• Title/Summary/Keyword: Physicochemical change

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Effect of Charcoal Packaging Materials on the Physicochemical Properties of White, Brown and Black Rice During Storage (숯 포장재가 백미, 현미, 흑미 저장 중 물리화학적 변화에 미치는 영향)

  • Chung Nam Yong;Choi Sung Sook;Choi Soon Nam
    • Korean journal of food and cookery science
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    • v.20 no.6 s.84
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    • pp.553-560
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    • 2004
  • This study was carried out to investigate the effect of packaging materials (general, charcoal) on the physicochemical properties of white, brown and black rices stored at 30'E . The weight losses of the rices were $2.2\~3.0\%$ during storage. The germination rates of the white rice packed with general (GW) and charcoal (CW) were both $0.0\%$, whereas those for the brown and black rices (GB and CB, and GBL and CBL) were 10.3 and $10.9\%$, and 11.8 and $12.1\%$, respectively, after 10 weeks of storage. With regard to the weight losses, there were no differences in the germination rates between the packaging materials. The hardness of the rice increased with increasing storage, but the change was smallest for the CBL (charcoal packed, black rice) and largest for the GW (general packed, white rice). The fat acidity of the rices was significantly increased with increasing storage time and those of the rices packed in charcoal materials were significantly lower than those packed in general packaging materials.

Physicochemical Properties and Gel Forming Properties of Mungbean and Buckwheat Crude Starches (녹두와 메밀 조전분의 이화학적 특성 및 겔 형성)

  • 주난영;이혜수
    • Korean journal of food and cookery science
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    • v.5 no.2
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    • pp.1-8
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    • 1989
  • The physicochemical properties and gel forming properties of mungbean and buckwheat crude starches were investigated. The results were as follows; 1. The granule size and shape of mungbean crude starch were $11~32\mu\textrm{m}$ and oval, and those of buckwheat crude starch were $3~10 \mu\textrm{m}$ and polygonal. 2. The amylose conteut of mungbean crude starch and buckwheat crude starch were 78.0% and 26.4% respectively. 3. The blue value of mungbean crude starch and buckwheat crude starch were 1.030 and 0.409, respectively. 4. Periodate oxidation of mungbean crude starch resulted that amylose had the average molecular weight of 95, 648, degree of polymerization of 590 and amylopectin had the degree of branching of 5.4, glucose unit per segment of 18.6, and periodate oxidation of buckwheat crude starch resulted that amylose had the average molecular weight of 133, 690, degree of polymerization of 825 and amylopectin had the degree of branching of 5.2, glucose unit per segment of 19.2 5. Water binding capacity of mungbean crude starch was 185.1% and that of buckwheat was 209.9% 6. The pattern of change in swelling power of mungbean crude starch for increasing temperature started to increase at $60^{\circ}C$ and increased rapidly from $70^{\circ}C$, and that of buckwheat increased slowly from $60^{\circ}C$ to $90^{\circ}C$ without rapid increase. 7 The ranges of gelatinization temp. of mungbean and buckwheat crude starches were 63. 9-$109^{\circ}C$ and 52.5-84.$2^{\circ}C$, respectively. 8. The gelatinization patterns for 6% munbean crude starch and 8% buckwheat crude starch were investigated by Brabender amglograph. Mungbean crude starch showed the initial pasting temperature of 77.6$^{\circ}C$ without peak height, and buckwheat crude starch showed that of $62.5^{\circ}C$ without peak height. In addition, sensory evaluation for sample starch gels (mungbean, buckwheat, cowpea) was done. 1. The difference of sensory characteristics for each starch gel was significant. 2. The sample starch gels were regarded as 'Mook' by pannels. 3. 74.44% of the degree of Mooklike was explained by hardness.

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Physicochemical Characteristics of Fermented Pig Manure Compost and Cow Manure Compost by Pelletizing (펠렛 가공처리에 따른 돈분 발효퇴비와 우분 발효퇴비의 물리화학적 특성)

  • Jeong, Kwang Hwa;Park, Chi Ho;Choi, Dong Yun;Kwak, Jung Hoon;Yang, Chang Bum;Kang, Ho
    • Journal of the Korea Organic Resources Recycling Association
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    • v.13 no.4
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    • pp.118-127
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    • 2005
  • The best way to treat livestock manure is a recycling the manure to arable land as an organic fertilizer. In this study, fermented cow manure compost and pig manure compost were used as a raw materials for pelletizing. The changes of physicochemical properties of each composts and pellets were investigated. The aim of this research was to improve availability of livestock manure compost. In pelletizing process of fermented livestock manure compost, the optimal water content to make pellet was around 40%. When clay was mixed by volume more than 15% as a bonding agent, the condition of pelletizing process was beginning to improve. On a dry matter basis, the contents of N, P and K of fermented pig manure compost were 2.05%, 1.89% and 1.31%, respectively. After pelletizing, the contents of compost pelleted with the pig manure compost were 1.96% 1.73% and 0.89%, respectively. The same parameters of cow manure compost were 2.52%, 1.01% and 2.98%, respectively. After processing, the contents of compost pelleted with the cow manure compost were 2.45%, 1.10% and 2.93%, respectively. After pelletizing, there were little change in the content of heavy metals such as Pb, Cd, As and Hg. When pelleted compost dried naturally was submerged in water, it was completely dissolved in 30 minutes. On the other hand, Pelleted compost dried with the mechanical convection oven set $70^{\circ}C$ for 24 hours was completely dissolved in 960 minutes. The volume and weight of pelleted compost were decreased with time. After 30 days of storing, the weight of pelleted compost was decreased by 15% compared with its original weight. The volume of it was decreased by 17~25% in the same time.

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Effects of Storage Temperature on Physicochemical and Sensory Characteristics of Soybean Sprouts (콩나물의 저장 중 온도변이에 따른 품질변화)

  • Jeon, Seung-Ho;Lee, Se-Hun;Kim, Young-Ju;Oh, Se-Yun;Kim, Kyung-Moon;Chung, Jong-Il;Shim, Sang-In
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.3
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    • pp.220-225
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    • 2010
  • Soybean sprouts produced at optimal temperature are placed or displayed for several days in market shelf of relatively cool temperature (ca. $13^{\circ}C$). During this period a number of changes occur including changes in color, smell, taste, nutritional quality, etc. In order to investigate the changes of these factors, soybean sprouts packed in plastic film bag (OPP+PE) were stored at the two different temperature ($3^{\circ}C$ and $13^{\circ}C$). Morphological characters, physicochemical changes and enzymes activity related to visible quality (color) of soybean sprouts were examined. The numbers of fine roots were greater and hypocotyls were longer in soybean sprouts stored at $13^{\circ}C$, although there was no significant difference in diameter, fresh weight and dry weight of hypocotyls between the two storage temperatures. Browning of hypocotyl, as an indicator of a typical deterioration in sprout quality, was highly dependent on the activity of polyphenol oxidase (PPO). Considering the low level of soluble protein in hypocotyls, the relatively higher activity of PPO suggested a critical role of PPO in stored soybean sprouts. PPO activity of sprouts stored at $13^{\circ}C$ was 2-fold higher than that of sprouts stored at $3^{\circ}C$ after 4 days. In sprouts stored at $13^{\circ}C$, the PPO activity was increased from day 0 until 6 days and since then, it was not detected. Crude protein content was increased to 30.9~35.4% based on dry weight with extended storage period. The change in crude protein was greater in sprouts stored at high temperature ($13^{\circ}C$). Total free amino acid content was increased in both temperatures. However, the changing rate of free amino acid was greater in sprouts stored at $13^{\circ}C$.

Changes in Functional Compounds and Antioxidant Activities in Storage Duration with Accelerated Age-Conditioning of Oats (노화가속화 조건에서 저장 기간에 따른 귀리의 기능성 성분 및 항산화 활성 변화)

  • Son, Yu Rim;Lee, Ji Hae;Park, Hyoung-Ho;Lee, Byong Won;Kim, Hyun-Joo;Han, Sang-Ik;Woo, Koan Sik;Lee, Byoung-kyu;Lee, Sang-Chul;Lee, Yu Young
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.63 no.2
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    • pp.149-157
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    • 2018
  • In this study, we investigated the changes in physicochemical properties, antioxidant activities, and contents of functional compounds, such as avenanthramides (AVNs), vitamin E, and ${\beta}$-glucan, in oats by accelerated age-conditioning (temperature: $45^{\circ}C$, relative humidity: 20%). No significant differences were observed in crude protein, crude fat, and AVNs contents of three oat cultivars, up to 63 days of storage; however, their antioxidant activities, as well as ${\beta}$-glucan, vitamin E, and fatty acid contents were significantly different (p < 0.05). ${\beta}$-glucan and fatty acid contents and the antioxidant activities of Deayang (DY) cultivar did not change during storage. ${\beta}$-glucan and unsaturated fatty acid contents of Choyang (CY) and Jopung (JP) increased during the storage period, while antioxidant activities did not (DPPH-CY; 48.1 to 26.9 mg TEAC/100 g, JP; 49.4 to 26.7 mg TEAC/100 g. ABTS-CY; 88.4 to 56.3 mg TEAC/100 g, JP; 80.0 to 55.8 mg TEAC/100 g). The total vitamin E content in DY (1.20 to 0.85 mg/100 g) and CY (1.73 to 1.33 mg/100 g) decreased, but it was maintained in JP. This study indicated that the changes in physicochemical properties and functional compounds of oat grains during storage depends on the cultivars. The result showed that DY, which has the highest AVNs content, has more stable functional compounds and antioxidant activities during storage. These results can serve as essential data for post-harvest management and development of functional food materials for extending the use of oats.

Seasonal phytoplankton dynamics in oligotriphic offshore water of Dokdo, 2018 (2018년 독도 주변 빈영양 수괴에서 계절별 식물플랑크톤 동태)

  • Lee, Minji;Kim, Yun-Bae;Kang, Jung Hoon;Park, Chan Hong;Baek, Seung Ho
    • Korean Journal of Environmental Biology
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    • v.37 no.1
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    • pp.19-30
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    • 2019
  • To investigate the characteristics of seasonal environment and phytoplankton community structure in the coastal area of Dokdo, a survey of Dokdo around waters was conducted during the four seasons. Phytoplankton of 4 phylum 72 species in four seasons were collected in Dokdo around water. The seasonal mean abundance of phytoplankton were $3.32{\times}10^4cells\;L^{-1}$ in winter, $1.04{\times}10^4cells\;L^{-1}$ in spring, $0.28{\times}10^4cells\;L^{-1}$ in summer, and $4.86{\times}10^4cells\;L^{-1}$ in autumn in Dokdo around water. During winter, the diatoms Chaetoceros spp. had dominated. During spring, when the nutrients in the euphotic layer were depleted, the nano-flagellates and Cryptomonas appeared at surface layer. In summer, the abundance of phytoplankton was relatively low, which lead to occurrence of diatoms such as genus of Chaetoceros, Rhizosolenia, and Skeletonema. In autumn, Pseudo-nitzschia spp. was the most dominant species and tropical species such as Amphisolenia sp. and Ornithocercus magnificus were observed, implying that they may have introduced within warm water current such as Kurosiwo Current. Therefore, although natural phytoplankton communities in the vicinity water of Dokdo are mainly influenced by Tsushima Warm Current branched Kurosiwo Current, their population dynamics was affected on the spatio-temporal change of physicochemical factors by short-term wind events, namely "island effect". Long-term survey research is needed to facilitate food-web response in marine ecosystem associated with phytoplankton biomass and physicochemical factors including the warm water current in oligotrophic offshore water of Dokdo, which may have significant role for sustainable use of Dokdo.

Ecological Network on Benthic Diatom in Estuary Environment by Bayesian Belief Network Modelling (베이지안 모델을 이용한 하구수생태계 부착돌말류의 생태 네트워크)

  • Kim, Keonhee;Park, Chaehong;Kim, Seung-hee;Won, Doo-Hee;Lee, Kyung-Lak;Jeon, Jiyoung
    • Korean Journal of Ecology and Environment
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    • v.55 no.1
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    • pp.60-75
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    • 2022
  • The Bayesian algorithm model is a model algorithm that calculates probabilities based on input data and is mainly used for complex disasters, water quality management, the ecological structure between living things or living-non-living factors. In this study, we analyzed the main factors affected Korean Estuary Trophic Diatom Index (KETDI) change based on the Bayesian network analysis using the diatom community and physicochemical factors in the domestic estuarine aquatic ecosystem. For Bayesian analysis, estuarine diatom habitat data and estuarine aquatic diatom health (2008~2019) data were used. Data were classified into habitat, physical, chemical, and biological factors. Each data was input to the Bayesian network model (GeNIE model) and performed estuary aquatic network analysis along with the nationwide and each coast. From 2008 to 2019, a total of 625 taxa of diatoms were identified, consisting of 2 orders, 5 suborders, 18 families, 141 genera, 595 species, 29 varieties, and 1 species. Nitzschia inconspicua had the highest cumulative cell density, followed by Nitzschia palea, Pseudostaurosira elliptica and Achnanthidium minutissimum. As a result of analyzing the ecological network of diatom health assessment in the estuary ecosystem using the Bayesian network model, the biological factor was the most sensitive factor influencing the health assessment score was. In contrast, the habitat and physicochemical factors had relatively low sensitivity. The most sensitive taxa of diatoms to the assessment of estuarine aquatic health were Nitzschia inconspicua, N. fonticola, Achnanthes convergens, and Pseudostaurosira elliptica. In addition, the ratio of industrial area and cattle shed near the habitat was sensitively linked to the health assessment. The major taxa sensitive to diatom health evaluation differed according to coast. Bayesian network analysis was useful to identify major variables including diatom taxa affecting aquatic health even in complex ecological structures such as estuary ecosystems. In addition, it is possible to identify the restoration target accurately when restoring the consequently damaged estuary aquatic ecosystem.

Physicochemical Variation by Weathering Degree of Granite from the Mireuksaji Temple Stone Pagoda, Iksan, Korea (익산 미륵사지석탑 화강암의 풍화에 의한 물리화학적 특성변화)

  • Yang, Hee-Jae;Han, Min-Su;Kim, Sa-Dug;Lee, Chan-Hee
    • Journal of Conservation Science
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    • v.23
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    • pp.11-24
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    • 2008
  • A physical characteristics and chemical compositions change by weathering on the granite were examined for the conservation treatment of the Mireuksaji temple stone pagoda. The natural weathered granite was collected from the Mt. Mireuk, and divided into the classification standards based on weathering degrees and strength measured by rock-test hammer. The results from comparison of the strength measured by undestructive rock-test hammer and the strength values converted from ultrasonic velocity showed that each strength measurement value was proportionate. The water absorption of the sample was 1.68 to 0.20%. The F-type of fresh rock was not naturally saturated and the WW-type was naturally saturated but took quite a long time. The water absorption was increased gradually in order of SW-type, the MW-type and the HW-type according to weathering condition. The CW-type samples showed the highest water absorption among the weathered classification samples. Through dyeing test, it was found out that only the feldspar was dyed out of the F-type and the WW-type. The SW-type and the MW-type were distinguished by the fact that plagioclase being dyed. And dyed area was expanded to quartz crack in HW-type and CW-type. Physical change by weathering of the rock-forming minerals could be classified with 3 grades. Through the XRD analysis, albite among the rock-forming mineral showed remarkable decrease. SEM-EDX analysis of the component change in the rock-forming minerals such as biotite, plagioclase, and orthoclase, showed that in case of highly-weathered grade samples compared with fresh samples, contents of the $Al_2O_3$, $K_2O$, $Na_2O$ increase and CaO, MgO decrease in the biotite, the CaO, $K_2O$ increase and $Na_2O$ decrease in the plagioclase, the $Al_2O_3$ a little increase and $K_2O$, $Na_2O$ decrease in the orthoclase. The results of extracted cation analysis using the powder samples of each weathering grade, the CaO, $Na_2O$, $K_2O$ and MgO are highly chemical variations in rock forming minerals and positive variation show high in the weathering grade of the WW-type and CW-type. This research will be used as an importance data to establish a plan for conservation treatment of composed stone in the Mireuksaji temple stone pagoda.

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A change of soil properties and forest vegetation present in burned areas in Geyjoksan, Daejeon metropolitan city (대전광역시 계족산 산화지의 토양 변화와 식생 현황)

  • Lee, Hang-Goo;Park, Gwan-Soo;Lee, Sang-Jin;Kim, Kil-Nam;Park, Beom-Hwan;Ko, Young-Woong;Yoon, Jun-Young;Kim, Hyoun-Sook;Lee, Sang-Hyuk;Kang, Kil-Nam
    • Korean Journal of Agricultural Science
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    • v.38 no.1
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    • pp.25-30
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    • 2011
  • This study was conducted to investigate changes on burned areas after a forest fire in Geyjoksan which occurred in April 2000. Both soil physicochemical properties and vegetation present were analyzed in burned and unburned sites of pinus densiflora according to two slope aspects(south and north-facing slopes). The results of the analysis are as follows. The appearance species of vegetation were 21, 15 and 18 for burned site, burned site-1 and burned site-2 of pinus densiflora community respectively, indicating that the occurrence of forest fire and slope aspects affect vegetation appearance. The pH values at 0~10cm soil depth of unburned and burned sites of pinus densiflora community were 5.04 and 5.12 respectively with no significant difference between them. Mean organic matter, total nitrogen and available P also had no significant difference. This results indicate that the forest recover its former pH, total nitrogen, mean organic matter and available P over time after a forest fire. North-facing slope had relatively higher soil water content thus implying that its pH values of soil lower than south-facing slope. On the other hand, south-facing slope had high organic matter and available P content of soil as compared to north-facing slope. With south facing slope having high water contents, humus was accumulated due to slow organic matter decomposition. The pH values also decreased due to organic acids from humus. However, we observed that organic matter and P concentration in soil increased.

A Study on the Physicochemical and Sensory Characteristics of Cod Stock by Hot Water Extraction Time (열수추출 시간에 따른 대구육수 이화학적 및 관능특성에 관한 연구)

  • Kim, Dong-Seok;Shin, Kyung-Eun;Lee, Wook;Bae, Gum-Kwang
    • Culinary science and hospitality research
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    • v.20 no.2
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    • pp.89-99
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    • 2014
  • This study aims to make stock using cod bones with the hot water extraction method. Moisture content, chromaticity, pH, salinity, sugar content, mineral contents, quantitative analysis, and overall acceptance were studied to determine the standard formula. The results are as follows. The moisture content decreased (p < 0.001) and color value increased as heating time increased. The pH was highest in CS5 which was heated for 30 minutes and lowest in CS1. The salinity and sugar content significantly increased with more heating time (p < 0.001). In terms of mineral contents, sodium was highest in 138.87~154.17 mg, magnesium and iron showed proportion difference with increased heating time. The mineral analysis test result revealed that sodium, magnesium and iron showed proportional difference with increased heating time, while potassium and calcium did not change. The result of quantitative analysis test showed transparency, fishy smell, delicate flavor, savory flavor, salt taste and umami taste became stronger as high-pressure heating time increased. From these result, CS4 was evaluated to be the best in appearance, flavor, taste, aftertest and overall acceptance. Also, 60 minute high-pressure heating time is the most desirable to produce stock using cod bones as a main ingredient.