• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.1040-1049
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• 2016

In this study, we aimed to develop a mixed tea prepared with roasted mulberry leaf and fruit using response surface methodology (RSM). Roasting of mulberry leaf was by 6 stages, as shown in Fig. 1; and mulberry fruit was roasted in 4 stages, as shown in Fig. 2. Subsequently, physicochemical measurements such as total polyphenol content, nitric oxide production content, and ${\alpha}$-glucosidase inhibitory effect were obtained for each sample. Central composite design was applied to prepare samples containing varying contents of roasted mulberry leaf (RoML) and roasted mulberry fruit (RoMF); subsequently, sensory evaluation was conducted. The total polyphenol content of roasted samples (RoML and RoMF) were significantly higher than that of raw samples (RaML and RaMF), respectively. The nitric oxide (NO) production of roasted samples were significantly lower than that of control (LPS induced RAW 264.7 cell). The ${\alpha}$-glucosidase inhibitory effect of roasted samples was significantly higher than that of raw samples, respectively. Based on the RSM estimation for determination of optimum ratio by sensory evaluation (taste, color, and flavor) among 13 mixed samples, the optimum mixing ratio of RoML and RoMF for taste, color, and flavor were 1.64 g (RoML) and 0.88 g (RoMF), 1.35 g (RoML) and 0.92 g (RoMF), 1.65 g (RoML) 1.03 g (RoMF), respectively. Based on results of three sensory evaluations, mixing ratio comprising 1.54 g of RoML and 0.92 g of RoMF is desirable for delicious tea with functionality.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.979-985
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• 2004

Effects of green tea, buckwheat, and grape leaf extracts on factors related to blood circulation were studied using rats fed high-cholesterol diet for 4 weeks. Rats were randomly divided into five groups, and plant extracts were orally administered. Green tea extract increased bleeding time in rat tails, suggesting it could prevent platelet aggregation. Administration of green tea, buckwheat, and grape leaf extracts decreased total cholesterol level in liver. Grape leaf extracts decreased thiobarbituric acid-reactive substances in plasma, whereas buckwheat and grape leaf extracts decreased the substances in liver. These results showed extracts of green tea, buckwheat, and grape leaf were effective for improving lipid composition in blood and liver and inhibiting lipid peroxidation in animal tissue, suggesting they may have potential to prevent cardiovascular diseases.

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.586-592
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• 2008

In this study, the nutritional components and functional activities of Sasa borealis leaf tea were evaluated. The proximate compositions were as follows; moisture 5.68%, crude protein 16.38%, crude fat 4.68%, nitrogen free extracts 32.37%, crude fiber 32.36%, and ash 8.53%, respectively. The mineral elements were as follows: K 2,133.83, Ca 1,144.09 and P 543.00 mg%, respectively. The amino acid contents of the Sasa borealis leaf tea were very rich in proline (1,275.26 mg/100 g) and deficient in cystine (71.49 mg/100 g). The major fatty acid components were linoleic acid (50.52%), palmitic acid (18.52%), and oleic acid (14.16%). Finally, based on our sensory evaluations, the $80^{\circ}C$ extracted Sasa borealis leaf tea evidenced the best overall quality. The contents of total phenol and total flavonoids of the 80% methanol and hot water extracts were 15.09, 7.69 mg/g and 12.03, 6.12 mg/g, respectively. The DPPH and $ABTS^+$ radical scavenging activities of the 80% methanol extract from Sasa borealis leaf tea were 86.87% and 83.85% at a concentration of 1.25 mg/mL. The 80% methanol and hot water extracts evidenced reducing power and inhibitory effects against acetylcholinesterase in a dose-dependent manner.

• Food Science and Preservation
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• v.18 no.5
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• pp.643-650
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• 2011

This study was carried out to analyze the quality change of mackerel treated of green tea and lotus leaf boiled water extracts. And investigate the antioxidant effects of them on the lipid peroxidation of mackerel during storage at $4^{\circ}C$ for 28 days. It was estimated periodical measurements of proximate composition, pH, carbonyl, volatile basic nitrogen, trimethylamine-N, acid, peroxide and thiobarbituric acid values. It had no effect on proximate composition compared with non- treated control nearly but, pH of all the samples was increase during 28 days continuously. The contents of volatile basic nitrogen and trimethylamine-N lower than control during storage. Also, acid, peroxide and thiobarbituric acid values of mackerel treated of green tea and lotus leaf boiled water extracts were significantly lower than control throughout storage period. Especially, mackerel treated of 2% green tea and lotus leaf boiled water extracts shows that more effective than 1% of things in antioxidant during storage. Results indicate that the application of green tea and lotus leaf boiled water extract on the surface of mackerel may be useful to lower the rancidity degree and fish odor during storage.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5646-5657
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• 2013

In this study, to evaluate the anti-obesity effects of mulberry leaf tea and its fermented product by Monascus pilosus, we investigated body and organ weight, blood and liver biomarkers in mice fed 1% tea infusions instead of water for 8 weeks. Mice were divided into three groups such as a normal control (NC), unfermented mulberry leaf tea infusion (UMI) and fermented mulberry leaf tea infusion (FMI). Although it is not significant, tea infusion groups showed reduction of body weight gains compared with NC group. Moreover, contents of LDL-cholesterol and lipid peroxide (LPO), altherogenic index, and xanthin oxidase (XO) activity were significantly decreased, and glutathione S-transferase (GST) activity was significantly elevated. The results from this study suggested that UMI and FMI may have an anti-obesity activity, upregulate antioxidant enzymes and reduce levels of oxidants related to liver damage.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.129-135
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• 2015

Objectives : Clerodendron trichotomumThunberg grows wild fields and mountains in South Korea and China. They have been used for anti-hypertension disease. This study was performed in order to observe the effects ofClerodendron trichotomumThunberg tea on anti-hypertension.Methods : For the study ofClerodendron trichotomumThunberg tea, we had divided male SHR (Spontaneously Hypertensive Rat) to ten groups. Control group is SHR. The treatment group is SHR which is administered tea extract at dose of 200 mg/kg/day and 500 mg/kg/day orally for 8 weeks. We measured systolic blood pressure, diastolic blood pressure, number of pulse, body weight, total cholesterol and triglyceride from blood serum.Results : The level of systolic and diastolic blood pressure were significantly decreased by 12.5% and 44.9% inClerodendron trichotomumThunberg tea groups than control group. Heart rate ofClerodendron trichotomumThunberg tea groups, 24.5%, was significantly lower than control group. We found that treatment with the water extract fromClerodendron trichotomumThunberg leave and flower significantly decreased weight of body, total cholesterol and triglyceride to 20.4% and 27.7% compared to untreated control group, significantly (P< 0.05).Conclusions : These results suggest that leaf and flower tea ofClerodendron trichotomumThunberg tea is effective in prevention and treatment of hypertension and decreasing cholesterol. Long term consumption ofClerodendron trichotomumThunberg leaf and flower tea can be help in lowering high systolic and blood diastolic pressure, heart rate and blood serum in SHR.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.95-101
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• 2012

Nutritional components of Ojuk leaf tea and Ojuk shoot tea prepared from the leaves and shoots of black bamboo (Phyllostachys nigra Munro) by tea manufacturing process were evaluated. In addition, the extraction yield of water soluble components from these teas in the general tea brewing condition (water extraction in $80^{\circ}C$ for 10 min.) and the contents of polyphenol and flavonoid were compared with not only the dried raw materials, but also green tea and mate tea. Finally, offline and online scavenging activities against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and di(phenyl)-(2,4,6 trinitrophenyl)iminoazanium free radicals were investigated to evaluate the antioxidant activity and explore the components showing ABTS free radical scavenging activity from tea infusion. These results demonstrated that these teas from black bamboo contain various nutritional components and can be used as traditional tea beneficial to human health.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.277-281
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• 1990

Injeulmi(Korean glutinous rice cake) was prepared without, 5, 10 and 15% of macerated tea leaves for utilizing unplucked low-graded tea leaves. The effect of firming rate by addition of tea leaf was determined using the Avrami's equation in terms of the texture parameters. Hardness of 5, 10 and 15% addition as compared with no addition was decreased gradually. Overall texture was softened in proportion to Increasing the content of added tea leaf and the addition of 5% and 10% were evaluated as the highest score as an acceptable sensory quality. Avrami exponents and time constant obtained from the Avrami's equation applicable for changes in hardness of without and 10% addition during 7days of storage at $20^{\circ}C$, $90{\sim}95%$ RH indicated 1.062, 15.3 and 0.989, 41.6, respectively, as showing the effect of delay on firming rate.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1128-1131
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• 1999

Antioxidative and antimicrobial effects of the extracts of Castanea crenata leaf tea, steamed tea and semi-fermented tea were investigated. Antioxidative effects were by measuring the 1,1-diphenyl-2-picrylhydrazyl(DPPH)-radical scavening activity of the extracts. The effects were stronger than that of synthetic antioxidant such as BHT at the same concentration. The $SC_{50}$ value (50% radical scavening effects of $1{\times}10^{-4}$ M DPPH) of steamed tea, semi-fermented tea and BHT were 53.3 ${\mu}g/mL$, 49.9 ${\mu}g/mL$ and 101.0 ${\mu}g/mL$, respectively. The antimicrobial effects of methanol extracts (8 mg, 20 mg) of 0.2 g and 0.5 g. eq. of Castanea crenata leaf tea were stronger than those of 0.65 mg of benzoic acid, against gram(+) bacteria such as S. aureus, S. epidermidis, M. luteus, L. mesenteroides and B. subtilis and gram(-) bacteria such as E. coli, S. typhimurium, and P. aeruginosa.