• Journal of the Korean Applied Science and Technology
• /
• v.35 no.4
• /
• pp.1213-1223
• /
• 2018

This study was carried out to investigate extraction efficiency by microwave for extraction of pesticide residues and the bioconversion of ginsenosides of ginseng leaf by using various lactic acid bacteria in order to promote the utilization of ginseng leaf. The hexane extraction by microwave of tolclofos-methyl and azoxystrobin in ginseng leaf was efficient. The optimal condition for extraction of tolclofos-methyl and azoxystrobin in ginseng leaf by microwave was 50 to 95 watts of power supply, 3 minutes of extraction.The gisenosides Rg1 and Rb1 contents have decreased, while the Rh1, Rg3, Rk1 and Rh2 have increased due to fermentation. The ginsenosides Rg3 of the fermented ginseng leaf has increased and the contents were $70.62{\sim}77.61{\mu}g/g$(control $2.77{\mu}g/g$). The total phenolic acid content and electron donating ability of the ginseng leaf have totally decreased after 7 days of fermentation. The total phenolic acid contents of the fermented ginseng leaf with various lactic acid bacteria did not show any tendency as different strains.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.8
• /
• pp.1062-1069
• /
• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximizing the functional properties of roasted Pleurotus eryngii. Based on the central composite design, independent variables were ethanol concentration ($0{\sim}100%$), extraction time ($1{\sim}9$ min) and microwave power ($25{\sim}125$ W). Soluble solid content, electron donating ability and nitrite-scavenging ability were mainly affected by ethanol concentration, but ACE inhibition activity was largely affected by extraction time. The optimum ranges of extraction conditions resulting from superimposing the response surface were predicted to be ethanol concentration ($25{\sim}50%$), extraction time ($3{\sim}9$ min) and microwave power ($80{\sim}125$ W). Total protein and total phenolic compound content of optimal extracts were 45.80 mg/g and 7.42 mg/g, respectively. In phenolic compounds of roasted Pleurotus eryngii extracts, protocatechuic acid was the highest concentration at 1226.32 ${\mu}g/g$, followed by salicylic acid, catechin, p-hydroxybenzoic acid, caffeic acid, coumaric acid and hesperidin.

• Food Engineering Progress
• /
• v.13 no.2
• /
• pp.147-153
• /
• 2009

Quercetin is one of the main flavonoids from onion. To use quercetin as a functional component for onion food products, the effects of various extraction assisting methods such as juicing methods, microwave, ultrasound and enzyme treatments on the yield of quercetin and its glucosides were investigated. For conventional solvent extraction, the highest yield of quercetin and its glycosides was achieved with 0.8 mL/g of 60% methanol at 50$^{\circ}C$ for 15 min. The juicing methods using mixer and screw showed no influence on the yield. Microwave and ultrasound treatments showed 2.14 times and 2.06 times more quercetin yields than non-treated extraction, respectively. For cellulase and viscozyme treatments, the highest yields of quercetin were achieved with 0.5 mL/g of 1% enzyme-0.1M sodium acetate (pH 5.2) buffer solution. Cellulase and viscozyme treatment improved quercetin yield 1.65 times and 2.29 times more than non-treated one, respectively.

• Food Science and Preservation
• /
• v.15 no.1
• /
• pp.133-138
• /
• 2008

This study investigated the antioxidant activities of extracts from Angelica dahurica roots after microwave-assisted extraction with different levels of energy (120, 240W) and extraction time (5, 10, 15 and 30 min). The highest extraction yield was 11.77 mg% in water at 240W for 30 min followed by 11.42 mg% in water at 120Wand 30 min. The highest total polyphenol contents was 32.36 mg/g in an ethanol extract, followed by 31.77mg/g in water extract at the same conditions of 240W, 30 min. The electron donating abilities both the ethanol extract obtained using 240W and 30 min and the water extract obtained employing 120W and 5min showed the highest values, 83.55% and 82.49% respectively at a concentration 1.0mg/mL. The highest superoxide dismutase (SOD)-like activity was 14.16% in ethanol extract at 120Wand 15min, followed by 13.22% in the water extract at 120W and 5 min. The best extraction yield and polyphenol content after microwave-assisted extraction were achieved with 240W and 30 min using water. The best condition for extraction of electron donating ability and SOD-like activity from A dahurica roots were 120W and 5 minutes using water.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.3
• /
• pp.348-354
• /
• 2007

Extraction characteristics of ginger (Zingiber officinale) and the functional properties of the corresponding extracts were monitored by the response surface methodology (RSM). The maximum extraction yield of 38.83% was obtained under the specific extraction conditions, such as microwave power of 126.68 W, ethanol concentration of 53.39% and extraction time of 8.15 min. The maximum electron donating ability (EDA) was found as 77.92% at the conditions of 58.25 W microwave power, 91.87% ethanol concentration and 5.54 min extraction time. The maximum inhibitory effect on tyrosinase was 79.39% at 106.08 W, 2.06% and 5.61 min. The maximum polyphenol content was 105.59% under the extraction conditions of 81.82 W, 99.52% and 4.06 min. Based on superimposition of four dimensional RSM with respect to extraction yield and electron donating ability and polyphenol content obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of $0{\sim}80\;W$, ethanol concentration of $0{\sim}40%$ and extraction time of $3{\sim}7$ min.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.3
• /
• pp.464-469
• /
• 2015

Response surface methodology (RSM) was used to monitor extraction characteristics of extracts from Sarcodon aspratus. Based on a central composite design, independent variables were microwave power (30~150 W), ethanol concentration (0~100%), and extraction time (1~9 min). Dependent variables were yield, electron-donating ability, total phenol contents, and SOD-like activity. Coefficients of determination ($R^2$) for dependent variables ranged from 0.80 at 0.97. The maximum extraction yield was 50.28% under conditions of 125.1 W microwave power, 18.67% ethanolic concentration, and 7.06 min extraction time. The maximum extraction electron-donating ability was 22.14% under conditions of 31.09 W, 45.76%, and 4.32 min. The maximum extraction total polyphenol content was 30.54 mg tannic acid equivalent/g at 122.54 W, 48.05%, and 8.36 min. The maximum extraction SOD-like activity was 33.44% at 121.17 W, 47.42%, and 8.41 min. Based on superimposition of four dimensional RSM with respect to extraction yield, electron-donating ability, total polyphenol content, and SOD-like activity obtained under various extraction conditions, optimum ranges of extraction conditions were found to be microwave power of 78~88 W, ethanol concentration of 39~57%, and extraction time of 3.5~9 min.

• Korean Journal of Food Science and Technology
• /
• v.31 no.2
• /
• pp.329-335
• /
• 1999

The yield of oleoresin content and functionality of fresh garlic were compared according to varying extraction conditions by microwave-assisted extraction (MAE) and conventional extraction (CE) methods. When different extracting conditions were applied, there was no significant difference of extraction methods in the oleoresin content. However, in the case of the CE, the optimum extraction time was two hours, while the other was about five minutes which meant that the extraction time was shortened drastically. The electron donating abilities showed a similar level which was 64% by both methods, using water. And, in the case of ethanol extraction, it resulted 63% and 51% by CE and MAE, respectively. The nitrite scavenging effect diminished while pH was increasing and especially, in the case of pH 1.2, it showed a high elimination effect of more than 90%. There was no difference of extraction methods. The tyrosinase inhibitory effect was 47% and 60% by CE and MAE, respectively in the case of the water extract. The ethanol extract showed similar or a slight lower inhibition of 45% and 39%. The angiotensin I-converting enzyme inhibitory effect showed more powerful activity in the case of MAE extract than CE extract, but there was not an increase relating to reaction time of enzyme. Also, pyruvic acid content was $44.8\;and\;36.0{\mu}moles$ per one gram of a garlic by CE and MAE, respectively when water was used, and was $28.6\;and\;32.0{\mu}moles$ by CE and MAE when ethanol was used. Again, there was no big difference between CE and MAE methods.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.1
• /
• pp.105-110
• /
• 2007

Extraction characteristics of onion (Allium cepa) and the functional properties of corresponding extracts were monitored by the response surface methodology (RSM). The maximum extraction yield of 44.02% was obtained under the specific extraction conditions, such as microwave power of 143.13 W, ethanol concentration of 61.77% and extraction time of 3.39 min. The maximum electron donating ability (EDA) was found as 45.85% at the conditions of 143.55 W microwave power, 27.52% ethanol concentration and 4.86 min extraction time. The maximum inhibitory effect on tyrosinase was 65.40% at 132.29 W, 36.47% and 7.62 min. The maximum superoxide dismutase (SOD)-like activity was 69.84% under the extraction conditions of 99.41 W, 8.47% and 7.13 min. Based on superimposition of four dimensional RSM with respect to extraction yield, electron donating ability and SOD-like activity obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of 0$\sim$120 W, ethanol concentration of 70$\sim$80% and extraction time of 2$\sim$10 min.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.250.2-250.2
• /
• 2010

빛과 공기 중의 이산화탄소를 고정화하여 생성되는 바이오매스(biomass)로부터 다양한 에너지 및 물질을 생산하는 연구는 석유고갈과 환경문제 해결의 한 방안으로서 활발히 진행되어 왔으며, 앞으로도 그 지속 가능성과 환경 친화성에 의해 바이오에너지 이용 및 보급은 꾸준한 증가세를 보일 것으로 전망된다. 바이오디젤, 바이오에탄올의 경우는 미국, 브라질, EU, 한국 등에서 상용화되어 사용되고 있으며 그 생산량이 계속적으로 증가하고 있다. 하지만, 바이오연료의 보급 증가는 식량 자원과의 충돌과 열대우림 파괴 등의 부작용을 일으키고 있다. 이러한 문제 해결의 일환으로 단위면적당 생산성이 대두, 유채보다 월등한 것으로 보고되는 미세조류에 대한 관심이 증가하고 있으며 우수 미세조류종 개발, 미세조류 고속배양 및 수확, 미세조류로부터 에너지 및 유용물질, 소재 생산에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 미세조류로부터 바이오디젤 원료유를 생산하기 위해 Soxhlet을 이용한 추출 방법을 이용하였다. 추출되는 오일은 사용 용매의 극성에 따라 물성과 추출 효율에 차이가 큰 것으로 나타났다. 강한 극성의 용매일 경우, 엽록소와 단백질이 같이 추출되는 문제가 있으며 약한 극성 용매는 세포벽의 방해로 용매가 세포내부로 흡수되지 못하는 문제가 있다. 추출 효율이 높은 극성용매의 경우 불순물을 제거해야 고순도의 바이오디젤의 생산이 가능하고 비극성 용매는 추출 오일의 물성은 좋으나 수율이 매우 낮게 측정되었다. 이러한 동시추출을 방지함과 동시에 추출 효율을 높이기 위해 본 연구에서는 세포벽 파괴 후 용매추출하는 방법으로서 미세조류를 Microwave에 노출시켜 오일 추출율을 증가시키는 전처리 연구를 수행하였다. 전처리시, Microwave에 의한 열 발생은 미세조류를 탄화시키기 때문에 열매체로서 물을 혼합하여 탄화를 방지하고 세포벽 내외부의 가열효과로 세포벽을 파괴하고자 하였다. Microwave에 의한 에너지 손실을 줄이며 세포벽 파괴에 효과적인 수분혼합비를 조사하였으며 Microwave에 노출 후 잔류수분을 건조하고 효율적으로 용매를 접촉시키기 위해 분쇄를 수행하였다. 모든 전처리 반응을 거친 미세조류에서 약 2배 증가된 추출수율을 얻을 수 있었으며, SEM을 통해 전처리 미세조류와 미전처리 미세조류를 분석해본 결과 전처리 미세조류의 다공성이 증가함을 확인하였다. 또한, 90%의 메탄올에 미세조류를 녹여 엽록소 함유량을 측정한 결과, 전처리 미세조류의 엽록소가 미전처리 미세조류보다 약 7배가량 감소함을 확인할 수 있었다.

• Journal of the Korean Ceramic Society
• /
• v.40 no.9
• /
• pp.897-901
• /
• 2003

The sulfating reaction of coal fly ash with ammonium sulfate and the microwave extraction of aluminum ions from the resultant materials using sulfuric acid have been investigated. The (NH$_4$)$_3$Al(SO$_4$)$_3$ formed by the reaction of coal fly ash and ammonium sulfate decomposed to NH$_4$Al(SO$_4$)$_2$ at $\geq$ 350$^{\circ}C$. The maximum efficiency of aluminum ions extracted from the sulfating reaction product (400$^{\circ}C$, 120 min) by microwave heating (90$^{\circ}C$, 240 min) using 1 M H$_2$SO$_4$ was 84％ (based on Al content in coal fly ash) but 77％ by conventional heating at same condition.