, and 100, respectively. Sweet taste and sweet after taste were not significantly different between the HFCS, aspartame, acesulfame-K, and glucosyl stevia solutions. On the other hand, bitter taste, first taste, and overall eating quality were significantly different between the HFCS and aspartame solutions and between the acesulfame-K and glucosyl stevia solutions. Finally, the ssanghwa beverages sweetened with HFCS, acesulfame-K, and aspartame only had slight differences in sensory properties. However, the sensory properties of the beverages sweetened with HFCS and glucosyl stevia, respectively, were significantly different.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.151-154
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• 2003

This study was conducted to determine the optimal concentrations of plant hormones (2,4-D, picloram, dicamba, NAA, kinetin) and the suitable explants among seeds, hypocotyl, and cotyledons on calls formation and plant regeneration of stevia(Stevia rebaudiana Bertoni). The frequency of cellus formation was higher in the young leaf-explants then the older ones, and in the seeds then the hypocotyls and cotyledons on MS medium with 1mg/L 2,4-D. After transfer of seed-derived stevia callus producing embryogenic callus on plant-regeneration medium, the frequency of plant regeneration from callus was 23.8% in MS medium with 1mg/L NAA and 3mg/L kinetin.

• Journal of the Korean Dietetic Association
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• v.23 no.1
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• pp.14-26
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• 2017

The purpose of this study was to determine the optimal recipe of rice cookies with two different amounts of Stevia rebaudiana leaf and grape seed oil, using a central composite design (CCD). In addition, mixing conditions of rice cookies were optimized by sensory evaluation and mechanical and physicochemical analysis using response surface methodology (RSM). RSM was used to obtain 10 experimental points (including two replicates of Stevia rebaudiana leaf and Grape seed oil), and the formulation of Stevia rebaudiana leaf added rice cookies was optimized using rheology. The results of mechanical and physicochemical analysis showed significant values for lightness, redness, yellowness, hardness, spread factor, loss rate, leavening rate, sweetness, moisture, pH, and density (P<0.001), results of the sensory evaluation showed significant values for color, flavor, taste, texture, appearance, and overall quality (P<0.05). As a results, optimal sensory ratio was found to be 1.98 g of Stevia rebaudiana leaf and 37.94 g of Grape seed oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.313-318
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• 2010

This study was carried out to evaluate the antioxidant activity of stevia extracts from Stevia rebaudiana Bertoni leaves. Stevia extracts were prepared by three different methods including hot water extraction (HWE) at $120^{\circ}C$ for 4 hr, vacuum extraction (VE) at $65^{\circ}C$ for 4 hr under 0.08 MPa, and fermentation of hot water extract (FHWE) using Lactobacillus buchneri. The antioxidant activities measured by radical scavenging activity, ferric-reducing antioxidant potential ability, and thiobarbituric acid reactive substance showed the highest values in vacuum extract. Also, the antioxidant activities of all extracts were higher than those of stevioside and rebaudioside at the same concentrations, known as the major active components in stevia. To define the antioxidative compound in stevia extracts, the total phenol content was measured, and it was shown that the highest contents of total phenolic compounds were in vacuum extract. These results suggest that the antioxidant activity of stevia extract was due to the phenolic compound components. In addition, vacuum extraction was the proper method to prepare stevia extract with higher antioxidant activity.

• Korean Journal of Pharmacognosy
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• v.9 no.3
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• pp.149-156
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• 1978

The result of the study about the cultivation, the constituents, the sweetenity, and the development of preparations of Stevia and Hydrangea are as follows: 1. Hydrangea thrived at $200{\sim}1,400m$ above the sea-level, and the good ones were brought up at $600{\sim}1,200m$. 2. The good ones which belonged to the genera of Hydrangea were produced in the damp, dark and cold place. 3. The growth and cultivated yield of Stevia was not significantly influenced by the acidity of the soil. 4. The best season was May and June for propagation of Stevia by cutting method. 5. The growth rate of Stevia and Hydrangea was really good in the sandy fertile soil, but in the mucotic soil it was not suitable. 6. The extraction and separation of phyllodulcin by solvent had many difficulties, because it was very soluble in water, ethanol, ether, petroleum ether, acetone and benzene, etc. 7. The solubility of stevioside on the solvent was as follows: It was very soluble in water and methanol, slightly soluble in ethanol and acetone, and insoluble in ether, petroleum ether and chloroform. 8. The alkaloid reaction by Mayer reagent in Hydrangea extract was positive. 9. The ashification rate of Stevia was 8.66% to 8.72% and that of Hydrangea 17.02% to 17.04%. 10. The tannin of Stevia leaf was 7.80% to 7.88% and its of Hydrangea decreased 9.46% to 6.08% by fermentation. 11. The percent rates in minimum concentration-occurring sweetness in sugar, glycyrrhiza methanol extract, Hydrangea water extract, Stevia leaf water extract, decoction of Stevia's leaf, decoction of Stevia's stem were as follows: 1.2, 0.1, 0.1, 0.2, 0.4, 0.01, 0.1, 0.6. and sweetenity ratios of those were 1, 12, 12, 6, 3, 64, 12, 2, 12. It was very meaningful to develop preparations of stevia as stevioside, micronized powder, water extract, methanol extract and compound teas and in Hydrangea, water extract, methanol extract, single tea, and compound teas were less meaningful. 13. The genera of Hydrangea which is natural species in Korea was positive in phyllodulcin-identification test, but it was not available to make the sweet tea because of having a little content.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.189-197
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• 2012

This study was carried out to develop the improved useful mutants for yield or composition of stevia plants using the gamma ray or chemical mutagens treatments. The seeds of stevia 'Suwon No. 11' were irradiated up to 400 Gy of gamma ray. Chemical mutagens were treated on the seeds of the 'Suwon No. 11' using 0.07% colchicine, 10 mM sodium azide, or 10 mM NMU for various durations. The germination rate, and shoot and root growth of seedling were estimated at 30 days after gamma ray irradiation or chemical mutagen treatment, and the plant height, the number of branches, and leaf length and width were examined at 3 months after mutagenesis treatments. In the case of gamma ray treatments, the germination rate and early-stage growth were decreased as the increase of radiation dose, and the 50% lethal dose was found to be 200 Gy. the plant height was decreased as the increase of radiation dose, while the number of branches per plant and leaf length were increased. Leaf shape was modified to the relatively longer one compared to the control, which was identified more apparently at the treatments of higher than 150 Gy. In the treatment of chemical mutagens, the rate of germination and survival were decreased as the increase of incubation time. The 50% lethal dose for germination rate were identified as the conditions of the 15 hours incubation in 0.07% colchicine, the 4 hrs in 10 mM sodium azide, and the 2 hrs in 10 mM NMU, in the three chemical mutagens treatments. Chemical mutagens had no influence on shoot growth, while root growth was increased, especially as the incubation time was extended. The highest root growth occurred in the NMU treatment at 6 hrs incubation time. The plant height was decreased as the increase of incubation time in the chemical mutagens treatments. Among the chemical mutagens, NMU was the most effective to induce the mutants with long-shaped or the least lobed leaves.

• Korean Journal of Plant Resources
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• v.32 no.3
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• pp.220-227
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• 2019

Stevia rebaudiana (Asteraceae), a perennial plant, has been used as a low-calorie sweetener and is being developed as a therapeutic agent for diabetes, hypertension, myocardial diseases, and microbial infections. Despite the common use of its leaves and stem, the bioavailability of the components present in S. rebaudiana flowers, when used as ingredients of cosmetics, has not been well investigated. Herein, we investigated the antioxidative and antimelanogenic effects of an aqueous extract of S. rebaudiana flowers (Stevia-F). Total flavonoid and phenolic content in Stevia-F were determined to be $8.64{\pm}0.23mg$ of quercetin equivalents/100 g and $631.5{\pm}2.01mg$ of gallic acid equivalents/100 g, respectively. The $IC_{50}$ values of Stevia-F for reducing power, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate radical, hydrogen peroxide, and nitric oxide scavenging activities were 5541.96, 131.39, 466.34, and $10.44{\mu}g/mL$, respectively. Stevia-F showed inhibitory effects on the tyrosinase ($IC_{50}=134.74{\mu}g/mL$) and ${\alpha}$-glucosidase ($IC_{50}=114.81{\mu}g/mL$) activities. No significant cytotoxicity of Stevia-F was observed in B16F10 cells, treated with up to $100{\mu}g/mL$ of the extract for 24 and 48 h (p > 0.05). Stevia-F ($1-100{\mu}g/mL$) suppressed ${\alpha}$-melanocyte stimulating hormone-induced melanin production in B16F10 cells (p < 0.05) and also inhibited the cellular tyrosinase activity (p < 0.05). Overall, our results show that Stevia-F possesses potential for inhibiting tyrosinase and ${\alpha}$-glucosidase activities and has significant antioxidant capacity. The antimelanogenic potential of Stevia-F should extend the usage of S. rebaudiana flowers in the development of skin-whitening products.

• Korean Journal of Human Ecology
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• v.9 no.1
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• pp.71-80
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• 2006

To investigate the effects of the supplementation of Stevia. Rebaudian Bertoni on serum and hepatic lipid levels and enzyme activities in rat administered with ethanol chronically. Sprague-Dawley male rats were orally treated with either an AIN-76 diet(C, control), a control diet plus ethanol(E, 4g/kg bw), E plus stevia extract-1(ES1, 1ml/kg bw), or E plus stevia extract-2(ES2, 2ml/kg bw) for 7 weeks. Serum triglyceride levels were increased in the E group and were decreased in the ES 1 group. Liver triglyceride levels were decreased significantly in the ES2 groups and Total-cholesterol were decreased in the ES1, ES2 groups compared with the E group. Liver $\gamma-GTP$ levels were decreased significantly in the ES1, ES2 groups compared with the E group. In addition, we have evaluated the serum or liver carnitine levels in those groups. Liver TCNE levels were increased significantly in the ES1, ES2 compared with the E group. These results may suggest that supplementation of Stevia. Rebaudian Bertoni has effects on the recovery of chronic ethanol-related diseases.

• Food Science and Preservation
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• v.11 no.4
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• pp.491-495
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• 2004

Consumers were tend to purchase more natural sweeting materials then atificial sweeting materials because of safety and the consumed amount of natural sweeting material was increased sharply with consumers concern to health. The proper harvest time with changes of sweeting material contents was investigated in the purpose of cultivation and utilization on functional foodstuff, Soluble solid content and extraction yield were increased with growth priod, but pH was decreased. Color value, transmittance and browning color showed little. L, a, b values was changed a little. Stevioside ratio($68.97\%$) in sweetness components was decreased to $61.09\%$. Rebaudioside A ratio was increased from $20.83\%\;to\;27.52\%$ stevioside contents was maximized to $12.80\%$ of August. The highest sweetening potencies of stevia leaves was 2530times to sugar. The stevia leaves harvested at May showed the best deliciousness.