• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.594-603
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• 1994

This study investigate the balance and biochemical status of riboflavin in Korean men. During the experimental period, four riboflavin diets with different levels of riboflavin(0.4, 0.6,0.8 and 1.0mg/1000kcal) were followed by eight healthy college men. the riboflavin status was assayed by erythrocyte glutathine reudcctase activity coefficient (EGRAC0 and urinary excretion of riboflavin. Riboflavin intake of the subjects who consumed a det was 0.46mg/1000kcal. the riboflavin intakes of the subjects who consumed the experimental diet with 0.4, 0.6, 0.8 and 1,0mg/1000kcal of riboflavin were 0.41, 0.60, 0.81 , 0.97mg, respectively. Fecal riboflavin loss, absorbed riboflavin , urinary riboflavin loss and retained riboflavin increased in the subjects consumed 0.4, 0.6, 0.8 and 1.0mg/1000kcal of riboflavin. The average EGRAC values for the subjects consumed 0.4, 0.6, 0.8 and 1.0mg/1000kcal of riboflavin were 1.303$\pm$0.029, 1.271$\pm$0.022, 1.239$\pm$0.013, 1.202$\pm$0.030, respectively and urinary riboflavin values ($\mu\textrm{g}$/g creatinine) were 86.89$\pm$ 20.07, 123.88$\pm$ 15.88, 240.70$\pm$57.14 and 393.36$\pm$76.94, respectively. Results indicate that 0.6mg/1000kcal is the level of riboflavin intake needed to maintain urinary riboflavin within the normal range. And above1.0mg/1000kcal of riboflavin is need to maintain urinary riboflavin with in the normal range. And above 1.0mg/1000 of riboflavin is needed to maintain the EGRAC within the normal range. The riboflavin intake correlated positively with urinary riboflavin value, but correlated negatively with the EGRAC value. The EGRAC value correlated negatively to protein intake as well as animal protein intake. The linear equation of between riboflavin intake and EGRAc was EGRA=-0.1667 $\times$riboflavin intake +1.3710. The riboflavin intake to maintain EGRAc below 1.20 was calculated 1.02mg/1000kcal by the above equation.

• Journal of Nutrition and Health
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• v.29 no.5
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• pp.507-516
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• 1996

This study was undertaken to estimate seasonal variation of riboflavin status and investigate the relationship between riboflavin intake and its biochemical status in rural women. Dietary intake was measured by determining both 24hr recall method and conventient method. The riboflavin intake was also estimated by food frequency method. Ribofiavin biochemeical status was assessed by erythrocyte glutathione reductase activity coefficient(EGR AC) and urinary riboflavin excretion. All information was repeatly collected in three seasons ; farming season (June), harvest season(October), nonfarming season(February). Mean daily riboflavin intake was below RDA for Koreans in all seasons. Cereal & pulse, vegetable were the primary sources of riboflavin intake and provided above 60% of the total dietary riboflavin intake in all seasons. Riboflavin biochemical status was significantly different among seasons(EGR AC P<0.005, 24hr urinary riboflavin excretion P<0.05), and riboflavin biochemical deficiency was highest in February. The mean values of EGR AC revealed riboflavin deficiency in all seasons. However the mean values of urinary riboflavin excretion were within the normal range except 24hr urinary riboflavin excretion in February. On the basis of EGR AC criteria, 44.7% of subjects were at risk of deficiency in June, 44.7% in October, 81.6% in February. Result of individual riboflavin status assessed by EGR AC or 24hr urinary riboflavin excretion criteria was quite alike. Urinary riboflavin excretion per gram of creatinine underestimated riboflavin deficiency. Significant correlations were observed among biochemical indexes. It also appeared that riboflavin intake measured by food frequency method showed significant correlation with biochemical indexes, especially high correlation with EGR AC (P<0.001). The results indicated that the prevalence of riboflavin deficiency seems to be high among rural women in all seasons and the inadequacy of dietary riboflavin intake was reflected in the abnormalcy of riboflavin biochemical status assessed by EGR, AC. Therefore EGR AC seems to be more sensitive measure of impaired riboflavin status compared to urinary excretion.

• Journal of Nutrition and Health
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• v.29 no.9
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• pp.1003-1012
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• 1996

We examined the relationship among riboflavin intake, work activity, erythrocyte glutathione reductase activity coefficient(EGR AC)and urinary riboflavin excretion. We also attempted to determine factors affecting seasonal riboflavin status of rural women. All information about nutrient intake, work activity and riboflavin biochemical status was repeatly collected in three seasons ; farming season(June), harvest season(October), nonfarming season(February). EGR AC was negatively correlated with riboflavin intake(P<0.005) and positively correlated with the duration(min) of farming activity(P<0.005) and the percentage of lean body mass(LBM) (%) representing long term physical activity(P<0.05) in harvestseason. Urinary riboflavin excretion was positively correlated with the ratio of riboflavin intake to 1,000kcal of energy expenditure (P<0.05) in farming season and negatively correlated with the duration(min) of farming activity (P<0.05) and crude nitrogen balance(P<0.005) in harvest season. It appeared that EGR AC seems to increase and urinary riboflavin excretion seems to decrease as work activity increase. Therefore work activity would be expected to deteriorate riboflavin status. Multiple regression analysis of variables showed that in general EGR AC was affected by riboflavin and energy intakes, energy expenditure, energy balance, the duration(min) of farming activity, LBM (%). Urinary riboflavin excretion was affected by riboflavin and protein intakes, LBM(kg) and crude nitrogen balance. Crude nitrogen balance affected urinary riboflavin excretion in all seasons. The result indicated that work activity as well as nutrient intake seemed to affect riboflavin status, especially EGR AC was affected preferentially be work activity in all seasons.

• Journal of Nutrition and Health
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• v.35 no.9
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• pp.970-981
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• 2002

To assess riboflavin status by dietary intake and urinary excretion of preschool children in Busan and to evaluate the relationship of intakes of food and nutrient with urinary riboflavin excretion, riboflavin food frequencies of 40 common foods affecting intakes of riboflavin by food fequency method, nutrient intake by 24hr recall and 24hr urinary riboflavin excretion were measured with 97 preschool children. The mean riboflavin intake was 0.90 mg and above RDA. Dairy group was the primary source of riboflavin intake and provided 44.8% of the total daily riboflavin intake. The mean urinary riboflavin excretion and riboflavin excretion per gram of creatinine were 395.21$\mu\textrm{g}$ and 2110.41$\mu\textrm{g}$ respectively, The mean riboflavin intake (p<0.01, p<0.01), riboflavin density (p <0.001, p<0.001) and urinary riboflavin excretion per gram of creatinine (p<0.05, p<0.05) were significantly low with the two patterns of food group intake where dairy group was omitted (GMVFDS = 111101, consuming no dairy group and GMVFDS=l11001, consuming no fruit and dairy groups). On the basis of urinary riboflavin excretion per gram of creatinine, 14.3% of subjects in the group aged 1 to 3 and 18.2% of subjects in the group aged 4 to 6 were at risk of deficiency respectively. The urinary riboflavin excretion per gram of creatinine showed positive significant correlations with usual intakes of riboflavin from food groups of dairy (p<0.05), meat (p<0.05) and animal (p<0.05). So nutritional education is needed in order to consume dairy food group daily and to increase usual intake of animal food group including meat.(Korean J Nutrition 35(9) : 970~981, 2002)

• Journal of Nutrition and Health
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• v.22 no.6
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• pp.507-515
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• 1989

Ten healthy wome 2-~25 years participated in a 5-week metabolic study to investigate the daily riboflavin requirement of Korean women. Three daily menu and meal patterns were used. Low riboflavin(LR) diet provided riboflavin at a level of 0.71mg / 1000Kcal based on food composition table. High riboflavin(HR) diet provided 1.14mg / 1000Kcal. The riboflavin status was assessed by erythrocyte glutathione reductase activity coefficient(EGRAC) and urinary exretion of riboflavin. Mean EGRAC of LR period and HR period were 1.17+0.08 and 1.01+0.03, repectively. There were discrepanices of riboflavin content of experimental diet between chemical analysis and calculation by Korean food composition table. Urinary riboflavin excretion of subjects was acceptable over the whole study period. It appeared that 0.71mg / 1000Kcal is requirement of riboflavin to maintain EGRAC withing normal range. Thus, it is suggested that current recommendation of 0.6mg / 1000Kcal of riboflavin intake may not be adequate as RDA level in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.219-223
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• 1987

A slightly modified method of Rashid and Potts(1980) to determine riboflavin in milk in which lead acetate was used as a precipitant was employed in tile present study to test applicability to determine that of fish as well. The lead acetate method was found to be sensitive, simple, inexpensive and rapid compared to the modified A.O.A.C. method by Cordon et al. (1979). But higher riboflavin values were obtained in this study than those reported so far. The riboflavin contents of 9 white fleshed fishes were in the range of $0.29\~0.48mg$ per 100g fresh sample. Linear regression equation Y=125.70X+0.71 (R=0.9993) was obtained for the calculation of riboflavin content in the white fleshed fish. Y is the concentration of riboflavin in the final solution to be chocked its OD at fluorometer and X is the dial reading of fluorometer. The stability of riboflavin as the freshness changes during icing storage$(at\;0^{\circ}C)$ was studied with file fish. During the initial stage of storage, the riboflavin content was found to by increased by $14\%$, but the difference was not statistically significant (p>0.05). K-value and VBN-value were increased along with storage time, but Proximate composition was not changed significantly during entire storage of 18 days.

• Journal of Nutrition and Health
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• v.19 no.3
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• pp.161-168
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• 1986

In order to investigate the effect of riboflavin on cholesterol and MLHP (methyl linoleate hydroperoxide) -induced fatty liver electron microscopically, riboflavin was given to rate receiving high cholestero and MLHP diet for 4 weeks, 8 week old male Sprague-Dawley rats were administrated diets daily, as following group ; usual diet (control ), riboflavin 910 ug/20gm BW), cholesterol (50mg/gm BW), MLHP(0.1ml/20gm BW), cholesterol plus MLHP, cholesterol plus riboflavin, cholesterol plus MLHP plus riboflavin, by means of intubation into the stomach for 4 weeks. Each group consisted of 10 rats, The liver of the animals were examined ultrstructurally by transmission electronmicroscope. The results wee as follows ; 1) The three group including cholesterol, MLHP, cholesterol plus MLHP feeding resulted in fatty liver. 2) The main finding of the fatty liver were swelling and vacuolation of mitochondria, a lot of lipid droplets, disarrangements and loss of rough endoplamic reticulums. 3) the most striking features in the group of cholesterol plus riboflavin, cholesterol plus MLHP plus riboflavin feeding were decrease of size and number of lipid droplets, mitochondrial swelling and vesiculation, with restortion of rough endoplasmic retriculums. It is postulated with above findings that riboflavin was effective in prevention of cholesterol and MLHP -induced fatty liver.

• Korean Journal of Community Nutrition
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• v.2 no.5
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• pp.701-710
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• 1997

this study was undertaken to compare the riboflavin status of rural women with different physical activity intensity and to determine factors influencing biochemical fiboflavin status. The study was carried out over three different farming seasons : planting (June), harvest(October) and interim(February) in two rural regions of Korea. One was a traditional farming region, the other a commercial farming region with heavier work intensity. Twenty women in the traditional region and eighteen women in the commercial region were involved. The intensity of physical activity was determined by a daily activity record. Body composition was assessed by bioelectrical impedence. Dietary riboflavin intake was measured by the food frequency method. Riboflavin biochemical status was assessed by erythrocyte glutathione reductase activity coefficient (EGR AC) and ruinary riboflavin excretion. The results from the EGR AC and urinary riboflavin excretion during the period showed the overall riboflavin status of the commercial farming women was significantly worse than that of the traditional farming women(EGR AC p<0.0001, urinary riboflavin excretion p<0.05). The traditional farming group had about 40% with risk of riboflavin deficiency, whereas the commercial farming group had about 70%. Overall mean nutrient intake was not significantly different between the two groups, however, overall mean percent lean body mass representing long term physical activity was significantly higher in the commercial farming group ( <0.005). It appears that the biochemical riboflavin status of traditional farming women was significantly influenced by riboflavin intake and crude nitrogen balance while the biochemical riboflavin status of the commercial farming women was significantly influenced by riboflavin intake and percent of lean body mass over the three seasons. (Korean J Community Nutrition 2(5) : 701∼710, 1997)

• Journal of Nutrition and Health
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• v.19 no.3
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• pp.169-176
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• 1986

The effect of riboflavin feeding on lipid emtabolism in rat were studied. 70 male Sprague-Dawley rats were divided into 7 diet group ; control, riboflavin, cholesterol, MLHP (methyl linoleate hydroperoxide) cholesterol plus MLHP, cholesterol plus riboflavin, cholesterol plus MLHP plus riboflavin. After 4 weeks formular feeding sera of animals were collected, then checked cholesterol, triglyceride, phospholipid levels and lipoprotein by use of cellulose acetate papter. The results were as follows ; 1) Marked increase of triglyceride and phospholipid levels were found in the group feeding with cholesterol, cholesterol plus MLHP. 2) Combined riboflavin feeding prevented the increase of triglyceride and phospholipid levels in the group of cholesterol, cholesterol plus MLPH. 3) Also combined riboflavin feeding prevented the increase of $\beta$-lipoprotein fraction in cholesterol feeding group. Our results demonstrate that riboflavin has an inhibitory effects on the derangements of lipid metabolism due to administration of cholesterol, cholesterol plus MLHP.

• Bulletin of the Korean Chemical Society
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• v.17 no.11
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• pp.1018-1022
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• 1996

Adenosine deaminase (ADA) has been utilized as the label in devising a potentiometric homogeneous assay for riboflavin and riboflavin binding protein (RBP). The proposed homogeneous assay method employs an ADA-biotin conjugate as the signal generator and an avidin-riboflavin conjugate as the signal modulator in the solution phase. The catalytic activity of the ADA-biotin conjugate is inhibited in the presence of an excess amount of the avidin-riboflavin conjugate, and the observed inhibition is reversed in an amount proportional to the concentration of RBP added. When the analyte riboflavin is added to this mixture of ADA-biotin, avidin-riboflavin and RBP, the activity of the enzyme conjugate is re-inhibited in an amount proportional to the concentration of riboflavin. Since the enzyme label used in this system is ADA, an ammonia-producing enzyme, a potentiometric rather than photometric detection scheme is used to monitor the enzymatic activity in the assay.