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

• Journal of the Korean Society of School Health
• /
• v.27 no.1
• /
• pp.31-38
• /
• 2014

Purpose: The purpose of this study was to identify the relationship between caffeinated beverage intake and sleep quality among university students. Methods: Data were collected through a survey of 262 university students in Ulsan conducted in Nov. 27 2013. The survey used a self-administered questionnaire, which was composed of questions regarding socio-demographic characteristics, sleep quality and the status of caffeinated beverage intake. The collected data were analyzed by descriptive statistics, pearson correlation analysis and multiple regression analysis, using SPSS/WIN 21 Program. Results: In average, The subjects consumed 6.43 cups of caffeinated beverage per week, intaking 397.60mg of caffeine. The correlations between sleep quality and the amount of caffeinated beverage intake and between sleep quality and the quantity of caffeine intake were statistically significant. By performing a multiple regression analysis, it was shown sleep quality decreased significantly as the amount of caffeine intake increased (p<.001). Conclusion: To improve university students' sleep quality, it is necessary to control their intake of caffeinated beverage.

• Sleep Medicine and Psychophysiology
• /
• v.22 no.2
• /
• pp.57-63
• /
• 2015

Background and Objectives: Internet addiction is an increasing problem in Korea. The previous studies in this area have targeted adolescents and young adults. This study was conducted to examine the risk of internet addiction in Korean adults and the effect of internet addiction on circadian rhythm. Materials and Methods: For this study, 508 subjects were chosen through population proportional sampling to represent the adult population in Korea, 325 of whom were included based on the Alcohol Use Disorder Identification Test-Korea (Audit-K), Zung's Self-Rating Depression Scale (SDS), drug use in the past year, and suicide attempts. In these subjects, sociodemographic factors including age, gender, and residential area were analyzed, and Young's Internet Addiction Scale (IAS), Morningness-Eveningness Questionnaire (MEQ), and an online survey examining sleep onset time on weekdays and weekends, wake-up time, and caffeinated drink intake were executed. Results: Of the 325 subjects, 136 (41.8%) belonged to a high-risk internet addiction group ($IAS{\geq}40$), and 189 (58.2%) belonged to a normal group (IAS < 40). There was a high proportion of male subjects (p = 0.03) in the high-risk group compared to the normal group. There was a high proportion of younger subjects (p = 0.055) in the high-risk group compared to the normal group, but this difference was not statistically significant. Compared to the normal group, there was a high proportion of the evening type ($MEQ{\leq}41$) in the high-risk group (p = 0.024), who also showed a high proportion of caffeinated drink intake (p < 0.001). Also, the high-risk group was found to go to bed and wake up late, but there was no statistically significant difference with the normal group. Conclusion: This study showed that many adults have a high-risk of internet addiction, and there was a significant correlation between internet addiction and sleep in adult, as has been found in adolescents and early adults. In the future, a longitudinal study will be needed to verify the causal relationship between internet addiction and morningness-eveningness.

• Journal of Food Hygiene and Safety
• /
• v.32 no.2
• /
• pp.89-95
• /
• 2017

A rapid, sensitive analytical method for glucuronolactone in beverages was developed and validated using hydrophilic interaction liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HILIC-ESI-MS/MS). To determine the optimum analytical conditions for glucuronolactone, three different kinds of HILIC columns and two mobile phases with different pH values were examined. An amide-bonded stationary phase with a pH 9 acetonitrile-rich mobile phase was the best condition in terms of column retention, ESI-MS/MS response area, and signal-to-noise ratio. After extraction, glucuronolactone was separated through the HILIC amide column and detected by negative ESI-MS/MS in selected reaction monitoring (SRM) mode. Nine energy drinks sold in Korea were spiked with glucuronolactone at a concentration of 5 ng/mL; the Monster $Energy^{TM}$ sample showed the smallest peak area and its signal-to-noise ratio was used for method validation. Good linearity was obtained in the concentration range from 20 to 1500 ng/mL with a correlation coefficient > 0.998. The developed method had a limit of detection (LOD) of 6 ng/mL and a limit of quantitation (LOQ) of 20 ng/mL. The recovery of this method at concentration of 20, 100, 500, and 1000 ng/mL was 96.3%-99.2% with relative standard deviations (RSD) of 1.6%-14.0%. A reproducibility precision assessment at concentration of 100 and 500 ng/mL was carried out among three laboratories. The recovery of that evaluation was 95.1%-102.3% with RSD of 2.7%-7.0%. An analysis of variance indicated that there was no difference between the recovery results of the three laboratories at the 5% significance level. The validated method is applicable to inspecting beverages adulterated with glucuronolactone in Korea.

• The Journal of Korean Society for School & Community Health Education
• /
• v.19 no.1
• /
• pp.27-45
• /
• 2018

목적: 본 연구는 한국 청소년의 가정환경, 건강행태, 심리적 요인 및 식습관 요인에 따른 주관적 건강상태의 차이를 분석하고, 주요 관련요인을 파악하고자 수행되었다. 방법: 분석자료로서 2015~2016년도 한국 청소년 건강행태 온라인조사 자료를 이용하였으며, 분석대상자 수는 중학생 53,791명, 고등학생 50,959명, 총 104,750명이었다. 학생들의 건강수준은 주관적 건강상태를 기준으로 건강집단과 비건강집단으로 구분하였다. 건강수준에 영향을 미치는 요인으로서 성별, 가정환경, 건강행태, 심리적 요인 및 식습관이 검토되었다. 이들 요인 간 건강집단과 비건강집단의 비율차이 검증을 위해 표본설계 정보를 반영한 Rao-scott 카이제곱검정을 실시하였다. 또한 주관적 건강수준에 영향을 주는 요인을 알아보고자 로지스틱회귀분석을 실시하였다. 결과 및 결론: 주관적 건강수준은 양친부모와 살지 않은 경우, 모의 교육수준이 낮을 때, 주관적 가정경제수준이 낮을수록 낮았다. 음주군, 고강도운동이나 근력운동을 실천하지 않는 군, 과체중이나 비만인군에서 주관적 건강수준이 낮았다. 또한 스트레스나 우울감 등 부정적인 감정이나 행복감을 느끼지 못할 때도 주관적 건강수준은 낮았다. 아침을 결식하거나 탄산음료, 고카페인음료, 패스트푸드 등의 비건강식품을 자주 섭취하는 군에서도 주관적 건강수준은 낮은 것으로 관찰되었다. 한국 청소년들에게서 건강 불평등(health inequalities)은 가정환경, 건강행태, 심리적 요인, 식습관 등 여러 요인들로부터 제기되는 것을 알 수 있었다. 이러한 요인들을 충분히 반영하여 청소년들이 건강해 질 수 있는 다각적 접근 방안이 모색되어야 할 것이다.

• The Journal of the Korea Contents Association
• /
• v.17 no.4
• /
• pp.645-654
• /
• 2017

The purpose of this study is to compare the types and capabilities of smartphone apps related to tea, coffee, wine and beer. As a result of examining the capabilities of 200 tea, coffee, wine and beer apps from Apple App Store, 17 types of capabilities were identified. The study found no significant difference in the capabilities of tea and coffee apps, but there was a significant difference in the capabilities of tea and wine apps, and tea and beer apps (p<0.01). Entertainment-oriented apps take up a higher proportion of tea-related apps while wine apps, provide a higher proportion of consumer usability-oriented apps such as finding information about wine, writing notes about wine characteristics, finding nearby shops/cafes. In order to increase practical use of tea-related apps, this study proposes capabilities of coffee, wine, and beer apps as examples and presents app menu to promote development of tea-related apps.

• Korean Journal of Food Science and Technology
• /
• v.45 no.3
• /
• pp.299-304
• /
• 2013

The major hydrophilic bioactive compounds (chlorogenic acid, caffeine, total phenolics, and flavonoids) and the antioxidant capacity in a single size were evaluated for regular coffee varieties commercially available in Korea. The content of total phenols (63.83-110.12 mg gallic acid equivalents) and flavonoids (35.27-69.27 mg catechin equivalents) were spectrophotometrically determined, and the content of chlorogenic acid (5.17-69.78 mg) and caffeine (74.38-146.32 mg) were determined using HPLC-UV. All varieties of regular coffee studied showed antioxidant potential (88.78-487.52 mg trolox equivalents/serving size), which was conferred by their concentrations of phenolic compounds, caffeine and chlorogenic acid. There were significant (p<0.01) correlations between the total phenolics ($r^2$=0.732) and flavonoids ($r^2$=0.8705) and the antioxidant capacity, suggesting that these components were likely a significant contributor to the antioxidant capacity of commercial regular coffee brews.

• Food Engineering Progress
• /
• v.22 no.4
• /
• pp.337-343
• /
• 2018

Coffee is a commonly consumed beverage that contains anti-inflammatory compounds such as caffeine, chlorogenic acid, cafestol, trigonelline, and kahweol. Lactobacillus plantarum is a lactic acid bacterium most frequently used in the fermentation of food products of plant origin. L. plantarum is able to degrade some food phenolic compounds and provide high value-added compounds such as powerful antioxidants or food additives approved as flavouring agents. In this study, we investigated the anti-inflammatory effects of coffee extract fermented by L. plantarum on RAW264.7 macrophages. In lipopolysaccharide-stimulated RAW264.7 cells, these coffee extracts exhibited anti-inflammatory activities through the reduction of nitric oxide (NO) production and inducible NO synthase expression. Fermented coffee extracts significantly decreased the expression of inflammatory cytokines such as tumor necrosis factor ${\alpha}$, interleukin $1{\beta}$, interleukin 6, and interferon ${\gamma}$. Cyclooxygenase-2, which is one of the key biomarkers for inflammation, was significantly suppressed. These results might be helpful for understanding the anti-inflammatory mechanism of fermented coffee extract on immune cells and, moreover, suggest that fermented coffee extract may be a beneficial anti-inflammatory agent.

• Journal of Service Research and Studies
• /
• v.12 no.4
• /
• pp.82-93
• /
• 2022

The food service industry is a major driver of global sustainable food consumption. By understanding food consumption behavior, restaurant managers can forecast demands and reduce pre-consumer food waste. This study investigates the relationship between influencing factors and the number of customers at restaurants and cafés. These factors are weather-related factors, including rain and temperature, and school-related factors, including exams and the day of the week. Based on these four factors, 24 possible combinations were created. Three representtive days were chosen for each weekday combination. Besides, one representative day was chosen for each weekend combination. In total, 48 days were sampled throughout the year. Customer data were collected from six restaurants and cafes on a Korean university campus. Conjoint analysis was used to determine the relative importance of each variable to customer numbers. Following that, utility scores were standardized and mapped to determine the best condition when the number of customers was at its peak. In addition, each store's sales were compared using Pearson's Correlation Coefficient. The findings support that temperature and rain influences are correlated with the number of customers. Furthermore, we discovered that temperature was far more significant than rain in determining the number of customers. The paper discusses the implications of weather to forecast food and beverage demand and predict meal choices.

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