• Title/Summary/Keyword: Catechins

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Maturation Effects of Don Tea on Physicochemical Components and Anti-Microbial (돈차(錢茶)의 숙성 기간이 이화학적 성분과 항균 활성에 미치는 영향)

  • Park, Yong-Seo;Ryu, Hyeun-Hee;Lee, Mi-Kyung;Kim, Hyun-Ju;Heo, Buk-Gu
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.1
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    • pp.32-37
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    • 2009

  • This study was carried out to gather basic data on the restoration and extent of Don tea (a coin-shaped tea), the traditional tea of Korea. We examined the physicochemical components and anti-microbial activity of Don tea extracts at 0, 5 and 10 months. The Hunter value $L^*$, of Don tea extracts which were matured for 10 months decreased from 7.01 to 4.97 compared to that when the extracts were first manufactured. However, the $b^*$ value increased from 0.09 to 2.67. There were higher contents of inorganic matter in Don tea extracts following manufacture in the order of K (14.12 mg/100 mL), Mg (0.94 mg/100 mL), P (0.88 mg/100 mL), Ca (0.16 mg/100 mL) and Mn (0.16 mg/100 mL). Classified catechins contents were found in the order of C (19.97 mg/100 mL), EGC (9.30 mg/100 mL), ECG (9.02 mg/100 mL), GCG (8.50 mg/100 mL), GC (7.61 mg/100 mL) and CG (5.63 mg/100 mL). The longer the maturation period of the Don tea extracts, the lower the contents of inorganic matter and catechins. However, this did not apply to the total phenol contents, particularly in the phenol contents of Don tea extracts matured for 10 months which increased by 93.82 mg/l00 mL. Don tea extracts which were matured for longer periods showed higher anti-microbial activities against Bacillus subtilis and Streptococcus mutans. However, there were lower activities against Staphylococcus aureus, Escherichia coli and Salmonella enteritidis. Consequently, it was concluded that a shorter maturation period was required for the effective utilization of the inorganic matter, the catechins and the gram-negative bacteria in the Don tea extracts. However, a longer maturation period of 10 months was found to effectively utilize the total phenol compound contents and the gram-positive bacteria.

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Effects of Polyphenol and Catechin Levels on Antioxidant Activity of Several Edible Flower Extracts (주요 식용꽃 추출물의 폴리페놀과 카테킨류 함량이 항산화 활성에 미치는 영향)

  • Lee, Mi-Kyung;Park, Jung-Suk;Song, Hee-Ja;Chon, Sang-Uk
    • Korean Journal of Plant Resources
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    • v.27 no.2
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    • pp.111-118
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    • 2014

  • Contents of phenolics, flavonoids, and catechins, and antioxidant activity were investigated in the ethanol extracts of three different flower species, Magnolia denudata, Prunus mume, Carthamus tinctorius. Total phenolics were more present in M. denudata than P. mume or C. tinctorius, ranging from 72.6 to 118.0 mg/kg (p < 0.05). Total flavonoids level had same tendency to total phenolics content, showing highest amount (25.1 mg/kg) in M. denudata. The antioxidant activity of the methanol extracts from all the flowers dose-dependently increased. DPPH free radical scavenging activity at 250 mg/kgwas higher in M. denudata and P. mume by 93.0 and 92.6%, respectively, than C. tinctorius by 23.0% (p < 0.05). Total catechins content including 6 compounds was higher in M. denudate (9,425.5 mg/kg) than that in P. mume or C. tinctorius (3,407.8 or 190.6 mg/kg). However, P. mume extracts showed highest amount in caffeine as well as vitamine C. DPPH radical scavenging activity in three different flowers was highly correlated with contents of total phenolics ($r^2=0.7994$), total flavonoids ($r^2=0.9131$), and total catechins ($r^2=0.5929$), and their content and activities were different depending on species.

  • https://doi.org/10.7732/kjpr.2014.27.2.111 인용 PDF KSCI KPUBS HTML

Changes in Phytochemical Stability and Food Functionality during Cooking and Processing (식품의 조리.가공 공정 중 phytochemical 및 기능성의 변화)

  • Kim, Hyun-Jung;Chun, Hyang-Sook
    • Korean journal of food and cookery science
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    • v.22 no.3 s.93
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    • pp.402-417
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    • 2006

  • Research interest on functional food and phytochemicals has mainly focused on their health effects, mechanism of action and structure-activity relationship for the development of nutraceuticals. Considering the intake of phytochemicals via the normal diet, further information is required on changes in food functionality or individual phytochemicals that occur during the cooking or processing of foods, in order to increase the intake of these bioactive compounds, because many of the unit-operating procedures involved in cooking or food processing may result in physicochemical changes of food constituents. This study reviews the changes of selected phytochemicals, i.e. flavonoids, organosulfur compounds and carotenoids, or food functionality by major cooking or processing procedures such as heating, fermentation, and pH changes. In general, heating has a negative effect on food functionality, although in some cases, mild heating increases bioactive phytochemical contents. Some phytochemicals, including anthocyanins and catechins, are stabilized in lower pH conditions. The structures of phytochemicals, including isoflavones and catechins, are changed by fermentation. The loss of bioactive compounds may be decreased by recently developed cooking or processing methods such as microwave cooking or use of high hydrostatic pressure. However, the effects of cooking and processing procedures on food functionality and phytochemicals are so diverse and dependent on test conditions that further research efforts are needed to form accurate conclusions on the effects of cooking and processing of foods.

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