This experiment was conducted to verify the effect of spraying ethanol extracts (green tea and wormwood) on pH, TBARS, VBN, and total microbes of chicken meat during storage. The ethanol extracts of green tea and wormwood were sprayed on the chicken carcasses (0.2 and 0.2 g extract/㎏meat, respectively). Treated sample showed higher lightness (L* values) and yellowness (b* values) and lower redness (a* values) than those of control. The TBARS values were significantly lower for the treatments than the control on storage day 4, especially, the treatment of the wormwood extracts had lowest TBARS value. The VBN values were relatively lower values for the treatments than the control on storage day 4, especially, the treatment of the wormwood extracts had lowest VBN value on storage day 6. Wormwood samples showed lower total aerobic and E. coli counts than the others on day 6. Therefore, the spray with natural wormwood extracts could be useful to extend the shelf-life by preventing lipid oxidation and reducing the microbial growth during storage of chicken meat.
This study was aimed to determine microbiological quality by adding green tea extracts to chicken meat salad. For this study, Chicken meat salad were prepared with two production method. (method 1: addition of green tea extracts to boiling phase, method 2: addition of green tea extracts to salad dressing) Microbiological effects of green tea extracts were assessed during production process by measuring process time, temperature, pH and Aw and determining total plate counts and coliforms. Effects of green tea extracts on total plate counts and coliforms were observed during holding at 3, 10, 25±1℃ for 12 hours. Green tea extracts improved the microbiological quality and showed antibacterial properties when they are added to chicken meat salad.
The extraction yield of MeOH extract of green teas, oolong tea and black tea were 3 to 5, 4 to 5, and 5 to 7 fold higher than those of EtOH and EtAC extract, respectively. The amount of total catechins of EtAC extract of the black tea, and of the green teas and oolong tea were three- and two-fold higher than that of EtOH or MeOH extract of the corresponding teas, respectively. The antioxidative activities of EtOH, MeOH and EtAc extract were considerably higher than that of BHT and dl-α-tocopherol at 200 ppm level. The antioxidative activities of EtOH and MeOH extract at 200 and 500 ppm level, and of EtAc extract at 200 ppm level varied depending on the type of tea as follows : green tea I $gt; green tea II $gt; green tea III $gt; oolong tea $gt; black tea. The antioxidative activity increased as the content of EGC increased. But the antioxidative activity of MeOH extract at 1000 ppm level, and of EtAc extract at 500 and 1000 ppm level were not affected by the content of EGC and EGCG.
Background : The health-promoting effects of green tea are mainly attributed to its polyphenol content, particularly flavanols and flavonols, which account for 30% of a fresh leaf’s dry weight, but the ingredients of the polyphenol content vary depending on the species. This study was conducted to select some candidates with superior anti-oxidative and anti-allergy effects from among seven cultivars of green tea.
Methods and Results : Green tea extracts were prepared by extraction with ethanol and by evaporation of the solvent at low pressure. To evaluate their anti-allergy effect and cell viability, the samples were tested for ß-hexosaminidase inhibitory activity and MTT assay of the RBL-2H3 cells, respectively. The anti-oxidation effects of the samples were analyzed with a DPPH radical scavenging activity. According to the results of the experiment, four extracts including Camelia sinensis var. Kemsull, C. sinensis var. Beachwisull, C. sinensis var. Chamnok and C. sinensis var. Fushun showed effective ß-hexosaminidase inhibitory activity at 12.5, 25, 50, 100 ㎍/㎖. At 50 ㎍/㎖, C. sinensis var. Saemidori had the highest cell viability as 86.1%, and all of the samples showed cell proliferation above 70% at 25 ㎍/㎖. The extract of C. sinensis var. Kemsull showed a 60 - 70% inhibitory effect on the DPPH radical at all of the tested concentrations, whereas the extracts of C. sinensis var. Ryohu, C. sinensis var. Saemidori, C. sinensis var. Yabukita showed lower DPPH inhibition effects at around 10 - 30%.
Conclusion : The results of this study indicate that the extracts of C. sinensis var. Kemsull, C. sinensis var. Beachwisull, and C. sinensis var. Chamnok have more prominent anti-oxidation and anti-allergy effects than other cultivars, and thus could be utilized as resources for improving health.
본 연구는 고등어의 지질산패에 미치는 녹차 및 연잎의 항산화 효과를 알아보기 위하여 1%와 2%의 농도의 녹차 및 연잎 열수추출물에 처리하여 28일간 냉장보관하면서 염장고등어의 품질특성에 대해 알아보았다. 수분은 대조구의 경우 저장기간 동안 점점 감소하는 현상을 보였으나 처리구에서는 14일까지 감소하였으며 조단백질과 조회분은 저장기간 동안 큰 변화는 없었다. 조지방의 경우 대조구에서는 저장기간 동안 점차 증가하였으나 처리구에서는 오히려 감소하였
녹차에 관한 최근까지의 연구결과에서, 녹차는 생리활성의 촉진작용뿐아니라 항암, 항산화, 고혈압 억제효과, 체중 조절 등 다방면의 약리효과를 보이는 것으로 보고되고 있다. 아울러, 녹차의 항균 및 항진균 작용에 관한 연구결과도 발표되고 있으며, 본 연구팀에 의해서도 녹차추출물의 항균작용을 확인한 바 있어, 본 연구에서는 탁월한 항균작용을 소유하고 있는 녹차분획물질을 분리하여 그 분자구조를 동정하는데 목적이 있다. 따라서, 녹차추출물에서 탁월한 항균
고 기능성 유용 차나무 품종육성 및 녹차의 이용성 증진 연구의 기초 자료를 제공하기 위해 녹차 함유 catechin 화합물 및 caffeine 성분을 동시에 분석할 수 있고, 재현성 및 검출 감도가 증진된 최적의 HPLC 분석 조건을 검토한 결과를 요약하면 다음과 같다. 1. 녹차에 함유된 catechin 화합물 및 caffeine의 동시분석을 위한 최적 HPLC 분석 조건을 검토한 결과 컬럼은 YMC-pak ODS-AM 303(25 cm)컬럼을 이용하고, 검출파장은 280 nm, 컬럼온도를 30℃ , 분당유속은 1 mL, 이동상 용매로는 A용매로 0.1% 인산 - 증류수, B용매로 100% MeOH를 사용하여 농도구배 조건으로 분석하는 것이 가장 효율적 분석법으로 조사되었다. 2. 녹차에 함유된 catechin 화합물 및 caffeine을 동시에 분석할 수 있는 최적 HPLC분석조건의 재현성 검정을 실시한 결과 머무름 시간(Rt.)의 변이계수는 최대 1.23% 미만, peak area의 변이계수는 최대 5.13% 미만을 나타내어 확립된 녹차 함유 catechin 9종 화합물 및 caffeine의 HPLC 정량분석법은 재현성이 높은 분석법으로 확인되었고, 각 cafechin 화합물 및 caffeine 성분의 최소 검출한계는 최소 50ppb(0.050 ppm, 50 ng/mL)이하로 조사되어, 확립된 HPLC 분석법은 녹차의 작물학적 특성 평가용으로 활용하기에 전혀 무리가 없는 분석법으로 판단되었다.
Green tea is of particular source as it has been found to have strong antioxidant activities. The extracts of green tea during the commercial harvest seasons from April, 2003 to August, 2003 were compared. The purpose of this study was to determine the correlation between the polyphenol content of green teas and its antioxidant activities. The con-tent of total polyphenols was analyzed and several antioxidant testings were performed. The levels of total polyphenols were higher in the green teas (e.g. Woojeon, Sejak) harvested during very early spring and lower in the green teas harvested late(eg. Ipha, Yepcha). In particular, the free radical scavenging, the inhibition of LDL oxidation, the cytoprotective effect and the inhibition of DNA damage were correlated with the total polyphenol contents of green tea extracts harvested early spring such as Woojeon, Sejak and Jungjak. The results obtained here show that all extracts of green teas including purified green tea catechin, GTC, have strong antioxidant activities on oxidative stress in vifrθ. The variation in polyphenol content and antioxidant activities among various types of green tea by the harvesting time may provide critical information for investigators and consumers using tea in purposes of nutrition and chemoprevention.
김치 제조시 녹차 물추출물의 첨가방법이 발효특성과 관능적 품질에 미치는 영향을 조사하기 위하여 배추의 절임시 1% 녹차 물 추출물을 함유하는 10%소금물로 24시간 절임한 후 담근 김치(SG), 10% 소금물로 24시간 절인 후 1% 녹차 추출물에 30분간 담근 후 담근 김치(DG) 및 1% 녹차 물 추출물과 양념을 혼합하여 담근 김치(MS)를 1에서 숙성키면서 발효 특성과 관능적 품질을 조사하였다. 김치의 숙성 중 pH는 전반적으로 녹차처리구가
Water extract of green tea(GTW) and 70% ethanol extract of green tea(GTE) were prepared for the test of antibacterial activity. The sensitivity of Staphylococcus aureus and Salmonella typhimurium to the green tea extracts in various pH of culture broth was tested. Tryptic soy broth(TSB) containing 0∼2%(w/v) of green tea extracts was adjusted to pH 5.0∼7.0 and inoculated with 105/∼106/ cells/ml of each bacteria. The plate counting method and clear zone test were used to determine inhibitory effect of green tea extracts. Green tea extracts completely inhibited the growth of S. aureus at 0.5% level and bactercidal at 0.5∼1.0% level of GTW and GTE at pH 5.0∼7.0. Green tea extracts were bactercidal to S. typhimurium at 1.5∼2.0% level of GTW and 1.0∼2.0% level of GTE at pH 7.0. Sal. typhimurium was more resistant than S. aureus. in same concentration of green tea extracts at same pH. The resistance of S. aureus and Sal. typhimurium was increased with decreasing pH of culture broth. The morphology of S. aureus cells treated with green tea extracts showed damage of cell wall and cytoplasmic membrane. Severely damaged cells of S. aureus lost electron dense material and cytoplasm. Green tea extracts stimulated autolysis and cell death of S. aureus. This result suggests that green tea extracts can be used as an effective natural antibacterial agent in food.