• Journal of Food Hygiene and Safety
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• 제29권3호
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• pp.211-216
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• 2014

Bacillus cereus was isolated in 155 of 4,318 food samples from 2012 to 2013. Of the isolates, 140 isolates were performed antimicrobial disk test against garlic, cinnamon, ginger, and green tea extracted at two different temperature, $25^{\circ}C$ and $70^{\circ}C$. The isolates from Powdered Red Pepper showed frequently to 48.65%, and followed by Agriculture Products (31.08%) and Kimchi (25.61%). The isolation rate of Cooked Foods in the Restaurant supposed to causing food poison was 1.17%. Analysis of antimicrobial activity showed that $25^{\circ}C$ garlic extract, $25^{\circ}C$ green tea extract, and $70^{\circ}C$ green tea extract resisted against all 140 isolates and the others resisted against some isolates. Antimicrobial activity was depended on the temperature; garlic > green tea > cinnamon in $25^{\circ}C$ and green tea > garlic > cinnamon in $70^{\circ}C$. The correlation analysis of each extracts showed that geen tea extract was different significantly with garlic and cinnamon extracting in $25^{\circ}C$ and with only garlic extracting in $70^{\circ}C$ at p < 0.05.

• Food Science and Preservation
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• 제16권3호
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• pp.333-341
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• 2009

The antioxidant properties of green tea leaves and powder extracts were determined using several tests including estimation of reducing power, DPPH(1,1-diphenyl-2- picrylhydrazyl) radical-scavenging activity, and FRAP(Ferric reducing/antioxidant power) assay. All tests indicated that extracts of green tea powder had higher antioxidant activities than extracts of green tea leaves, and the activities were concentration-dependent. However, each test yielded somewhat different results with respect to storage conditions. The reducing power of green tea leaves was highest at $1,000{\mu}g/mL$, storage at $4^{\circ}C$, and an Aw(water activity) value of 0.23. However, the reducing power of green tea powder, assayed at $1,000{\mu}g/mL$, was high under all storage conditions(with variations in temperature and Aw), and was about 1.5.2-fold greater than that of green tea leaves. Radical-scavenging activity, as assessed by the DPPH assay, increased in a dose-dependent manner over the range $15{\sim}125{\mu}g/mL$. At higher concentrations, activities were $80{\sim}90%$ of maximal were attained. The FRAP activity of green tea extract also increased with rising concentration. Particularly in the case of green tea leaves, antioxidant activity was most greatest with storage at $-20^{\circ}C$ and Aw values of 0.69 and 0.23 when assayed at a concentration of $1,000{\mu}g/mL$. These results indicate that the most important factor during storage of green tea is not the Aw value but rather temperature, and that use of refrigeration($4^{\circ}C$) is preferable to increase or maintain the antioxidant activities of biological components in green tea.

• Journal of the Korean Society of Food Science and Nutrition
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• 제33권4호
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• pp.633-640
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• 2004

This study was performed to investigate the cytotoxic effect of the water-extract from Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea in HCT-15 human colon carcinoma, AGS human gastric carcinoma and NIH3T3 mouse normal fibroblast cells using viable cell count and MTT assay. The water-extract from Chaga mushroom compositions induced inhibitory effects on proliferation of HCT-15 and AGS cells in the MTT assay and viable cell count. However, mouse normal NIH3T3 cells were exhibited 80% survival under the same condition. Chaga mushroom compositions showed highly antiproliferative effect in human cancer cell line HCT-15 and AGS, but not in mouse normal cell line NIH3T3. These results suggest that Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea are the candidate for chemoprevention in colon and gastric cancer.

• Journal of the East Asian Society of Dietary Life
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• 제14권5호
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• pp.495-500
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• 2004

This study was carried out to develop a new product using Cheonggukjang (fermented soybean product) and sub-ingredients(lactic acid bacillus powder, chlorella, lactose, green tea). Fresh Cheonggukjang was dried by a infrared drying(50℃, 36hr) and powdered by a roll mill. The powder was mixed with sub-ingredients and then moulded as tablet type by a press moulder. The pH of tablet was low with the addition of lactobacillus and total sugar content was high with the addition of lactose. Disintegration, absorption capacity and textural properties of tablet were not affected by the addition of any sub-ingredient. Color of non-added tablet was yellow to red, but changed to green when chlorella was added. Sensory properties(color, taste, flavor, chewiness, hardness, acceptability) were not affected by the addition of sub-ingredients. The results indicate that functional healthy tablet could be made from Cheonggukjang powder and various sub-ingredients.

• Journal of Food Hygiene and Safety
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• 제31권2호
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• pp.132-139
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• 2016

The purpose of this study was to investigate the contents of antioxidant compounds and antioxidant activities in teas. A total of 99 teas were tested for their antioxidant activities based on their ability to scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. Antioxidant activity was expressed as mg of ascorbic acid equivalents per 100 g tea sample (L-ascorbic acid equivalent antioxidant capacity, AEAC) and was expressed as mg per 1 serving size (free radical scavenging activity, $FSC_{50}$). The total polyphenol contents of the extracts was quantified using the Folin-Ciocalteu method and the total flavonoid contents of the extracts was determined using a modied method of Davis. Vitamin C was analyzed by HPLC method. According to the AEAC value, mate tea, green tea, black tea, oriental raisin tea, chamomile tea and burdock tea showed relatively high antioxidant activities. Polyphenolic compounds were the major naturally occurring antioxidant compounds found in teas and the high concentrations of total polyphenol compounds were observed in black tea, green tea and mate tea. The high concentrations of total flavonoid compounds were observed in mate tea, black tea and yam tea and the amount of vitamin C contents were found to be high in citron tea and green tea. As a result, steeping tea was much higher in antioxidant activity than either powdered tea or liquefied tea. According to the study, a high correlation was demonstrated between the total polyphenol contents and antioxidant activities in teas (r = 0.846) and correlations between the total flavonoid contents and antioxidant activities was statistically significant in teas (r = 0.625). It was found that also the proportional relationship established among the total polyphenol content and antioxidant activities. That is, antioxidant activity of teas has been confirmed to have been caused by the total polyphenol.

• Food Science and Preservation
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• 제15권5호
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• pp.743-748
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• 2008

Amyloid $\beta$ peptide ($A{\beta}$) is known to increase oxidative stress in nerve cells, leading to apoptosis that is characterized by free radical formation and lipid peroxidation. Neurodegenerative diseases such as Alzheimer's disease (AD) are characterized by large deposits of $A{\beta}$ in the brain. In our study, neuronal protective effects of green tea, along with water activity (0.813), and leaf storage periods (fresh leaf, or leaf stored for up to 4 weeks) were investigated. We measured protective effects against $A{\beta}$-induced cytotoxicity in neuron-like PC12 cells. Powdered green tea was extracted with distilled water at $70^{\circ}C$ for 5 min, and this extract was freeze-dried and stored at $-20^{\circ}C$ until use. In cell viability assays using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), the fresh extract, and that obtained after 1 week of leaf storage, showed the best protective effects against $A{\beta}$-induced neurotoxicity. As oxidative stress causes membrane breakdown, the protective effect of green tea extracts was investigated using lactate dehydrogenase (LDH) and trypan blue exclusion assays. LDH release into the medium was inhibited (by 20-25%) in all tests. In addition, all green tea extracts (fresh, or stored before extraction for up to 4 weeks) showed better cell protective effects ($93.3{\pm}1.8-96.2{\pm}2.4$) than did vitamin C ($91.0{\pm}1.6$), used as a positive control. The results suggest that effectiveness of green tea extracts falls with prolonged leaf storage.

• Korean Journal of Food Science and Technology
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• 제50권1호
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• pp.92-97
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• 2018

The antioxidant activities and quality characteristics of Matcha (powdered green tea) spreads containing coconut milk were evaluated. Matcha spreads containing coconut milk was prepared with different amounts (0, 4, 8, 12, and 16 g) of Matcha, and indicated as S1, S2, S3, S4 and S5, respectively. The moisture content, viscosity, color, pH and sugar content were influenced by the concentration of Matcha. Total phenolic content and total flavonoid content of Matcha were found to be 226 mg GAE/g and 809.42 mg QE/g respectively. Also, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power of Matcha was found to be $5.76{\mu}g/mL$ ($IC_{50}$) and 2.26 O.D., respectively. The antioxidant activities of the Matcha spreads containing coconut milk increased with increasing concentration of Matcha. Sensory evaluation indicated that S3 (8 g) was the most preferred in terms of color, taste, texture, and overall acceptance. Based on these results, it is suggested that S3 (8 g) was appropriate for achieving good quality coconut milk based spread containing Matcha.

• Food Science and Preservation
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• 제10권3호
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• pp.354-359
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• 2003

This study was conducted to investigate the fermentation characteristics of kimchi treated with different methods of water extracts of powdered green tea(GT). Four different kimchis, the SB-kimchi(control) which was not treatment of the extracts, SG-kimchi prepared with Chinese cabbage(CC) salted in 1％ GT containing 10％ brine, DG-kimchi prepared with CC dipped in 1％ GT for 30 min after salting, MS-kimchi prepared with the salted CC mixed with 1％ GT containing seasonings. All kimchis was fermented at 10$^{\circ}C$. The pH of treated-kimchis were maintained higher than those of control products during fermentation, but it showed no big difference between each treated groups. Total microbe of SB-kimchi(6.27-9.37 cfu/mL) was higher than those of GT-treated kimchi(5.17-9.20) during fermentation. The ratio of lactic acid bacteria against total microbe was higher than the treated kimchis. Total polyphenol content of kimchi was 52.75 mg％ in DG-kimchi, 47.71 mg％ in MS-kimchi, 44.89 mg％ in SG-kimchi, 30.70 mg％ in SB-kimchi on the 5th days of fermentation. Scores of crispy taste of SG- and DG-kimchi on the 5th days of fermentation was 4.03 and 4.01 points, respectively which was higher than control products. Scores of fishy and hot taste of GT-treated kimchi were lower than those of control products during all fermentation periods.

• Food Science and Preservation
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• 제10권3호
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• pp.345-359
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• 2003

This study was conducted to investigate the fermentation characteristics of kimchi treated with different methods of water extracts of powdered green tea(GT). Four different kimchis, the SB-kimchi(control) which was not treatment of the extracts, SG-kimchi prepared with Chinese cabbage(CC) salted in 1％ GT containing 10％ brine, DG-kimchi prepared with CC dipped in 1％ GT for 30 min after salting, MS-kimchi prepared with the salted CC mixed with 1％ GT containing seasonings. All kimchis was fermented at 10$^{\circ}C$. The pH of treated-kimchis were maintained higher than those of control products during fermentation, but it showed no big difference between each treated groups. Total microbe of SB-kimchi(6.27-9.37 cfu/mL) was higher than those of GT-treated kimchi(5.17-9.20) during fermentation. The ratio of lactic acid bacteria against total microbe was higher than the treated kimchis. Total polyphenol content of kimchi was 52.75 mg％ in DG-kimchi, 47.71 mg％ in MS-kimchi, 44.89 mg％ in SG-kimchi, 30.70 mg％ in SB-kimchi on the 5th days of fermentation. Scores of crispy taste of SG- and DG-kimchi on the 5th days of fermentation was 4.03 and 4.01 points, respectively which was higher than control products. Scores of fishy and hot taste of GT-treated kimchi were lower than those of control products during all fermentation periods.

• Food Science and Preservation
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• 제15권1호
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• pp.161-168
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• 2008

The effects tea beverages (TBs) prepared from powdered green tea (Gt), oolong tea (Ot), black tea (Bt), or pure tea (Pt) with lemon, orange, grenadine etc on cadmium toxicity in rats were investigated Sensory evaluations of the TBs are better than those of each water extracted teas. Cadmium (50 ppm) was administered to experimental rats fed a basic diet, or a diet with various TBs (15% w/v), for 5 weeks. Although body weight gains, feed intakes, and fecal weights in all Cd-treated groups were lower than those in the normal control group (NC), feed efficiency ratio, urine volumes, liver weights, and kidney weights did not differ significantly between groups. The serum ALT and AST levels in the Cd-treated control group (Cd-Co) were higher than those in the NC animals. Serum ALT and AST levels in all Cd-treated rats fed TB-supplemented diets were lower than in animals of the Cd-Co group. Tibia and femur weights in Cd-Co animals were lower than those in NC rats. Tibia and femur weights in Cd-treated rats fed TB-supplemented diets were higher than those in Cd-Co animals. There were no between-group differences in tibia lengths; animals in the NC and TB-supplemented diet groups showed femur lengths longer than those of Cd-Co rats. Although the contents of crude ash and cadmium in the femurs of Cd-Co mts was markedly higher than in the femurs of NC animals, the cadmium content in femurs of Cd-Co rats was significantly lower than that in the femurs of NC animals. The changes in mineral levels caused by Cd administration were alleviated by every TB-supplemented diet tested Whereas fecal calcium excretion by Cd-Co animals was significantly higher than that of NC rats, calcium excretion by Cd-treated rats fed TB-supplemented diets was significantly lower than that of Cd-Co animals. Fecal cadmium excretion by all Cd-treated rats fed TB-supplemented diets was significantly higher than that of Cd-Co animals. In conclusion, this study provides experimental evidence that various TBs may regulate cadmium-induced organ toxicity by reducing cadmium accumulation in tissues through the mechanism of increasing the fecal excretion of cadmium.