• Journal of Plant Biology
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• v.17 no.1
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• pp.15-21
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• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.

• Journal of Plant Biology
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• v.35 no.1
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• pp.1-8
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• 1992

The characteristic of Cyanophyte genus SG63 is similar to that of Aphanot hece sp. The optimal growth was found with the concentration of NaCI and $MgSO_4{\cdot}7H_2O$ on the culture medium. The most optimal condition is 56%0 of NaCl (S4 medium) and 20%0 of $MgSO_4{\cdot}7H_2O$ (M2 medium). The synthesis of chlorophyll a, phycocyanin and soluble proteins is affected by the concentration of the two mineral elements in culture. Especially, the content of chlorophyll a and phycocyanin decreases on the most highly saline medium. The identified principal carotenoids are ${\beta}-carotene$, echinenone, zeaxanthin and myxoxanthophyll. The rates of concentration of protein/chlorophyll a and phycocyanin/chlorophyll a are low on the S4 medium. Inversely, these rates are the highest on the M2 medium. Accordingly, the high concentration of $MgSO_4{\cdot}7H_2O$ provoke the synthesis of phycocyanin and total proteins.oteins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.1-9
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• 1998

This study was designed to determine the most suitable manufacturing conditions of stewed pumpkin juice(SPJ) in terms of nutrition and taste. Well ripened pumpkin was heated for 3, 4, 5, 6 and 7 hours in a pressure cooker and then extracted and packed in retort pouches. These were kept at 4$^{\circ}C$ and 28$^{\circ}C$ for 30 days, respectively and changes of the physicochemical components of SPJ were investigated. The free amino acid compositions of pumpkin and SPJ occupied asparagine, aspartic acid, glutamine, arginine and serine in increasing order of abundance. Except SPJ heated for 3 hours, SPJ stored at 28$^{\circ}C$ had the most abundant free amino acids, followed by SPJ stored at 4$^{\circ}C$, and SPJ not stored. The fatty acid composition of pumpkin occupied behenic acid, erucic acid, palmitic acid, linoleic acid, heneicosanoic aicd, in order of abundance. When SPJ was heated over 3 hours, palmitic acid and linolenic acid decreased greatly. SPJ stored at 4$^{\circ}C$ and 28$^{\circ}C$ increased contents of saturated fatty acids such as behenic acid, palmitic acid than SPJ not stored. As SPJ was heated for a long time, carotenoid was mostly destroyed and the Hunter "L", "a" and "b" values of SPJ decreased. Among the mineral constituents of SPJ, Na and Ca were dominantly occupied. It was found that the range of the total visible cell count was 3~4CFU/ml from the SPJ which was heated for 3 hours and it increased by 1$\times$109CFU/ml when the SPJ was stored at 28$^{\circ}C$. It seems that the contamination by microorganism have occurred at packing process. In sensory evaluation, the SPJ which was heated for 5 hours had the highest scores in overall preference, sweet smell and sweetness.ce, sweet smell and sweetness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.21-25
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• 1987

In order to obtain a basic understanding of the storage of Satsuma mandarin sacs, the canned sacs were stored at room temperature from Feb. 20 to June 20(4 months), after dipping in chlorine solution and pasteurization as a pretreatment before canning. In general, the brix, acidity and pH of the sacs were almost not affected by the chlorine treatment ana a variety of pasteurization temperatures during storage. The broken rate was apperently increased by chlorine treatment, especially in the early stage of storage. However, the broken sacs were partially recovered in the end of storage. The contents of total carotenoid were almost not decreased by the conditions of the pretreatments during storage. The contents of vitamin C were sharply decreased between 3rd and 4th month of storage time on all sample. As a result, the decrement of vitamin C in canned sacs was caused by storage temperature rather than the condition of the pretreament.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.716-722
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• 2006

Various light sources including LEDs (Light emitting diodes) affecting on shoot growth was examined using in vitro shoots of E. pellita. Generally, it appeared that ventilation treatment was the most important factor affecting on normal shoot growth, irrespective of irradiation sources. Ventilation resulted in better performance of the cultures under 100% blue LED radiation. These include better shoot growth, more number of leaves, more number of internodes, more number of axillary buds, and heavier dry matters. The highest total chlorophyll content was obtained under both cool-white fluorescent lamps and R5B5 (50% red LED + 50% blue LED). The value was $24.5{\mu}g/g$ and $20.1{\mu}g/g$, respectively. In addition, ventilation resulted in higher carotenoid content in all irradiation sources except 100% red LED radiation. In conclusion, shoot growth of E. pellita could be reached maximum by ventilation under R5B5 (50% red LED + 50% blue LED).

• Korean Journal of Community Nutrition
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• v.17 no.1
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• pp.14-25
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• 2012

The purpose of this study was to estimate the daily intake of vitamin A in Korean female university students. Vitamin A intake was estimated using an inconsecutive 3-day dietary intake survey from 481 young women. Vitamin A intake values were calculated based on the data in USDA database. Average age, height, and weight of the subjects were 20.05 years, 162.13 cm and 54.38 kg, respectively. The subject's average intake of energy was 1645.67 kcal. The mean vitamin A, retinol and ${\beta}$ carotene intakes were $908.35{\pm}863.18$ ug retinol equivalent/day, $199.19{\pm}166.00$ ug/day and $3872.59{\pm}4972.17$ ug/day, respectively. The 21.83% of the subjects consumed less than the Estimated Average Requirement (EAR) for vitamin A. And subjects consumed 141.69% of the Recommended Nutrient Intake (RNI) for vitamin A. Food groups consumed with high vitamin A content in our subjects included vegetables (423.96 ug RE/day), potato and starches (213.64 ug RE/day), cereals (62.60 ug RE/day), eggs (55.17 ug RE/day) and milks (53.45 ug RE/day). The major food sources of vitamin A were sweet potato, carrot, spinach, egg, and cereal, and the top 30 foods provided 89.57% of total vitamin A. Also animal-derived food provided 9.65% of the vitamin A intake from the top 30 foods. In conclusion, judging from RNI, the vitamin A intake of the Korean female university students in this study was generally adequate. The result of our study may be used as a basis for follow-up studies of vitamin A intake like assessment of vitamin A nutritional status or evaluation of carotenoid food sources in Korean young women.

• Journal of Nutrition and Health
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• v.30 no.5
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• pp.489-498
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• 1997

Recent researches suggest that carotenoids are important not only as provitamin A but also for prevention of chronic diseases. This study was conduction to determine levels and factors affecting serum levels of lutein + zeaxanthin, $\beta$-cryptoxanthin, and $\beta$-carotene in 93 adults living in rural area of Korea. Fasting blood samples were collected and serum carotenoid levels were measured by HPLC. Dietary intake was estimated by 24 hour recall method and frequency questionnare of major food groups. Mean serum concentration of lutein + zeaxanthin was 616.32 nmol/L, $\beta$-cryptoxanthin was 856.95nmol/L, and $\beta$-carotene was 242.90nmol/L. Serum $\beta$-carotene levels in study subjects were very low. Both $\beta$-cryptxanthin and $\beta$-carotene were negatively correlated with serum triglyceride and positively correlated with total-choesterol and LDL-cholesterol. Serum levels of female subjects were significantly higher than males in all carotenoids. For age groups, subjects in their 30's were shown to have the highest concentration of all carotenoids. Lutein + zeaxanthin were lowest in subjects in theri 40's while $\beta$-crytoxanthin and $\beta$-carotene levels were lowest in subjects in their 60's. The $\beta$-carotene levels in non-smokers were significantly higher than in drinkers. Lutein+zeaxanthin levels were significantly higher among subjects consuming more green and yellow vegetables by frequency questionnarie. In conclusion, serum carotenoids were affected by sex, age, serum lipids, smoking, and alcohol intake. Intake of vegetables and fruits could affect by sex, serum lipids, smoking, and alchol intake. Intake of vegetables and fruits could affect serum lutein+zeaxanthin level. This data indicated that compared to other studies, Korean adults in rural areas have high lutein+zeaxanthin concentratins and low $\beta$-carotene concentrations in serum. High lutein+zeaxanthin levels may be related to high consumption of vegetables in these subjects.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.389-397
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• 2022

A total of 51 vegetables and fruits, commonly consumed agriculture products in Korea, were analyzed for their α-carotene, β-carotene, and β-cryptoxanthin contents as provitamin A. The beta-carotene content (㎍/100 g) was high in a few green leaf vegetables such as coriander (5,924.07), gegeol radish leaf (5.855.72), and curried mallow (5,138.01), while α-carotene and β-cryptoxanthin contents were not detected. The β-carotene in 8 kinds of 20 general vegetables was detected in the range of 214.06~1,437.67 ㎍/100 g, while α-carotene was detected at 460.17 ㎍/100 g in only old pumpkin. The β-cryptoxanthin was detected in the range of 106.55~315.49 ㎍/100 g in Japanese elm, watermelon, white cucumber, and lettuce. However, carotenoids were not detected in 10 kinds of agricultural products including oriental melon, potato, etc. In fruits, the beta-carotene contents ranged from 165.72~3,997.39 ㎍/100 g, showing maximum value in apple mango and minimum value in persimmon. The β-cryptoxanthin was detected at 232.22 ㎍/100 g in only passion fruit, while the α-carotene was detected at 77.25 ㎍/100 g in only darae. Thus, based on the analyzed results of carotenoids of agriculture products consumed or cultivated in Korea, and it was found that green leaf vegetables comprise high beta-carotene overall.

• Journal of Microbiology and Biotechnology
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• v.31 no.4
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• pp.601-609
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• 2021

Erythrobacter species are extensively studied marine bacteria that produce various carotenoids. Due to their photoheterotrophic ability, it has been suggested that they play a crucial role in marine ecosystems. It is essential to identify the genome sequence and the genes of the species to predict their role in the marine ecosystem. In this study, we report the complete genome sequence of the marine bacterium Erythrobacter sp. 3-20A1M. The genome size was 3.1 Mbp and its GC content was 64.8%. In total, 2998 genetic features were annotated, of which 2882 were annotated as functional coding genes. Using the genetic information of Erythrobacter sp. 3-20A1M, we performed pan-genome analysis with other Erythrobacter species. This revealed highly conserved secondary metabolite biosynthesis-related COG functions across Erythrobacter species. Through subsequent secondary metabolite biosynthetic gene cluster prediction and KEGG analysis, the carotenoid biosynthetic pathway was proven conserved in all Erythrobacter species, except for the spheroidene and spirilloxanthin pathways, which are only found in photosynthetic Erythrobacter species. The presence of virulence genes, especially the plant-algae cell wall degrading genes, revealed that Erythrobacter sp. 3-20A1M is a potential marine plant-algae scavenger.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.2
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• pp.109-115
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• 2023

Ammonium (NH₄⁺) serves as a nitrogen source, but its elevated levels can hinder plant growth and production. Excess NH₄⁺ with α-ketoglutarate is assimilated into glutamate, a precursor of proline and glutathione (GSH). This study aimed to investigate the effects of excessive NH₄⁺ on the regulation of proline and GSH synthesis. Detached leaves from oilseed rape (Brassica napus L.) were fed with 0, 50, 100, 500, and 1000 mM NH₄Cl for 16 h. As the NH₄⁺ concentrations increased, the leaves exhibited progressive wilting and yellowing. Furthermore, total carotenoid and chlorophyll concentrations declined in response to all NH₄⁺ treatments, with the lowest levels observed in 1000 mM NH₄⁺ treatment. Hydrogen peroxide (H₂O₂) concentration showed a minor increase at low NH₄⁺ concentration (50 and 100 mM) treatments but a significant increase at high NH₄⁺ (500 and 1000 mM), which was consistent with the localization of H₂O₂. Amino acid concentrations increased with increasing in NH₄⁺ concentration, while the protein concentration displayed the opposite trend. Proline and cysteine concentrations exhibited a gradual increase in response to increasing NH₄⁺ concentrations. However, GSH concentrations rose only in the 50 mM NH₄⁺ treatment and decreased in the 500 and 1000 mM NH₄⁺ treatments. These results indicate that excessive NH₄⁺ is primarily assimilated into proline, while GSH synthesis is adversely affected.