• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.13-20
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• 2000

This study was designed the antioxidative effect of the ethanol extract obtained Rooibos tea (Aspalathus linearis) on various kinds of oil, and examined the synergistic effect of Rooibos tea extract by addition of citric acid to the antioxidation activity and also investigate to antioxidation effect of the extract in food production and storage peroids. The antioxidative activity of 0.2mg of Rooibos tea extract was showed similar to same doses of $\alpha$-tocopherol, BHA and BHT in linolieic acid-ethanol system. The antioxidative effect of the mixture with 0.1% Rooibos tea extract on lard was more effective than that of the mixture with same doses of $\alpha$-tocopherol, BHA and BHT. The antioxidative effect of Rooibos tea extract was showed slightly effects on lard or soybean oil. Antioxidative effects of Rooiboe tea extract in addition of citric acid as synergist showed more effective in linoleic acid-ethanol system, but did not showed in the other oils. In the application of Rooibos tea extract to food prodctuction and storage period, the antioxidative effect was more effective in biscult, preparation added lard mixed with 0.1% Rooibos tea extract.

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.141-145
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• 2009

The purpose of this study was to investigate the effect of endurance training and Rooibos-tea treatment during 12 week on lipid peroxidation(MDA), oxidative DNA damage(8-hydroxyguanine), and antioxidant enzymes(SOD, GPX) in human. The subjects were divided into three groups; Train+Rooi, Train, and Rooi groups. The Train+Rooi and Rooi group took 3 g of Rooibos-tea for 12 weeks. Blood samples were taken from antecubital vein at before training, after 6week, and after 12 week training. Data were analyzed by two-way ANOVA with repeated measures using the SPSS/PC⁺. The results are summarized as follows: MDA and 8-hydroxyguanine concentration were no significantly differences between group(p>.05). SOD and GPX concentration were significantly increased in Train+Rooi, Rooi group than Train group(p<.05). This results suggested that effects of Rooibos-tea treatment has associated with improve scavenger of antioxidant.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1222-1228
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• 1998

Stress will induce various changes in human metabolism. The remarkable phenomenon of these changes is increased energy metabolism that can induce many reactive oxygen species (ROS) production. ROS can peroxidize cellular macromolecules including lipid and protein. The object of this study was to investigate that stress may induce cellular damage by producing ROS and that Rooibos tea can protect cells against reactive oxygen species by immobilization stress in SD rat. The stress group significantly increased in 5-hydroxyindole acetic acid (5-HIAA), one of the stress hormone. Rooibos tea treatment had no effects on 5-HIAA contents, but body weight of Rooibos tea treated rat more increased than that of only the stress group. It was suggested that Rooibos tea colud not affect stress response itself, but protect against the another mechanism. We thought that the oxidative damage was caused by increased energy metabolism. Protein degradation level and lipid peroxide formation on index of oxidative damage significantly increased in the stress group. But the stress-induced activity change could not be observed in antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and glutathione reductase. But the catalase activity of the brain significantly was inhibited by the stress. From these results, it was suggested that the immobilization stress induce the brain oxidative damage. However the oxidative damage was inhibited by feeding Rooibos tea containing various antioxidants, such as polyphenol, flavonoid and so on. Therefore, Rooibos tea have the protective effects against the stress caused by the ROS mediated cellular damage.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.389-395
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• 2017

A simultaneous determination of 5 phenolic acids (gallic acid, chlorogenic acid, caffeic acid, pcoumaric acid, trans ferulic acid) and 9 flavonoids (procyanidin b1, aspalathin, rutin, vitexin, hyperoside, isoquercitrin, luteolin, quercetin, chrysoeriol) in rooibos tea has been carried out by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). A validated analysis method in this study was applied to rooibos aqueous infusions. Rooibos tea is an antioxidant-rich tea which has anti-cancer, anti-aging, anti-inflammatory, anti-diabetic effect. Extraction yield of phenolics depends on steeping time and temperature of water. Tea infusions were prepared by placing 1 g of tea leaves or 1 tea bag in 100 mL of boiled water, and then at 3, 6 and 30 minutes intervals the infused teas were taken to carry out the analysis of phenolic contents. Another tea infusion was conducted with cold water ($25-30^{\circ}C$) for 30 minuntes. As a result, the total amount of phenolics was highest in rooibos tea steeped with hot water for 30 minutes, followed by 6 minutes, 3 minutes and cold water 30minutes and the result has statistical significance.

• Food Science and Preservation
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• v.15 no.4
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• pp.582-586
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• 2008

Total phenolic compounds and antioxidative activities of rooibos tea(Aspalathus linearis) fractions were studied. Three extracts, using hexane, ethyl acetate, and ethanol, were prepared. Total phenolic compounds were 3069.3 mg/100 g extract in the hexane fraction, 18604.4 mg/100 g extract in the ethyl acetate fraction, and 13458.8 mg/100 g extract in the ethanol fraction. Levels of vanillic acid, caffeic acid, syringic acid, 4-coumaric acid, and ferulic acid were analyzed by RP-HPLC, and totals of 3452.6 and 3156.1 mg/100 g of extract were found in the ethanol and ethyl acetate fraction, respectively. In the DPPH assay, the ethanol fraction(82.2% of contol) and the ethyl acetate fraction(78.9%) showed the highest free radical scavenging capacities. The induction period of each tea fraction in the fish oil rancimat assay was measured. When 500 ppm of the ethanol fraction was applied, a 1.19 h induction period was observed. This was 2-fold greater than the induction period of the control.

• Journal of Life Science
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• v.14 no.2
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• pp.291-295
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• 2004

Rooibos (Aspalathus linearis) (RB) is a leguminous shrub native to the mountainous areas of the northwestern Cape Province in South Africa. RB tea infusions are the fermentation products of its leaves and fine sterns, and known to have a high antioxidative activity due to the presence of flavonoids and phenolic acids. We investigated the effects of RB tea on the alleviation of oxidative stress on cultured rat cortical neurons in a hypoxic model. Measurement of lactate dehydrogenase (LDH) released into culture media revealed that RB increased cell viabilities in both normoxia (6-18%) and hypoxia (2-24%) dose-dependently (10-100 $\mu\textrm{g}$/ml) on 16 days in vitro (3 days after treatment). Visualization of cell morphology by expression of GFP-Hsc70 fusion protein showed that RB (50 $\mu\textrm{g}$/ml) reduced the average vacuolated soma from 55.4$\pm$4.59% (no RB addition) to 40.9$\pm$6.3% (RB addition) on 5 days after hypoxia. Our results proves efficacy of RB in the neuroprotection of hypoxic neurons and extend application for RB into the prevention and/or treatment of neuronal damages.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.215-219
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• 2006

Artemisia spp. collections, AC60, AC67, and AC77, that showed the high levels of antioxidant activities and had good growth characters and productivity, were cultivated for mass production. Using selected excellent ones, AC60, AC67, and AC77, after mass production, mugwort teas were made through rubbing and drying processes. Total phenolic compound content, nitrite scavenging ability, and SOD-like activity in mugwort teas and commercial teas were compared. Total phenolic compound content was the highest in AC67 with 109.6 mg/100 ml. Nitrite scavenging ability of AC67 tea was relatively high with 92.5% at pH 1.2 and Jasmine (98.1%), Persimmon Leaf Tea (96.4%), Green tea (98.5%), and Jakseolcha (98.7%) were very high as well. In SOD-like activity, mugwort teas, AC67 (91.7%) and AC77 (93.7%), were high as well as those of Seolrokcha (92.1%) and Rooibos Tea (93.8%). This suggests that AC60, AC67, and AC77 could be used fur making high quality teas as well as Seolrokcha, Jasmine, Green tea, Jakseolcha, Rooibos Tea, Peppermint Herb Tea.

• Journal of dental hygiene science
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• v.22 no.1
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• pp.57-66
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• 2022

Background: This study aimed to investigate the effect of selecting commercially available blending teas and applying them to bovine teeth on color change over time. Methods: After selecting healthy bovine teeth, using a cutting-disc, 105 specimens with a dimension of 5×5×3 mm were prepared, and 15 specimens were distributed to each group. Black tea was used as a positive control, water was used as a negative control, and blended tea of five types was used as an experimental group. First, pH and buffering capacity were measured with a pH meter, and tooth color was determined using a spectrophotometer before immersion in the blending tea solution and 1, 5, 7, 14, and 21 days after immersion. Thereafter, the shape change of the enamel surface was observed using a scanning electron microscope, and SPSS ver.26 was used to analyze the color change. Results: The average pH of the five blending teas in the experimental group was 3.78, and the pH of group 3 (strawberry rhubarb) was the lowest at 3.22. The pH levels of black tea and water were 5.19 and 7.30, respectively. The buffering capacity was the highest in group 3 at both pH levels of 5.5 and 7.0. The L^*a^*b^* color change according to immersion time was the largest in group 4 (rooibos yellow flower), and the amount of color change was large in black tea and group 4. As a result of observing the enamel surface of bovine teeth, changes in the surface shape were noted in all groups immersed in the experimental solution for 21 days, except for water. Conclusion: There was a significant difference between the experimental groups in terms of color change according to the immersion time, and color and enamel surface changes were observed in black tea and all experimental groups, except for water.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.455-461
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• 2022

In this study, kombucha was prepared using saccharified rice solution to assess this possible means of increasing rice consumption. Chucheong rice yielded the highest starch content (80.40±1.33%) when used to produce saccharified rice solution. The resultant saccharified rice solution showed the highest 10.42 °Brix at 90 min of saccharification. Chamdream rice yielded the highest acidity at 0.38%, and Kawaji No.1 yielded the lowest at 0.24%. Organic acid analysis on the 15th day of fermenting kombucha made with different rice varieties indicated an acetic acid content of 111.70±1.09 ppm in Chamdream, and 46.86±1.00 ppm in Dongjinchal. Comparison of enzymes used in saccharified rice kombucha fermentation revealed that α-amylase resulted in the highest acidity (1.06%), and β-amylase yielded the lowest acidity (0.58%). Kombucha with green tea yielded the highest acidity (1.09%), and kombucha with rooibos tea yielded the lowest (0.37%). Polyphenol analysis indicated that the amount of polyphenol increased the most (1,623.75 ppm to 3,989.00 ppm) on day 0 of fermentation with green tea. Organic acid analysis revealed that the acetic acid content of kombucha supplemented with green tea increased from 172.89 ppm on day 0 of fermentation to 2,649.11 ppm on day 15. Kombucha with 2.0% added alcohol had the highest acidity (1.32%), and kombucha with 0.5% alcohol had the lowest (0.97%). Taken together, these results confirm that it is possible to make kombucha using saccharified rice solutions.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1162-1162
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• 2001

Whereas NIR spectroscopy has been applied in agriculture for more than 20 years, few studies refer to those plant substances occurring only in smaller amounts. Nevertheless there is a growing interest today to support efficiently activities in the production of high-quality medicinal and spice plants by this fast and non-invasive method. Therefore, it was the aim of this study to develop new NIR methods for the reliable prediction of secondary metabolites found as valuable substances in various plant species. First, sophisticated NIR methods were established to perform fast quality analyses of intact fennel, caraway and dill fruits deriving from single-plants [1]. Later on, a characterization of several leaf drugs and the corresponding fresh material has been successfully performed. In this context robust calibrations have been developed for dried peppermint, rosemary and sage leaves for the determination of their individual essential oil content and composition [2]. A specially adopted NIR method has been developed also for the analysis of carnosic acid in the leaves of numerous rosemary and sage gene bank accessions. Carnosic acid is an antioxidative substance for which several health promoting properties including cancer preservation are assumed. Also some other calibrations have been developed for non-volatile substances such as aspalathin (in unfermented rooibos leaves), catechins (in green tea) and echinacoside (in different Echinacea species) [3]. Some NIR analyses have also been successfully performed on fresh material, too. In spite of the fact that these measurements showed less accuracy in comparison to dried samples, the calibration equations are precise enough to register the individual plant ontogenesis and genetic background. Based on the information received, the farmers and breeders are able to determine the right harvest time (when the valuable components have reached their optimum profile) and to select high-quality genotypes during breeding experiments, respectively. First promising attempts have also been made to introduce mobile diode array spectrometers to collect the spectral data directly on the field or in the individual natural habitats. Since the development of reliable NIRS methods in this special field of application is very time-consuming and needs continuous maintenance of the calibration equations over a longer period, it is convenient to supply the corresponding calibration data to interested user via NIRS network. The present status of all activities, preformed in this context during the last three years, will be presented in detail.