• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.451-460
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• 2017

This study optimized the extraction of antioxidants from Gugija (Lycium chinensis Mill). To determine operational parameters, including ethanol concentration ($X_1$, 0~80%) and extraction time ($X_2$, 1~5 hr), response surface methodology was applied to monitor yield, anthocyanins, flavonoids and DPPH radical scavenging activity. Coefficients of determinations ($R^2$) of the models were range of 0.8645~0.9859 (p<0.01~0.1) in dependant parameters. Yield of Gugija extracts was maximized 23.12% in extraction conditions of 4.22 h at 8.25% ethanol. Anthocyanins was maximized 1.43 (OD in 530 nm) in extraction conditions of 3.06 h at 79.98% ethanol. Flavonoids was maximized $3,100{\mu}g/100g$ in extraction conditions of 3.37 h at 67.02% ethanol. DPPH radical scavenging activity was maximized 96.93% in extraction conditions of 1.67 h at 69.81% ethanol. Optimum extraction conditions (2.5 h extraction at 70% ethanol) were obtained by superimposing the contour maps with regard to anthocyanins, flavonoids and DPPH radical scavenging activity of Gugija. Maximum values of anthocyanins, flavonoids and DPPH radical scavenging activity in optimum extraction condition were 1.0080 (OD in 530 nm), $3,145{\mu}g/100g$, 96.96%, respectively. But values of anthocyanins, flavonoids and DPPH radical scavenging activity in water extraction condition (1 h at water) were 0.4652 (OD in 530 nm), $1,633{\mu}g/100g$, 86.98%, respectively.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.918-921
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• 2005

Quantitative analysis of flavonoids in commercial propolis extract products were compared by three colorimetric methods; aluminum chloride method, dinitrophenylhydrazine method and aluminum nitrate method, Aluminum nitrate method in Korea Health Supplement Food Code was proved to be specific only for flavones and flavonols same as aluminum chloride method, while dinitrophenylhydrazine method was specific for flavanones and dihydroflavonols. Therefore, the sum of flavonoid contents determined by 2,4-Dinitrophenylhydrazine method and aluminum nitrate method may represent the real content of total flavonoids. As for the 25 commercial propolis extract products examined, the contents of flavonoid varied from 2.15% to 9.53% except for one product.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.86-86
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• 2018

인공재배한 매실나무겨우살이를 이용한 기능성 막걸리를 개발하기 위해, 겨우살이, 기장과 쌀을 활용하여 원료의 배합비율 및 발효방법에 따른 총 폴리페놀, 플라보노이드 함량 및 DPPH free radical 소거능을 비교하였다. 최적의 배합비율을 찾기 위해 백미 100%, 백미와 기장 7:3, 5:5, 3:7 및 기장 100%의 비율로 막걸리를 제조하였다. 발효방법은 Shaking incubator($30{\sim}35^{\circ}C$, 100 rpm, 19 days), Hand Shaking($21^{\circ}C$, per 12hr, 19days)하였고, 발효가 끝난 막걸리는 80 mesh 망으로 여과하였다. 총 폴리페놀 함량은 Machine shaking과 Hand shaking 모두 쌀과 기장의 비율 7:3에 겨우살이를 10% 첨가한 막걸리가 각각 $795.83{\mu}g/ml$, $757.87{\mu}g/ml$로 가장 높았고, 기장 100% 막걸리가 각각 $503.73{\mu}g/ml$, $435.3{\mu}g/ml$로 가장 낮았다. 총 플라보노이드 함량은 Machine shaking, Hand shaking 모두 쌀과 기장의 비율이 7:3에 겨우살이를 10% 첨가한 막걸리가 $93.48{\mu}g/ml$, $84.56{\mu}g/ml$로 가장 높았고, 기장 100% 막걸리가 각각 $37.75{\mu}g/ml$, $21.86{\mu}g/ml$로 가장 낮았다. DPPH free radical 소거능은 겨우살이를 10% 첨가한 막걸 리가 가장 높았는데 Machine shaking은 평균 92.08%, Hand shaking은 평균 91.63%로 가장 높았으며 통계적으로 유의한 차이가 없었다. Machine shaking은 쌀과 기장의 비율이 7:3일 때, 73.37%, Hand shaking은 기장 100% 막걸리가 64.03%로 가장 낮았다. 결론적으로, 총 폴리페놀 및 플라보노이드 함량은 기장의 비율이 증가함에 따라 감소하는 경향을 보였고, DPPH free radical 소거능은 겨우살이를 첨가한 모든 막걸리에서 비교적 높았다. 발효방법은 Machine shaking이 Hand shaking 보다 총 폴리페놀 및 플라보노이드 함량, DPPH free radical 소거능이 비교적 높아 발효방법으로 더 적합하였다.

• Journal of Applied Biological Chemistry
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• v.52 no.2
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• pp.70-76
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• 2009

In order to find out antioxidant principle in pepper leaves, the contents of total ascorbic acid, total phenolic, and total flavonoid compounds from thirteen cultivars were measured by spectrophotometer. The contents of total phenolic and flavonoid compounds ranged from 231 mg/100 g to 516 mg/100 g and from 251 mg/100 g to 689 mg/100 g respectively. Antioxidant effects of pepper leaves were determined by three different in vitro bioassays including DPPH, ABTS, and FRAP. The relationship between ascorbic acid and antioxidant activity showed a positive correlation and significantly high correlation coefficients were observed between the contents of total phenolic and antioxidant assays including DPPH, ABTS, and FRAP. Especially, the antioxidant effect of pepper leaves was in parallel with the contents of flavonoid. These results suggest that flavonoid contents considerably affect antioxidant activity of pepper leaves. Among the various pepper cultivars, pepper leaves showed different level of antioxidant activity. This study will provide good information about antioxidant activity and their compounds of pepper leaves.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.1
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• pp.140-145
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• 2017

Pinus koraiensis cone (PKC) extract was prepared by mixing PKC with sugar at a weight ratio of 1:1 and then removing PKC after incubating the mixture at room temperature for 100 days. The resulting PKC extract was examined for its physicochemical properties and antioxidant activities using Prunus mume fruit extract, which is similar to PKC extract in terms of preparation procedure and product usage, as a control. PKC extract consisted mainly of moisture (21.76%) and sugar (70.03%), leading to high viscosity. PKC extract was apparently yellowish, and therefore its browning index and color intensity were appreciably lower than the control (P=0.0000), indicating that Maillard reaction was not facilitated during fermentation. Compared with the control, PKC extract was not appreciably different in terms of total flavonoid content, whereas its organic acid content and total reducing capacity were significantly lower. Nevertheless, its metal-chelating activity and DPPH radical scavenging activity were comparable to those of the control. In addition, SOD-like activity of PKC extract was 2-fold higher than that of 6.6 mM quercetin, which had a higher total flavonoid content than PKC extract. This indicates that PKC extract contains certain flavonoids with higher antioxidant activities than quercetin. The results show that PKC extract provides antioxidant activity as well as characteristically different sensory properties due to its higher sugar and lower organic acid contents compared with Prunus mume fruit extract.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.415-423
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• 2018

The aim of this study was to evaluate the individual glucosinolate (GSL), total phenol, total flavonoid, and vitamin C content, and antioxidant activity under various light quality condition, mainly focusing on red (R) to far-red (FR) light ratios in three Brassica sprouts (radish, Chinese cabbage, and broccoli). Three R/FR ratio of 0.6, 1.3, and 2.0 were exposed to 5-day old sprouts for 48 h in a controlled environment, and the targeted phytochemical contents and antioxidant activities were compared with three separate control plot of dark, fluorescent, and red:blue 8:2 conditions. Total GSL content was highest in broccoli among the cultivars throughout the respective treatments, and increased with the increasing of R/FR ratio in the broccoli sprouts, while the content showed non-significant results in the Chinese cabbage sprouts. The progoitrin, a major GSL in Chinese Cabbage and broccoli, content decreased by upto 38% and 69%, respectively, with decreasing the R/FR ratio compared to the control plots (fluorescent, red:blue 8:2, and dark condition). The contents of phenol, flavonoid, and vitamin C were lowest in dark condition in all the three Brassica sprouts. The total phenol content and antioxidant activities increased with decreasing the R/FR ratio in all the Brassica sprouts, while total flavonoid and vitamin C content showed different patterns depending upon the Brassica sprouts. These results suggest that additional use of FR is expected to improve the functional quality of Brassica sprouts in different ways.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.924-932
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• 2013

This study investigated the antioxidant activities of processed Deoduck (Codonopsis lanceolata) extracts treated through high-pressure extraction and steaming with fermentation. The antioxidant activities were determined for DPPH and ABTS radical-scavenging activity, SOD-like activity, ferric reducing antioxidant power (FRAP), and $Fe^{2+}$ chelating. Total phenolic and flavonoid contents were also measured. Among eight Deoduck extracts, the S5FDW extract had the highest total phenolic and flavonoid content, 73.9 mg GAE/g and 50.9 mg QUE/g, respectively. The S5FDW extract had the highest DPPH radical-scavenging activity (27%) at a 1.0 mg/mL concentration. The ABTS radical-scavenging activity was highest for S5FDW extract (82.1%) at a 10 mg/mL concentration. The HFDE extract showed the highest SOD-like activity (29.7%) at a 1.0 mg/mL concentration. FRAP was highest in S5FDW extract (140.8 ${\mu}M$) at a 1.0 mg/mL concentration. The DE extract showed the highest $Fe^{2+}$ chelating (46%) at a 1.0 mg/mL concentration. The phenolic and flavonoid contents significantly correlated with the antioxidant activity of several processed Deoduck extracts and was higher in the processed Deoduck extracts compared to the raw Deoduck extracts. Therefore, processing techniques can be useful methods for making Deoduck a more potent and natural antioxidant.

• Journal of Plant Biotechnology
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• v.47 no.3
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• pp.248-253
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• 2020

Moringa (Moringa oleifera), which is native to tropical and subtropical climates, now grows in Korea due to its warming climate. Since it is also imported and used for food and other products in various countries, it is necessary to analyze the properties of moringa being imported into Korea. In this study, the antioxidant activity and total phenol and flavonoid content were high in the leaves and twigs and showed a positive correlation. The mineral content was also high in the leaves and twigs, and potassium ions were the most abundant mineral. In addition, seven phenolic acids (caffeic acid, chlorogenic acid, cinnamic acid, coumaric acid, ferulic acid, gallic acid, and syringic acid) and four flavonoids (kaempferol, myricetin, quercetin, and rutin) were detected in the leaves, twigs, and stems, and the ferulic acid and quercetin content was particularly high. The results of this study can be used as comparative data for domestic moringa growers in the future.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.66-72
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• 2018

Corn stover is known as a good candidate for a functional food ingredient when the main lignocellulosic material, lignin, is used as bioactive materials as form of polyphenolic compounds. The purpose of this study was to determine the microwave extraction conditions under which total phenolic compounds (TPC) and flavonoid contents of corn stover were maximized. Microwave-assisted extracts using sulfuric acid ranging from 0 to 1.0 mol with extraction time between 40 and 240 sec were conducted by using response surface methodology (RSM). Microwave power showed significant effects (p<0.05) and the concentrations of TPC and flavonoids increased with increased level of microwave power and extraction time. The optimum conditions for corn stover extraction were determined as 698.6 W, 240 sec, and 0 mol sulfuric acid, and the predicted value of TPC and flavonoid is 82.4 mg GAE/g DM and 18.1 mg/g DM, respectively. Microwave extraction was evaluated as an economic process with low energy consumption, short extraction and high extraction yield of bioactive including TPC and flavonoids compared to conventional extractions.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.185-190
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• 2017

Antioxidative ability of 50% ethanol extract from leaves of Leucaena leucocephala (Lam.) de Wit was investigated. The extraction yield, total polyphenols and total flavonoids of the ethanol extract were $18.3{\pm}0.40%$, $121.3{\pm}11.04{\mu}g$ gallic acid equivalents/mg and $105.2{\pm}2.77{\mu}g$ quercetin equivalents/mg, respectively. The ethanol extract possessed the antioxidative activities such as free radical, cation radical, and nitrite scavenging activities as well as reducing power and lipid peroxidation inhibitory activity. These antioxidative activities of the ethanol extract increased in proportion to the extract concentration. $EC_{50}$ values for free radical scavenging, cation radical scavenging nitrite scavenging, and reducing power were $133.51{\mu}g/mL$, $667.22{\mu}g/mL$, 2.58 mg/mL, and $250.00{\mu}g/mL$, respectively. Polyphenols and flavonoids are suggested to be the key contributors for the antioxidative ability of the ethanol extract from Leucaena leucocephala leaves.