• 한국환경과학회지
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• 제22권7호
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• pp.905-913
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• 2013

We compared the applicability and economical efficiency of peroxone process with those of ozone process in the existing water treatment plant on downstream of Nakdong River. After comparing the peroxone process for removing geosmin with the ozone process in lab scale test, peroxone process showed much higher removal efficiency than the ozone process at the same ozone dosage. Proper range of $H_2O_2/O_3$ ratio were 0.5~1.0 and the half-life of geosmin was about 5.5~6.8 min when the $H_2O_2/O_3$ ratio was set to 0.5 during 1~2 mg/L of ozone dosage. Peroxone process could reduce the ozone dosage about 50 to maximum 30% for the same geosmin removal efficiency compared to the ozone process in the pilot scale test. In case of 1,4-dioxane treatment, peroxone process could have 3~4 times higher efficiency than ozone process at the same ozone dosage. The results of estimating the economical efficiency of ozone and peroxone process for treating geosmin and 1,4-dioxane by using pilot scale test, in case of the removal target was set to 85% for these two materials, the cost of peroxane process could be reduced about 1.5 times compared to ozone process, and in the same production cost peroxone process could have 2~3 times higher removal efficiency than ozone process. The removal efficiency by peroxone process showed a large difference depending on the physicochemical characteristics of target materials and raw water, therefore detailed examination should be carried out before appling peroxone process.

• 한국약용작물학회지
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• 제27권5호
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• pp.330-338
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• 2019

Background: This study was conducted to compare the physicochemical properties of 12 different cultivars of Rehmannia glutinosa, a plant used in Korean traditional herbal medicine. Method and Results: We investigated the following 12 cultivars of R. glutinosa; Jihwang1, Goryeo, Daegyung, Gogang, Togang, Dagang, Wongang, Yeongang, Hwanggang, Dahwang, Segang and Chunggang. We measured water content, chromaticity, hardness, active components levels, and antioxidant activity. Our results showed that Togang has the lowest water content and the highest yield. The catalpol content was the highest in Togang (40.50 mg/g) and the lowest in Chunggang (22.17 mg/g). The aucubin content was the highest in Hwanggang (0.28 mg/g). Chunggang had the lowest aucubin content, but the highest level of verbascoside. Total flavonoid and total polyphenol were the highest in Daegyung and Chunggang, respectively. There was a strong correlation between the total flavonoid and total polyphenol (r = 0.89) content. Conclusions: There were significant differences in physicochemical properties among 12 cultivars. These properties will affect suitability for processing and final product quality. We therefore suggest the selection of appropriate cultivars for different uses.

• 한국환경복원기술학회지
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• 제4권3호
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• pp.30-37
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• 2001

This study was conducted to investigate physicochemical property changes from July 1998 to August 2001 in Mt. Bukhansan National Park. Four water sampling points were selected to measure the quality of stream water in the northeastern part of the Mt. Bukhansan National Park. The results were summarized as follows; In spring, the average pH of stream water was below the first class of the river water quality standard, while it was normal level in summer. The average electrical conductivity was about 2.3~3.3 times higher in downstream water than in upstream water during spring and summer. The contents of anions($Cl^-$, $NO{_3}^-$, $SO{_4}^{2-}$) were about 1.1~7.4 and 0.4~11.4 times higher in downstream than in upstream water, respectively. These results indicate that water quality was poorer in downstream than in upstream water. We suggest that stream water in the Mt. Bukhansan National Park should be protected from impacts of snow melting mineral particles in spring season and human impacts like wastewater of point source in summer season.

• 한국축산식품학회지
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• 제27권1호
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• pp.16-21
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• 2007

20개의 돼지 등심육을 각각 1주일씩 건염과 습염을 한 다음 2주일간 숙성하여 생햄을 제조한 후 진공포장하여 10과 $25^{\circ}C$에서 90일간 저장하면서 물리화학적 및 관능학적 품질을 조사하였다. 생햄의 10과 $25^{\circ}C$에서 저장 중 식염 함량은 모두 약 5.1% 수준을 유지하였다. 그리고 수분, 조단백질, 조지방 및 회분 등 일반성분의 함량에 있어서 저장 온도와 기간에 따른 시료 간 차이는 나타나지 않았다. TBA와 VBN값은 저장기간 중 계속 증가함으로써 지방과 단백질의 분해가 진공포장한 상태에서도 지속적으로 이루어졌다는 것을 알 수 있었다. 본 연구에서 조사된 pH, 수분활성도, 물성, TBA와 VBN값, 그리고 관능학적 품질 변화는 $10^{\circ}C$에서보다 $25^{\circ}C$에 저장된 시료에서 더 크게 일어나는 경향을 보였다. 저장 기간이 연장될수록 경도, 부서짐성, 탄성, 응집성, 검성 및 점착성 등과 같은 조직감에서의 유의적인 품질 저하가 관찰되었다(p<0.05). 색은 10과 $25^{\circ}C$ 시료 간, 그리고 저장구간별 큰 차이가 없었다. 관능검사 결과에 따른 생햄의 저장수명은 10과 $25^{\circ}C$에서 각각 75와 45일로 추정되었다.

• Journal of Animal Science and Technology
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• 제57권7호
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• pp.24.1-24.5
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• 2015

The objective of this study was to investigate the physicochemical and microbial quality of loin (m. longissimus dorsi) and top round (m. Semimembranosus) in Holstein veal produced from two slaughter age groups (5 and 8 months of age). A total of 20 Holstein calves were randomly selected from a local cattle farm. The slaughtered cold carcasses were vacuum-packaged. The samples were analyzed for proximate composition and physicochemical analyses and stored for 1, 7, 10, 20 and 30 days for microbiological analyses. Fat and protein contents of loin for the 8 month group were higher than those for the 5 month groups (p < 0.05). For both loin and top round muscles, the pH, cooking loss and the shear force values for the 5 month group was higher than those for the 8 month group (p < 0.05). On the other hands, the water-holding capacity (WHC) for the 8 month group was higher than those for the 5 month group (p < 0.05). In terms of meat color, CIE $L^*$ (lightness) for both muscle were higher in the 5 month group than in the 8 month groups. On the other hands, $a^*$ (redness) were higher in the 8 month group than in the 5 month groups (p < 0.05). Total aerobic counts in all samples remained up to 30 days at values less than 7 log CFU/g. However, there was no significant difference for both muscles between the two age groups. The results indicate that Holstein muscles from the 8 month group had desirable quality properties than those from the 5 month group.

• 한국축산식품학회지
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• 제40권3호
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• pp.474-483
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• 2020

This study was conducted to investigate the physicochemical properties of hams obtained from loin and tenderloin cuts from standard pigs and sows. pH levels of loin ham before cooking, standard pig was significantly lower than that of sow (p<0.001). The lightness (L*) and yellowness (b*) values of loin ham from standard pigs were significantly higher than those of sow loin ham (p<0.001). The water-holding capacity (WHC) and curing yield of sow loin was significantly higher than standard loin (p<0.01). The cooking loss of standard pig loin ham was significantly higher than that of sow loin ham (p<0.01). Differences in sensory quality evaluation, except in the case of tenderness, for the two loin hams were not significant. pH levels of tenderloin ham before cooking, standard pig was significantly lower than that of sow (p<0.001). Redness (a*) values of before and after cooking tenderloin ham of sow was higher than that of standard pig (p<0.001). L* values of tenderloin ham of standard pig was significantly higher than that of sow (p<0.001). WHC and curing yield of tenderloin ham from sow was significantly higher than that from a standard pig (p<0.001, p<0.05). The cooking losses of sow and standard pig tenderloin ham were 26.06% and 28.31%, respectively (p<0.001). Differences in sensory quality evaluation, except in the case of tenderness and color, for the two tenderloin hams were not significant. In conclusion, sow pigs loin and tenderloin is suitable for ham product more than standard pigs loin and tenderloin.

• 한국축산식품학회지
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• 제34권4호
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• pp.482-495
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• 2014

The objectives of this study were to know the effect of repeated freeze-thaw cycles of beef on the sensory, physicochemical quality and microbiological assessment. The effects of three successive freeze-thaw cycles on beef forelimb were investigated comparing with unfrozen fresh beef for 75 d by keeping at $-20{\pm}1^{\circ}C$. The freeze-thaw cycles were subjected to three thawing methods and carried out to know the best one. As the number of freeze-thaw cycles increased color and odor declined significantly before cook within the cycles and tenderness, overall acceptability also declined among the cycles after cook by thawing methods. The thawing loss increased and dripping loss decreased significantly (p<0.05). Water holding capacity (WHC) increased (p<0.05) until two cycles and then decreased. Cooking loss increased in cycle 1 and 3, but decreased in cycle 2. pH decreased significantly (p<0.05) among the cycles. Moreover, drip loss, cooking loss and WHC were affected (p<0.05) by thawing methods within the cycles. 2-Thiobarbituric acid (TBARS) value increased (p<0.05) gradually within the cycles and among the cycles by thawing methods. Total viable bacteria, total coliform and total yeast-mould count decreased significantly (p<0.05) within and among the cycles in comparison to the initial count in repeated freeze-thaw cycles. As a result, repeated freeze-thaw cycles affected the sensory, physicochemical and microbiological quality of beef, causing the deterioration of beef quality, but improved the microbiological quality. Although repeated freeze-thaw cycles did not affect much on beef quality and safety but it may be concluded that repeated freeze and thaw should be minimized in terms of beef color for commercial value and WHC and tenderness/juiciness for eating quality.

• 한국식품영양학회지
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• 제31권1호
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• pp.149-159
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• 2018

The change of quality and physicochemical characteristics of mung-bean flours after germination and roasting treatment were evaluated. The moisture content of the roasted mung-bean flours decreased significantly according to the roasting temperatures and times, and the crude ash, protein and fat contents increased. The lightness of the roasted mung-bean flours significantly decreased, and the redness and yellowness increased. The water binding capacity of the roasted mung-bean flours without and with germination were 151.71 and 192.77% at $240^{\circ}C$ for 20 min, respectively. The water solubility index and swelling power decreased with an increase in roasting temperatures and times. The phenolic compounds and radical scavenging activity of the roasted mung-bean flours increased with an increase in the roasting temperatures and times. The total polyphenol contents of the roasted mung-bean flours without and with germination were 4.81~7.71 and 4.22~5.63 mg GAE/g, and the total flavonoid contents were 2.46~3.05 and 2.45~2.87 mg CE/g, respectively. The DPPH radical scavenging activity of the roasted mung-bean flours, without and with germination, were 106.83~376.08 and 174.41~346.70 mg TE/100 g, and the ABTS radical scavenging activity was 251.67~534.31 and 274.39~430.02 mg TE/100 g, respectively. As a result, it is necessary to set quality standards for each application considering the quality and antioxidant properties of the roasted mung-bean flours.

• 환경생물
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• 제40권2호
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• pp.172-186
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• 2022

본 연구에서는 2019년~2020년 2년 동안 양재천과 여의천을 대상으로, 이화학적 수질항목(17항목)과 함께 저서동물지수와 우점도지수 및 다양도지수 등의 군집지수와 연계하여 두 하천의 생태건강성을 평가하였다. 또한 저서동물 생물지수의 현장 적용성 평가 및 및 두 하천 간 저서동물 분포특성을 통계적으로 비교하기 위하여 각각 상관분석(correlation analysis)과 비계량적 다차원척도법(nMDS, nonmetric multidimensional scaling)을 활용하였고, 이를 통해 도심하천의 하천생태계 현황을 진단하는 기초자료를 제공하고자 하였다. 조사 결과, 양재천(주암교, 보도교, 대치교)은 총 39종, 3,787개체가 출현하였으며, 양재천 수질(BOD, TOC, TP 기준)은 II등급(약간 좋음) 이상이며, 저서동물을 이용한 BMI는 모든 지점에서 C등급(보통)으로 나타났다. 여의천(상류, 새원교, 여의교)은 총 51종, 4,199개체가 출현하였으며, 여의천 수질(BOD, TOC, TP 기준)은 양재천과 유사하게 II등급(약간 좋음) 이상으로, BMI는 상류 및 새원교 모두 B등급(좋음), 여의교는 C등급(보통)으로 나타나는 등 전반적으로 양재천과 여의천 모두 수질 및 하천 환경상태는 유사한 것으로 확인되었다. 특히 저서동물 분포상태를 비계량적 다차원척도법으로 분석한 결과에서도 두 하천 간의 유의미한 차이를 볼 수 없었으며(p=0.1491), 이때 수온과 DO 환경인자가 두 하천에서의 저서동물 분포와 상관성이 높은 것으로 나타났다. 저서동물 생물지수와 주요 수질항목과의 상관분석 결과, 풍부도지수와 저서동물지수가 현장 수질평가에 활용될 수 있을 것으로 확인되었다.

• 한국식품과학회지
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• 제26권4호
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• pp.453-458
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• 1994

새로운 품질지표를 개발하기 위하여 고오지 고추장을 표준화된 산업적 공정으로 제조한 후 가속조건인 $37^{\circ}C$에서 105일간 저장하면서 이화학적 특성을 측정하고 통계분석한 결과 고오지 고추장의 제조후 저장기간과 유의적인 상관관계를 보이는 특성은 43종 중 12종으로서 여기에는 맛과 색에 대한 기호도 이외에 색도(L, a, b, E), HMF, capsanthin, 포르몰태질소, threonine, 수분 및 수분활성도가 포함되었다. 이 중 7종의 특성은 색과 관련된 지표로서, 특히 색도는 고추장의 색에 대한 기호도와도 유의적 상관성이 높았으므로 기존 국가규격에 추가하는 것이 바람직하다고 사료된다 한편, 수거된 9개사 27종의 시판 공장산 고추장에 있어서 L값은 $28.21{\pm}1.48$, a값은 $9.37{\pm}2.54$, b값은 $4.35{\pm}2.9$, E값은 $30.09{\pm}2.42$로 나타났다.