• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.672-679
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• 2006

Postharvest nut quality, and changes of soluble solids content and kernel hardness during cold storage in 13 Korean prevailing chestnut cultivars were investigated to establish the chestnut grading and standardization for marketing and processing industry. Chestnut quality attributes such as nut weight, soluble solids content, kernel hardness, % with the pericarp split, and % of polyembryonic nuts were measured from 2001 to 2005. There were significant difference among cultivars in quality characteristics, and also annual variation within same cultivar, corresponded to the high genetic and environmental variability. During cold storage at $2^{\circ}C$ for 16 weeks, remarkable changes in soluble solids content were observed, and Isseumo showed the highest increase of 8% at 16 weeks of cold storage compared with postharvest. In case of most cultivars except early ripening cultivars, soluble solids content of chestnut increased until 12 weeks during cold storage, followed by decreased gradually thereafter. Kernel hardness of most cultivars except lshizuchi during cold storage increased slightly, but it was not statistically significant. This work would be a useful reference to the quality of each chestnut cultivar for the growers and breeders alike.

• Food Science and Preservation
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• v.30 no.3
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• pp.369-382
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• 2023

We examined the changes in the physicochemical quality characteristics and antioxidant activity of fresh-cut Fuji apples (Malus pumila) during processing and storage after treatment with browning inhibitors. The primary aim was to elucidate processing suitability and storability. We observed that in the processing stage of slicing fresh Fuji apples, there were no significant differences in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging ability and ferric-reducing antioxidant power (FRAP). However, after NaClO treatment, total flavonoid and total polyphenol contents decreased. When freshcut Fuji apples were treated with browning inhibitors and stored at 4℃, the L value and hardness decreased; however, the weight loss rate increased based on the storage period of all fruit groups treated with Citrus unshiu Markovich (CuM), calcium ascorbate (CA), and ascorbic acid (AA). The pH increased after 2 days of storage in 1% CuM and after 6 days of storage in 1% CA; however, no changes in pH were observed during the storage period in 1% AA. The DPPH radical scavenging activity was generally good under storage conditions of 1% AA at 4℃ and 1% CA at 20℃. Furthermore, FRAP remained relatively constant under storage conditions of 1% CA. The quality characteristics and antioxidant activity of fresh-cut fruits during processing and storage can be used as basic data for industries. Furthermore, we can gain confidence in quality improvements by improving the production and distribution environment of fresh-cut agricultural products.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.51-70
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• 2003

In recent years, Korean rice must compete with the rice of advanced countries under Doha Development Agenda(DDA) and free Trade Agreement(FTA). Therefore we should find more active and positive solution in rice industry according to the inncreasing power of international pressure. Increasing rice production was the most important policy during the past food-deficient days, but recently, with overproduction of rice, various circulation system by the brand(price)-differentiation should be settled in a recent market of Korea. Nowadays, some advanced rice farmers and Rice Processing Complex(RPC) managers developed new brands of rice with high-quality, adding healthy materials and environment-friendly farming methods. Therefore, the future strategy of making a new brand rice should be planned including selection of rice variety, cultural and post-harvest techniques, circulation and processing methods to compete against foreign rice. And environment-friendly farming is also recommendable for food safety and differentiate from imported rice. For the purpose of successful brand-rice, the following points might be considered. Firstly, selection of good quality rice and continual development of good variety must be conducted for the differentiation of Korean rice from foreign rice. Secondly, a special contract between producer and consumer with functional-rice, organic filming-rice, specific-rice will be recommendable. Thirdly, improvement of post-harvest management and milling system are necessary for the production of differentiated-rice. Fortunately, standard of inspection, rules of description for brand-rice must be developed by a more scientific examination in order to settlement of trust for consumer. Finally, provincial or regional-representative brand rice must be settled and conducted for the development of agreement market system between producer and consumer.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.2_1
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• pp.79-89
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• 2021

Poly(lactic acid) (PLA) is considered as one of the most promising bio-based polymers due to its high strength, high modulus, good processability, transparency after processing, and commercial availability. This study aimed to investigate the mechanical, thermal, and migration properties of poly(lactic acid)/zeolite (10 phr) composites prepared with various biocompatible plasticizers, such as triethyl citrate(TEC), tributyl citrate(TBC), and poly(ethylene glycol)(PEG400), through differential scanning calorimetry(DSC), thermo-gravimetric analysis(TGA) and standard tensile testing. The incorporation of PEG400 significantly increased the elongation at break, and DSC results showed that the addition of plasticizers drastically decreased the T_g of PLA/zeolite composites and improved the melt flow and processability. Besides, it was found from TGA results that PLA/zeolites composites plasticized by TEC and TBC were more easily to be thermally degraded than the composites plasticized by PEG400.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.171-177
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• 2014

In an effort to investigate special distribution of glucose content of potato tuber of a cultivar 'Superior' after harvest, a whole tuber was longitudinally cut into halves and cut-surface was divided into 11 regions. Approximate glucose concentration of each section was determined using a commercial blood glucose meter. Higher level of glucose was detected in the outer layers of tissue than inner part of tuber although there were lower coefficients of variation value, 37.4% and 34.1% among individual tubers and among defined sections, respectively. A positive correlation between the whole tuber and individual section was existed in glucose content, where the central pith tissue gave the highest coefficient (r = 0.921) and bud end tissue did the lowest (r = 0.544). Glucose content of the tubers stored for 4 months at $2.0^{\circ}C$ was 5.5 fold higher compared to the tubers kept in ambient temperature. The chip color of the former tubers was much brighter than those of the latter tubers. The result obtained in the present study suggests that the blood glucose meter can be used to a rapid and simple evaluation of glucose content and therein be applied to estimate the processing quality of potato tubers during postharvest handling.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.54-63
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• 2002

Post-harvest technology for rice was focused on in-bin drying system, which consists of about 100, 000 facilities in 1980s. The modernized Rice Processing Complex (RPC) and Drying Storage Center (DSC) became popular for rice dry, storage, process and distribution from 1990s. However, the percentage of artificial drying for rice is 48% (2001) and the ability of bulk storage is about 15%. Therefore it is necessary to build enough drying and bulk storage facilities. The definition of high quality rice is to satisfy both good appearance and good taste. The index for good taste in rice is a below 7% of protein, 17-20% of amylose, 15.5-16.5% of moisture contents and high concentration of Mg and K. To obtain a high quality rice, it is absolutely needed to integrate high technologies including breeding program, cropping methods, harvesting time, drying, storing and processing methodologies. Generally, consumers prefer to rice retaining below b value of 5 in colorimetry, and the whiteness, the hardness and the moisture contents of rice are in order of consumer preference in rice quality. By selection of rice cultivars according to acceptable quality, the periods between harvesting time and drying reduced up to about 20 days. Therefore it is necessary to develop a low temperature grain drying system in order to (1) increase the rate of artificial rice drying up to 85%, (2) keep the drying temperature of below 45C, (3) maintain high quality in rice and (4) save energy consumption. Bulk storage facilities with low temperature storage system (7-15C) for rice using grain cooler should be built to reduce labor for handling and transportation and to keep a quality of rice. In the cooled rice, there is no loss of grain quality due to respiration, insect and microorganism, which results in high quality rice containing 16% of moisture contents all year round. In addition, introducing a low temperature milling system reduced the percentage of broken rice to 2% and increased the percentage of head rice to 3% because of proper hardness of grain. It has been noted that the broken rice and cracking reduced significantly by using low pressure milling and wet milling. Our mission for improving rice market competitiveness goes to (1) produce environment friendly, functional rice cultivars, (2) establish a grade standard of rice quality, (3) breed a new cultivar for consumer oriented and (4) extend the period of storage and shelf life of rice during postharvest.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.46-53
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• 2002

The self-sufficiency of rice production was attained in 1975 through development of Tongil-type high-yielding rices and rapid dissemination to farmers and innovation of cultivation technologies, so-called "green revolution" in Korea. It can be continued during the last twenty seven years except some years with meterological disasters. The national average of milled rice yield per ha was only 3.1 ton at the first half of 1960′s, but it drastically increased to 5.0 ton at the 2nd half of 1990′s. Also, the rice quality was highly improved through the continuous varietal improvement of high-yielding japonica rice cultivars. The amounts of rice stock will go beyond about 1.9 million tons in 2002 due to the recent continuos bumper rice crop and relatively rapid reducing in rice consumption. There are so many rice brands over 1,200 in Korea, but most of rice commodities are not enough controlled in terms of marketing quality and palatability of cooked rice. Although the most rice brands are not properly controlled in quality management, its average level of grain quality is largely improved through the continuously increased diffusion of newly-developed high-quality rice cultivars since 1991. The rapid construction of rice processing complex(RPC) since 1992 also accelerates the production and distribution of brand rices. Especially, about half of distribution amounts are covered by brand rice commodities of the agricultural cooperative associations. The rice is mainly consumed by the type of cooked rice. The amounts of rice consumption for food processing is only below 4% of total rice consumption. The processed rice foods is mainly consumed as various processed cooked rices, rice cakes, and rice wines.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.268-277
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• 2014

This study assessed microbiological hazards at postharvest stage of dropwort farms (A, B, C, D, E, F, G, H, I) located in 4 different areas in Korea. The samples were assessed for sanitary indication bacteria (total aerobic bacteria, coliform, and Escherichia coli) and pathogenic bacteria (Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus). Total aerobic bacteria and coliform in 9 dropwort farms were detected at the levels of 0~7.00 and 0~4.25 log CFU/g, mL, of $100cm^2$. In particular, microbial contamination in worker's hand showed higher than cultivation environment factors. Escherichia coli was detected in several farms of soil, irrigation water, washing water and worker's hand and also, dropwort in these farms was contaminated with E. coli (positive reaction). In case of pathogenic bacteria, B. cereus was detected at the highest levels in soil. S. aureus was detected qualitatively from only one sample of dropwort washed by water. E. coli O157:H7 and L. monocytogenes were not detected. Although dropwort pass through 2 process (trimming and washing), the microbial contamination was not differ significantly before and after which indicates that current washing system was not effect on reduction of microorganism. From these results, the postharvest environment and workers have been considered as cross-contamination factors. Thus, processing equipments and personal hygiene should be managed to reduce the microbial contamination of dropwort. Accordingly management system such as good agricultural practices (GAP) criteria is needed for the safety of dropwort

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.124-134
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• 2002

The sweetpotato, Ipomoea batatas L. (Lam.), is one of the important summer upland crops in Korea and has been used as human food, industrial yaw material and vegetable. Sweetpotato has been consumed for human foods such as boiled, roasted, fried or salad etc. It should be developed for higher quality as a snack or health food, primarily through improving the eating and marketing qualities as well as nutritional value. Its quality after cooking or processing is a complex one combining the aroma, taste, texture and fiber content. The other important qualities for consumers are root shape, size, skin color, flesh color, insect and disease resistance, nutritional components and safety from phytoalexins(toxic stress metabolites) etc. Korean people generally prefer to red skin color, round or elliptic shape and dry texture, yellow flesh color of sweetpotato which is high in starch content including vitamins and nutrients. The almost factors of quality components of sweetpotato are genetically controlled by breeder, but postharvest handlings and marketing management for making high quality goods should be done thoroughly according to the quality evaluation criteria of sweetpotato from the moment of harvest until shipping them to the market by farmers and the other users. This paper describes current status and prospects of the quality evaluations and researches in sweetpotato roots in Korea.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.170.1-170
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• 2003

최근 경제성장과 더불어 쌀 소비 형태가 양보다 질을 우선하게 됨에 따라 다양한 지역 브랜드 쌀, 고품질 친환경 쌀, 씻지 않는 쌀, 버섯쌀과 강화미와 같은 기능성 쌀 등을 생산하여 차별화를 죄하고 있다. 이처럼 최고의 쌀을 소비자에게 공급하기 위하여 쌀의 다양한 상품화가 필요하다. 따라서 동의보감, 본초강목, 중약대사전 등에서 중풍, 경기, 가슴답답할 때 효과가 있다고 알려진 대나무를 가열할 때 나오는 진액인 죽력을 이용하여 기능성 쌀을 제조하였다. 대나무 추출방법에 따른 추출물 $\ulcorner$죽력$\lrcorner$ 은 가용성 고형분과 총 페놀 함량은 에탄을 추출물이 가장 높았고 증발잔사는 직접가열에 의한 추출물이 가장 많았다. 추출물을 코팅한 쌀의 취반후 관능은 에탄을 추출물을 코팅한 처리가 향과 맛이 가장 우수하였고 조직감은 추출방법 간에 차이가 없었다. 대나무 에탄을 추출물의 코팅 량별 쌀의 색도 L, a, b값은 코팅 농도가 증가될수록 증가되었으나 취반후 밥은 L값만 감소되었다. 취반 후 밥의 관능은 10% 코팅 처리에서 향과 맛이 가장 양호하였다. 죽력을 코팅한 쌀의 무기성분은 무코팅 쌀 보다 모든 성분함량이 높았는데 특히 K 함량이 월등하였다. 죽력 코팅 쌀의 취반 특성은 무코팅 쌀 보다 흡수율은 낮았고 팽창율은 떨어졌으나 토요 식미지수는 높았다. 코팅 쌀의 취반 후 물성은 경도, 검성, 씹힘성은 무코팅 쌀 보다 높았고 응집성, 탄력성, 부착성은 낮은 경향이었다.