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        검색결과 45

        1.
        2023.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study monitored the caffeine content of ready-to-drink coffee and verified the appropriateness of the labeling. The caffeine content was analyzed using HPLC. The average caffeine content of cold brew coffee was 0.31-1.04 mg/mL, with an average of 0.55 mg/mL. The average content of product was 147.27 mg/bottle, and taking into account the recommended daily intake, an adult can consume 2.7 bottles. Americano coffee was 0.15- 0.38 mg/mL, with an average of 0.28 mg/mL. The average content of product was 110.42 mg/bottle, and considering the recommended daily intake, an adult can consume 3.6 bottles. The caffeine content of decaffeinated cold brew coffee was 5.14 mg/bottle and compared to Americano coffee, more than 95% of the caffeine was removed. In addition, we verified the tolerance level of the total caffeine content in ready-to-drink coffee, and none of them exceeded 120%, signifying that all commercial products were effectively managed.
        4,000원
        3.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 원액상태로 장시간 보관이 용이하고 특유의 향을 유지할 수 있는 콜드브루커피가 남녀노소에게 크게 인기를 얻음에 따라 커피판매업체의 규모와 수가 증가하고 있으며, 명절 선물용으로도 각광을 받고 있다. 콜드브루커피는 차가운 물로 장시간 추출한 커피이므로 세균에 노출될 가능성이 크다. 따라서 본 연구는 시중판매되고 있는 콜드브루커피의 안전성을 조사하여 소비자에게 올바른 정보와 건강한 먹거리를 제공하고자 하였다. 총 75건 의 콜드브루커피를 대상으로 식품공전 액상커피의 규격 기준(세균수, 대장균군)과 식중독균 9종 및 카페인 함량 검사를 실시하였다. 조사한 결과 온라인에서 구매한 9개 제품의 세균수가 규격기준을 크게 초과하여 검출되었으며, 대장균군 및 식중독균 9종은 검출되지 않았다. 또한 조사한 콜드브루 제품의 평균 카페인 함량은 1.6 mg/mL (240 mL 제품의 경우 카페인 384 mg 함유)이며, 카페인 과다 섭취 시 불면증, 신경과민 등 부정적인 작용들이 존재하므로 성인 기준으로 카페인 최대 일일섭취권고량 400 mg/day을 초과하지 않도록 주의가 필요한 것으로 나타났다.
        4,000원
        4.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 광주지역 커피전문점에서 유통되고 있는 커피류 중 주요 성분인 카페인과 커피콩의 로스팅 과정에서 발생할 수 있는 유해 성분인 benzo[a]pyrene, 그리고 중금속(lead, cadmium) 등의 함량을 분석하였다. 커피음료는 대형(12), 중형(13) 프랜차이즈 그리고 지역 소규모 커피 전문점(75) 등 100개 지점에서 총 114건(Americano 100건, Cold-brew 14건)을 구매하여 시험 검체로 하였고, 검체의 1회 제공량은 175-460 (Americano 220-460, Cold-brew 175-400) mL로 조사되었다. 커피음료의 성분 분석 결과 카페인은 0.25-1.49 mg/mL (72.58-290.18 mg/cup)으로 고카페인 함유 기준인 0.15 mg/mL를 상회하는 수준이었고, 1회 제공량 기준으로 일부 커피음료는 2잔만 섭취하여도 성인 카페인 최대 섭취 권고량인 400 mg/day를 초과하는 것으로 확인되었다. 벤조피렌(Benzo[a]pyrene)은 ND-55.35 ng/kg (ND-15.22 ng/cup)으로 분석되었다. 현재 커피음료에 대한 벤조피렌 함량 기준은 없으나 다른 식품유형의 기준인 1.0 μg/kg(특수용도식품) 이하 보다 낮은 수준으로 확인되었다. 중금속은 납(Pb)과 카드뮴(Cd)이 각각 ND- 29.00 μg/kg (ND-8.4 μg/cup)과 ND-12.0 μg/kg (ND-4.7 μg/ cup)의 분포를 보였으나 대부분이 불검출로 확인되었다. 본 조사를 통해 시중에 유통되고 있는 원두 추출 커피음료 중 벤조피렌과 중금속(납, 카드뮴)은 안전한 수준으로 확인되었으나, 카페인은 함량이 비교적 높게 확인되어 커 피음료 섭취 시 카페인 함량에 대한 고려가 필요할 것으 로 판단된다. 또한, 소비자를 위해 향후 커피음료에 카페인 함량 표시도 필요할 것으로 보인다.
        4,000원
        5.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The physiologically advantageous aspects of green tea have been identified recently and green tea has been a favorite drink of many people. Due to the increased awareness of green tea’s positive effects on human health, the demand for foods containing green tea has increased. This has led to the development of diverse green tea-related beverages; thereby many companies in Korea have put a wide variety of manufactured green tea beverages on the market. However, the components within green tea beverages have not been examined in Korea yet. In this study, we investigated the contents of the physiologically functional materials found in green tea, such as catechin, catechin gallate, epicatechin, epicatechin gallate, epigallocatecin gallate, gallocatechin gallate and caffeine. Fifty-six green tea products purchased from the local grocery stores and cafes were analyzed using high performance liquid chromatography (HPLC) analysis. As a result, all tested products contained catechin and caffeine, although the amount of each component was largely different. The total amount of catechin derivatives in the manufactured green tea beverages purchased from cafes was 263.17 mg/L, while they were 61.99 mg/L in the beverages purchased from the local grocery stores. And, to the almost samples the amount of caffeine was proportional to the amount of catechin.
        4,000원
        7.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In most mammals, metaphase II (MII) oocytes having high maturation promoting factor (MPF) activity have been considered as good oocytes and then used for assisted reproductive technologies including somatic cell nuclear transfer (SCNT). Caffeine increases MPF activity in mammalian oocytes by inhibiting p34cdc2 phosphorylation. The objective of this study was to investigate the effects of caffeine treatment during in Vitro maturation (IVM) on oocyte maturation and embryonic development after SCNT in pigs. To this end, morphologically good (MGCOCs) and poor oocytes (MPCOCs) based on the thickness of cumulus cell layer were untreated or treated with 2.5 mM caffeine during 22-42, 34-42, or 38-42 h of IVM according to the experimental design. Caffeine treatment for 20 h during 22-42 h of IVM significantly inhibited nuclear maturation compared to no treatment. Blastocyst formation of SCNT embryos was not influenced by the caffeine treatment during 38-42 h of IVM in MGCOCs (41.1-42.1%) but was significantly improved in MPCOCs compared to no treatment (43.4 vs. 30.1%, P<0.05). No significant effects of caffeine treatment was observed in embryo cleavage (78.7-88.0%) and mean cell number in blastocyst (38.7-43.5 cells). The MPF activity of MII oocytes in terms of p34cdc2 kinase activity was not influenced by the caffeine treatment in MGCOCs (160.4 vs. 194.3 pg/ml) but significantly increased in MPCOCs (133.9 vs. 204.8 pg/ml). Our results demonstrate that caffeine treatment during 38-42 h of IVM improves developmental competence of SCNT embryos derived from MPCOCs by influencing cytoplasmic maturation including increased MPF activity in IVM oocytes in pigs.
        4,000원
        8.
        2017.05 구독 인증기관·개인회원 무료
        The objective of this study was to investigate the influence of the addition of caffeine (alkaloid family) to the ejaculates of boar sperm quality as well as investigate their optimum concentrations for increasing the movement of sperms. Semen was collected from 9 boars by the gloved-hand technique one week interval. Semen followed by cryopreservation with egg yolk extender freezing medium using freezing protocol. The collected semen were frozen on the same day. Motility was assessed for % motile cell characteristics using computer-assisted semen analysis (CASA; SAIS SI-100, Medical supply, Korea). Frozen boar sperms were thawed in Beltsville Thawing Solution (BTS) with 5, 10, and 15mM caffeine were then incubated at 38 celsius degree for 20 minutes. In experiment 1, semen were diluted BTS and addition of different concentration of caffeine to the pre-freeze semen cryopreservation. In experiment 2, incubation of frozen-thawed sperm in BTS supplemented with different concentration of caffeine for 20 minutes improved (P<0.05) after semen cryopreservation-thawing on sperm quality. After thawing significantly increased progressive and total motility. The addition of 10 mM caffeine to cryopreserved semen after thawing significantly increased progressive and total motility compared with other treatment. These result suggest that caffeine enhanced post-thaw motility of cryopreserved boar sperm when added after thawing.
        9.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the correlation between frequency of high-caffeine energy drink intake in adolescents and their mental health status using data from the Korean adolescent health behaviors online survey (2014-15). Mental health was classified by the five categories: Perception of stress (PS), Insufficient relief of fatigue after sleep (IRFS), Experience of sadness despair (SD), Suicidal ideation (SI), and Subjective unhappiness (SU). Regarding general characteristics, higher age, height, and body weight of subjects were associated with higher frequency of high-caffeine energy drink (HCED) intake (p< .0001). In the OR analysis, when the lowest group (≤2/wk) and highest group (1≥day) were compared, the highest group showed significantly higher OR in all five categories of mental health. According to gender, males did not show better PS, SD, and SI than females who had a high frequency of HCED (p for trend<.0001). According to school level, middle school students showed a higher risk rate than high school students in PS, IRFS, and SD (p for trend< .0001). Based on the above results, higher frequency of HCED intake among adolescents was associated with more adverse effects on mental health.
        4,000원
        10.
        2016.10 구독 인증기관·개인회원 무료
        The present study was conducted to investigate the effect of caffeine and theophilline on sperm motility during in vitro fertilization (IVF). Briefly, commercial boar semen was centrifuged and resuspended (5x107 sperms/ml) with fertilization medium (mTBM) supplemented with 2 mM caffeine (Caf), 5 mM theophylline (The), 2 mM caffeine + 5mM theophylline (Caf + The), and not supplemented control. The semen parameters of the four groups were analyzed by computer-assisted semen analysis (CASA, Medical Supply Co. Ltd) system at 6 h as time for IVF at 38.5 C under 5 % CO2 in air. The groups were examined 11 semen parameters such as total motility (TM), curvilinier velocity (VCL), straight-line velocity (VSL), average-path velocity (VAP), and hyperactivated (HYP), etc. A total motility of control group (41.3 %) at 6 h showed significantly (P<0.05) higher than those of other groups (Caf, 37.2; The, 35.2; Caf + The, 30.1 %). Results from many other sperm parameters indicated that the theophylline and caffeine negatively affected on sperm motility during IVF. These results suggested that the supplementation of caffeine and/or theophylline was not essential for IVF in pigs. To prove this suggestion, further studies are needed to analyze fertility and embryonic development after IVF with or without the supplementation of caffeine and/or theophylline.
        11.
        2016.10 구독 인증기관·개인회원 무료
        In mature oocytes, maturation promoting factor (MPF) activity is playing important roles in arrest at M-phase and its continuous phenomenon, oocyte aging. In most mammals, metaphase II oocytes show high MPF activity and have been used as ooplasts in somatic cell nuclear transfer (SCNT). Caffeine has been found to regulate MPF activity in mammalian oocytes. Caffeine inhibits p34cdc2 phosphorylation and increases MPF activity. The present study investigated the effects of caffeine treatment during last 4 hours of in vitro maturation (IVM) on oocyte maturation and embryonic development after parthenogenesis (PA) and SCNT. The IVM medium was medium-199, 10% (v/v) PFF, cysteine, pyruvate, epidermal growth factor, kanamycin, insulin, and hormones. Immature oocytes were matured in IVM medium without or with 2.5 mM caffeine during the last 4 hours of IVM. The in vitro culture medium for embryonic development was porcine zygote medium-3 containing 0.3% (w/v) bovine serum albumin. Nuclear maturation (83.6–87.2%) and intraoocyte glutathione contents (0.9–1.0 pixels/oocyte) of oocytes were not influenced by the caffeine treatment. The membrane fusion of cell-cytoplast couplets (75.5–76.5%) and cleavage (85.4–86.2%) were also not altered by the caffeine treatment. However, caffeine-treated oocytes showed higher (P<0.05) blastocyst formation after SCNT (47.5 vs. 34.3%) than untreated oocytes. Our results demonstrate that caffeine treatment during last 4 hour of IVM improves the developmental competence of SCNT embryos probably by influencing MPF activity.
        13.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effect of activated carbon particle diameter (i.e. US sieve No. 8×10 (dp ≈ 2.19 mm), 18×20 (dp ≈ 0.92 mm), 50×60 (dp ≈ 0.27 mm) and 170×200 (dp ≈ 0.081 mm)) on caffeine adsorption is investigated. BET surface area was increased with decreasing particle diameter (dp), and caffeine adsorption rates increased with decreasing dp. Moreover, pseudo-second order model is predicted the experimental data more accurately than pseudo-first order model, and the fastest rate constant (k2) was 1.7 g mg-1 min-1 when dp was 0.081 mm. Surface diffusion coefficient (Ds) was decreased with decreasing dp based on the minimum sum of square error (SSE). Practically, certain ranges of Ds are acceptable with high reliability (R2) and it is determined that the effect of dp on Ds is unclear. The effect of pH on caffeine adsorption indicated the dependency of m/L ratio (mass liquid ratio) and pHPZC. The pHPZC (i.e. 7.9 ± 0.2) was not affected by dp. The higher caffeine adsorption at pH 4 and pH 7 than at pH 10 is due to pHPZC, not pka of caffeine.
        4,000원
        14.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Surveys on the consumption of caffeinated beverages by high school students (n=886) were performed. Of the students, 97.0% consumed a variety of caffeinated beverages, including carbonated drinks (90.0%), processed milk and cocoa (79.0%), coffee (63.0), teas (52.1), energy drinks (16.4%) and nourishment drinks (15.5%). The frequency of intake per student was 8.2 times per week. Caffeine intake through the caffeinated beverages was 41.53 mg/day, which was accounted for by coffee (51.5%), carbonated drinks (19.6%), processed milk and cocoa (11.5%), teas (11.4%), energy drinks (5.0%) and nourishment drinks (1.1%). Students with high levels of stress, those who consumed snacks twice a day, and those who used a computer (or smart phone) for more than 3 hours per day showed significantly higher caffeine intake. The groups with high caffeine intake experienced heart palpitations, insomnia and pollakiuria. Students indicated that they consumed the caffeinated beverages for the taste (57.9%), waking up (18.0%), thirst (13.2%), etc. (10.9%). They tended to consume drinks with a high content of caffeine to sleep less. In addition, they rarely checked the label, and showed a lack of awareness of the caffeine contents in the beverages, which calls for education.
        4,300원
        15.
        2013.12 구독 인증기관 무료, 개인회원 유료
        In mammal, unfertilized oocytes remain in the oviduct or under in vitro culture, which is called "oocyte aging". This asynchrony negatively affects fertilization in pre- and post-implantation embryo development. Caffeine a phos-phodiesterase inhibitor is known to rescue oocyte aging in several species. The objective of this study is to determine the cytoskeleton distribution in aged oocytes and the embryo developmental ability of aged oocytes in the present or absence of caffeine during maturation. Caffeine treatment increased the incidence of normal spindle assembly of aged oocytes (treatment, 67.57±4.11% aging, 44.61±6.4%) and no significant differences compared to control group. Fluorescence values were compared using ROS (Reactive oxidation species) stain. Fluorescence values appear of con-trol group intensity rate (51.53.±3.80), aging group (68.10±5.54) and treatment of caffeine (45.04±2.98). Aged oocytes that were derived from addition of caffeine to the IVM (in vitro maturation) medium had significantly increased 2-cell that developed to the blastocyst stage compared to the aging group. Blastocysts, derived from caffeine treatment group, significantly increased the total cell number compare aging (90.44±10.18 VS 67.88±7.72). Apoptotic fragments of genomic DNA were measured in individual embryo using TUNEL assay. Blastocyst derived from caffeine treatment group decreased significantly the apoptotic index compared to blastocyst derived from aging group. In conclusion, we inferred that the caffeine treatment during oocyte aging can improve the developmental rate and quality in bovine embryos developing in vitro
        4,000원
        17.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The influence of the culture media on the growth and catechins and caffeine production was investigated in adventitious root cultures of tea tree. The growth rate of adventitious roots was higher than that of solid medium. Growth rate of adventitious roots was noted to be optimal in N6 liquid medium. Yields of (-)-epicatechin gallate (ECG) and caffeine were the highest when adventitious root cultures were maintained in Nitsch and B5 liquid medium, respectively. The production of (-)-epicatechin (EC) and (-)-epigallocatechin gallate (EGCG) from adventitious roots was maximal when cultured in 1/2MS liquid medium. The adventitious root extracts of tea tree produced on catechins as EC (20.77 mg/g) and EGCG (1.84 mg/g) in 1/2MS medium; EGC (24.39 mg/g) and caffeine (12.97 mg/g) in B5 medium and (-)-epigallocatechin (ECG) (2.16 mg/g) in Nitsch liquid medium.
        4,000원
        18.
        2012.12 구독 인증기관 무료, 개인회원 유료
        The technique of SCNT is now well established but still remains inefficient. The in vitro development of SCNT embryos is dependent upon numerous factors including the recipient cytoplast and karyoplast. Above all, the metaphase of the second meiotic division (MII) oocytes have typically become the recipient of choice. Generally high level of MPF present in MII oocytes induces the transferred nucleus to enter mitotic division precociously and causes NEBD and PCC, which may be the critical role for nuclear reprogramming. In the present study we investigated the in vitro development and pregnancy of White-Hanwoo SCNT embryos treated with caffeine (a protein kinase phosphatase inhibitor). As results, the treatment of 10 mM caffeine for 6 h significantly increased MPF activity in bovine oocytes but does not affect the developmental competence to the blastocyst stage in bovine SCNT embryos. However, a significant increase in the mean cell number of blastocysts and the frequency of pregnant on 150 days of White-Hanwoo SCNT embryos produced using caffeine treated cytoplasts was observed. These results indicated that the recipient cytoplast treated with caffeine for a short period prior to reconstruction of SCNT embryos is able to increase the frequency of pregnancy in cow.
        4,000원
        19.
        2012.06 구독 인증기관·개인회원 무료
        In mammal, oocytes are arrested at the metaphase Ⅱ until fertilization. However, unfertilized oocytes that remain in the oviduct or under in vitro culture, which is called "oocyte aging". Asynchrony negatively affects fertilization, pre- and post-implantation embryo development. Caffeine is known to phosphodiesterase inhibitor that rescues oocyte aging in several species. Nevertheless, the effect of caffeine was not clear in bovine aging oocytes. In this study investigated the cytoskeleton distribution in aged oocytes and the embryo development ability of aged oocytes from treated with or without caffeine during maturation. The cumulus and oocyte complexes (COCs) were cultured in 10% FBSTCM199 for up to 22h at 38.5℃ in 5% CO₂. For oocyte aging study, the COCs were cultured in 10% FBS-TCM199 supplemented with or without 10 mM caffeine for 40hs. And then oocytes underwent in vitro fertilization using highly motile sperm recovered from frozen and than thawed bull semen. As a result normal cytoskeleton percentage of caffeine treatment group more than the aging group (67.57%±4.11 VS 44.61%±6.40) and no significantly different compared to control group. Aged oocytes derived from addition of caffeine to the in vitro maturation medium significantly increased the percentage of 2- cell that developed to the blastocyst stage compared to the aging group. Blastocysts derived from caffeine treatment group significantly increased the total cell number compare aging (90.44%±10.18 VS 67.88%±7.72). Apoptotic fragmenting of genomic DNA was measured in individual embryos using the TUNEL assay. Blastocyst derived from caffeine treatment group significantly decereased the apoptotic index compared to blastocyst derived from aging group. In conclusion, we inferred that the caffeine treatment during oocytes aging periode can improved the develpmental rate and quaility in bovine embryos developing in vitro.
        20.
        2011.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, 160 tea tree (Camellia sinensis L.) lines were classified by caffeine content using colorimetric methods. Among them, caffeine-rich lines (HR-78, HR-137, HR-82 and HR-123) and poor lines (HP-85, HP-88, HP-19, and HP-131) were selected. To know the difference in morphological and genetic characters between caffeine-rich and poor lines, we used leaf/shoot growth and RAPD methods. Cluster pattern of morphological characters (leaf width, leaf length, leaf area and shoot length) showed that shoot length was longer in caffein-rich lines than in -poor lines. In genetic analysis, amplified DNA bands having various sizes were detected in RAPD analysis where 30 random primers were used. However, the discriminated primer set that distinguish caffein-rich tree line from -poor lines was not found. These results can be used as the basic data to determine the morphological and genetic differences among caffein-rich and -poor lines
        4,000원
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