• The Korean Journal of Food And Nutrition
• /
• v.21 no.2
• /
• pp.197-203
• /
• 2008

This study was performed to aid the development of a reduced-calorie ssanghwa beverage, by using substitutes for high fructose com syrup(HFCS). Sensory scores were examined for ssanghwa beverages containing different levels of glucosyl stevia, aspartame, and acesulfame-K(0, 50, and 100%, respectively) in place of HFCS. The results showed that sensory scores were not significantly different for the beverages containing different levels of acesulfame-K, including aftertaste, ssanghwa taste, and overall eating quality. In contrast, the sensory scores of beverages containing 0 and 100% glucosyl stevia were significantly different. Data were also gathered comparing the sensory scores of beverages according to the different types of sweeteners. Bitter taste and astringency were not significantly different between the beverages sweetened with HFCS, KP(containing 50% acesulfame-K and 50% aspartame), SP(containing 50% glucosyl stevia and 50% aspartame), and SK(containing 50% glucosyl stevia and 50% acesulfame-K), respectively. Finally, aftertaste and overall eating quality were not significantly different between the HFCS and SP sweetened beverages.

• The Korean Journal of Food And Nutrition
• /
• v.27 no.2
• /
• pp.156-163
• /
• 2014

In order to develop tea by using the leaves of stevia, which is a herbal plant, and to solve the disadvantages of stevia dried leaf tea, we have manufactured the steamed tea, stir-fried tea and fermented tea by changing the manufacturing processes. As a result of the sensory tests, the steamed tea, stir-fried tea and fermented tea received higher evaluations than the dried leaf tea. In terms of efficiency, it is desired that the total number of steaming and stir-frying is only once, but the fermentation is found to be the most desirable for 2 days. There are no trends for changes in the general ingredients, mineral and free amino acid contents of stevia leaf teas by different manufacturing processes. As a result for the measurement of antioxidant activities, the steamed tea and dried leaf tea did not show significant differences, but the stir-fried tea and the fermented tea show significantly low antioxidant activities as compared to the steamed tea. The contents of stevioside in both the stir-fried tea and the fermented tea were less than that in the dried leaf tea, but in the steamed tea, there was no significant difference in the content of stevioside. Base on the present observations, this study supports high potentials of steaming process in order to produce new stevia leaf tea.

• Journal of Life Science
• /
• v.16 no.6
• /
• pp.994-1000
• /
• 2006

Stevia rebaudiana Bertoni is a sweet herb of the Asteraceae family originally derived from South America. Twenty three bacterial strains and ten yeast strains were isolated from fermented Stevia extract and identified by general taxonomic methods and molecular genetic method. Isolated strains from fermented Stevia extract include ten species of bacteria which belong to five genus and one species of yeast. Based on 16S and 18S rDNA sequence analysis, phylogenetic trees were constructed. Antimicrobial activity of the isolated strains was examined against various bacteria and plant-pathogenic fungi. Among them, Lactobacillus paracasei SB13 showed strong antibacterial activity towards a wide range of bacteria. These results may be useful to develop environmentally friendly microbial agent for soil improvement.

• Applied Biological Chemistry
• /
• v.40 no.6
• /
• pp.501-507
• /
• 1997

Chloroplasts isolated from Stevia rebaudiana Bertoni leaves contained an enzyme activity which catalyzed hydroxylation of ent-kaurenoic acid (ent-kaur-16-en-19-oic acid; ent-KA) to steviol (ent-13-hydroxy kaur-16-en-19-oic acid), the diterpenoid carboxylic alcohol which is the aglycone of sweet stevioside-related glycosides. $[^(14)C]-methylated$ ent-KA was used to localize ent-KA hydroxylase. $[^(14)C]-methyl-KA$ was most actively was transformed into methyl-steviol in chloroplast. The enzymatic activity was found in stroma fraction but not in thylakoid membrane in Stevia rebaudiana Bertoni. However, ent-KA 13-hydroxylase activity was not detected in stroma fraction of either Spinacia oleracea and Solidago altissima. The reaction products using $[^(14)C]-methyl-KA$ were purified and identified on TLC autoradiogram. The hydroxylation of ent-KA from stromal protein to form steviol required NADPH and oxygen. FAD and riboflavin stimulated the enzyme activity 1.5-and 1.7-fold, respectively. It also turned out that the activity of this enzyme using methyl-KA as a substrate was 16.7% that of ent-KA. The purified ent-KA 13-hydroxylase did not act on t-cinnamic acid, 4-hydroxyphenyl acetic acid, choline and resorcinol, known as monooxygenase and hydroxylase substrates.

• Microbiology and Biotechnology Letters
• /
• v.49 no.2
• /
• pp.201-209
• /
• 2021

Agarwood (Aquilaria spp) has high economic value. However, essential oil production from agarwood is a time-consuming process. Additionally, agarwood leaves have not been utilized even though they contain various bioactive ingredients. In this study, agarwood leaves were fermented using Lactobacillus plantarum ATCC 8014 with or without Stevia (4, 8, and 12%; v/v). The fermented fluid was mixed with maltodextrin (15%; w/v) and subjected to spray drying (inlet temperature, 120℃; outlet temperature, 65-70℃). The contents of polyphenols, polysaccharides, saponins, and flavonoids and the viability of L. plantarum were determined. Fermentation enhanced the levels of bioactive compounds. The contents of polyphenol (69.19 ± 4.05 mg GAE/g of sample), polysaccharide (20.75 ± 0.98 mg GE/g of sample), saponin (305.23 ± 4.21 mg OAE/g of sample), and flavonoid (7.86 ± 0.72 mg QE/g of sample), and the viability of L. plantarum (8.72 ± 0.17 log CFU/ml) were markedly upregulated in the samples containing Stevia (12%; v/v). This indicated that the supplementation of Stevia during fermentation decreases the fermentation time (9 h), upregulates bioactive compound production in agarwood leaves, enhances microencapsulation during spray drying, and increases the viability of L. plantarum under simulated gastric digestion conditions.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1977.05a
• /
• pp.27.2-28
• /
• 1977

• Korean Journal of Food Science and Technology
• /
• v.45 no.6
• /
• pp.754-762
• /
• 2013

This study investigated the relative sweetness of various sweeteners (tagatose, xylose, erythritol, sucralose, and enzyme treated stevia) in milk and instant coffee systems. Additionally, the effects of interactions with other ingredients on the sensory characteristics of milk and coffee were explored. In the case of a banana-flavored milk system, sucrose was added to a concentration of 5%, and the five types of sweetener were added to a concentration of equal sweetness to a 5% concentration of sucrose. For coffee systems, 5.9% sucrose level and sweeteners' concentration equivalent to this level was added. A generic descriptive analysis was performed using ten trained panelists. The results showed that the relative sweetness of all the sweeteners was identical to that identified in the aqueous system, except for stevia in the milk system and in the coffee system with added vegetable cream. For the black coffee system, the relative sweetness decreased for tagatose, erythritol and for stevia. Fat and vegetable cream significantly affected the sensory qualities of milk and coffee, respectively.

• Journal of Dairy Science and Biotechnology
• /
• v.34 no.4
• /
• pp.263-270
• /
• 2016

This study was carried out to evaluate the antioxidant activity and total polyphnol content of Greek-style yogurt in 12% solid content with added stevia leaf extracts. Stevia leaf extracts used as sweetener in preparing Greek-style yogurt were prepared in hot water ($100^{\circ}C$ for 6 h 3 times, and by 70% fermented ethanol for 24 h at room temperature 3 times). The antioxidant activities were measured by assessing the radical scavenging effect through DPPH, ABTS, and FRAP assays. To identify the compounds present, total polyphenol content was evaluated using a Folin-Dennis assay. The capability to scavenge free radicals and total polyphenolic content were the highest in Greek-style yogurt containing 1% stevia extract and fermented in 70% ethanol. According to the results, antioxidant activities significantly increased when high concentration of stevia extracts were added to the yogurt (p<0.05). Therefore, these results suggest that stevia leaf extracts can be used as a source of functional compounds in Greek-style yogurt. We also suggest that fermented ethanol extraction can be used to obtain stevia leaf extracts.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.11
• /
• pp.1648-1657
• /
• 2014

In this study, the hepatic lipid-lowering effects and related mechanism of action of sujeonggwa were examined in hypercholesterolemia-induced apoprotein E knockout (apo E ko) mice. Sujeonggwa drink was prepared with cinnamon, ginger, and sugar by modifying the traditional recipe of sujeonggwa. Sugar was partially substituted with either stevia or short chain fructooligosaccharide (scFOS) in order to reduce the calorie content of sujeonggwa, which was measured by descriptive analysis. Apo E ko mice (n=42) were induced to have hypercholesterolemia (plasma total cholesterol concentration >1,000 mg/dL) by administration of a high cholesterol diet for 4 weeks, followed by division into six groups. Experimental groups were orally administered water as a vehicle (normal group), sugar solution (control group), commercially available 'V' sujeonggwa drink (positive control group), or three different types of sujeonggwa drinks (S-sugar, S-stevia, and S-scFOS group) for 6 weeks while high cholesterol diet was provided to all animals. Compared to the control group, concentrations of hepatic triglycerides, total cholesterol, thiobarbituric acid reactive substances, and reactive oxygen species in S-sugar, S-stevia, S-scFOS were significantly reduced (P<0.05), indicating that sujeonggwa had inhibitory effects on hepatic lipid accumulation. Protein expression levels of fatty acid synthase (FAS) and its transcription factor, sterol regulatory element-binding protein (SREBP)-1 responsible for triglyceride synthesis, as well as 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and its transcription factor, SREBP-2 responsible for cholesterol synthesis, were also reduced in S-sugar, S-stevia, and S-scFOS groups (P<0.05). These benefits of sujeonggwa were even greater in S-stevia and S-scFOS compared to S-sugar. The beneficial effects of S-stevia on regulation of hepatic lipid metabolism were slightly greater than those of S-scFOS although the differences were not significant. In conclusion, sujeonggwa drinks, especially functional sujeonggwa drinks in which sugar was partially substituted with stevia or scFOS, inhibited hepatic lipid accumulation via suppressing FAS and HMGCR protein expression through down-regulation of SREBP-1 and 2.

• Korean Journal of Food Science and Technology
• /
• v.11 no.4
• /
• pp.224-231
• /
• 1979

The safety of the sweetening component of stevia was studied by administrating it to the rats. The $LD_{50}$ determined by intraperitoneal injection was 3,400 mg/Kg as the stevia extract containing 50 % stevioside, i.e. $LD_{50}$ of stevioside was more than 1,700 mg/Kg. Oral administration of large quantities of the stevia extract for 56 days resulted in no effect on the growth of rats. The analyses of total blood (RBC, WBC, Hb and Hct), 17 blood serum components including total protein, glucose, cholesterol, GOT, and 11 items of findings on the liver tissues including nuclear deterioration of liver cells, proliferation of Kupffer cells, fibrosis of portal area showed no significant differences between control and treatments except lactate dehydrogenase activity after 56 day-oral administration of the extract. From the results obtained, it was supposed that the stevia extract/stevioside revealed no acute or sub-acute toxic effects on rats.