• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.627-632
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• 1991

The heat treatment indicators such as HMF contents, lactulose contents and whey protein denaturation rates were measured to refer to the heat treatment intensity of domestic market infant formulae. The HMF contents showed $21.0{\sim}43.9{\mu}mol/l:$ in the case of powder types, the HMF contents in enriched nutrient products(ii) were higher whereas in the case of liquid types they were packed in cans(i). The lactulose contents showed $2.5{\sim}11.4mg/100ml$ in the powder type and $27.0{\sim}164.8mg/100ml$ in the liquid type. There was much difference in the lactulose contents according to the product types. Compared with the ADPI standards, most of infant formulae were considered to be medium-heat class. The whey protein denaturation rates were $1.1{\sim}69.4%$ in the powder type and $37.4{\sim}71.3%$ in the liquid type.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.1015-1026
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• 2021

The objective of this study was to determine amino acid and protein contents of brown and milled non-glutinous rice of 13 cultivars in Korea. Protein contents of MRs (milled rices) were in order of Haepum (7.27%) > Hanareum No. 4 (7.14%) > Odae (6.84%). Protein contents of BRs (brown rices) were in order of Haepum (7.68%) > Odae (7.63%) > Hanareum No. 4 (7.60%). The amino acid content was the highest in Haepum (MR 5.76%, BR 6.49%), followed by Haedeul (MR 5.71%, BR 6.30%), and Odae (MR 5.63%, BR 6.29%). The essential amino acid contents of non-glutinous rices were in order of Haepum (MR 2.34%, BR 2.57%) > Haedeul (MR 2.31%, BR 2.48%) > Odae (MR 2.20%, BR 2.56%). The contents of amino acid and protein in BRs were considerably higher than those in MRs. Protein and most of amino acid contents were higher in Haepum than the other cultivars. The certificated reference material (CRM) 1849a (infant/adults nutritional formular) from National Institute of Standard and Technology (NIST) was used as the test sample to determine the precision and accuracy of the analytical method. The regression analyses revealed good correlations (correlation coefficient), greater than 0.99. The recovery values of the amino acids ranged from 93.17 to 99.59%. The limit of detection (LODs) ranged from 0.01 - 0.07 mg·100 g^-1 and the limit of quantitation (LOQs) ranged from 0.03 - 0.21 mg·100 g^-1 for all analytes.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.97-105
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• 2023

Concentration of nitrogen, one of the major elements, and ratio of two nitrogen forms (NH₄⁺ and NO₃^-) in the nutrient solution affect the quality and food safety of fresh vegetable produce. This study was conducted to find an appropriate strength and NH₄⁺:NO₃^- ratio of a nutrient solution for growth and development of a Romaine lettuce (Lactuca sativa L. var. longiflora) 'Caesar Green', a representative leafy vegetable, grown in a home hydroponic system. In the first experiment, plants were grown using three types of nutrient solution: A commercial nutrient solution (Peters) and two strengths (GNU1 and GNU2) of a multipurpose nutrient solution (GNU solution) developed in a Gyeongsang National University lab. Plants grown with the GNU1 and GNU2 had greater shoot length, leaf length and width, and biomass yield than Peters. On the other hand, the root hairs of plants grown with Peters were short and dark in color. Tissue NH₄⁺ content in the Peters was higher than that of the GNU1 and GNU2. The higher contents of NH₄⁺ in this solution may have caused ammonium toxicity. In the second experiment, eight treatment solutions, combining GNU1 and GNU2 solutions with four ratios of NO₃^- :NH₄⁺ named as 1, 2, 3 and 4 were used. Both experiments showed more growth in the GNU2 group, which had a relatively low ionic strength of the nutrient solution. The growth of Romaine lettuce showed the greatest fresh weight along with low tissue NO₃^- content in the GNU2-2. This was more advantageous in terms of food safety in that it suppressed the accumulation of surplus NO₃^- in tissues due to the low ionic trength of the GNU2 subgroup. In addition, this is preferable in that it can reduce the absolute amount of the input of inorganic nutrients to the nutrient solution.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.44-48
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• 1990

This study was conducted to find out the effects of fertilizer application amounts on the root yield and the available constituents contents in root of Scutellaria baicalensis George. The baicalin contents decreased when nitrogen was applied at 18Kg/10a, but were not effected by P and K application. The contents of fructose, glucose and sucrose increased as applying P nutrient, but decreased with N application. The contents of ash, ethanol extract were not effected by fertilizer application, but acid-insoluble ash contents decreased as the N and P application increased. The root yield increased when nitrogen and potassium were applied at 12Kg/10a and 6Kg/10a, respectively.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.187-192
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• 1997

We carried out a survey on tributary streams in some agricultural areas along Nakdong River to evaluate the effects of agricultural practices on pollution of stream water and groundwater. General properties, nutrient materials and heavy metals in water samples were measured. General physicochemical properties of tributary stream waters were at levels favorable for agricultural water. Heavy metals, except Zn, were mostly not detected. Total-N contents were much higher than the criteria of agricultural water, and nitrate-N accounts for more than a half of total-N. Phosphorus contents were higher than the lower level of P for algae growth and the contents were high especially in summer. In ground waters which are used for irrigation, P were mostly at same levels as those in streams, and nitrate contents were higher than 10mg/L in some samples. In these results only those N and P contents in stream and ground waters higher than pollution criteria are problematic and they are traceable to agricultural nonpoint sources-fertilizers, livestock farms and sewage. Further researches are needed to evaluate contributions of each nonpoint source on stream water pollutions.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.4
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• pp.46-57
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• 1992

This study was carried out to compare physiological characteristics of winter green cultivar (Buxus microphylla van. koreana 'Hanlim') with those of native cultuvar and clucidate the effect of environmental factors such as light intensity, time of shading, and nutrients etc. on leaf color in Korean boxwood(Buxus microphylla var. koreana Nakai). The results are summarized as followed; The 'Hanlim' cultivar had higher contents of chlorophyll as compared with native cultivar from September, 1989 to March, 1990. However, at April, 1990, native cultivar had higher chlorophyll contents. In the rate of photosynthesis, 'Hanlim' cultivar was higher than native cultivar from September to December, 1989, but showed the opposite trend from March to April, 1990. As to the period of browning, 'Hanlim'cultivar had stayed green even after November 22, 1989, while the foliage of native cultivar turned yellowish brown color through the winter. The contents of nitrogen and potassium of 'Hanlim' cultivar werehigher than those of the native cultivar. However native cultivar had higher rate of phosphorus, magnessium, and calcium. In the effect of environmental factors such as light intensity, time of shading, and nutrients etc. on leaf color in Korean boxwood(Buxus microphylla var. koreana Nakai), chlorophyll contents were increased with shading and leaves grown 70% shading had twice as much as those of full sunlight, fertilized plot. Nutrient fertilization increased chlorophyll contents and values of color in boxwood too. In the shading times, early shading time maintained effectively green color of boxwood in winter. Therefore, in case of native cultivars, it has planted at full sunlight area until now and color of leaves turned yellowish brown color through the witner. However, it will maintain green color of leaves by planting at shade area. In addition to, as 'Hanlim' cultivar had benefits of maintain green color of leaves during winter, it will be planted at full sunlight area to landscape plants.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.841-846
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• 2017

This study investigated the nutritional compositions and physiochemical properties of three domestically cultivated jujube fruits (Boeun, Sangwhang, and Bokjo). Nutrient contents were analyzed by freeze-drying the jujube fruits. The results showed that the proximate compositions of the three jujube cultivars ranged from 7.85~13.52% for moisture, 4.65~5.24% for crude protein, 1.29~2.38% for crude ash, 0.17~1.09% for crude lipid, and 7.66~16.63% for crude fiber. The above proximate contents of jujube cultivars were significantly different. Mineral contents of Al, Fe, Mg, Ca, Na, and K in the three jujube fruits were also determined. Mn, Cu and Zn were not detected in any of the varieties. The content of Al was higher in Sangwhang, while Boeun had higher contents of Ca and K. The total polyphenol, ABTS values, and hypoglycemic effect were slightly higher in Boeun as compared to the other varieties. Taken together, Boeun could be an important source of natural antioxidant as a functional food.

• Nutritional Sciences
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• v.9 no.4
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• pp.323-329
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• 2006

To more accurately estimate vitamin A and vitamin E intake of Koreans, food composition databases of the tocopherol and carotenoid contents of Korean foods are needed. In this study, the tocopherol $(\alpha-,\;\gamma-,\;and\;\delta-)$ and carotenoid ($\alpha-carotene,\;\beta-carotene,\;\beta-ctyptoxanthin$, lutein, and zeaxanthin) contents of 12 Korean cooked combination foods commonly consumed by children in Kwangju, Republic of Korea, were determined using reversed-phase HPLC. All samples were obtained from 3 different households in Kwangju during summer, 2005. All cooked foods in this study had detectable quantities of $\alpha-tocopherol,\;\gamma-tocopherol$ except for shoegogimugook, and $\delta-tocopherol$ except for myulchibokkeum Doejigogibokkeum had the highest $\alpha-tocopherol$ content (0.64 mg/l00 g edible portion), and $\gamma-tocopherol\;and\;\delta-tocopherol$ contents of gimbab were the highest among the foods (1.01 and 0.26 mg/l00 g edible portion). $\beta-carotene$ was found in all food samples. Gimbab had the highest contents of $\alpha-carotene,\;\beta-carotene$, and lutein among Korean cooked combination foods (158.3, 266.6, and $375.4{\mu}g/100g$ edible portion). Miyukgook contained only $\beta-carotene$ ($2.5{\mu}g/100g$ edible portion). Considerable sample-to-sample variability in tocopherol and carotenoid compositions were observed in several Korean cooked combination foods included in this study. Some of these carotenoids $(\alpha-carotene,\;\beta-carotene,\;and\;\beta-cryptoxanthin)$ are vitamin A precursors. The findings of this study may be valuable for use in Korean databases as well as nutrient consumption research for vitamin A and vitamin E.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.85-95
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• 2010

The purpose of this study was to quantitatively measure both growth performances and nutrient responses of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla seedlings, which are commercially planted in Korea, to nitrogen, phosphorus, and potassium fertilization. We used Dickson's quality index (QI) to compare growth performances and vector diagnosis to interpret nutrient status. Nitrogen fertilization increased more height and root collar diameter growth in F. rhynchophylla and F. mandshurica relative to no fertilization treatment. The QI of F. rhynchophylla and F. mandshurica was the highest on N treatment, but there were no significant differences between treatments for P. koraiensis and A. holophylla. Nitrogen fertilization increased total dry weight by 43, 41, 26, -9% for F. rhynchophylla, F. mandshurica, P. koraiensis and A. holophylla, respectively. In F. rhynchophylla, N fertilization increased N contents with similar N concentrations ("sufficiency"), decreased both P concentrations and P contents ("antagonism"), and decreased K contents with similar K concentrations ("toxic accumulation"). In P. koraiensis, N fertilization decreased N, P, and K concentrations because of more dry weight increases compared to uptaken contents ("dilution"), but N fertilization decreased N, P, and K contents with similar N, P, and K concentrations ("toxic accumulation"). In the light of quality index and vector diagnosis, F. rhynchophylla and F. mandshurica seedlings treated with N fertilization would have high field performance.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.140-146
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• 2018

This research was conducted to determine the influence of incorporation levels of sulfur into a coir dust+pine bark medium (1:1, v/v) on the changes in the bicarbonate ($HCO_3{^-}$) concentrations and pH of soil solution, crop growth, and nutrient uptake of 'Ssanta' strawberry. In the preparing of the mixed medium, sulfur powder was added with the rate of 0 (control), 0.23, 0.45, 0.90, and $1.80g{\cdot}L^{-1}$ and Hoagland nutrient solution containing $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ was supplied during the crop cultivation. The growth measurements and tissue analysis for the determination of nutrient contents were carried out 140 days after solution application and the soil solution analysis was performed every two weeks. As the level of sulfur was elevated, the overall growth of mother plants became better showing that the growth indexes except chlorophyll contents were the lowest in control treatment but the statistical differences were not found among the three treatments of $0.45g{\cdot}L^{-1}$ or higher sulfur. The higher the levels of sulfur incorporation, the higher the occurrence of runners and the growth of daughter plants. The length of the runners and the number of daughter plants occurred per mother plants were higher in the treatments of 0.90 and $1.80g{\cdot}L^{-1}$ than the three treatments of 0, 0.23, and $0.45g{\cdot}L^{-1}$, but the statistical differences were not observed between the 0.90 and $1.80g{\cdot}L^{-1}$ treatments. The rose of pH and $HCO_3{^-}$ concentrations in soil solution of root media continued all the cropping period, but those decreased slightly in the treatments of $0.90g{\cdot}L^{-1}$ or higher. The soil solution concentrations of $K^+$ and $PO_4{^3-}$ in the treatments of 0.90 and $1.80g{\cdot}L^{-1}$ was lower than those in other treatments and the statistical differences in the $Ca^{2+}$ and $Mg^{2+}$ concentrations were not observed among all treatments. The nutrient contents in tissue analyzed in this experiment were the lowest in the control treatments and those increased as incorporation rates of sulfur were elevated. Above results indicated that when 'Ssanta' strawberry is grown hydroponically and the root medium is coir dust and the pine bark (5:5, v/v) mix, the sulfur incorporation rate as pre-planting fertilizer has to be higher than $0.9g{\cdot}L^{-1}$ root medium to reduce the $HCO_3{^-}$ injury.