• Journal of Biosystems Engineering
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• 제23권5호
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• pp.473-480
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• 1998

This study was performed to analyze the variation of various physicochemical factors related to the freshness of apple and tomato during post-harvest period. The total soluble solids content, uronic acid content, cell surface roughness. density, rupture deformation and rupture force were measured for 39 days at 7-day intervals for apple and for 11 days at 2-day intervals for tomato. respectively. The cell surface roughness of apple increased with the elapsed time, while the rupture force decreased. In case of tomato, uronic acid content, density and rupture deformation increased with the elapsed time whereas the rupture force decreased. Both apple and tomato exhibited the significant correlations among those physicochemical factors.

• 한국식품영양과학회지
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• 제30권2호
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• pp.283-287
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• 2001

Persimmon vinegar was clarified with 400mg/L chitosans of two different molecular weights (MW 150 and 37 kDa), and its quality changes were investigated during storage at room temperature for 6 months. No significant changes in pH, acidity, and tannin content were observed. However, turbidity and browning slightly increased while protein content slightly decreased. Soluble solids content slightly decreased when treated with high MW chitosan. Color L* value decreased while a* and b* values increased with storage periods. The major organic acid in the persimmon vinegar after 6 months storage was acetic acid with minor lactic, malic, tartaric, galacturonic, and succinic acids. Overall, the quality of persimmon vinegar clarified by chitosan treatment, irrespective of molecular weight, was more stable without noticeable changes during storage than that of control group without chitosan treatment.

• 한국식품영양과학회지
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• 제27권4호
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• pp.596-602
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• 1998

Two kinds of sweet potato puree were prepared with Benihayato cultivar of yellow sweet potato with or without $\alpha$-amylase enzyme treatment. Chemical and rheological properties of enzyme-treated puree were different from those of control puree. Reducing sugar content and iodine value increased by $\alpha$-amylase enzyme treatment, while alcohol insoluble solids and viscosity decreased by enzyme treatment. However, the changes of carotenoid content were not significantly different. Hunter-b-values(yellowness) were 27.19 and 23.54 for no enzyme-treated puree(NTP) and enzyme-treated puree(ETP), respectively. Hunter-a values(redness) were 2.24 and 6.05 for NTP abd ETP, respectively. Content of total carotenoid of canned puree heated at 13$0^{\circ}C$ for 30 min decreased by 59 percents.

• 한국식품영양과학회지
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• 제27권5호
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• pp.827-832
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• 1998

Soybeans(Hwangkeum Kong) were stored at 5$^{\circ}C$, $25^{\circ}C$ and 35$^{\circ}C$ for 8 months to investigate the changes of the physicochemical properties. Less physicochemical changes were detected in the soybeans stored at 5$^{\circ}C$ than those stored at $25^{\circ}C$ and 35$^{\circ}C$. High temperature and long term storage caused a decrease in the nitrogen solubility index, whereas increases in acid value and organic acid content were detected. As the storage period was extended at high temperatues, the content of unsaturated fatty acids decreased, but the content of saturated fatty acids increased. Decoloration of soybeans was clearly recognized under high temperatures. The water soluble compoents such as total solids, nitrogen and reducing sugar during water-soaking at 2$0^{\circ}C$ for 16hrs were appreciably eluted from the soybeans stored for 8 months at high temperatures. The pH of the water extract slightly shifted to the acidic range.

• 한국환경농학회지
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• 제33권1호
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• pp.57-62
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• 2014

BACKGROUND: Defoliation in grapevine cultivation is practically used to improve light environment within the canopy and thereby fruit quality. Effects of defoliation in five-year-old 'Pione' grapevine during cultivation with heating were investigated to find out optimum ratio of leaf area to fruit cluster weight (L/F). METHODS AND RESULTS: The grapevines were defoliated with berry-thinning 20 days after full bloom to provide various levels of L/F. At harvest, total leaf area values of fruit bearing branches were between 0.23 and $0.60m^2$. With increasing L/F, soluble solids and anthocyanin contents curvilinearly increased ($R^2=0.76^{**}$). At L/F over $0.6m^2/kg$, soluble solids content (SSC) leveled off. With increasing L/F, titratable acidity (TA) linearly decreased ($R^2=0.87^{**}$), but the ratio of SSC to TA linearly increased ($R^2=0.86^{**}$). Anthocyanin content was significantly correlated with SSC and the ratio of SSC to TA ($R^2=0.80^{**}$ and $0.82^{**}$, respectively). When total leaf area per fruit bearing branch was maintained $0.40m^2$, soluble solids and anthocyanin contents linearly decreased ($R^2=0.79^{**}$ and $0.85^{**}$, respectively), but TA linearly increased with increasing fruit cluster weight ($R^2=0.70^{**}$). Fruit was low in quality when the L/F was below $0.6m^2/kg$. CONCLUSION: L/F is recommended to be maintained at least $0.6m^2/kg$ in 'Pione' grapevine during cultivation with heating to produce higher-quality fruits.

• 한국식품과학회지
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• 제27권3호
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• pp.358-364
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• 1995

건조산채의 안전저장 수분함량을 결정하기 위하여 네 가지 채소 즉, 호박고지, 고구마줄기, 토란대, 및 도라지의 건조특성과 등온흡습특성을 조사하였다. 이들 채소의 건조곡선은 초기의 평형조절기간과 항률건조기 및 감률건조기간의 3단계로 뚜렷하게 구분이 되었으며, 감출건조기는 종류에 따라 다시 $2{\sim}3$단계로 구분되었다. 감률건조곡선은 섬유질상 식품의 건조 특징인 위로 볼록한 형태를 보였으며, 임계수분함량은 호박고지가 $8.29{\sim}9.75$, 고구마줄기가 $10.40{\sim}15.08$ 토란대가 $9.51{\sim}14.52$, 도라지가 $3.29{\sim}3.56g\;H_2O/g$ dry solids였다. 감률건조기간 중의 건조속도에 대한 활성화에너지값은 호박고지가 2.30, 고구마줄기가 2.11, 토란대가 4.97, 도라지가 2.80 kcal/mol이었다. 각 채소의 단분자층 수분함량값은 건조시의 임계수분함량값과 유사하였는데, 호박고지가 $10.05{\sim}13.59$, 고구마줄기가 $9.49{\sim}12.69$, 토란대가 $9.50{\sim}16.48$, 도라지가 $5.01{\sim}5.44g\;H_2O/g$ dry solids였다. 결과적으로 이들 채소를 안전하게 저장하기 위해서는 수분함량을 단분자층 수분함량 이하로 또는 임계수분함량 이하로 건조시킬 필요가 있음을 알 수 있다.

• 원예과학기술지
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• 제28권3호
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• pp.387-393
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• 2010

복숭아 과실 부위별 유리당 축적와 효소와의 관계를 살펴보고자 2006년 8월에서 9월까지 '장호원황도' 복숭아의 과경부, 과정부, 과피부, 핵주위의 유리당 함량과 당 관련 효소활성 변화를 살펴보았다. 당도는 만개 후 150일까지 증가하는 경향을 나타냈고 과정부에서 가장 높은 당도를 보였으며, 모든 부위에서 총 유리당 함량은 당도 변화와 매우 유사하게 나타났다. 비교적 전분의 함량이 높았던 만개 후 120일에 과정부에서 높은 전분 함량을 보였으나 만개 후 150일에는 부위별로 함량 차이가 작게 나타났다. 부위별 유리당 조성의 변화는 시기에 따라서 차이를 보였으며 자당 함량은 만개 후 150일까지 점차 증가하였으나 솔비톨은 만개 후 130일 이후에 점차 감소하였다. 만개 후 150일까지 모든 부위에서 자당은 증가하고 반대로 포도당, 과당, 솔비톨은 감소하는 경향을 보였다. 또한, 과실 발육 동안 자당 함량의 증가는 sucrose phosphate synthase(SPS) 활성보다는 sucrose synthase(SS)활성에 의하여 더 많은 영향을 받는 것으로 나타났다. SS효소활성은 만개 후 120일에는 낮게 나타났으나 acid invertase(AI) 활성은 높았으며, 만개 후 150일에는 반대의 경향을 나타냈다. 따라서 유리당을 합성하거나 분해하는 효소의 활성에 따라서 복숭아 과실 생육시기별 축적되는 유리당 함량이 영향을 받았으나, 과실의 각 부위에 따라서 모든 유리당 함량을 관련 효소활성으로만 설명하기는 어려웠다.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 2007년도 춘계 학술대회 및 정기총회
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• pp.182-184
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• 2007

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 추계학술발표회 논문집
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• pp.1-8
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• 2011

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제1권2호
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• pp.125-136
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• 1997

Digestion of a municipal wastewater sludge by the anaerobic sequencing batch reactor(ASBR) was investigated to evaluate the performance of the ASBR process at a critical condition of high-solids-content feed. The reactors were operated at an HRT of 10 days with an equivalent loading rate of 0.8-1.5 gVS/L/d at $35^{\circ}C.$ The main conclusions drawn from this study were as follows: 1. Digestion of a municipal wastewater sludge was possible using the ASBR in spite of high concentration of settleable solids in the sludge. The ASBRS with 3- and 4-day cycle period showed almost identical high digestion performances. 2. No adverse effect on digestion stability was observed in the ASBRS in spite of withdrawal and replenishment of $30\%\;or\;40\%$ of liquid contents. A conventional anaerobic digester could be easily converted to the ASBR without any stability problem. 3. Flotation thickening occurred in thicken step of the ASBRS throughout steady state, and floating bed volume at the end of thicken period occupied about $70\%$ of the working volume of the reactor. Efficiency of flotation thickening in the ASBRS could be comparable to that of additional gravity thickening of a completely mixed digester. 4. Solids were accumulated rapidly in the ASBR during start-up period. Solids concentrations in the ASBRS were 2.6 times higher than that in the completely mixed control reactor at steady state. Dehydrogenase activity had a strong correlation with the solids concentration. Dehydrogenase activity of the digested sludge in the ASBR was 2.9 times higher than that of the sludge in the control reactor, and about 25 times higher than that of the subnatant in the ASBR. 5. Remarkable increase in equivalent gas production of $52\%$ was observed at the ASBRS compared with the control reactor in spite of similar Quality of clarified effluent from the ASBRS and control reactor. The increase in gas production from the ASBRS was believed to be combined results of accumulation of microorganisms, higher driving force applied, and additional long-term degradation of organics continuously accumulated.