• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.843-859
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• 2017

The JK-1 isolate which was the best producer of indole-3-acetic acid and carotenoid among the 388 strains isolated from 28 wetlands in Jeju, was identified to be Rhodopseudomonas palustirs belongs to a typical group of non sulfur purple bacteria based on 16S sRNA sequencing. This study investigated the effect of different cultural conditions of pH, temperature, agitation, light and aeration on growth, IAA and carotenoid production of photosynthetic bacterium JK-1 for optimization of IAA and carotenoid production. It was found that growth, IAA, carotenoid, and bacteriochlorophyll production with light (3,000~3,500 Lux) and agitation (100 rpm) showed better results than those with dark/static or dark/agitation (100 rpm) in anaerobic conditions. The optimal pH, temperature and agitation speed for cell growth were 7, $30^{\circ}C$, 150 rpm, for IAA production were 9, $30^{\circ}C$, 150rpm and for carotenoid production were 6, $25^{\circ}C$, 50 rpm, cultured for 72 h under anaerobic light, respectively. The growth and IAA production were high in aerobic culture compared with anaerocic culture, whereas carotenoid and bacteriochlorophyll content were decreased extremely in aerobic condition (0.5~1 vvm). Subsequently, the optimal culture conditions for JK-1 were selected with pH 7, $30^{\circ}C$ and 100 rpm under anaerobic light and the effect on plant growth was tested by pot assay. Inoculation of JK-1 with 3% (v/v) level caused increase in shoot and root dry weigh that varied from 20%~58% to 40%~28% in young radish in camparison to uninoculated treatment at 50 days of growth. The study suggests that the JK-1 isolate may serve as efficient biofertilizer inoculants to promote plant growth.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.87-90
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• 2013

The average annual and winter ambient air temperatures in Korea have risen by $0.7^{\circ}C$ and $1.4^{\circ}C$, respectively, during the last 30 years. Due to climate change, the occurrence of abnormal weather conditions has become more frequent, causing damage to vegetable crops grown in Korea. Hot pepper, chinese cabbage and radish, the three most popular vegetables in Korea, are produced more in the field than in the greenhouse. It has been a trend that the time for field transplanting of seedlings is getting earlier and earlier as the spring temperatures keep rising. Seedlings transplanted too early in the spring take a longer time to resume the normal growth, because they are exposed to suboptimal temperature conditions. This experiment was carried out to figure out the change of cellular tissue of chinese cabbage under the condition of low temperature to provide the information regarding the coming climatic change, on the performance of 'Chunkwang' chinese cabbage during the spring growing season. In our study, plant height, number of leaf, chlorophyll and leaf area was lower at the open field cultivation than heating house treatment after transplanting 50 days. Especially in fresh weight, compared with heating treatment, open field and not heated treatment were notably low with the 1/3 level. Of damage symptoms due to low temperature cabbage leaves about 10 sheets when $-3.0^{\circ}C$ conditions in chinese cabbage was a little bit of water soaking symptoms on the leaves. $-7.4^{\circ}C$ under increasingly severe water soaking symptoms of leaf turns yellow was dry. Microscopy results showed symptoms of $-3.0^{\circ}C$ when the mesophyll cell of palisade tissue and spongy tissue collapse, $-7.4^{\circ}C$ palisade tissue and spongy tissue was completely collapsed. The result of this study suggests that the growers should be cautioned not to transplant their chinese cabbage seedlings too early into the field, and should be re-transplanting or transplanting other plants if chinese cabbage are exposed to suboptimal temperature conditions ($-3.0^{\circ}C$ or $-7.4^{\circ}C$).

• Journal of Nutrition and Health
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• v.49 no.4
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• pp.258-268
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• 2016

Purpose: The purpose of this study was to estimate dietary vitamin A intake and examine major food sources of vitamin A in Korean adults. Methods: Using data from the 2007~2012 Korea National Health and Nutrition Examination Survey, a total of 33,069 subjects over 19-years-old were included in this study. We estimated individual daily intakes of retinol, carotenoids such as ${\alpha}$-carotene, ${\beta}$-carotene, ${\beta}$-cryptoxanthin, lutein/zeaxanthin, and lycopene, and vitamin A by linking food consumption data with the vitamin A database of commonly consumed foods. We compared individual vitamin A intakes with the reference value of Dietary Reference Intakes for Koreans. Results: Average dietary vitamin A intakes of study subjects were $864.3{\mu}g$ retinol equivalent/day ($495.7{\mu}g$ retinol activity equivalent/day) in men and $715.0{\mu}g$ retinol equivalent/day ($403.6{\mu}g$ retinol activity equivalent/day) in women. Exactly 42.9% and 70.6% of total subjects consumed less vitamin A than the Estimated Average Requirement (EAR) based on retinol equivalent and retinol activity equivalent, respectively. The major food sources of vitamin A were Korean radish leaves, carrot, red pepper, and laver, and the top 20 foods provided about 80% of total vitamin A intake. Conclusion: This study provides basic data for estimation of vitamin A intake in Korean adults. Further research will be needed to analyze the association of insufficient or excess intakes of vitamin A and health problems in the Korean population.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.5
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• pp.209-217
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• 2015

Development of food industry and increased city life induced enlarged generation of food waste which is currently reused in a wide range of way. In this study, treatment of food waste generated from the public agricultural product wholesale markets (they are categorized as business places which imposes the duty for reducing the food waste discarded) in Korea was investigated, and subsequently, a scheme for improving the food waste recycling business was suggested. The food waste treatment plants are mainly located in Kyeongki-do at 39.5% of total plants in Korea and the other provinces have less than 10% of the total numbers, among which public treatment plant was 38.0% and private plant was 62.0%. The treatment methods included recycling as animal feed at 47.5%, as compost at 36.4%, and the rest of food waste (12.6%) was treated in other ways. Remarkably, it was noticed that the amount of food waste treated in anaerobic digestion have been increased up to 5.4% since 2011. This implied that food waste treated in anaerobic digestion method is gradually increased according to government policy. Amongst 33 public agricultural product wholesale markets distributed all over the country, the trading volume dealt in Garakdong market in Seoul, Gangseo market in Seoul, Daegu market in Daeju, Eomgung market in Busan, Guri market in Guri accounted for 34.67, 7.47, 6.98, 5.41, and 5.30% of the total trading volume in Korea, respectively. 2.65% of the total trading agricultural products dealt in the markets were remained as food waste and treated. In 2006, Ministry of Agriculture, Food and Rural Affairs implemented the package policy for radish and Chinese cabbage in order to reduce the amount of food waste and indeed, food waste generated in Garakdong market declined to one third of the food waste before the package policy implementation. In 2010, the food waste amount treated by 'dehydration', 'discarding as raw materials', and 'drying after dehydration' accounted for 56.3%, 33.7%, and 10.0% of the total food waste generated in the public agricultural product wholesale market. However, in 2013, discarding as raw materials accounted for the most at 56.3% followed by dehydration at 37.5%, and by drying after dehydration at 6.3%. The remarkable increment of the food waste discarded as raw materials was attributed to the increase of them in Garakdong market in Seoul. In general, the agricultural food waste contains high amount of moisture at 88% in average and low amount of salt at 0.02% in average. Therefore, it is highly recommended to treat the agricultural food waste through drying after dehydration in order for improving the treatment capability. Also, this recommendation can be supported by the fact that the end-products via drying after dehydration can be utilized as compost material. Overall, the agricultural food waste recycling business can be developed through integration of the treatment via 'drying after dehydration' and compost production.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.430-437
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• 2020

This is an approach study on the sensory properties (taste and odor) of 15 types of Korean conventional soups and stews using electronic nose and tongue. The relative sensor intensity for the taste components of the samples using electronic tongue was demonstrated. By SRS (sourness) sensor, sogogi-baechuguk (beef and cabbage soup) had the highest rate of 9.0. The STS (saltiness) sensor showed the highest score of 8.2 for ojingeoguk (squid soup). For the UMS (umami) sensor, which identifies savoriness, the sogogi-baechuguk was the highest at 10.1. The SWS (sweetness) sensors showed relatively little difference, with sigeumchi-doenjangguk (spinach and bean paste soup) at the highest of 7.3. According to the BRS sensor, which tests for bitterness, the siraegi-doenjangguk (dried radish green and bean paste soup) was the highest at 7.8. By principal component analysis (PCA), we observed variances of 56.21% in principal component 1 (PC1) and 25.23% in PC2. For each flavor component, we observed -0.95 and -0.20 for factor loading of PC1 and PC2 for SRS sensors, 0.96 and 0.14 for STS sensors, and -0.94 and 0.22 for PC1 and PC2 for UMS sensors, and PC1 and 0.22 for PC1 and PC2 loading for SWS sensors. The similarity between the samples identified by clustering analysis was largely identified by 4 clusters. A total of 25 kinds of volatile compounds in 15 samples were identified, and the ones showing the highest relative content in all samples were identified as ethanol and 2-methylthiophhene. The main ingredient analysis confirmed variances of 28.54% in PC1 and 20.80% in PC2 as a result of the pattern for volatile compounds in 15 samples. In the cluster analysis, it was found to be largely classified into 3 clusters. The data in this study can be used for a sensory property database of conventional Korean soups and stews using electronic sensors.

• Journal of Nutrition and Health
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• v.41 no.2
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• pp.156-164
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• 2008

The purpose of this study was to investigate factors related to bone mineral contents (BMC) at os calcis of adolescents. The subjects were 604 students (327 boys and 277 girls) between 7th and 9th grade in Seoul, Korea. The mean age was 14.2 ${\pm}$ 0.9 years. General characteristics were collected by a questionnaire, bone mineral contents (BMC) were measured in os calcis by Duel Energy X-ray Absorptiometry (PIXI, General Electronics, USA) and height and weight were measured by bioelectrical impedance analysis method (Inbody 4.0, Biospace Co. Ltd, Seoul, Korea). Mean BMC of os calsis were 2.241 g. Height (p <.0001), weight (p <.0001I), BMC (p <.0001I) ofboys were higher than those of girls. Percent body fat of girls, however, was higher than that of boys (p <.0001). Anthropometric measurement, pocket money, sibling, experience of fracture, pubertal stage, intake of supplements, physical or outdoors activity, and eating habit had significant influence on BMC of boys. Anthropometric measurement, physical or outdoors activity, and eating habit had significant influence on BMC of girls. Multivariate regression with adjustment for sex and age showed that BMC was associated positively with height, BMI, frequency of regular activity, and intake of spinach or radish leaves (all p <0.05), and negatively with percent body fat (p <.0000 and Korean traditional diet pattern (p = 0.01). On the basis of these results, it is recommended to develop nutrition education and physical activity program for adolescents to improve BMC and prevent osteoporosis.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.495-503
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• 2011

We evaluated the quality characteristics of fresh-cut produce (potato, sweet potato, carrot, radish, zucchini, cucumber, and green bell pepper) washed with sodium hypochlorite, which were vacuum packaged, and stored at 4 and 10$^{\circ}C$. The L-values of the fresh-cut potato and sweet potato decreased during storage. Lower PPO activities of potato and sweet potato were observed at 4$^{\circ}C$ than those at 10$^{\circ}C$ and development of potato and sweet potato browning was delayed at 4$^{\circ}C$. Total aerobic count and coliform increased continuously at 10$^{\circ}C$ during storage. Diced zucchini and shredded sweet potato had the greatest reduction in hardness among the fresh-cut produce during storage. Differences in the rate of quality change were observed according to the kinds and cut types of produce. Thus, a quality maintenance period for each type of fresh-cut produce must be determined, which will lead to the safe use of fresh cut produce in foodservice establishments.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.29-36
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• 2007

The using frequency of processed foods and dietician's perception against management of food service at 98 food service institutions located in Jeollabuk-Do were surveyed. Food service institutions included 13 hospitals,38 schools,40 enterprises, and 7 others. Single menu (75.5%) with two (33.7%) or three (57.1%) side dish was offered. In addition, the offering ratio of boiled water and spring water was 37.8 and 32.7%, respectively. The processed foods with high using frequency were kochujang (1.19), sesame oil (1.22), and doenjang (1.30), but that of leek, onion, Chinese cabbage, and radish were 4.95, 4.62, 4.60, and 4.26, respectively. Dietician's major affairs in all type of food service institutions were cooking (64.3%), purchase (48.0%), and personnel managements (39.8%). Dieticians, however, had a low perception against safety and nutrition management. Therefore, in order to prevent the outbreak of food-borne diseases, we estimated that the education and the conversion of dietician' perception against safety and nutrition management were needed.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.317-324
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• 2012

In order to determine an authenticity of food ingredient, we used DNA barcode method by universal primers. For identification of animal food ingredients, LCO1490/HCO2198 and VF2/FISH R2 designed for amplifying cytochrome c oxidase subunit1 (CO1) region and L14724/H15915 for cytochrome b (cyt b) region on mitochondrial DNA were used. Livestock (cow, pig, goat, sheep, a horse and deer) was amplified by LCO1490/HCO 2198, VF2/FISH R2 and L14724/H15915 primers. Poultry (chicken, duck, turkey and ostrich) was amplified by LCO1490/HCO 2198 and VF2/FISH R2 primers. But, Fishes (walleye pollack, herring, codfish, blue codfish, trout, tuna and rockfish) were only amplified by VF2/FISH R2 primers. For plant food ingredients, 3 types of primers (trnH/psbA, rpoB 1F/4R and rbcL 1F/724R) have been used an intergenic spacer, a RNA polymerase beta subunit and a ribulose bisphosphate carboxylase region on plastid, respectively. Garlic, onion, radish, green tea and spinach were amplified by trnH/psbA, rpoB 1F/4R and rbcL 1F/724R. The PCR product sizes were same by rpoB 1F/4R and rbcL 1F/724R but, the PCR product size using trnH/psbA primer was different with others for plants each. We established PCR condition and universal primer selection for 17 item's raw materials for foods and determine base sequences aim to PCR products in this study. This study can apply to determine an authenticity of foods through making an comparison between databases and base sequences in gene bank. Therefore, DNA barcode method using universal primers can be a useful for species identification techniques not only raw materials but also processed foods that are difficult to analyze by chemical analysis.

• Food Science and Preservation
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• v.18 no.5
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• pp.661-668
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• 2011

This study was conducted to devise appropriate blanching-process conditions as a means to convert Doraji, which is widely used in Korean food due to its unique fragrance and flavor, into frozen food materials for various uses. For the Hunter L values representing the brightness transformation among the surface color and gloss changes that were observed in Doraji before and after freezing, and after Doraji went through a blanching process, the specimen that went through a blanching process at $80^{\circ}C$ showed a significantly higher value compared to another specimen processed at a higher temperature, and the first specimen's value also rose after freezing. Meanwhile, for the hardness values, they declined more as the blanching temperature became higher and as the processing time became longer. For the number of total counts and the number of coliform groups, the number of total counts at $3.75{\times}10^5$ and $1.25{\times}10^5$ cfu/g before the blanching process was reduced into the approximately 2-3 log scale, and no coliform group was detected after the blanching process. As for the peroxidase activity, its activation was decreased by the blanching process, and more than 89% of the peroxidase became inactivated in all the specimens that went through the blanching process. The sensory characteristics of the frozen-thawed Doraji by test group showed the radish leaves blanched at $90^{\circ}C$ for 1 min to be the most highly evaluated in terms of the overall preference level (p<0.05).