• Korean Journal of Food Science and Technology
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• v.4 no.2
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• pp.61-71
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• 1972

The selenium content of a wide variety of Korean food was determined by neutron activation analysis. Most fruits and vegetables contained quantities of selenium less than $0.4{\mu}g/g$. Grain products varied widely in their selenium content with $0.5{\mu}g/g$ and barley cereal as high as $0.7{\mu}g/g$. Dried milk powder sample ranged from $0.7\;to\;0.15{\mu}g/g$. Chicken muscle contained about $0.7{\mu}g/g$. The content of sea food was generally higher, ranging from $0.3\;to\;3.65{\mu}g/g$. These values suggest that a diet well balanced in other nutrients is probably also nutritionally adequate with regard to selenium, although possible effects of cooking and biological availability remain to be investigated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1242-1248
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• 2013

This study was performed to determine the effects of pretreatment (NT: non-treatment, BTS: boiling treatment with 3% sodium chloride, DTG: dipping treatment in glycerol) and drying methods (sun drying, hot air drying, and cold air drying) on the physicochemical properties and antioxidant activities of dried jujube (Zizyphus jujuba Mill.) fruits. Our results show that moisture content is lower (P<0.05) with DTG, and that moisture content is lower with hot air drying compared to other drying methods. The bulk density was highest with BTS. The soluble solids content was highest with DTG. Additionally, the soluble solids content were highest in the following order: hot air drying> cold air drying> sun drying. The titratable acidity of hot air drying was highest of all the drying methods. The titratable acidity was higher with NT and DTG, and the brix and acid ratio of sun drying was higher than other drying methods. Among the drying methods, BTS showed the best browning-retarding effect, whereas boiling treatment affected quality and color. The total polyphenol content from hot air drying and NT or DTG treatment was relatively higher than the content from BTS. The flavonoid content was highest with BTS, and all dried jujube showed relatively high antioxidant activities. The sensory evaluation results indicated that the organoleptic scores for overall preference were higher in the NT and DTG treatment groups. These results suggest that pretreatment and drying methods affect the quality of dried jujube fruit, and show that glycerol treatment with hot air drying can be applied to the production of high quality dried jujube.

• Food Science and Preservation
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• v.13 no.4
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• pp.432-437
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• 2006

To compare the content of natural existence with artificial addition experimental subject of 152 cases(25 kinds) were classified by two category of 42 fresh samples(14 kinds) and 110 processed samples(23 kinds). The content of sulfur dioxide were determined by Monnier-Williams's modified method. In mean content of 42 non-processed samples studied the range of contents was between 0.00 and 9.46 mg/kg. Radish contained the highest amount of sulfur dioxide(8.97 mg/kg), followed by onion(8.04 mg/kg). In mean content of 110 processed samples studied, the range of content was between 0.00 and 1,828.59 mg/kg. Gourd contained the highest amount of sulfur dioxide(1,064.61 mg/kg), followed by apricot(869.62 mg/kg), dried persimmon(64.11 mg/kg), dried radish(29.00 mg/kg), dried pumpkin(17.63 mg/kg), and those were lowe. than criteria. To supply safe food for the citizens, the quantitative level is required to be reinforced to supply safe foot continuously.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.325-332
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• 2020

This study was conducted on cultivation farms in the Gimcheon area, which is the main production area of walnuts, in order to compare and analyze the yield and fruit quality of walnut trees (Juglans sinensis Dode) derived from seedlings. The official trees were classified into nine classes from 10 to 60 years old, and a total of 135 trees were selected, with 15 trees selected for each grade. The growth and fruit characteristics for each age group were then examined. The average tree height was 10.3 m, and the average crown area was 63.7 ㎡. The average number of fruit settings per tree was 573.1, with the largest number of walnuts per tree at 35 years (974.0 walnuts), and the lowest walnuts per tree at 10 years (124.7 walnuts). In addition, the number of fruit settings per bearing mother branch in 35 year old trees was the highest at 3.1. The average weight for each fruit type was found to be 58.7 ± 4.0 g of walnuts in green peel, 10.5 ± 0.5 g of dried shell walnuts, and 4.9 ± 0.2 g of walnuts, respectively. The average yield by fruit type was 32.5 ± 13.8 kg of walnuts in green peel, 5.9 ± 2.5 kg of dried shell walnut, and 2.8 ± 1.2 kg of walnuts. The yield was positively correlated with the crown area, the number of fruits setting per bearing mother branch, and the number of fruits setting per 1 ㎥. The formula used to estimate the yield per tree by age was calculated as y = 8993.9 ln (tree age-9) 8230.3, R² = 0.8531 (walnut in green peel) and y = 1647.1 ln (tree age-9) 1442.1, R² = 0.8527 (dried shell walnut).

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.95-113
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• 1988

In order to find out changes of chemical components related to browning of dried jujube, four varieties were subjected to the proximate analysis. Boeun, one of the major varieties in Korea, was sun-dried and stored for 12 months and analyzed periodically for one year. Browning, titrable acidity, pH, contents of ascorbic acid, organic acid, total amino acid, free amino acid, free sugar, hydroxymethylfurfural (HMF) and phenolic compounds were determined and compared with those of fresh jujube. The results obtained are summarized as follows; 1. In comparison with other similar fruits, jujube was high contents of ascorbic acid (62-79mg%) and carbohydrate (22-28%) excluding fiber. 2. Browning was increased in both steam-treated and nontreated plot together as storage period was prolonged. 3. Ascorbic acid content of fresh jujube was as high as 297.4mg% DB, but it was decreased to 20.2mg% DB, after 12 months storage. Therefore, loss of ascorbic acid was very great up to 93% of its original content. 4. Five kinds of organic acid, oxalic, succinic, fumaric, malic and citric acid were identified as major organic acids. It was interesting that only fumaric acid content was increased while others decreased during storage. 5. Seventeen kinds of amino acid were identified in the analysis of total amino acid content. Major amino acids were found to be proline, threonine, glutamic acid and lysine. During 12 months storage, 30% of original total amino acid was decreased and this was mostly accounted for free amino acids. 6. Threonine, proline, alanine and valine were identified as free amino acids which showed 85% decrease after 12 months storage. 7. Free sugars of jujube were composed of fructose, glucose and sucrose. They showed 24% decrease after 12 months storage, Especially sucrose was not detected after 4 months storage. 8. HMF of dried jujube was isolated and identified. Its content was increased up to great extent as storage period prolonged. 9. Caffeic, ferulic and P-coumaric acid were identified as jujube phenolic compounds which were significantly decreased during storage. In conclusion, non-enzymatic browning was thought to be more important than enzymatic reaction in the dried jujube. Amino-carbonyl reaction, ascorbic acid oxidation and reaction between phenolic compounds and sugar or nitrogen compounds were observed to be related to this browning.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.146-153
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• 2009

This study was conducted to examine the effects of fruits and stems of Opuntia ficus-indica var. saboten Makino on water intake, feed intake, body weight, blood glucose level and glucose tolerance in streptozotocin (STZ)-induced diabetic rats. Forty Sprague-Dawley male rats were divided into non-diabetic control (NC), diabetic control (DC), 8% Opuntia fruit (DOF), 5% Opuntia stem (DO-5) and 10% Opuntia stem (DO-10) groups. Fruits and stems of Opuntia ficus-indica were freeze-dried and ground before use in the experiment. Animals were fed experimental diet for 3 weeks. DOF, DO-5 and DO-10 groups showed lower water and feed intake as well as less body weight loss than DC group. The fasting blood glucose levels were 100 mg/dL for NC and 379 mg/dL for DC. Fasting glucose level of DOF was a significantly low level of 28% (p<0.05), whereas DO-5 and DO-10 had a decrease of 5% and 9% compared to DC. As for the glucose tolerance test, the highest blood glucose levels for NC and DC-10 group were observed at 30 minutes after glucose injection while those of DOF and DO-5 groups were after 60 minutes. DOF and DO-5 plasma insulin level improved. Plasma total cholesterol, triglyceride, non-esterified fatty acid (NEFA) and LDL-cholesterol concentrations were also lower in DOF, DO-5 and DO-10 groups, although HDL-cholesterol level was only slightly affected by experimental diets compared to DC. These results suggest that the feeding of Opuntia ficus-indica fruits and stems improved blood glucose and lipid metabolism in STZ-induced diabetic rats.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.545-549
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• 2013

Liquid paraffin is a mixture of heavier alkanes derived from petroleum. It can be used as a lubricant in processing machinery, as a coating agent, or as a releasing agent. The purpose of this study was to analyze liquid paraffins in foods by using a gas chromatography-flame ionized detector (GC-FID). Liquid paraffin was extracted from the food samples using n-hexane. Non-polar aromatic or olefinic co-extractives were removed by alkaline permanganate oxidation followed by clean up on an aluminium oxide SPE cartridge before the GC-FID analysis. The results of recovery tests were 91.5-103.2%. Based on this optimized method, we investigated the amount of liquid paraffin in various food samples purchased from domestic markets. The levels of liquid paraffin in bread were $95.5{\pm}156.0$ mg/kg (0.008%), those in capsules were $40.2{\pm}54.5$ mg/kg (0.001%), and those in dried fruits and vegetables were $3.0{\pm}18.1$ mg/kg (0.0001%). No liquid paraffin was detected in fresh fruits and vegetables. We propose that our method can be used to monitor and detect liquid paraffin in foods for food safety management.

• Korean Journal of Community Nutrition
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• v.15 no.1
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• pp.50-60
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• 2010

The purpose of this study was to conduct nutrition education using animations for the establishment of proper eating habits among elementary school students and to evaluate its effectiveness. The subjects of this study were two classes of fourth grade students in an elementary school located in Daegu-city. There were 29 students in each class. One class, the "nutrition-education" group, received nutrition education; the other class, the "no-education" group, did not receive the education. After completing the eight nutrition lessons, the effectiveness of the education was analyzed by measuring changes in the nutrition knowledge, eating habits and food preferences of the nutrition-education group vs. the no-education group. Before nutrition education, there was no significant difference between the two groups in terms of nutrition knowledge. However, after the nutrition education, the nutrition-education group's nutrition knowledge was significantly improved, compared to that of the no-education group (p < 0.001). Following education, the nutrition-education group's responses to the "eating habit" item, "I eat fruits every day," were significantly more positive, compared to the responses of the no-education group (p < 0.01). However, for the ten food groups listed as food preferences, except for fish and shellfish (p < 0.05), there was no significant difference in the responses of the two groups. Following the education, the nutrition-education group showed significantly increased preferences for 12 food items (red beans, mackerels, yellow corvinas, dried laver, kelps, radish, lettuce, pears, kiwi fruits, plums, grapes and sweet drinks made from fermented rice) out of 112 items, compared to the selected preferences of the no-education group. After education, 75.9% of the students in the nutrition-education group indicated changes in their eating habits, and 89.6% of them answered that the nutrition education helped them change their eating habits. The most helpful medium for changing their eating habits was animations (31.0%), followed by songs (20.7%) and lectures (17.2%). As a result of this study, after completing the nutrition education, students in the nutrition-education group showed significant changes in food preferences, and their level of nutrition knowledge was significantly increased. However, their eating habits did not actively change. Therefore, in order to establish proper eating habits, a longer period of consistent education is required, using various educational media and learning methods such as extracurricular activities and discretionary activity programs.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.370-375
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• 2009

Overproduction of peroxynitrite ($ONOO^-$) causes a variety of disease such as atherosclerosis, hypercholesterolemia, diabetes mellitus or obesity. Peroxynitrite scavenging activities and HPLC analysis on the five Oriental medicinal drugs belonging to the genus Citrus, Aurantium or Poncirus (Rutaceae family) and HPLC analysis were taken to evaluate flavanone glycosides with peroxynitrite scavenging activity. The $IC_{50}s$ of the five crude drugs were shown as follows: Aurantii nobilis Pericarpium (Jinpi, 18.3 ${\mu}g$/ml), Citrii unshiu Pericarpium (Chungpi, 7.50${\mu}g$/ml), Citrii unshiu Semen (Gyulhaek, >50.0${\mu}g$/ml), Aurantii Fructus (Jigak, 18.3${\mu}g$/ml), and Poncirii Fructus (Jisil, >50.0${\mu}g$/ml) where Korean crude drug's names are noted in the parenthesis. Peroxynitrite scavenging effect of flavanones or their glycosides usually contained in Citrus species were observed as follows: hesperetin (1.89 ${\mu}g$/ml), naringenin (7.77 ${\mu}g$/ml), hesperidin (8.44 ${\mu}g$/ml), poncirin (>50.0 ${\mu}g$/ml)and ponciretin(>50.0 ${\mu}g$/ml). The activities of naringin and poncirin with ${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}2$)-${\beta}$-D-glucopyranosyl moiety were weak. HPLC analytical data revealed that Jinpi (the peels of mature fruits of Citrus unshiu) and Chungpi (the peels of immature fruits of C. unshiu) had high quantities of hesperidin as the value of 142.1${\pm}$0.21 and 104.51${\pm}$1.10 mg/g dried weight, respectively. Poncirin was clearly detected in only Jisil and naringenin and naringin were not observed on the HPLC chromatogram of the five crude drugs.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.342-347
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• 2007

The dried fruit of the Rubus coreanus, which is well-known in Korea and referred to as 'Bokbunja,' has been employed as a traditional medicine for centuries. This crude drug has been utilized in Korea for the management of impotence, spermatorrhea, enuresis, asthma, and allergic diseases. Our previous study demonstrated that the ethanol extracts of R. coreanus have anti-inflammatory effects. The principal objective of the present study was to conduct a comparison of the anti-inflammatory effects of the ethanol extracts of R. coreanus and R. occidentalis; here, we tested the unripe (URCE), half-ripened (HRCE), and ripened fruits (RCE) of R. coreanus, and the unripe (UROE), half-ripened (HROE), and ripened fruits (ROE) of R. occidentalis. We found that URCE, UROE, HRCE, and HROE reduced the production of nitric oxide and prostaglandin $E_{2}$ as well as pro-inflammatory cytokines in lipopolysaccharide-stimulated RAW264.7 murine macrophages. Interestingly, the R. coreanus extracts showed stronger inhibitory effects on the production of these inflammatory mediators than the R. occidentalis extracts.