• 한국약용작물학회:학술대회논문집
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• 2007.05a
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• pp.163-164
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• 2007

• 한국약용작물학회:학술대회논문집
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• 2007.05a
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• pp.169-170
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• 2007

• 한국약용작물학회:학술대회논문집
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• 2007.05a
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• pp.167-168
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• 2007

• 한국약용작물학회:학술대회논문집
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• 2007.05a
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• pp.53-54
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• 2007

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.77-86
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• 2017

Objectives: The purpose of this study was to compare permeation characteristics in three skin types using oil-soluble benzoic acid and water-soluble caffeine after method condition optimization based on OECD guideline 428. Methods: A Franz diffusion cell, a reliable alternative method for skin permeation, was used. One-milliliter samples were taken and immediately replaced with fresh solution in the receptor chamber at regular time intervals (1, 2, 4, 7, 10 and 24 hr). The amount of test substances was measured by LC-MS/MS. Results: The permeation rate increased dose-dependently, and the permeation orders were $KeraSkin^{TM}$ > hairless mouse full skin > human cadaver epidermis for skin types, and benzoic acid solution > caffeine solution > benzoic acid cream > caffeine cream for type of test materials. Conclusion: According to the definitions of Marzulli, benzoic acid and caffeine would be classified as 'fast' and 'moderate' compared with the permeation of other chemical species. The setting conditions and permeation characteristics performed in this study are expected to contribute to future permeation studies.

• The Korean Journal of Food And Nutrition
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• v.32 no.5
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• pp.504-510
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• 2019

The purpose of this study was to compare the effects of soaking and ultrasonic extraction by observing the change of contents with extraction time of physicochemical properties (solid content, colorness, caffeine, chlorogenic acid, total polyphenols, DPPH, and ABTS). As a result of the analysis, solid content increased with longer extraction time and the whiteness tended to decrease with longer extraction time. Conversely, the extraction of functional materials showed a tendency to increase as the extraction time increased. Caffeine reached the maximum value after two hours soaking, but showed the same result as one hour for sonication. Chlorogenic acid did not show difference from the content of coffee extracted for one hour soaking only by sonication extraction for 30 minutes. The total polyphenols eluted with approximately two hours of soaking even after 30 minutes of sonication. DPPH and ABTS were insignificant in their concentrations, but their antioxidative effect was more than two hours of soaking with only 30 minutes of sonication. Sonication has a short time extraction from a functional aspect (caffeine content, chlorogenic acid, polyphenol content, and antioxidant capacity) and this experiment can provide basic data for the development of innovative recipes.

• Journal of the Korean Society of Food Culture
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• v.32 no.1
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• pp.66-74
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• 2017

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 (${\leq}2/wk$) and highest group ($1{\geq}day$) 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.

• The Korean Journal of Food And Nutrition
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• v.31 no.3
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• pp.416-424
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• 2018

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.

• Culinary science and hospitality research
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• v.22 no.6
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• pp.114-119
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• 2016

This study aimed to investigate changes in the diverse compound in coffee beans under different roasting conditions. Four different kinds of chemical characteristics (phenolic contents, flavonoid contents, chlorogenic acid, and caffeine) were analyzed. According to the temperature of coffee roasting, this study categorized green bean, extract A ($191^{\circ}C$), B ($202^{\circ}C$), C ($220^{\circ}C$), and D ($233^{\circ}C$). As a result, total phenol compound showed low level of total phenol compound at lower temperatures. Extract A showed significantly higher level of total flavonoid ($111.33{\pm}10.14$), green bean showed $83.67{\pm}2.43$, Extract B $46.11{\pm}2.38$, C and D showed $31.44{\pm}0.12$, $19.22{\pm}0.46$ respectively. Green bean showed higher level of chlorogenic acid ($64.47{\pm}0.51$), Extract A ($39.66{\pm}0.47$), extract B ($12.45{\pm}0.99$), C, D ($3.59{\pm}0.31$, $0.63{\pm}0.12$) respectively. This study also noted that there are significant different in terms of caffeine content. Extract A has higher level of caffeine content ($38.45{\pm}1.70$) significantly, green bean ($27.14{\pm}2.27$), extract B ($18.95{\pm}0.64$), extract C ($17.89{\pm}0.96$). As a conclusion, we revealed that roasting conditions play an important role in the composition of coffee compounds.

• Advances in nano research
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• v.9 no.1
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• pp.25-32
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• 2020

In this work, we report the use of caffeine as an alternative source of nitrogen to successfully dope graphene (quaternary 400.6 eV and pyridinic at 398 eV according XPS), as well as the growth of silver nanowires (in-situ) in the surface of nitrogen doped graphene (NG) sheets. We used the improved graphene oxide method (IGO), chemical reduction of graphene oxide (GOx), and impregnation with caffeine as source of nitrogen for doping and subsequently, silver nanowires (NW) grow in the surface by the reduction of silver salts in the presence of NG, achieving a numerous of growth of NW in the graphene sheets. As supporting experimental evidence, the samples were analyzed using conventional characterization techniques: SEM-EDX, XRD, FT-IR, micro RAMAN, TEM, and XPS.