• 한국응용과학기술학회지
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• 제40권6호
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• pp.1363-1372
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• 2023

This study is concerned with the optimization of the manufacturing process of a hot water extract containing antioxidant activity from Lycium barbarum, traditionally known to have various physiological activities. For the establishment of the optimization process, the central composite design of response surface methodology(RSM) was used. Thirteen extraction processes were performed by encoding the independent variables, extraction temperature (65.9℃-94.1℃) and extraction time (2.59 hr-5.41 hr). As a result of the experiment, the optimal manufacturing conditions for the extract were 340.0 mg/100 g of GAE at an extraction temperature of 94.1℃ and an extraction time of 5 hr. The maximum yield of flavonoids was 22.44 mg/100 g of HES at an extraction temperature of 94.1℃ and an extraction time of 4 hr. The conditions for producing the extract with the maximum antioxidant capacity (DPPH 92.12%) were 90℃ and 4.5 hr extraction time. Therefore, the optimal manufacturing process conditions for extracts containing total phenol content, flavonoid content, and DPPH radical scavenging activity, which are dependent variables, were extraction temperature of 90-95℃ and extraction time of 4 hr, which were not significantly different from the actual values. Therefore, Lycium barbarum extract rich in total phenol and flavonoid content related to antioxidant function is expected to be used as a functional food and cosmetic material.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술회의 초록집
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• pp.16-16
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• 2010

GaN-based light-emitting diodes (LEDs) are attracting great interest as candidates for next-generation solid-state lighting, because of their long lifetime, small size, high efficacy, and low energy consumption. However, for general illumination applications, the external quantum efficiency of LEDs, determined by the internal quantum efficiency (IQE) and the light extraction efficiency, must be further increased. The IQE is determined by crystal quality and epitaxial layer structure and high value of IQE more than 70% for blue LEDs have been already reported. However, there is much room for improvement of light extraction efficiency because most of the generated photons from active layer remain inside LEDs by total internal reflection at the interface of semiconductor with air due to the high refractive index difference between LEDs epilayer (for GaN, n=2.5) and air (n=1). The light confining in LEDs will be reabsorbed by the metal electrode or active layer, reducing the efficacy of LEDs. Here, we present the first demonstration of enhanced light extraction by forming a MgO nano-pyramids structure on the surface of vertical-LEDs. The MgO nano-pyramids structure was successfully fabricated at room temperature using conventional electron-beam evaporation without any additional process. The nano-sized pyramids of MgO are formed on the surface during growth due to anisotropic characteristics between (111) and (200) plane of MgO. The ZnO layer with quarter-wavelength in thickness is inserted between GaN and MgO layers to increase the critical angle for total internal reflection, because the refractive index of ZnO (n=1.94) could be matched between GaN (n=2.5) and MgO (n=1.73). The MgO nano-pyramids structure and ZnO refractive-index modulation layer enhanced the light extraction efficiency ofV-LEDs with by 49%, comparing with the V-LEDs with a flat n-GaN surface. The angular-dependent emission intensity shows the enhanced light extraction through the side walls of V-LEDs as well as through the top surface of the n-GaN, because of the increase in critical angle for total internal reflection as well as light scattering at the MgO nano-pyramids surface.

• Journal of Ginseng Research
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• 제37권4호
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• pp.468-474
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• 2013

Ginseng seed oil was prepared using compressed, solvent, and supercritical fluid extraction methods of ginseng seeds, and the extraction yield, color, phenolic compounds, fatty acid contents, and phytosterol contents of the ginseng seed oil were analyzed. Yields were different depending on the roasting pretreatment and extraction method. Among the extraction methods, the yield of ginseng seed oil from supercritical fluid extraction under the conditions of 500 bar and $65^{\circ}C$ was the highest, at 17.48%. Color was not different based on the extraction method, but the b-value increased as the roasting time for compression extraction was increased. The b-values of ginseng seed oil following supercritical fluid extraction were 3.54 to 15.6 and those following compression extraction after roasting treatment at $200^{\circ}C$ for 30 min, were 20.49, which was the highest value. The result of the phenolic compounds composition showed the presence of gentisic acid, vanillic acid, ferulic acid, and cinnamic acid in the ginseng seed oil. No differences were detected in phenolic acid levels in ginseng seed oil extracted by compression extraction or solvent extraction, but vanillic acid tended to decrease as extraction pressure and temperature were increased for seed oil extracted by a supercritical fluid extraction method. The fatty acid composition of ginseng seed oil was not different based on the extraction method, and unsaturated fatty acids were >90% of all fatty acids, among which, oleic acid was the highest at 80%. Phytosterol analysis showed that ${\beta}$-sitosterol and stigmasterol were detected. The phytosterol content of ginseng seed oil following supercritical fluid extraction was 100.4 to 135.5 mg/100 g, and the phytosterol content following compression extraction and solvent extraction was 71.8 to 80.9 mg/100 g.

• 한국식품저장유통학회지
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• 제30권5호
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• pp.857-867
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• 2023

본 연구에서는 홍삼과 흑삼의 기능성 성분 추출 극대화를 위해 추출 용액의 ethanol 농도와 추출 온도를 고려하여 추출 수율, 산성다당체 및 ginsenosides의 함량 변화를 반응표면분석법을 통해 모니터링해 보고 적정 추출조건을 찾아보았다. 홍삼 및 흑삼의 가용성 고형분 함량에 대한 모델식의 R²는 각각 0.9679(p<0.01), 0.8545(p<0.1)였다. 홍삼가용성 고형분의 최적 추출조건은 ethanol 농도 1.52%에서 67.27℃로 추출 시 그 함량이 5.29%였으며, 흑삼 가용성 고형분의 최적 추출조건은 ethanol 농도 3.12%에서 66.13℃로 추출 시 그 함량이 6.11%였다. 홍삼 및 흑삼의 산성다당체 함량에 대한 모델식의 R²는 각각 0.9251(p<0.05), 0.88379(p<0.1)였다. 홍삼의 산성다당체 최적 추출조건은 ethanol 농도 4.03%에서 69.61℃로 추출 시 그 함량이 1.86 mg/mL였다. 흑삼의 산성다당체 최적 추출조건은 ethanol 용액 농도 24.67%에서 71.14℃로 추출 시 그 함량이 1.80 mg/mL였다. 홍삼의 ginsenoside Rg₁ 및 Rb₁ 함량에 대한 모델식의 R²는 각각 0.8941(p<0.05), 0.8718(p<0.1)이었다. 홍삼의 ginsenosides 최적 추출조건은 ethanol 농도 79.92%에서 70.62℃로 추출 시 ginsenoside Rg₁ 함량이 0.22 mg/mL였으며, ethanol 농도 79.94%에서 69.46℃에서 ginsenoside Rb₁ 함량이 0.36 mg/mL였다. 흑삼의 ginsenosides 최적 추출조건은 ethanol 농도 75.11%에서 65.21℃로 추출할 경우 ginsenoside Rb₁ 함량이 0.28 mg/mL였으며, ethanol 농도 75.70%에서 65.49℃에서 ginsenoside Rg₃ 함량이 0.31 mg/mL였다. 홍삼 및 흑삼의 산성다당체 수율과 ginsenoside 수율을 모두 만족하는 최적추출조건은 ethanol 농도 35-50%의 범위 내에서 70℃였다.

• 한국식품영양학회지
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• 제35권1호
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• pp.62-73
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• 2022

Omija seed oil was extracted from Omija seeds, a by-product of Omija, using an eco-friendly pressed extraction method. Physicochemical properties and antioxidant activities of 12 extracts using different combinations of seed moisture content (5, 7.5, and 10%) and extraction temperature (25, 49, 75, and 100℃) were then investigated. The highest extraction yield was 31.33% at moisture of 5% and temperature of 75℃. The lowest acid value was 4.18±0.25 at moisture of 5% and temperature of 49℃or moisture of 7.5% and temperature of 25℃. Peroxide value, iodine value, and saponification value were the lowest at 0.64±0.56 meq/kg, 159.38± 6.03, and 57.60±9.40, respectively, at moisture of 5% and temperature of 25℃. The content of total polyphenolics was the highest at 4,413±125 mg TAE/100 g when the moisture content was 10% and the extraction temperature was 25℃. DPPH radical scavenging activities of oil extracts at 20~100 mg/mL were 28.68±7.30~87.65±2.20%. The maximum antioxidant activity and IC₅₀ were 87.65±2.20% and <20 mg/mL, respectively, for extract obtained at moisture of 10% and temperature at 100℃. As a result, the extraction yield, acid value, peroxide value, iodine value, saponification value, and so on were excellent at moisture content of 5% and extraction temperature of 25℃ or 49℃. However, the content of total polyphenolic compounds and antioxidant activity were the highest at moisture of 10% and extraction temperature of 100℃. In conclusion, extracting Omija seed oil from Omija seeds, a by-product of Omija, is effective with a pressed extraction method.

• 한국식품영양과학회지
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• 제42권11호
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• pp.1776-1782
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• 2013

추출 온도와 시간에 따른 옻나무 부위별 추출물의 총 페놀 및 플라보노이드 함량과 항산화활성을 측정하였다. 옻나무 추출물의 총페놀 함량은 추출 온도 $160^{\circ}C$에서 47.82 mg GAE/g으로 가장 높았으며, $100^{\circ}C$ 이하의 추출 온도에서는 유의적인 차이가 없었으나 $120^{\circ}C$ 이상의 추출 온도에서는 추출 시간 3시간까지는 증가하다가 5시간에서는 감소하였다. 총 플라보노이드는 추출 온도가 증가함에 따라 증가하여 $140^{\circ}C$, 1시간에서 8.04 mg CE/g으로 가장 높은 함량을 나타내었다. DPPH 라디칼 소거활성은 추출 시간의 증가에 따라 증가하여 $140^{\circ}C$, 3시간에서 34.23 mg TE/g으로 가장 높았으며, 그 이후에는 감소하였다. ABTS 라디칼 소거활성은 DPPH 라디칼 소거활성과 유사하였고 $140^{\circ}C$에서 3시간 추출한 수피 추출물에서 51.58 mg AEAC/g으로 높게 나타났다. 총 페놀과 총 플라보노이드 함량과 DPPH와 ABTS 라디칼 소거활성을 감안할 때 옻나무 부위별 효율적인 추출조건은 추출 온도 $140^{\circ}C$와 추출 시간 3시간이었다.

• 한국식품영양과학회지
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• 제43권11호
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• pp.1701-1708
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• 2014

참취의 활용 및 생리활성을 증가시킬 수 있는 적정 추출방법을 알아보고자 상온교반, 환류냉각, 가압가열, 저온고압 및 초음파 추출법을 이용하여 추출한 두벌 째 수확 참취 추출물의 생리활성을 비교하였다. 추출 수율은 환류냉각추출, 초음파추출, 가압가열추출, 상온추출, 저온고압추출 순으로 높았다. 폴리페놀, 플라보노이드 함량은 저온고압추출에서 유의적으로 높았고, 상압가열, 고온고압, 초음파추출에서는 대등한 함량을 나타내었다. 페놀화합물 정량의 경우 chlorogenic acid 함량은 가압가열추출에서 유의적으로 높았으며 cynarin 함량의 경우 환류냉각, 저온고압 및 초음파 추출에서 유의적으로 높았고, astragalin 함량의 경우 저온고압추출에서 높은 함량이 검출되었다. Xanthine oxidase(XO), angiotensin I-converting enzyme(ACE), HMG-CoA reductase 저해활성의 경우 저온고압추출 및 초음파 추출물에서 우수한 활성을 나타내었으며, 소화효소 저해활성(${\alpha}$-amylase, trypsin, lipase)에서도 유사한 경향을 나타내었다. 이러한 결과를 종합해 볼 때 저온고압 및 초음파 추출물에서 소재 활용가치가 높을 것으로 사료되며 천연 항산화제 및 기능성 증진을 위한 소재로 이용 가능할 것으로 판단된다.

• 한국식품과학회지
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• 제52권3호
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• pp.290-295
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• 2020

본 연구에서는 고구마 끝순과 괴근으로부터 자색색소인 안토시아니딘을 추출하기 위한 최적조건을 확립하였다. 에탄올 농도(10-90%), citric acid 농도(0.1-0.5%) 그리고 추출온도(30-70℃)를 변수로 중심합성계획법으로 설계하고 반응표면분석법으로 최적화 하였다. 세가지 변수 모두 안토시아니딘 추출에 유의적인 영향을 주었으며, 산 농도나 추출 온도보다는 에탄올 농도의 영향력이 컸다. 각각의 추출조건 중 에탄올 농도 50%, citric acid 농도 0.3%, 추출 온도 50℃에서 끝순은 26.58±0.07 mg/100 g을 나타내었고 괴근은 117.32±0.39 mg/100 g으로 가장 높았다. 반응표면분석에 의한 최적추출조건은 끝순은 에탄올 농도 56.10%, citric acid 농도 0.25% 그리고 추출 온도 52.24℃이었으며, 괴근은 각각 55.08, 0.30, 53.06℃이었다. 최적추출조건에서의 예측값은 각각 27.45, 119.61 mg/100 g이었으며, 실측값은 각각 27.09±0.11, 118.72±0.67 mg/100 g이었다. 예측값과 비교할 때 각각 98.69, 99.26%로 나타나 추출조건의 유효성이 확인되었다.

• 한국식품저장유통학회지
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• 제9권4호
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• pp.396-399
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• 2002

An attempt was made in this study to investigate the optimum extracting time from meat with bone of goat and the nutritional component of its extract. for the trials, the mixtures of meat with bone and water were adjusted to the ratios of five to four by weight and extracted for 6, 9 and 12 hours at 120$\^{C}$ under autoclave. Judging from the content of mineral and amino acid, nonenzymatic browning and yield, the optimum extracting time was 9 hours. The major components of mineral were composed of 47.7mg％ potassium, 12.7mg% calcium, 150.0mg% sodium, 105.3mg% phosphorus and 0.5mg% iron, and of amino acids composed of 1,308.0mg% glutamic acid, 1,464.2mg% glycine, 750.2mg% alanine and 828.lmg% proline in extract. The yield of extract was 32.1 percentage by dry basis.

• 분석과학
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• 제6권3호
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• pp.307-311
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• 1993

5원자 헤테로고리를 포함하는 열린고리형의 ionophore를 합성하였다. 이 때 합성한 ionophore를 착화제로 이용하여 수용액 중의 $Mg^{2+}$을 염석추출법으로 추출하여 원자 흡광 광도법으로 정량하였다. Acetate 완충용액으로 pH를 4.2로 조절한 $Mg^{2+}$를 포함하는 수용액에 ionophore-AN 용액을 넣어 $Mg^{2+}$-ionophore 착물을 형성시킨 다음, 염석제를 첨가하여 유기층으로 추출하고, 유기층의 착물의 흡광도를 원자 흡광 광도계로서 측정하여 $Mg^{2+}$를 정량하였다. 최적 추출 조건을 조사해 본 결과, 최적 pH는 2.5~5.0이었으며, 염석제인 황산암모늄[$(NH_4)_2SO_4$]의 양은 5g 이상이면 정량적으로 추출되었다. 또한 $Mg^{2+}$과 ionophore의 착물 조성비는 1:2이었다. $Mg^{2+}$의 정량범위는 0.24ppm~2.4ppm이었으며 $Ca^{2+}$이온 및 EDTA의 방해효과가 크게 나타났다.