• 동아시아식생활학회지
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• 제11권2호
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• pp.131-139
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• 2001

The physicochemical and sensory characteristics of brown rice flakes by different processing conditions such as flaking Process and their heat treatments were investigated to establish the brown rice flake processing procedure. To successfully make the compressed rice grain type flakes, the most appropriate water steeping conditions were 5 hours at 60'C. The brown rice flakes by compressed flaking procedure and heat treatment with microwave toasting showed the best crispiness-texture that tested from textrometer or sensory evaluation, and there was no significant difference between the source of rice varieties. The water absorption index(WAI) of tested flakes were negatively correlated with the water soluble index( WSI) and positively correlated with bowl life. The flakes made by compressed flaking procedure and heat treatment with microwave toasting showed longer bowl life, which is the length of the time that the cereal can retain its crispness after being soaked in milk.

• 동아시아식생활학회지
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• 제2권2호
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• pp.277-282
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• 1992

This study was designedto investigate changes in phsicochemical properties of rice extrudate with added glycerin fatty acid ester extruded by single screw extruder. According to emulsifier content, expansion ratio and water solubility index were represented minimum in rice extrudate with added 2.0% and 2.5% glycerin fatty acid ester. Extrudate with added 1.5% emulsifier revealed lowest break strength and bulk density, so got a tender and light texture. Meanwhile water absorption index was showed maximum at 1.5% emulsifier content. As emulsifier content increased, lightness raised. By the microstructure obsorved with image analyzer, addition of emulsifier had decreased area and fractarea of air cells of cross section of extrudates. On the results of this research, quality of extrudate with added 1.5% glycerin fatty acid ester was considered very well than 100% rice extrudate, because of tender and light texture, highest water absorption indexand fine structure with higher lightness.

• 한국식품영양과학회지
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• 제42권3호
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• pp.427-433
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• 2013

본 연구는 옥수수 섬유질을 수분주입량의 변화에 따라 압출성형 옥수수 섬유질과 탈전분 압출성형 옥수수 섬유질의 물리화학적 특성 변화를 측정하였다. 원료의 수분주입량은 30, 40, 50%로 조절하였으며 스크루 회전속도와 사출구 온도는 각각 200 rpm, $140^{\circ}C$로 고정시켜 압출성형 하였다. 일반성분 함량은 원료에 비해 감소하였으며, 수분주입량이 30%일 때 옥수수 섬유질과 탈전분 옥수수 섬유질의 불용성 식이섬유 함량은 감소하고 수용성 식이섬유 함량은 증가하였다. 압출성형 옥수수 섬유질의 비기계적 에너지, 직경팽화율, 밀도, 파괴력, 탄성계수는 수분함량이 증가할수록 감소하였고, 비길이는 증가하였다. 압출성형 옥수수 섬유질의 수분흡착지수와 환원당은 수분주입량이 증가할수록 변화가 없었으며 수분용해지수는 감소하였다. 반면에 탈전분 옥수수 섬유질의 수분흡착지수는 감소하고 수분용해지수와 환원당은 증가하였다. 수분주입량 30%일 때 유용성분의 추출이 미량 증가하는 것으로 보아 압출성형공정의 적용하여 섬유질에 포함된 유용성분의 추출이 용이할 것으로 생각된다.

• Journal of Animal Science and Technology
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• 제57권12호
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• pp.44.1-44.9
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• 2015

Background: Heat shock proteins play an important role in protection from stress stimuli and metabolic insults in almost all organisms. Methods: In this study, computational tools were used to deeply analyse the physicochemical characteristics and, using homology modelling, reliably predict the tertiary structure of the blunt snout bream (Ma-) Hsp70 and Hsc70 proteins. Derived three-dimensional models were then used to predict the function of the proteins. Results: Previously published predictions regarding the protein length, molecular weight, theoretical isoelectric point and total number of positive and negative residues were corroborated. Among the new findings are: the extinction coefficient (33725/33350 and 35090/34840 - Ma-Hsp70/ Ma-Hsc70, respectively), instability index (33.68/35.56 - both stable), aliphatic index (83.44/80.23 - both very stable), half-life estimates (both relatively stable), grand average of hydropathicity (-0.431/-0.473 - both hydrophilic) and amino acid composition (alanine-lysine-glycine/glycine-lysine-aspartic acid were the most abundant, no disulphide bonds, the N-terminal of both proteins was methionine). Homology modelling was performed by SWISS-MODEL program and the proposed model was evaluated as highly reliable based on PROCHECK's Ramachandran plot, ERRAT, PROVE, Verify 3D, ProQ and ProSA analyses. Conclusions: The research revealed a high structural similarity to Hsp70 and Hsc70 proteins from several taxonomically distant animal species, corroborating a remarkably high level of evolutionary conservation among the members of this protein family. Functional annotation based on structural similarity provides a reliable additional indirect evidence for a high level of functional conservation of these two genes/proteins in blunt snout bream, but it is not sensitive enough to functionally distinguish the two isoforms.

• 한국물환경학회지
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• 제23권1호
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• pp.144-154
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• 2007

The acute and chronic toxicity of ambient and effluent water discharged to Lake Shihwa were investigated by using Vibrio fischeri, Daphnia magna and Oryzias latipes. Physicochemical characteristics including biochemical oxygen demand (BOD) and nine heavy metals in a total of 15 water samples were evaluated and were satisfied with relevant Korean Water Quality Standards (KWQS) except for Hg in one sample. Acute toxicity was observed in five samples collected from three sampling locations. When impacts on reproduction and growth after chronic exposure were evaluated with D. magna, all the samples showed significant chronic effects. Reproduction appeared relatively more sensitive endpoint. In 21 days chronic tests on O. latipes, survival, mean egg number per female per day, hatching success rate and time to hatch were affected by increasing sample concentration. The organ-level changes such as gonadosomatic index (GSI), and hepatosomatic index (HSI), and molecular biomarker of vitellogenin (Vtg) induction that evaluated with O. latipes increased as exposure concentrations increased. It is noteworthy that the samples that did not exceed the KWQS resulted in acute and chronic toxicities. The results suggested that numeric criteria based on physicochemical parameters may not be protective of aquatic ecosystem. Acute and chronic toxicity tests with organisms representing different trophic groups should be supplemented in order to provide adequate level of environmental protection.

• 생태와환경
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• 제50권1호
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• pp.169-185
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• 2017

Physicochemical properties of water quality were analyzed to understand the long-term variations in Lake Youngrang from 1998 to 2015. Nonparametric statistical methods were applied to deduct correlation among water quality parameters and water quality trend. In total observations(N=64), the Secchi depth (SD) transparency showed significant positive correlation with salinity (r=0.458) and highly significant negative correlation with chlorophyll-a (r= -0.649) for p<0.0001 in two-tailed test of Spearman's rank correlation. Significant negative correlations of SD were observed with chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN). These correlation patterns were very similar in rainy (N=25) and non-rainy (N=39) periods too. Chlorophyll-a (Chl-a) had significant correlation with COD. Sen's slope test was performed along with Mann-Kendall trend test (significance ${\alpha}=0.05$, two-tailed) to find water quality trend. Positive trends were observed for SD and salinity with Sen's slopes 0.012 and 0.385, respectively (p<0.0001). Negative significant trends were observed for total nitrogen (TN) and Chl-a with Sen's slopes -0.02 (p<0.0001) and -0.346 (p=0.0010), respectively. Temperature, COD and phosphorus components had no trends. Carlson's trophic state index (TSI) for SD, TP and Chl-a were obtained in the ranges of 46~80, 37~82 and 39~82, respectively. Trophic index values suggest that Lake Youngrang was mesoeutrophic to eutrophic and there could be possibility of anoxia during the summer and dominance of blue-green algae. Excess nutrient inputs from external and internal sources were the causes of eutrophication in this lake. The findings of this study would be helpful to recognize water quality variables to manage the water body.

• 한국식품과학회지
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• 제20권4호
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• pp.470-475
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• 1988

압출성형시 원료의 수분함량이 낮을수록 팽화율이 커졌으며, 수분함량이 증가되면 호화도, 가밀도 및 전단강도가 증가하였다. 또한 아밀로그램이나 리올로지 특성에 있어서도 수분함량이 증가할수록 점도가 증가하였으며 의가소성 유동특성을 보여주었다. 수분함량이 증가하면 WAI값은 증가하나 WSI값은 감소하였다. 수분함량이 낮으면 황색도가 증가하였다. 미세구조에 있어서도 수분 함량이 높을수록 전분질의 호화특성을 관찰할 수 있었다. 품종간의 대체적인 물성특성은 삼강보다는 추청품종이 우수하였다.

• 한국식생활문화학회지
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• 제37권1호
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• pp.90-98
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• 2022

This study investigated the physicochemical and antioxidant properties of sponge cakes made using different amounts (2 and 4%) of barley sprout powder (BSP) and green tea powder (GTP), respectively. The results showed that the baking loss rate of GS2 (2% green tea) and GS4 (4% green tea) was 12.39% and 11.96%, respectively in the green tea addition group, which was higher than that of the barley sprout group, but significantly lower than that of the control group at 13.34% (p<0.05). The specific volumes of the sponge cake containing barley sprout and green tea 2% and 4% were between 2.84-2.95 mL/g, which was significantly higher compared to the control group at 2.69 mL/g (p<0.05). The sugar content was significantly higher in the control group and the barley sprout addition group at 2.30°Brix (p<0.05). As for the volume index, the control group with the lowest value at 13.43 showed a significant difference compared to the addition groups. The volume index significantly decreased as the addition amount increased, measuring 14.07 in BS4 (4% BSP) compared to 14.87 of BS2 (2% BSP) in the barley sprout group (p<0.05). In cross-sectional photography, the color became darker than that of the control group as the quantum of additives increased. In terms of the DPPH and ABTS radical scavenging activity, the total phenol content, and total flavonoid content, the groups with the addition of barley sprout and green tea showed higher antioxidant activity than the control group (p<0.05).

• 지질공학
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• 제31권4호
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• pp.731-739
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• 2021

본 연구는 토양 보전을 위한 표토 특성 분석 및 심토의 표토촉진화가 목적으로써 지질별 표토와 심토의 물리화학적 특성을 비교하고 정량적 차이를 분석하였다. 토양 시료는 암종별로 총 102개 지역에서 204개 시료를 채취하였으며 입도분석, 함수율, 단위중량, X-선 형광분석, X-선 회절분석에 대한 실험을 수행하고 표토와 심토에 대해 분석하였다. 분석결과 표토와 심토의 물리적 특성 차이가 확인되었으며 표토의 풍화변질지수가 심토보다 높게 나타났다. 이는 표토가 심토보다 풍화에 직접적인 영향을 더 많이 받기 때문에 점토광물의 함량이 높게 나타나는 것으로 판단되며 특히 버미큘라이트의 경우 풍화에서 발생하는 최종산물이므로 표토에서 특히 많이 나타난다.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1487-1494
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• 2009

The effects of drying temperature (55, 60, and $65^{\circ}C$) and addition levels of maltodextrin (MD) (10, 20, and 30%) on the physicochemical properties and nutritional quality of purple sweet potato flour were investigated. MD-added flours had higher $L^*$ values, water soluble index, total phenolic, and anthocyanin contents than untreated flour. However, $a^*$, $b^*$ values, water absorption index, and swelling capacity were dependent on the drying temperature and MD concentration. On the other hand, untreated flour had a higher ascorbic acid content compared to the MD-treated flour. Ascorbic acid contents decreased, whereas anthocyanin content was not significantly different, with increasing drying temperatures. MD was positively correlated with phenolic content, anthocyanin, hue angle, and water soluble index. However, there was no correlation between quality parameters and glass transition temperature. The best quality product was obtained when samples were pretreated with MD before drying, regardless of drying temperature.