• Horticultural Science & Technology
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• v.18 no.3
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• pp.399-403
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• 2000

Recently, abnormal leaf chlorosis has been observed in jujube trees of the major production area in Kyongbuk province. To determine possible causes for the observation, physico-chemical properties of the orchard soil and nutrient contents in the jujube trees were investigated. The chlorosis symptoms were categorized into three types based on the site of chlorosis initiation; leaf center, petiole, and intravein. Of the three, leaf center chlorosis was the most common. The symptom occurred more frequently in Ihyeon, Gyuam, and Geugrag soil series with previous history of apple orchard. In general, the soil and the tree showing leaf chlorosis had lesser nutrient contents than normal except P, Fe, and Zn. In particular, Mg contents in leaf, branchlet, and fruit of the tree were as much as 4 times lesser than those in normal tree; the soil also had 7.8 times lesser Mg contents. The results indicate that the abnormal leaf chlorosis in jujube tree may be caused by nutrient deficiency in soil and could be cured by proper fertilization.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.140-144
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• 1998

A survey on four tributary streams in agricultural areas along Nakdong River was carried out to evaluate the effect of agricultural practices on the quality of streamwater. Typicalpaddy and upland farmings were major agriculturalpractice in two survey areas. Apple orchards were located along Imgo -Cheon. Intensive farming in plastic film house was conducted along the Habin cheon. Electriclal condutivity and nutrient contents were measured. Comparing to the reference water sample collected from very upper part of Yangsang -Cheon in Moonkyong, water in the streams studied were quite polluted and such pollution could be due to the farmings conducted along the streams. Phosphorus content were higher than the minimum level for eutrophication (0.01-0.05 mg/L). Nitrogeon content were also significantly high in many sites to cause harmful effects on crops when normalfertilizer level was applicated. Among the four stream, water quality in paddy area were relatively less polluted. High nitrogen level in Imgo-Cheon and high level of EC in Habin-Cheon were problematic. As farming is the major sources of pollution in the streams studied, this are traceable to the agricultural nonpoint sources. To maintain water quality of the stream, the agricultural nonpoint source along thributary streams should be properly controlled.

• Korean Journal of Food Science and Technology
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• v.3 no.3
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• pp.163-167
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• 1971

Tasty constituents of the Chinese quince such as polyphenols, amino acids, sugars and organic acids were surveyed through the course of this study. The results are as follows: 1. The major moiety of the polyphenol constituents were catechin, leucoanthocyan, and associated tannins. 2. Amino acids were mostly composed of aspartic acid, glutamic acid, arginine and ${\beta}-alanine$. 3. Citric and malic acids were the main organic acids. 4. Sugars detected were glucose, fructose, sucrose and xylose. 5. When compared with apple and/or pear: the total amount of amino acids were quite similar, sugars decreased from half to one third, but the total amount of polyphenol constituents increased from 20 up to 50 times and 3 to 5 times in organic acids. These indicates unambiguously that the origin of rough and acidic taste is due to these high level of polyphenols and organic acids.

• Food Science and Preservation
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• v.10 no.4
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• pp.459-465
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• 2003

This study was carried out to investigate the changes in internal pressure according to various freezing methods, as basic research to protect the destruction of tissues when fruits and vegetables are frozen. The rate of weight loss, caused by the freezing of fruits and vegetables, was found to be the least (0.44∼1.38％) when the immersion freezing method was applied. The difference in the rate of weight loss was the highest when freezing methods were applied to watermelon, and the freezing rate of watermelon whose moisture contents were greater have relatively greater influence on the weight loss. The difference in internal pressures was the least and caused by the volume increase and decrease, when pear, apple, and melon were frozen using the immersion freezing method, while the diffeyence the greatest when the air-blast freezing method was used. As the freezing rate was greater, the internal pressure was less. However, the internal pressure of strawberry and watermelon was the greatest when the immersion freezing method was applied. Frozen without using the thermal equalizing method, the change in internal pressure of fruits was about 2 psig. In contrast, the internal pressure of watermelon applied with the thermal equalizing method was changed in a way similar to that of watermelon not applied with the method, but the former generated a certain level of internal pressure and maintained a significantly low level of internal pressure (about 1.3 psig). When thawed, the internal pressure of samples to which the thermal equalizing method was applied was less than that of what the thermal equalizing method was not applied to. In comparison with the application of multi-step thermal equalizing method, 3∼4 times of application of the thermal equalizing method to the freezing resulted in the decrease of fluctuation range of internal pressure.

• Food Science and Preservation
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• v.7 no.4
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• pp.395-402
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• 2000

To enlarge application field of electrolyzed acid-water(EAW) on food industry, the changes of EAW properties by storage conditions and heating were investigatet. It was showed that storing EAW in closed container is mon effective to keep up the oxidation-reduction potentials(ORP), hyperchloride content and pH than stored in opened ones. ORP of EAW stored in closed container could be kept mon than 1 month as 1,150 mV levels. Ruing heating from 2$0^{\circ}C$ to 95$^{\circ}C$, ORP was increased to 1,150 mV levels at 95$^{\circ}C$ after gradual decrease to 5$0^{\circ}C$. Tyrosinase activity was decreased approximately to 26%~35% in EAW having a 950 mV~1,140 mV ORP. Also it was confirmed that EAW has anti-browning effect as sliced apple and potato, and their juices treated with EAW had conspicous difference in their $\Delta$E value. 12 kinds of pesticides such as aldrine, capful diazinon, diedrin, $\alpha$-endosulfan $\beta$-endosulfan, endosulfan sulfate, endrin, $\alpha$-BHC, o,p'-DDT, procymidone, PCNB added in EAW were recovered from ND~73.6% comparing to ones added in distilled water. The recovered amounts of pesticides, procymidone and diazinon in lettuce after soaking in EAW were 1.12 ppm and ND, compared with those of amounts soaked in distilled water were 3.67 ppm and 3.05 ppm respectively. So, it seems that EAW has potentials to promote the degradation of pesticides.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.135-141
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• 2006

We isolated a bacterium which produces antifungal substances from the Sanktpeterburg soils at Russia. The iso-lated strain was identified as Brevibacillus sp. and shown a strong antifungal activity on plant pathogenic fungi. Brevibacillus sp. KMU-391 produced maximum level of antifungal substances under incubation aerobically at $30^{\circ}C$ for 48 hours in trypticase soybean broth containing 1.0% sucrose and 1.0% polypeptone at 180 rpm and initiated pH adjusted to 7.0. Precipitate of culture broth by $30{\sim}60%$ ammonium sulfate precipitation exhibited strong antifungal activity against Didymella bryoniae by dry cell weight. Butanol extract of cultured broth also shown fungal growth inhibitory activity against Botrytis cinerea KACC 40573, Botrytis fabae KACC 40962, Colletotrichum gloeosporioides KACC 40804, Colletotrichum orbiculare KACC 40808, Didymella bryoniae KACC 40669, Fusarium graminearum KACC 41040, Fusarium oxysporum KACC 40037, Fusarium oxysporum KACC 40052, Fusarium oxysporum f, sp. radicis-Iycopersici KACC 40537, Fusarium oxysporum KACC 40902, Monosporascus cannonballus KACC 40940, Phytophthora camvibora KACC 40160, Rhizoctonia solani AG-1(IA) KACC 40101, Rhizoctonia solani AG-4 KACC 40142, and Scleotinia scleotiorum KACC 41065 by agar diffusion method.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.556-559
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• 2009

"Hongso" was originated from a cross between "Yoko" and "Hongro" in NIHHS, RDA, in 1989. "Hongso" was preliminarily selected in 2002 for its high fruit quality. After regional adaptability test at five sites from 2003 to 2006 as "Wonkyo Ga-30" it was finally selected in 2006. Optimum harvest time is early September which is similar to that of "Hongro". Fruit shape is globose conical and skin color is light red. Mean fruit weight is 295g and soluble solids content is 14.1oBrix. Fruits acidity is 0.34%, which is higher than that of "Hongro"(0.23%). It has a good taste for harmony of sugar and acidity. Storability is 3 weeks in room temperature. It is apt to russet on fruit skin. It is susceptible to Bitter rot. "Hongso" has a good cross compatibility with major cultivars such as "Fuji", "Hongro" and "Tsugaru". Tree habit is semi-spreading and tree vigor is weak. "Hongso" is high-density cultivation type cultivar, because it has a precocity, spur-type.

• The Korean Journal of Food And Nutrition
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• v.34 no.5
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• pp.477-486
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• 2021

To utilize Malus pruniforia Borkh. as a functional material, cold-water (CW), hot-water (HW), and 70% ethanol (EtOH) extracts were prepared, and their antioxidant and anti-inflammatory activities were compared. The antioxidant activity of the HW extract evaluated by ABTS and DPPH radical scavenging and FRAP activity was significantly effective. The total polyphenol content of the HW extract was also higher by 15.5±0.7 mg GAE/g extract compared to other extracts. The EtOH extract showed significantly decreased TNF-α (39.8%), IL-6 (65.5%), and NO (34.9%) levels in RAW 264.7 cells compared to the LPS-induced control group. The levels of IL-6 (21.1%) and IL-8 (19.3%) were significantly decreased by treatment of EtOH extract in HaCaT keratinocytes induced with TNF-α and IFN-γ. The UHPLC-MS results indicated that the EtOH extract might have chlorogenic acid and phlorizin as the major compounds. This was validated using HPLC-DAD, which showed that the EtOH extract had higher levels of chlorogenic acid and phlorizin (1,185±58 and 470±10 ㎍/g extract, respectively). In conclusion, the present study suggested that the anti-inflammatory activity of the EtOH extract was more effective than the CW and HW extracts, and chlorogenic acid and phlorizin could be used as indicator compounds and functional substances.

• Korean Journal of Environmental Agriculture
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• v.38 no.2
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• pp.110-118
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• 2019

BACKGROUND: Residual organochlorine pesticides (OCPs) are designated as persistent organic pollutants (POPs) by Stockholm Convention because they bioaccumulate through the food web, and pose a risk of causing adverse effect to human health and the environment. Apple and pear is economic crop in agriculture, and its cultivation area and yield has been increased. Therefore, we tried to investigate the OCPs residue in apple and pear orchard soils and fruits. METHODS AND RESULTS: Extraction and clean-up method were developed using the modified QuEChERS method for residual organochlorine pesticides (ROCPs) in apple and pear orchard soil and fruits. Recovery and limit of quantitation (LOQ) of ROCPs in soil and fruits were 75.4-101.4 and 76.9-93.4%, 0.03-0.21 and $0.6-1.2{\mu}g/kg$, respectively. Detected ROCPs in apple and pear orchard soil was 2,4-DDT, 4,4-DDD, 4,4-DDE, 4,4-DDT, and endosulfan sulfate, the residues were 2.2, 1.9-48.0, 1.3-84.1, 90.6-863.1, and $11.3-239.0{\mu}g/kg$, respectively. But five pesticides in all fruit samples were not detected. CONCLUSION: These results showed that ROCPs residues in apple and pear orchard soil had no effect on safety of agricultural products.

• Korean Journal of Plant Taxonomy
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• v.50 no.4
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• pp.427-452
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• 2020

This study of vascular plants was conducted over a period of 33 days from March to October of 2018 in Byeonsanbando National Park, South Korea. Based on voucher specimens and photographs, 829 taxa in total were recorded, including 141 families, 458 genera, 748 species, 16 subspecies, 59 varieties, and 6 forma. Two endangered taxa were identified, Iris koreana Nakai and Saururus chinensis (Lour.) Baill. Five rare taxa were found, including Abeliophyllum distichum Nakai and Hypodematium glanduloso-pilosum (Tagawa) Ohwi. A total of 17 Korean endemic plants were investigated. Examples include Elsholtzia byeonsanensis M. Kim, Eranthis byunsanensis B. Y. Sun, and Lycoris flavescens M. Kim & S. T. Lee. Of floristic regional indicators (third to fifth degree), 52 taxa were identified. Naturalized plants were identified, which included 79 taxa, and 7 species of ecosystem disturbance plants, such as Ambrosia artemisiifolia L., Lactuca serriola L., and Solidago altissima L. were found. We recorded 39 taxa of the plants vulnerable to climate change.