• Journal of the Korean Home Economics Association
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• v.12 no.34
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• pp.737-741
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• 1974

Coffee is a popular beverage with many people at home and in the tea-room, Caffeine is a major chemical compound of the coffee. A little caffeine is a stimulant to the movement and spiritual nerve, but much caffeine influences sleep, nervousness, non-concentration, headache and giddliness depending upon each person. The writhe expresses the result of the caffeine content in the coffee which is collected from the coffee-shapes of Seoul. The contents are as follows : 1) Caffeine content of the coffee of the tea-room was researched dividing into the contral Seoul city and the outskirts of Seoul. 2) Caffeine content of the coffee in the outskirts tea-rooms is 0.32-1.23 mg/ml and the average is 0.546 mg/ml (SD 0.19). 3) Caffeine content of the coffee of the central city is 0.34-0.73 mg/ml and the average is 0.513 mg/ml (SD 0.12). 4) There was no difference between the outskirts and the central city. 5) Caffeine content of the coffee of the tea-rooms according to each season is going to be researched.

• Journal of the Korean Society of Food Science and Nutrition
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• v.4 no.1
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• pp.45-48
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• 1975

Coffee is a popular beverage with many people at home and in the tea-room. Caffeine is a major chemical compound of coffee. A little caffeine is a stimulant to the movement and spiritual nerve, but much caffeine influences sleep, nervousness, non-concentration, headache and giddiness depending upon each person. The writer expresses the result of the caffeine content in the coffee which is collected from the coffee- shops of Seoul. The contents are as follows : 1) Caffeine content of the coffee of the tea-room was researched dividing into the central Seoul city and the outskirts of Seoul. 2) Caffeine content of the coffee in the outskirts tea-rooms is $0.32{\sim}1.23mg/ml$ and the average is 0.546mg/ml (SD 0.19). 3) Caffeine content of the coffee of the central city is $0.34{\sim}0.73mg/ml$ and the average is 0.513mg/ml(SD 0.12). 4) There was no difference between the outskirts and the central city. 5) Caffeine content of the coffee of the tea-rooms according to each season is going to be researched.

• The Korean Journal of Zoology
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• v.19 no.4
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• pp.161-170
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• 1976

Since caffeine inhibits the active uptake of Ca by the sarcoplasmic reticulum, the action of caffeine on the fragmented sarcoplasmic reticulum of rabbit skeletal muscle was studied. Caffeine seemed not to bind tightly to the sarcoplasmic reticulum. The determination of sulfhydryl content of the fragmented sarcoplasmic reticulum, however, suggested that caffeine in some unknown manner influences the protein moiety and thereby increases the sulfhydryl content. The inhibition of Ca uptake by caffeine therefore might be considered as due to the result of this change in protein sulfhydryl content.

• Natural Product Sciences
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• v.19 no.2
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• pp.166-172
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• 2013

Caffeine and epigallocatechin gallate (EGCG) are major constituents of green tea, the leaves of Camellia sinensis (Theaceae). Although EGCG is well known for diverse beneficial effect, caffeine is sometimes harmful with adverse effects. Therefore, the extraction efficiency was investigated using different extraction method such as extraction solvent, extraction time, extraction method, and repeated extraction. The content of EGCG and caffeine in green tea extract was quantitated by HPLC analysis. The extraction condition exerted difference on the extraction yield. The content of EGCG was also affected by different extraction condition. Especially, the extraction solvent greatly affected the content of EGCG in the extract. However, the content of caffeine was less affected compared to that of EGCG. The inhibitory effect of green tea extract on pancreatic lipase was almost similar regardless of extraction condition. Taken together, optimization of extraction condition will provide best efficacy for further development of green tea as anti-obesity therapeutics.

• Journal of Nutrition and Health
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• v.26 no.9
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• pp.1118-1128
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• 1993

This study was undertaken to investigate the acute effect of caffeine consumption on the change of mineral concentration in serum and urinary mineral excretion in healthy young females. On two separate mornings at one week intervals, each subject drank a coffee which contained no caffeine and 3mg/kg body weight caffeine. To obviate dietary effects on mineral concentration in serum and urine, each subject fasted at least ten hours before consuming the test beverage. At one, two, three and four hours, serum and urine production collected seperately for measurement of sodium, potassium, calcium, phosphorus and magnesium concentration. The results were as following : 1) Mean age of subjects was 20.6$\pm$0.32, Mean body mass index of subjects was 21.64$\pm$0.89, which was within $\pm$10% of ideal body weight. 2) Total urine volume of caffein groups for 4 hour after caffeine consumption was higher than that of decaffeine one, but urine pH was unchanged after caffeine consumption. Total urinary four hour excretion of creatinine was not affected by caffeine consumption and creatinine clearance also was not different from the control value. 3) In serum, mean three hour content of sodium(p<0.01) and phosphorus was higher in the subject given the caffeine. Mean serum magnesium and calcium contents were lower in caffeine group than that of decaffeine one. Mean serum magnesium content for three hour after caffeine ingestion was affected by caffeine consumption(p<0.001). Mean serum content of potassium was unaffected by caffeine consumption. 4) Total urinary four hour excretion of sodium, increased significantly after caffeine consumption(p<0.05), while total urinary four hour excretion of potassium, calcium, phosphorus and magnesium was unchanged after caffeine intake. Urinary excretion of Na, Ca, P and Mg was greatest at one hour after caffeine consumption, especially urinary sodium and potassium excretion was significantly high(p<0.05, p<0.01). The above results show that only 3mg caffeine per kg body weight increase the urinary macro mineral excretion in healthy young females.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.561-567
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• 1994

This study was designed to evaluate the effects of dietary vitamin E and caffeine on the activities of lipid peroxidation related enzymes in rat liver . Male Sprague-Dawley rats were fed on diets containing three level of vitamin E (37.5, 750 or 1,5oomg/kg diet) and with or without 0.3% caffeine. The rats were sacrificed after 5 and 10 weeks of feeding. Results obtained from this study were as follows ; The content of cytochrome P450 tended to increase as dietary vitamin E level was raised. The activity of xanthine oxidase increased in the caffeine groups, but it decreased by the increasing level of vitamin E. Superoxide dismutase and catalase activity were slightly elevated by dietary supplementation of vitamin E. And there was a tendency of higher these enzyme activity of caffeine groups. The activity of glutathione perxidase tended to decrease as dietary vitamin E level increased. But it was raised by caffeine supplementation . Liver glutathione content was not affected by dietary supplementation of vitamin E, but it showed a decreasing tendency in caffeine groups. There was a tendency of more lipid peroxide content of caffeine groups than that of the only vitamin E supplemented group. But the degree of increment of this decreased as dietary vitamin E level increased.

• Journal of the Korean Dietetic Association
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• v.27 no.3
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• pp.179-190
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• 2021

The high caffeine intake by adolescents has been a concern. The purpose of this study was to examine the awareness and consumption of caffeine-containing foods among 443 high school students using a questionnaire. An analysis of the spending patterns of the students' weekly allowance showed that the amounts spent on purchasing caffeine-containing foods were higher for female students than male students (P <0.001). The scoring of the perception of caffeine was 3.1 out of 5, interest in the caffeine content of food was 2.6, consumption of caffeine-containing foods was 2.6, and usefulness of caffeine-containing foods was 2.7. The awareness of caffeine content in food was significantly higher in females (7.3 out of 11) than male students (6.7) (P<0.01). Approximately 59% of students perceived that the relationship between caffeine-containing foods and health, was harmful, and the experience of side effects after taking caffeine was significantly higher in female students than males. These side effects include heartburn (P<0.001), headache or dizziness (P<0.001), irregular heartbeat (P<0.05), and hands and feet shake (P<0.01). Caffeine-containing foods were purchased at convenience stores (62.1%). The factor considered when purchasing caffeine-containing foods was taste (72.2%), and the use of nutrition labeling for caffeine-containing foods scored 2.0 out of 5 points. When assessing the intake of caffeine-containing foods, the foods consumed more than once a week were in the order of coke, chocolate, chocolate milk, chocolate pie, and chocolate bars. These results suggest that it is necessary to prepare a caffeine-related nutrition guide improvement by sales management, and strengthen food labeling standards for the desirable recognition of caffeine and its safe intake by adolescents.

• The Korean Journal of Food And Nutrition
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• v.21 no.3
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• pp.336-343
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• 2008

This study was conducted to investigate the effects of caffeine on lipid and mineral content in the serum of rats given a caffeine free diet(FC), a low caffeine diet(LC), a medium caffeine diet(MC), a high caffeine diet(HC) or a super-high caffeine diet(SHC) for 5 weeks. Thirty male Sprague-Dawley rats(body weight, $110{\pm}0.3$ g) were blocked into 5 groups and fed diets with or without pure caffeine. Caffeine intake models showed a lower mean-weight gain, food intake and food efficiency in the high caffeine diet groups(MC, HC and SHC groups) than the groups receiving a caffeine free or low caffeine diet(FC and LC groups). Serum total lipid, total cholesterol and LDL-cholesterol levels decreased, but the serum HDL-cholesterol level increased according to the increase in caffeine intake. Serum total lipid, HDL-cholesterol and serum triglyceride were significantly lower in the HC and SHC groups than the FC group. All of the serum minerals decreased as caffeine intake increased. Serum iron, calcium, magnesium and phosphorus significantly decreased in the HC and SHC groups compared to the FC group. Caffeine intake was associated with less weight gain and reduced serum total cholesterol, triglyceride and total lipid. The results suggest that rats fed high amounts of caffeine may be susceptible to osteoporosis due to their low levels of calcium, magnesium and phosphorus.

• YAKHAK HOEJI
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• v.31 no.5
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• pp.343-346
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• 1987

The effect of mixing ratios of active ingredient on the content uniformity of tablets was studied using caffeine as active ingredient and hydroxypropyl starch as diluent. In the case that caffeine content was not more than 1%, the standard deviation of individual tablet assays was inversely proportional to caffeine content. In the case of more than 1%, the standard deviation was constant independently of caffeine content. In the case that the designed tablet weight was not more than 200mg, the standard deviation of individual tablet assays was inversley proportional to tablet weight designed. In the case of more than 200mg, it was constant and the results for weight variation against the designed weight showed same tendency.

• Culinary science and hospitality research
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• v.6 no.3
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• pp.343-355
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• 2000

Caffeine is widely consumed ingredient and it belongs to alkaloids. Many foods that we intake contain caffeine ; coffee, tea cocoa, chocolate, and coke. And it is also added to many commercial remedies ; cold tablets, headache tablets, etc. Effect of caffeine that is known to us so far is as follows; 1. Remaining awake for long hours 2. Increasing concentration and decreasing fatigue 3. Increasing basal metabolic rate 4. decomposing glycogen and body fat and providing energy 5. Stimulating gastric acid 6. Increasing urinary excretion. Caffeine containing beverages(especially, coffee)are also favorite food in adult. In case of children and youth, chocolate and coke are favorite food. So, to intake caffeine containing foods moderately can be a vitality of life. But, a long-term intake or overdose of caffeine can result in many side effects. For example, headache, irritability, restlessness, hypertension, fetal abnormality, etc. Therefore, it is desirable that caffeine intake is under 300-400mg per day. To decrease intake of caffeine, 1. Use decaffeinated coffee 2. Product of decaffeinated coffee bean through gene transformation 3. Indicate content and function of caffeine on caffeine-food container 4. Provide an information of caffeine to public.