• 한국식생활문화학회지
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• 제28권3호
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• pp.320-327
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• 2013

The quality characteristics of Omija (Schizandra chinesis Baillon) extracts under various extraction temperatures and times were examined. The pH level of the extracts ranged from 3.35-3.47. The sugar and solid content of the samples significantly increased with increasing extraction temperatures and times (p<0.01). In contrast, the lightness of the extracts decreased with increasing extraction temperatures and times (p<0.001). In a palatability test, extracts boiled at $80^{\circ}C$ for 30 minutes scored high in terms of color, flavor, turbidity, sourness, and overall acceptability. Hydroxy radical scavenging activity and polyphenol content of the extracts significantly increased with increasing extraction temperatures and times (p<0.01). Furthermore, direct correlations between hydroxy radical scavenging activity and polyphenol content (or flavonoid content) were established through simple regression (r>0.9) for different extraction temperatures and times. From these results, extracts boiled at $80^{\circ}C$ for 120 minutes is the best to product omija beverage considering functionality and sensory evaluation as well.

• 생명과학회지
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• 제10권2호
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• pp.202-209
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• 2000

The factors affecting chemical composition of green tea (Camellia sinensis L.) during extraction process were temperatures and times. The optimum extraction conditions were measured in relation to the changes of chemical compositions from water extracts of green tea (Camellia sinensis L.) under different extraction temperatures (50, 70, 9$0^{\circ}C$) and extraction times (1, 3, 5 minute). The change of color intensity during browning reaction, flavonoid components, contents of total phenols and hydrogen donating activity (reducing activity for $\alpha$, $\alpha$'-diphenyl-$\beta$ -picryhydrazyl) of water extracts form green tea increased as extraction temperatures increased from 50 to 9$0^{\circ}C$ and extraction times prolonged from 1 to 5 min. The contents of important free sugars such as sucrose and glucose slightly increased as the extraction time was prolonged, while little difference in the content of fructose with the prolonged extraction time. Catechins contents extracted from the commercial steamed green tea were increased at higher temperature and longer extraction time. Epigallocatechin (EGC) extracted from 9$0^{\circ}C$ (extraction time 5 min). presented 99.9 mg/g in highest composition of catechin followed by epigallocatechin gallate (EGCg), epicatechin (EC), epicatechin gallate (ECg). The content of vitamin C extracted from green tea was increased about 2 times as the extraction temperature increased from 50 to 9$0^{\circ}C$ and as the extraction time increased from 1 to 5 min. with exception at 9$0^{\circ}C$(extraction time:5 min) which showed less vitamin C content than 7$0^{\circ}C$(extraction time : 3 min) probably due to possible destruction of vitamin C by high temperature.

• 산업식품공학
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• 제23권1호
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• pp.22-29
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• 2019

본 연구는 밀 배아의 기능성 물질인 2,6-DMBQ와 아라비노자일란 추출 효율을 증가시키기 위하여 상업용 효소인 Celluclast 1.5L을 사용하여 추출하였다. 추출 시 온도는 30, 45, 60℃였고, 추출 시간은 0, 6, 12, 18, 24, 30시간 추출 후 상등액 pH 변화와 건조물을 분석하였다. 추출물의 pH는 WEWG와 ETWG 모두 추출 온도 30℃에서는 18시간 추출 시부터 급격하게 감소하였으며, 45℃는 12시간부터 감소하였고, 60℃는 다른 추출 온도와 비교하여 큰 변화는 없었다. 2,6-DMBQ는 WEWG와 ETWG 모두 추출 시간이 경과함에 따라 증가하였다. 추출 온도 30℃에서 가장 높은 함량으로 추출되었으며, 30시간 추출할 때 2,6-DMBQ 함량은 ETWG에서 WEWG 보다 추출 온도 30℃에서 27.60%, 45℃에서 65.03%, 60℃에서 151.05% 증가하였다. 수용성 아라비노자일란 함량은 WEWG와 비교하여 ETWG가 높게 측정되었으며, 효소 처리 후 60℃에서 15.23±0.08 mg/g으로 가장 높은 함량으로 나타났다. 30시간 추출 시 ETWG와 WEWG에서의 수용성 아라비노자일란 함량을 비교했을 때 30℃에서 7.92%, 45℃에서 31.20%, 60℃에서 54.38% 증가하였다. 본 연구 결과는 제분 부산물인 밀 배아에 항염 활성을 보유하는 기능성 소재로서의 활용을 위한 기초자료로 이용될 수 있을 것으로 판단된다.

• Elastomers and Composites
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• 제48권4호
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• pp.288-293
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• 2013

무수말레산-그래프트 EPDM (MAH-g-EPDM)/산화아연 복합체를 디클로로아세트산(DCA)/톨루엔 공용매로 처리하고 추출 온도에 따른 무게 감소와 가교밀도 측정을 이용하여 가교 특성을 조사하였다. 감쇠전반-후리에변환 적외선분광법(ATR-FTIR)을 이용하여 화학적 변화를 분석하였다. 상온 추출보다 고온($90^{\circ}C$) 추출에 의한 무게 감소가 월등히 높았으며, DCA/톨루엔 공용매 추출에 의한 무게 감소는 톨루엔 추출에 의한 무게 감소보다 5배 이상 높았다. 용매 추출 후 가교밀도를 측정하였으며, 1차 가교밀도보다 2차 가교밀도가 높았다. 1차 가교밀도는 추출온도가 높은 경우 더 낮았고 DCA/톨루엔 공용매로 추출한 것이 톨루엔으로 추출한 것보다 훨씬 낮았다. 2차 가교밀도는 DCA/톨루엔 공용매로 추출한 것이 톨루엔으로 추출한 것보다 높았다. 고온에서 DCA/톨루엔 공용매로 추출하면 강한 가교 그물망만 남는 반면, 상온에서 톨루엔으로 추출하면 미가교 고분자 사슬이 추출되는 등 추출 용매와 온도에 따라 추출되는 성분이 달랐다. 따라서 추출 용매와 온도에 따른 추출 성분의 비교와 연속 가교밀도 측정에 의해 MAH-g-EPDM/산화아연 복합체의 가교 특성을 분석할 수 있다.

• 반도체디스플레이기술학회지
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• 제15권1호
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• pp.70-75
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• 2016

GZO films prepared on ITO glasses were annealed at various temperatures in a vacuum condition to research the relationship between oxygen vacancies and optical properties. GZO films after annealing in a vacuum showed the various optical-chemical properties depending on the annealing temperatures and oxygen gas flow rate during the deposition. The oxygen vacancy of GZO film prepared by oxygen gas flows of 22 sccm increased with increasing the annealing temperatures, because of the extraction of oxygen by the annealing. But the intensity of photoluminance of GZO with 22 sccm decreased in accordance with the annealing temperature, because of the reduction of ionized charge carriers. The oxygen vacancy by the extraction of oxygen enhanced a depletion, so the widen depletion had the strong Schottky barrier and the PL intensity due to the low carrier density decreased.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.317-319
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• 2002

Exo-polygalacturonase (EPG) from Rhizopus sp. was applied to the extraction of alginic acid from sea mustard to increase extraction yield. EPG digestion was examined under distinct conditions within temperatures from $25^{\circ}C$ to 5$0^{\circ}C$, pH 5 to 9, and treatment times from 0 to 36 hr. The optimal conditions fur alginic acid extraction with EPG were: pH 7.0 at 3$0^{\circ}C$ for 24 hrs. The EPG hot water extraction yield was 3.4 times higher yield than hot water extraction alone. Using EPG to extract alginic acid from sea mustard should be considered a viable alternative to conventional extraction, with the advantage of reducing hazardous wastes such as strong acid and alkali solutions.

• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.159-165
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• 2014

In this study, Krill Eupausia superba oil was extracted using different solvents and supercritical carbon dioxide (SC-$CO_2$). During SC-$CO_2$ extraction, the pressure was set at 40 MPa and temperatures ranged from $40^{\circ}C$ to $55^{\circ}C$. We examined the differences in volatile compounds and safety profiles among extraction methods. Volatile compounds were determined using the thermal desorption system integrated with gas chromatography-mass spectrometry (GC-MS). Heavy metal content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). According to our results 10 volatile compounds were identified in krill sample. After SC-$CO_2$ extraction of oil, the concentrations of volatile compounds decreased, but increased after solvent extraction. In krill, heavy metal concentrations remained within the permissible limit. Moreover, Zn and Fe which have health benefits were detected at high concentrations. During a 90 days storage period at different temperatures, microbial activity was found to be lowest in SC-$CO_2$ extracted residues. Thus, the quality of krill oil and the residues obtained using SC-$CO_2$ extraction was higher and the oil was safer than those obtained using conventional solvent extraction. These results can be applied to the food industry to maintain high quality krill products.

• Preventive Nutrition and Food Science
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• 제17권2호
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• pp.166-171
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• 2012

6-Shogaol, a dehydrated form of 6-gingerol, is a minor component in ginger (Zingiber officinale Roscoe) and has recently been reported to have more potent bioactivity than 6-gingerol. Based on the thermal instability of gingerols (their dehydration to corresponding shogaols at high temperature), we aimed to develop an optimal process to maximize the 6-shogaol content during ginger extraction by modulating temperature and pH. Fresh gingers were dried under various conditions: freeze-, room temperature (RT)- or convection oven-drying at 60 or $80^{\circ}C$, and extracted by 95% ethanol at RT, 60 or $80^{\circ}C$. The content of 6-shogaol was augmented by increasing both drying and extraction temperatures. The highest production of 6-shogaol was achieved at $80^{\circ}C$ extraction after drying at the same temperature and the content of 6-shogaol was about 7-fold compared to the lowest producing process by freezing and extraction at RT. Adjustment of pH (pH 1, 4, 7 and 10) for the 6-shogaol-richest extract (dried and extracted both at $80^{\circ}C$) also affected the chemical composition of ginger and the yield of 6-shogaol was maximized at the most acidic condition of pH 1. Taken together, the current study shows for the first time that a maximized production of 6-shogaol can be achieved during practical drying and extraction process of ginger by increasing both drying and extracting temperatures. Adjustment of pH to extraction solvent with strong acid also helps increase the production of 6-shogaol. Our data could be usefully employed in the fields of food processing as well as nutraceutical industry.

• 한국식품영양과학회지
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• 제29권5호
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• pp.790-795
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• 2000

To establish the optimum conditions for the extraction of anthocyanin pigment from purple-fleshed sweet potato, a suitable extraction solvent with the optimum citric acid concentration for acidification of the solvent, and the optimum extraction time and temperature were determined. Twenty percent ethanol solution acidified with citric acid was found to be a good solvent for the extraction of the pigment from purple-fleshed sweet potato. About 10 hour extraction at room temperature was appropriate for the extraction. pH of the extract was below 3 when more than 0.7% citric acid was added. The higher the concentration of citric acid added was, the higher the total optical density (TOD) of the extract was. However, the increase in TOD of the extract was insignificant when more than 1% of citric acid was added. Therefore, addition of 1% citric acid was determined for acidification of the extracting solvent. Though the initial rate of the pigment extraction increased as the extracting temperature increased, extraction at higher temperatures of 60 or 8$0^{\circ}C$ for an extended time caused a decrease in the extraction yield due to degradation of the pigment. The optimum extraction temperature for the anthocyanin pigment from purple-fleshed sweet potato with the solvent used was determined as 4$0^{\circ}C$.

• 한국환경과학회지
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• 제32권4호
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• pp.221-232
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• 2023

This study investigated the antioxidant effect of Hermetia illucens larvae using different extraction temperatures and solvents. We found significant differences in total phenolic content (TPC), total flavonoid content (TFC), an in three antioxidant indexes 2,2-diphenyl-1-picrylhydrazyl (DPPH), 1,1'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and ferric-reducing antioxidant power (FRAP) contents, among the samples depending on the extraction temperature and solvent used. The sample extracted with water at 45℃ (HIW-45℃) showed the highest TPC, DPPH, ABTS, and FRAP contents, while the sample extracted with water at 90℃ (HIW-90℃) showed the highest TFC. These differences can be due to the different chemical structures of the extracted components. Based on these results, HIW-45℃ was the optimal extraction method for Hermetia illucens. We intend to further investigate the availability of functional materials for Hermetia illucens using this method.