• The Korea Journal of Herbology
• /
• v.32 no.4
• /
• pp.39-46
• /
• 2017

Objectives : This study aims to provide basic data about Portulacae Herba (PH) extracts as natural antioxidants by considering diverse antioxidant activities of PH depending on solvents. Methods : The samples of PH were pulverized, and A hot water and a 70% EtOH were stir-extracted for two hours three times repeatedly in a water bath with a temperature of 95 degrees and at room temperature respectively to measure 7 kinds of antioxidant activities. Results : There were significant differences in total phenol content, because the total phenol content of the 70% EtOH extract was higher than the hot water extract's, and the total flavonoid content of the 70% EtOH extract($4.40{\mu}g/mg$) was nearly 3.8 times higher than the hot water extract's($1.16{\mu}g/mg$). DPPH and ABTS radical scavenging activities were 70% EtOH extract showed a little higher activity than the hot water extract, and at a concentration of $500{\mu}g/mg$, the highest scavenging activity was found in the 70% EtOH extract, not in the control group. Hydroxyl radical and $Fe^{2+}$ chelatingactivities were slightly higher in hot water extract than in 70% EtOH extract, and increased in a dose-dependent manner. Nitrite scavenging activities increased dose-dependently in the hot water and the 70% EtOH extract, regardless of the pH level, and scavenging activity of the 70% EtOH extract was higher at pH 1.2 than at pH 3.0. Conclusions : In conclusion, it is thought that PH hot water and 70% EtOH extract have antioxidant activities, and can be used as natural antioxidants in future.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.23 no.2
• /
• pp.109-117
• /
• 2017

Due to the rise of customer's alertness about fresh foods to health, in the past few years, the consumption of fresh food has increased sturdily. The use of gas scavengers is the most appropriate packaging technologies for fresh, fresh-cut produces and in ready to eat products. The gas absorber/scavenger has ability to protect or stabilize the wanted properties and shelf life of food. The success of gas absorbers in food depends on many parameters such as types of foods, storage temperature, relative humidity, initial gas concentration, and the characteristics of package materials. In this review article, we focus on the most recent research trends in gas scavenging systems used in food packaging, future trends. Intense research from industry and engineers remains important to the development of gas scavenging package that fulfill consumer requirements, enhance product quality, and offer environmentally friendly design and cost-effective application.

• Journal of the Korean Society of Food Culture
• /
• v.32 no.2
• /
• pp.144-149
• /
• 2017

This study was designed to investigate the contents of icariin during ripening of Epimedium koreanum with sugar and Soju (25, 30, and 35% alcohol contents) using a homemade method. Contents of icariin of Epimedium wine were examined using high performance liquid chromatography. Icariin levels in Epimedium wine increased during the first 3 days of storage; after 6 days, icariin contents decreased gradually until 30 days. Contents of icariin in Epimedium wine by storage temperature (5 and $20^{\circ}C$) were not different during storage. After 30 days, icaiin was not detected in all tested Epimedium wines. Epimedium wines were assessed for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and (ABTS) radical scavenging activity. DPPH and ABTS radical scavenging activities increased in early storage periods, however, after 6 or 9 days, activities decreased gradually.

• ALGAE
• /
• v.21 no.1
• /
• pp.141-148
• /
• 2006

Benthic diatoms are known as a good food for shellfish in nature and in commercial hatchery of Jeju Island, Korea. Grammatophora marina is commonly found as dominant benthic micro-algae in Jeju coastal waters throughout the year. To know the best growth conditions of this species, culture was done in terms of three parameters; water temperature, salinity and nutrients. Each parameter was controlled by temperature of 15, 20 and 25°C; salinity of 25, 30 and 35 psu; and nutrient concentrations of 50, 100 and 200%. F/2 media was used with artificial seawater for the culture, which was continued for two weeks with L:D cycle 12:12 by using fluorescent light. Maximum specific growth rate was recorded 1.68 d–1 at temperature of 25°C with salinity of 35 psu and nutrient concentration of 200% on 6th day during the culture period. Maximum biomass was also observed 4.9 × 105 cells mL–1 in the same condition. This species may belong to the euryhaline and eutrophic habitat with warm condition. For nutritional aspects of this species, protein, lipid and carbohydrate were measured. The value of protein, lipid and carbohydrate was 4.96%, 15.82% and 5.65%, respectively. The antioxidant activities of 80% methanolic extract were 46.7%, 23.7% and 23.8% on DPPH (1,1-Diphenyl-2-picrylydrazy) radical, superoxide anion radical and hydrogen peroxide scavenging, respectively. Percentage metal chelating activity was 81.2%. Enzymatic extracts of Alcalase and Ultraflow showed remarkable scavenging activities on DPPH radical (86.5% and 57.2%, respectively), and superoxide anion scavenging activities were 45.3% and 41.4% from Kojizyme and Viscozyme extracts, respectively. Extract of Protomex revealed 24.8% activity on hydrogen peroxide and Neutase showed 30.8% on hydroxyl radical scavenging effects. Celluclast and Viscozyme extracts showed 33.2% and 32.1% activities on nitric oxide scavenging, respectively, while Alcalase showed 61.5% on metal chelating. This species contains higher lipids among the biochemical compounds and higher metal chelating activities from both 80% methanolic and enzymatic extracts.

• Food Engineering Progress
• /
• v.15 no.3
• /
• pp.221-229
• /
• 2011

Optimization study of the hot water extraction for enhancing antioxidative activity from Auricularia auricula was performed by Taguchi approach using orthogonal matrix $L_9(3^4)$ method. The correlation between DPPH radical scavenging activity and the components of samples extracted from different extraction conditions were also analyzed. The correlation coefficient between DPPH radical scavenging activity and melanin content of A. auricula were 0.93, indicating 'good correlation'. The optimum extraction conditions was obtained at the extraction time of 1 hr. temperature of $85^{\circ}C$, solid: water ratio of 1: 40(w/v) and frequency of 2 times. Under these conditions, values of maximum DPPH free radical scavenging activity and melanin contents of A. auricula were $67.21{\pm}2.17$ and $52.94{\pm}2.10 mg/g$, respectively. Melanin content of 1.6 times and DPPH free radical scavenging effect of 130% were enhanced by optimization.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.6
• /
• pp.759-764
• /
• 2005

The radical scavenging activity of ethanol, acetone and distilled water extracts of broccoli including leaf, flower, flower plus stem, stem, peel and positive control vitamin C, respectively, were investigated. Each sample under assay condition exhibited free radical scavenging activity (FRSA) toward DPPH radical. Among five samples, S (stem) extracts, F (flower) extracts and L (leaf) extracts of broccoli showed the FRSA in the dot-blot assay. Strong FRSA potential of the ethanol extracts of broccoli revealed at pH $2\~6$ of acid regions and at $60\~80^{\circ}C$. The extracts of green tea and Artermisia were found to have effect against Staphylococcus aureus. Whereas, only the aqueous extracts of broccoli F and FS (flower-stem) of the five extracts marked strong antibacterial activity against Bacillus amyloliquefaciens in high temperature.

• Journal of Ginseng Research
• /
• v.36 no.3
• /
• pp.256-262
• /
• 2012

Reactive oxygen species play critical role in kidney damage. Free radical-scavenging activities of Panax ginseng are known to be increased by heat-processing. The structural change of ginsenoside and the generation of Maillard reaction products (MRPs) are closely related to the increased free radical-scavenging activities. In the present study, we have demonstrated the Maillard reaction model experiment using ginsenoside Re and glycine mixture to identify the renoprotective effect of MRPs from ginseng or ginsenosides. Ginsenoside Re was transformed into less-polar ginsenosides, namely Rg2, Rg6 and F4 by heat-processing. The free radical-scavenging activity of ginsenoside Re-glycine mixture was increased in a temperature-dependant manner by heatprocessing. The improved free radical-scavenging activity by heat-processing was mediated by the generation of antioxidant MRPs which led to the protection of LLC-PK1 renal epithelial cells from oxidative stress. Although the free radical scavenging activities of less-polar ginsenosides were weak, they could protect LLC-PK1 cells from oxidative stress. Therefore, MRPs and less-polar ginsenosides contributed to the combined renoprotective effects against oxidative renal damage.

• Journal of Marine Bioscience and Biotechnology
• /
• v.1 no.4
• /
• pp.252-259
• /
• 2006

Extracts which were prepared by four different extractions - 80% methanol extracts (ME) at high ($70^{\circ}C$) and a room temperature ($20^{\circ}C$), respectively and aqueous extracts (AE) at both temperatures with the residue after the methanol extracts - of 10 green, 19 brown and 25 red seaweeds collected in Jeju Island coast were examined for their DPPH free radical scavenging activity using a ESR (electron spin resonance) spectroscopy. A variety of the extracts showed positive scavenging effect against DPPH free radical (except the green seaweeds). Among the extracts, the brown seaweed extracts exhibited the highest scavenging activity. Especially, Sargassum spp. of the brown seaweeds have remarkable scavenging activities - both methanolic and aqueous at the both temperatures ($20^{\circ}C$ and $70^{\circ}C$). On the other hand, ME showed better scavenging activity than AE in the red seaweed extracts. These results indicate that autogenous seaweeds in Jeju will be potential natural antioxidants for functional food compounds.

• Food Engineering Progress
• /
• v.21 no.3
• /
• pp.256-266
• /
• 2017

This study was designed to optimize ethanol extraction process of unfertilized corn silk (UCS) to maximize phytochemical contents and bioactivities. The response surface methodology (RSM) with central composite design (CCD) was employed to obtain the optimal extraction conditions. The influence of ethanol concentration, extraction temperature and extraction time on total polyphenol contents, total flavonoid contents, maysin contents, 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activities and tyrosinase inhibition were analyzed. For all dependable variables, the most significant factor was ethanol concentration followed by extraction temperature and extraction time. The following optimum conditions were determined by simultaneous optimization of several responses with the Derringer's desirability function using the numerical optimization function of the Design-Expert program: ethanol concentration 80.45%, extraction temperature $53.49^{\circ}C$, and extraction time 4.95 h. Under these conditions, the predicted values of total polyphenol contents, total flavonoid contents, maysin contents, DPPH radical scavenging activity and tyrosinase inhibition were $2758.74{\mu}g\;GAE/g$ dried sample, $1520.81{\mu}g\;QUE/g$ dried sample, 810.26 mg/100g dried sample, 56.86% and 43.49%, respectively, and the overall desirability (D) was 0.74.

• Korean Journal of Food Science and Technology
• /
• v.40 no.3
• /
• pp.283-289
• /
• 2008

This study used response surface methodology (RSM) in an effort to optimize the hot water extraction conditions of dandelion leaves in order to increase antioxidant activity in the extract. A central composite design was applied to investigate the effects of independent variables, which included the ratio of solvent to sample ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables of the extracts, including soluble solid ($Y_1$), total polyphenols ($Y_2$), total flavonoid ($Y_3$), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability ($Y_4$), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability ($Y_5$), and superoxide radical scavenging ability ($Y_6$). The estimated optimal conditions were as follows: $83.77{\pm}1.07^{\circ}C$ of the extraction temperature, $20.85{\pm}0.24 mL/g$ of solvent per sample, and $1.59{\pm}0.12$ hr of extraction time. At the optimal conditions, the predicted characteristic values were: a yield of 38.98%, a total polyphenol level of $74.28{\mu}g/mg$, a total flavonoid level of $74.00{\mu}g/mg$, a DPPH radical scavenging ability ($IC_{50}$) of 0.14 mg/mL, a ABTS radical scavenging ability ($IC_{50}$) of 3.24 mg/mL, and a superoxide radical scavenging ability ($IC_{50}$) of 2.49 mg/mL.