• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.377-385
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• 2020

Recently, wheat consumption has been increasing in Korea, requiring increased production. Nitrogen fertilization is a critical determinant in crop yield; therefore, it is necessary to optimize the nitrogen fertilization regime with current trends that emphasize the minimum impact of nitrogen fertilizer on the environment. In this study, both nondestructive spectral analysis using a hyperspectral camera and growth analysis were performed to determine the optimal N top-dressing rates after heading. The nitrogen application regimes consisted of three conditions according to the secondary top-dressing rate: N_4:3:0 (0 kg 10 a^-1), N_4:3:3 (2.73 kg 10 a^-1), and N_4:3:6 (5.46 kg 10 a^-1). Subsequently, growth and physiological investigations were performed at the jointing, heading, and ripening stages of wheat, and spectral investigations were conducted. On April 29, as the nitrogen fertilization rate was increased to N_4:3:3 and N_4:3:6, plant height and grain yield increased by 4% and 8%, and 8% and 52%, respectively, compared to those under N_4:3:0. Leaf area index and SPAD value also increased by 13% and 24%, and 32% and 43%, respectively. The R (red), G (green), and B (blue) of leaf color were lowered by 15, 11, and 4 in N_4:3:3 and 44, 34, and 18 in N_4:3:6, respectively, as compared to the control. Grain yield was the highest at high top-dressing (N_4:3:6), however, there was no difference between no top-dressing (N_4:3:0) and intermediat top-dressing (N_4:3:3). The reflectance analyzed using a hyperspectral camera showed a difference in the near-infrared (NIR) region on March 19, and on April 29, there was a difference both in the visible light region greater than 550 nm and the NIR region. Vegetation indices differed according to fertilization regime, except for the greenness index (GI). The results of this study showed that not only growth and physiological analysis but also spectral indices can be used to optimize the nitrogen top-dressing rate.

• Journal of the Korean Society of Food Culture
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• v.11 no.2
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• pp.229-233
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• 1996

This study was carried out to analyze the changes in nitrogen compounds, free-amino acids and volatile organic acids of traditional Korean Soy Sauce with two different fermentation jars and varying Meju concentration. Total nitrogen content in the glass jar was higher than that of the clay jar. However, the glass jar contained more nitrogen in ammonia type nitrogen and less in amino type nitrogen than clay jar, resulting in inferior quality. Total free amino acids content was highest on the 150th day. Among free amino acids, the concentration of glutamic acids, aspartic acid, serine, alanine and lysine, which give sweet and savory taste, were higher than that of the others. Phenylalanine, valine, leucine and isoleucine, which give bitter taste, were also present in significant quantities. Among identified volitile organic acids, acetic acid was present in the hightest concentration, and it's concentration was higher in the jar than in the glass jar. Meju concentration 1:4 showed slow increse while 1.3:4 showed similar trends in the glass jar 1:4 and clay jar 1.3:4, and it's concentration decreased after the ripening period in all samples. In addition valerie acid and capric acid were also present in small quantities.

• The Korean Journal of Food And Nutrition
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• v.14 no.6
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• pp.512-520
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• 2001

Kimchi is one of the traditional Korean food and a very popular side dish in Korea. To obtain funda mental data on how to prevent over ripening in kimchi after acidity of 0.4% was reached during the lactate fermentation, the physicochemical characteristics such as pH. acidity. organic acids, enzyme activity were measured and the time dependent ecology of microorganism were observed. In the initial stages of fermentation, the pH of kimchi was markedly changed and slowly decreased in 0.5% acidity The acidity was slowly increased and markedly increased in pH 4 by growth of microorganism. HPLC analysis showed oxalic acid, lactic acid, acetic acid, malic acid and succinic acid and this results reconfirmed by GC-MSD. Lactic acid was changed a lot during fermentation period as the time of storage went on, where as malic was decreased. Kimchi A, having acidity of 0.75%, showed the highest acidic Protease and lipase activity. Also, the amylase activity was high in kimchi C, having 0.95% acidity. The total viable bacteria showed 8.1$\times$10$^{5}$ , 4.7$\times$10$^4$, 1.2$\times$10$^3$, 3.2$\times$10$^4$, 4.9$\times$10$^{5}$ cfu/ml in the kimchi A, B, C, D and E, respectively. The numbers of lactic acid bacteria counted 1.0$\times$10$^{5}$ , 1.3$\times$10s, 1.2$\times$10$^3$, 2.3$\times$ 10$^3$, 2.1$\times$10$^4$c1u/m1 in the kimchi A, B, C, D and E, respectively. The numbers of acetobactor were counted 1.8$\times$10$^{5}$ , 9.3$\times$10$^4$, 7.0$\times$10$^1$, 4.5$\times$10$^4$, 5.3$\times$10$^3$cfu/m1 in the kimchi A, B, C, D and E, respectively.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.4
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• pp.363-372
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• 2019

The leaves and stems of Centella asiatica have a long history of their usage as a medicine for the treatment of skin diseases such as ulcers and psoriasis, especially in Asia. Triterpenoids, the active components of Centella asiatica including asiaticoside, madecasosside, asiatic acid and madecassic acid, have shown to inhibit skin inflammation as well as improve skin photoaging. The main objective of this study is to investigate whether the Centella asiatica ripened with lava seawater which is rich in minerals known to be beneficial to human body can provide anti-inflammatory and moisturizing effects to skin. HPLC analysis showed that the concentration of triterpenoids increased further after ripening Centella asiatica with lava seawater. In order to confirm the inflammatory efficacy of the extract of the extract of the ripened Centella asiatica, the production of NO in LPS-activated RAW 264.7 cells and the expression of inflammatory cytokines in PM10 or UVB-induced HaCaT cells were observed. We found that the extract of the ripened Centella asiatica inhibited the expression of NO, IL-6, IL-8, and TNF-a and had higher inhibitory effect compared to the extract of the non-ripened Centella asiatica. In order to confirm the skin moisturizing effect, we investigated the synthesis of HA in HaCaT cells. The result showed HA production was enhanced in a concentration-dependent manner from the ripened group, while there was no efficacy from the non-ripened group. Taken together, it is concluded that the extract of the Centella asiatica ripened with lava seawater was effective in anti-inflammation and moisturization.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.1-15
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• 2015

Before the advent of pasteurization and other microbiological controls in the dairy industry, milk product-borne diseases such as scarlet fever, typhoid fever, septic sore throat, and tuberculosis were globally widespread. Pasteurization was invented by Louis Pasteur, and it has been considered as one of the most effective ways to control milk product-borne diseases since the 20th century. Nevertheless, till date, various types of cheese in the EU, the USA, and other countries are made from unpasteurized milk as artisan cheese, following the specific food regulations of each nation. Furthermore, after the effectiveness of the Free Trade Agreement (FTA) negotiations between Korea and many nations, the import of various types of cheese made in different conditions and influenced by acidity, preservatives, temperature, competing flora, water activity, and salt concentration increased yearly. Hence, the objective of this review was to describe (1) the 60-day aging rule of cheese, (2) characteristics of the outbreaks linked to cheese manufactured from unpasteurized milk since 1998 to 2011 in USA, and (3) serious health risks from unpasteurized milk, to ensure food protection and safety and to use this basic information for risk assessment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.34-44
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• 1989

The stability of rice cultivation in Korea is largely depended on climatic conditions, especially, low temperature at the period of early growth stage and after heading. The improvement of cold tolerant varieties and appropriate cultural practices in rice are very effective to minimize the cold damage. This paper is summarized the mechanism and counterplans of cold injury of rice plants. The paddy area having commonly cold injury in Korea is approximately 15, 522ha in 1,709 sites on the national scale. The cold damage at seedling stage in nursery bed appeared to poor germination, leaf discoloration, dead seedlings and seedling rot ect.. At the vegetative stage, the decreased tiller number due to poor rooting and the delayed heading caused by slow growth and panicle differentiation are commonly showed. The cold injury at early reproductive stage appeared to the degeneration of spikelets and rachis - branches, while that at meiosis stage showed to increased sterility due to poor development of pollen and shortened panicle length with delaying heading, therefore the grain yield is largely decreased. The cold damage at heading and ripening stages showed to poor pollination and fertilization, low panicle exsertion, poor grain filling and finally grain quality became low. To minimize the cold injury to rice plants by low temperature, following counterplans would be recommonded ; Improvement of the cold toelrant rice varieties for the regions of midmountains and alpines. Raising healthy seedlings at upland nursery beds and by using of growth regulators such as ABA, Fuchiwang and Tachiace. Soil improvement and organic matter application to reduce cold damage by increasing water and fertilizer holding capacities in the paddy field having commonly cold water and in the place where cold damage is regularly occurred. Appropriate fertilization for raising healthy rice plants to tolerate under low temperature condition. Water management to increase water temperature in the paddy such as depth watering, round channels and polyethylene tubes around the field. Establishment of the optimum cultivation time of rice based on minimum, mean and maximum temperatures at different regions with appropriate rice varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.1-10
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• 1982

Degree of grain shattering which is of varietal character is an important determinant for the magnitude of field loss of grains during harvest and threshing. Seven Indica \times Japonica progeny varieties and four Japonica varieties were subjected to measurements of tensile strength of grains, degree of grain shattering when panicles were dropped at 1.5m above concrete floor, and moisture content of grains (wet basis) during a period 35 to 63 days after heading. In addition, two varieties were tested for the relation of tensile strength of grains to the magnitude of field loss of grains in actual binder harvest. The 11 varieties differed conspicuously in tensile strength of grains and the degree of grain shattering: the weakest average tensile strength of grains of a variety was about 90g and the strongest about 250g with varying standard deviation of 30 to 60g. Three Indica \times Japonica varieties and one Japonica variety shattered I to 30% of the grains under the falling test. The threshold tensile strength of grains allowing grain shattering was estimated to be 180g on average for a sampling unit of 10 panicles, but only the grains having tensile strength weaker than 98g within the samples shattered. A decrease in average tensile strength by 10g below the threshold value corresponded to an increase of 3 to 5% in grain shattering. Most varieties did not change appreciably the tensile strength of grains and degree of grain shattering with delay in time of harvest and showed a negative correlation between the tensile strength and the moisture content of grains. The average tensile strength of grains was negatively correlated linearly with field loss in binder harvest. The average tensile strength for zero field loss in binder harvest was estimated to be 174g and a decrease in the average tensile strength by 10g corresponded to an increase of 40kg per hectare in field loss of grains. Instead of the average tensile strength of grains, the percentage of grains having tensile strength weaker than 100g is recommended as a criterion for the estimation of field loss of grains during harvesting operations as well as a basis of variety classification for grain shattering, since the standard deviation of tensile strength of grains varies much with variety and time of harvest, and individual grains having tensile strength stronger than 98 did not shatter practically.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.102-109
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• 2014

This study was carried out to investigate the effects of diffused light materials on marketable yield and quality of sunlight dried red pepper in plastic film house. The after ripening methods were composed of 3 treatments; using electric bulk dryer (Bulk), sealing house (House), and PE sealing. The diffused light materials were control, tent, shading 35% (Shading net), white polypropylene (PP (white)), and black polypropylene (PP (Black)). The marketable yield was high in order of Bulk as 300 g, House as 275 g, and PE sealing as 112 g. The redness of PE sealing was the highest as 17.85 and that of Bulk was the lowest as 10.65. There was significant difference in redness among the treatments. The moisture content of red pepper was the most rapidly reduced in control, and was the most slowly reduced in Shading net treatment. The marketable yield index was the higher in PP (white) as 114% than control. The redness had a significant difference in PP (Black) and tent compared to the other treatments. The capsaicin content showed the highest as $160mg{\cdot}100g^{-1}$ in PP (white) treatment. Conclusively, the most effective method for sunlight drying red pepper was House with PP (White) treatment. It delayed drying for 2 days but increased marketable yield at 114% than control when sunlight dried red pepper in plastic house. Our results also provided an optimized method for improvement of drying red pepper with sunlight, and will be useful for further drying red pepper research.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.53-60
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• 1989

The results of the investigation on the effects of plant nutrio-physiological status and reemergence of sudden wilting in rice on the occurrence of sudden wilting were summarized as follows: 1. The occurrence of sudden wilting, degree of damage and occurring time in the investigated variety showed to concur with the results of the previous experiment. 2. Nitrogen and Potassium contents in leaves related an occurrence of sudden wilting at heading stage have a very high negative co-relation (the value is -0.9224 at Yushin and -0.8243 at Milyang 23). 3. Regarding the relation between occurrence of sudden wilting and root activity capacity at the late growth stage, the root activity capacity at productive growth stage showed higher than at reproductive growth stage, which is the same in the two varieties but Milyang 23 is higher than Yushin. It is confirmed that root activity capacity in the two varieties has become very low at reproductive growth stage. 4. The toot activity capacity in the field with potassium showed a small occurrence of sudden wilting and the root activity capacity in the field with no potassium showed a very high co-relation value (the value is 0.8947 at Yushin and 0.7301 at Milyang 23). 5. Regarding the relation between the occurrence of sudden wilting and water evaporation quantity, water evaporation quantity after the heading date has a more direct relation to sudden wilting than that which occurrs prior to the heading date. Water evaporation quantity is higher in the field with no potassium, low leaves and Yushin, than in the field with potassium high leaves and Milyang 23. 6. The starch content in culm of Yushin and Milyang 23 at ripening stage showed high value in proportion to potassium quantity, and the starch content is lower as internode is lower. However, in fourth internode, the starch content is greatly increased in the field with potassium contrasted to the field with no potassium.