• 신재생에너지
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• 제9권2호
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• pp.5-14
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• 2013

The efficiency of microwave-assisted acid hydrolysis of seaweeds for the production of ethanol was investigated and its effect on hydrolysis into reducing sugar and fermentation into ethanol evaluated as compared with those by conventional heating. A brown seaweed, Laminaria japonica (10-100g/L) was hydrolysed under dilute acidic condition (0.5N $H_2SO_4$, $100^{\circ}C$) with two sorts of heating: microwave irradiation for ${\leq}10min$ and conventional heating for 10-60min. Microwave-assisted hydrolysis was shown to be more efficient. A similar range of reducing sugar and ethanol yields as with the conventional autoclave heating procedure(${\geq}30min$) was observed, but it was obvious that production of ethanol from microwave-assisted hydrolysis had a 3 times faster reaction rate leading to very short production times, lower energy consumption/loss than from the conventional heating mode, and higher biomass loading without significant reducing ethanol yield, thus microwave-assisted acid hydrolysis is a potential alternative method for more effective hydrolysis of Laminaria japonica.

• 한국식품과학회지
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• 제45권1호
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• pp.34-39
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• 2013

본 연구는 전분 및 단백질 함량이 높은 녹두를 산으로 가수분해 시킨 다음 열처리를 통한 항산화 활성의 변화를 조사하였다. 유리당 및 유리아미노산 최대생성 가수분해조건은 6 N 염산으로 2시간 처리조건으로 선정하였으며, $130^{\circ}C$에서 2시간 열처리 한 다음 갈변도, 5'-HMF함량, 환원당, 항산화 성분 및 활성을 검토하였다. 갈변도는 가수분해 시키지 않은 열처리에서는 0.17이었지만 가수분해 후 열처리에서 2.31로 최대 값을 나타내었으며, 5'-HMF 함량도 산가수분해 시키지 않은 열처리에서는 검출되지 않았지만 가수분해 후 열처리에서 81.61 mg/g로 증가하였다. 환원당은 열처리 전 가수분해만 하였을 경우 190.48 mg/g이었지만 열처리 후 137.34 mg/g으로 감소하였다. 총 폴리페놀 함량은 가수분해 시키지 않은 열처리에서는 8.79 mg/g이었지만 열처리 후에는 55.95 mg/g으로 증가하였다. ABTS 라디칼소거능은 가수분해 시키지 않은 열처리에서는 1.75 mg AA eq/g이었지만 열처리 후에는 22.18 mg AA eq/g으로 증가하였으며, DPPH 라디칼소거능은 0에서 3.644 mg Trolox eq/g으로 증가하였다.

• 한국식품영양과학회지
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• 제35권10호
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• pp.1420-1426
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• 2006

여러 유도체 형태로 존재하는 대두 isoflavone을 산 가수 분해 방법 및 시간을 달리하면서 isoflavone 배당체의 aglycone으로의 전환율 및 aglycone의 분해여부를 실험하였다. 산 가수분해시 가열처리 조건을 $105^{\circ}C$ 항온기, $95^{\circ}C$ 수욕조, $120^{\circ}C$ heating block 및 hot plate로 달리한 결과 환류냉각장치를 이용하고 heating block에서 가수분해시키는 방법이 가장 적절한 가수분해 방법인 것으로 나타났다. 가수분해 시간 동안 aglycone의 안정성을 검토한 결과 적정 가수분해 시간인 60분 동안에는 genistein, daidzein 및 glycitein 모두 큰 함량변화가 없었다. 가수분해하는 시료의 양과 산의 비율은 시료 $10\sim30mg$당 1 N HCl 용액 1 mL의 비율이 적정하였다. 이상의 결과로부터 정량법은 0.5 g의 대두 시료에 1 N HCl용액 15 mL를 첨가하고 $120^{\circ}C$의 heating block에서 60분간 가수분해시킨 후 methanol로 50 mL로 정용하고 HPLC로 분석하도록 확립하였다. 이에 따라 대두 가공부산물의 iosflavone을 분석한 결과 착유 및 착유 후 hexane 제거를 위한 열처리 공정에서 isoflavone의 손실은 적은 것으로 나타났다.

• 상하수도학회지
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• 제38권2호
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• pp.109-117
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• 2024

In this study, various pre-treatment methods were evaluated for microalgae separation. These methods aimed to facilitate safe, rapid, and cost-effective online imaging for real-time observation and cell counting. As pre-treatment techniques, heating, chemical hydrolysis, heating combined with chemical hydrolysis, and sonication were employed. The effectiveness of these methods was evaluated in the context of online imaging quality through experimentation on cultivated microalgae (Chlorella vulgaris and Scenedesmus quadricauda). The chemical treatment method was found to be inappropriate for improving image acquisition. The heating pre-treatment method exhibited a drawback of prolonged cell dispersion time. Additionally, the heating combined with chemical hydrolysis method was confirmed to have the lowest dispersion effect for Chlorella vulgaris. Conversely, ultrasonication emerged as a promising technique for microalgae separation in terms of repeatability and reproducibility. This study suggests the potential for selecting optimal pre-treatment methods to effectively operate real-time online monitoring devices, paving the way for future research and applications in microalgae cultivation and imaging.

• Preventive Nutrition and Food Science
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• 제21권4호
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• pp.338-347
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• 2016

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G', G") of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities.

• 유기물자원화
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• 제23권3호
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• pp.51-59
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• 2015

가축분뇨 슬러지는 유기물의 농도가 높고 일부 중금속이 높은 농도로 혼합되어 있어 해양에 배출될 경우 환경에 부정적인 영향을 끼칠 수 있다. 본 연구에서는 가축분뇨 슬러지 처리에 열가수분해 기술을 적용하여 연료화 가능성을 판단하고 최적 운전조건을 도출하고자 하였다. 밀폐형 고압반응기를 사용하여 가축분뇨 슬러지를 $170{\sim}210^{\circ}C$까지 온도변화를 주면서 열가수분해 하였고, 반응 후 생성된 액상생성물과 탈수케이크의 분석을 실시하였다. 반응온도 $190^{\circ}C$로 운전하는 것이 가장 효과적인 것으로 나타났으며, 반응온도 $190^{\circ}C$일 때 고체생성물의 고위발열량은 5,050 kcal/kg, 저위발열량은 4,740 kcal/kg으로 연료로서 충분히 가치가 있는 것으로 판단되었다.

• 대한화학회지
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• 제4권1호
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• pp.85-87
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• 1957

We have studied on the effect of hydrochloric acid on the hydrolysis of dried cuttlefish, sardine, shrimp, sea mussel and undaria taking various concentration of acid, heating at various periods at constant temperatures and under atmospheric pressure following results were obtained. 1. The addition of HCl increases hydrolysis ratio of marine products rapidly, having maximum point of its ratio at 30% of dried cuttlefish and shrimp, at 25% of sea mussel and undaria, at 15% of sardine. 2. Hydrolysis ratios of cuttlefish and shirmp, sea mussel and undaria, and sardine reach maximum values at 30% of HCl, 25% of HCl and 15% of HCl, respectively.

• 한국식품과학회지
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• 제34권5호
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• pp.916-918
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• 2002

산가수분해시 산의 농도가 탈지대두박의 isoflavone 양에 미치는 영향을 조사하였다. 측정한 isoflavone은 daidzin, genistin 등 glucosides와 daidzein, genistein 등 aglycons이었다. 산가수분해는 탈지대두박 분말에 0.25 N-3.00 N HCl을 가하고 $95^{\circ}C$에서 4시간 가열하였다. 그 결과 총 isoflavone은 0.25 N-1.0 N HCl의 범위에서 가열이 진행되면서 증가하여 2시간 후에는 약 40% 증가함을 보였다. 그러나 그 이상의 농도에서는 현저한 감소가 있어 4시간 후에는 52%의 감소가 있었다. 이 결과는 낮은 HCl 농도에서의 증가는 isoflavone isomer가 isoflavone으로 전환되었음을 보여주고 높은 농도에서의 감소는 isoflavone이 분해됨을 보여주고 있다. 가열 중 각각의 isoflavone의 변화는 전체적으로 glucosides는 감소하고 aglycons는 증가하는 경향이었다. 특히 2 N HCl에서의 60분 반응시 daidzin과 genistin, glycitin 등 glucosides는 검출되지 않았다.

• 동아시아식생활학회지
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• 제11권2호
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• pp.104-111
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• 2001

The first purpose of this study was to determine the changes in the allergenicity of milk and egg with heat treatment. The allergenicity of milk and egg is known to have a strong antigen. The second purpose of this study was to observe changes of disestibility of milk and egg after heat treatment. For this study, passive cutaneous anaphylaxis(PCA) inhibition experiment by using guinea pig and nonprotein nitrogen(NPN)experiment were attempted. The result were following: 1. The allergenicity of both milk and egg was reduced by heat treatment. 2. The degree of hydrolysis and PCA inhibition increased with longer heating time. 3. The increse in both the degree of hydrolysis and PCA inhibition of milk was higher than that of egg. 4. Egg contained a greater amount of allergen than milk after heat treatment. 5. The digestibility of both milk and egg was reduced by heat treatment. 6. The digestibility was reduced further by increasing heating time. 7. The digestibility of egg was lower than that of milk after the treatment.

• 한국세라믹학회지
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• 제47권4호
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• pp.343-352
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• 2010

A zirconia gel/polymer hybrid nanofiber was produced in a nonwoven fabric mode by electrospinning a sol derived from hydrolysis of zirconium butoxide with a polyvinyl butyral. Results indicated that the hydroxyl groups on the vinyl alcohol units in the backbone of the polymer were involved in the hydrolysis as well as grafting the hydrolyzed zirconium butoxide. In addition, use of acetic acid as a catalyst resulted in further hydrolysis and condensation in the sol, which led to the growth of -Zr-O-Zr- networks among the polymer chains. These networks gradually transformed into a crystalline zirconia structure upon heating. The as-spun fiber was smooth but partially wrinkled on the surface. The average fiber diameter was $690{\pm}110\;nm$. The fiber exhibited a strong but broad blue photoluminescence with its maximum intensity at a wavelength of ~410 nm at room temperature. When the fiber was heat-treated at $400^{\circ}C$, the fiber diameter shrunk to $250{\pm}60\;nm$. Nanocrystals which belonged to a tetragonal zirconia phase and were ~5 nm in size appeared. A strong white photoluminescence was observed in this fiber. This suggests that oxygen or carbon defects associated with the formation of the nanocrystals play a role in generating the photoluminescence. Further heating to $800^{\circ}C$ resulted in a monoclinic phase beginning to form In the heat-treated fibers, coloring occurred but varied depending on the heating temperature. Crystallization, coloring, and phase transition to the monoclinic structure influenced the photoluminescence. At $600^{\circ}C$, the fiber appeared to be fully crystallized to a tetragonal zirconia phase.