• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1784-1791
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• 2016

Garlic was subjected to eight different cooking methods (raw, boiling, steaming, microwave cooking, deep-frying, oven-roasting, pan-frying, and pan-roasting) utilized for typical Korean cuisine. Garlic was analyzed for antioxidant activities and physicochemical properties to elucidate effects of cooking. Garlic cooked at higher temperatures showed significantly lower lightness and higher yellowness (P<0.001). In particular, deep-frying and pan-frying resulted in lowest lightness and soluble solid content, indicating that non-enzymatic browning reactions were more facilitated. Compared with raw garlic, all cooked garlic tended to have lower thiosulfinates, presumably due to decomposition into polysulfides and/or leaching into cooking water and oil. Microwave cooking retained organic acids, total reducing capacity, and flavonoids, which can be attributed to low microwave intensity and shorter cooking time under which heat-labile bioactive components might have undergone less decomposition. Cooking significantly increased metal-chelating activity (P<0.001). In addition, oven-roasting and pan-roasting enhanced total reducing capacity and flavonoid content, indicating that thermal treatments increased the extractability of bioactive components from garlic. However, boiling, deep-frying, and pan-frying, in which garlic is in contact directly with a hot cooking medium, reduced antioxidant activities. Deep-frying resulted in largest reduction in DPPH radical scavenging activity of garlic, which correlated well with reduction of total reducing capacity and flavonoid content. The results show that the antioxidant activity of garlic could be affected by cooking method, particularly heat intensity and/or direct contact of the cooking medium.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.67-67
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• 2012

식생활 및 사회 환경 변화에 따라 식품 폐기물이 많이 발생하고 있다. 이 폐기물을 처리하는 데 막대한 비용이 소요되고 환경오염도 심각한 상황이다. 이에 식품 폐기물의 자원화를 통해 자원의 부가가치를 높이고, 처리비용 절감과 함께 환경오염 방지, 새로운 유기소재의 확보 등의 효과를 볼 것으로 사료된다. 본 연구는 바나나 껍질로부터 추출한 물질의 다양한 기능성을 조사하고, 인디고의 환원제로서 유효성을 확인하여 천연염색 분야에 식품 폐기물의 활용 방안을 모색하는데 목적이 있다. 이를 위하여 바나나 껍질은 건조 후 증류수로 $100^{\circ}C$에서 1시간 동안 추출, 농축하여 분말로 만들어 사용하였다. 바나나 껍질 추출물의 기능성을 알아보기 위해 총당분석(Phenol- sulfuric method), 항산화(DPPH radicals 소거활성), 황색포도상구균에 대한 항균성 실험(Paper disc diffusion)을 하였다. 또한 인디고 염색시 화학환원제 대신 이 분말을 사용하였고, 그 환원력 측정은 환원 포텐셜과 염색 실험을 통해 평가하였다. 본 연구에서 제조한 바나나 껍질 추출물은 항산화능이 우수하였고, 높은 당 함량을 나타냈다. 황색 포도상구균에 대한 항균성을 지녀 향후 기능성 물질로서 응용가능성이 클 것으로 전망된다. 바나나껍질 추출물은 합성인디고 환원에 효과적이었다. 인디고 환원은 바나나껍질 추출물을 첨가하면서 바로 시작되고, 24시간 경과 후 최대 염착량과 최고 전압값을 나타냈다. 바나나 껍질 추출물의 농도가 높아질수록 인디고 환원력은 높아지고 염착량도 증가하는 것으로 나타났다. 따라서 바나나 껍질 추출물은 인디고 환원에서 화학물질인 하이드로설파이트를 대체하여 사용할 수 있는 효과적인 천연유기환원제로 사용할 수 있을 것으로 기대된다.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.24-31
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• 2008

Sulfate reducing bacteria (SRB) is universally distributed in the sediment, especially in marine environment. SRB reduce sulfate as electron acceptor to hydrogen sulfide in anaerobic condition. Hydrogen sulfide is reducing agent enhancing the reduction of the organic and inorganic compounds. With SRB, therefore, the degradability of organic contaminants is expected to be enhanced. Ferrous iron reduced from the ferric iron which is mainly present in sediment also renders chlorinated organic compounds to be reduced state. The objectives of this study are: 1) to investigate the reduction of TCE by hydrogen sulfide generated by tht growth of SRB, 2) to estimate the reduction of TCE by ferrous iron generated due to oxidation of hydrogen sulfide, and 3) to illuminate the interaction between SRB and ferrous iron. Mixed bacteria was cultivated from the sludge of the sewage treatment plant. Increasing hydrogen sulfide and decreasing sulfate confirmed the existence of SRB in mixed culture. Although hydrogen sulfide lonely could reduce TCE, the concentration of hydrogen sulfide produced by SRB was not sufficient to reduce TCE directly. With hematite as ferric iron, hydrogen sulfide produced by SRB was consumed to reduce ferric ion to ferrous ion and ferrous iron produced by hydrogen sulfide oxidation decreased the concentration of TCE. Tests with seawater confirmed that the activity of SRB was dependent on the carbon source concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.278-283
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• 2006

Styela clava was processed by four different kinds of method including FR (fresh S. clava), H1 (heat treated S. clava at $110^{\circ}C$ for 15 min) H2 (heat treated S. clava at $120^{\circ}C$ for 5 min), and FD (freeze dried S. clava). Each S. clava sample was treated with methanol, ethanol, acetone, and water, then antioxidant and anticancer activities of the extracts were evaluated. In extracts from non-dried S. clava (FR, H1, and H2), total extract yield decreased with increasing treated temperature. The extraction yield was in the order of ethanol>methanol>water>acetone among treated solvents. In case of dried S. clava (FR), the extraction yield was lower than non-dried samples, and was in the order of methanol>ethanol>water>acetone. The radical scavenging activity (RSA) of non-dried S. clava (FR, H1, and H2) was in the order of acetone>ethanol>methanol and heat treatment also decreased RSA. RSA of FD was the highest in ethanol extract, while acetone and water extracts did not show RSA. When antioxidant activity was determined by reducing power (RD), methanol extract of FR showed the highest values and heat treatment decreased RD, too. RD of FD was in the order of methanol>ethanol>water>acetone. The acetone extracts from FD showed significant anticancer activity against human colon cancer cell line HT-29. These results indicated that extraction yield and properties of extracts from S. clava were dependent on processing temperature, solvent and/or physicochemical state. The appropriate extraction process should provide some valuable bioactive materials from S. clava.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.934-940
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• 2012

Antioxidant activities such as reducing power, electron donating ability(EDA) and oxidation stability of Rumex crispus extracts with ethanol were examined, and adsorption of Pb(II) and Cd(II) with dried Rumex crispus powder in aqueous solution was experimented. Extraction yields based on the soluble solid contents ranged 1.9% to 3.0%, and were inversely proportional to solvent ratio but proportional to extraction temperature. Reducing power and EDA were also increased with extraction temperature but decreased with solvent ratio. These were corresponded to 86.4% and 91.0% of ascorbic acid reducing power and EDA, respectively, on 20 folds of solvent ratio and $75^{\circ}C$ Oxidation stability of Rumex crispus extracts on the corn seed oil was 86~91.3% of butylated hydroxytoluene. Pb(II) adsorptivity of Rumex crispus was higher than Cd(II), and adsorption rate of Pb(II) was 88% in 20 ppm concentration and 60min.

• Food Science and Preservation
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• v.22 no.4
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• pp.577-584
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• 2015

The objective of this study was to investigate the antioxidant activity of imported tropical and subtropical fruits including dragon fruits, green kiwi, papaya, pineapple, pomegranate, and yellow mango. A seventy percent of ethanol extracts were prepared. Total phenolic content, DPPH (1,1-diphenyl-2-picryl hydrazyl)-, ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), superoxide anion radical scavenging activity, FRAP (ferric reducing antioxidant power), tyrosinase inhibitory activity, and reducing power were investigated for the comparisons of antioxidant activities. The phenolic content expressed as gallic acid equivalents (GAE) was found to be highest in pomegranate (12.22 mg GAE/g), followed by pineapple (3.77 mg GAE/g). Pomegranate and pineapple exhibited higher antioxidant activity than those of other fruits except for FRAP. DPPH and ABTS radical scavenging activity from pomegranate were 93.00%, and 98.98%, respectively, at a concentration of 5 mg/mL, which were equal to those of ascorbic acid used for a positive control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1301-1304
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• 2012

Mineral contents of various salts were determined by the ICP-OES method. Bamboo salt (baked 9 times) contained more potassium, calcium, magnesium, and manganese, compared to purified and solar salts. Bamboo salt had a pH of 11.04, higher than those of purified (6.29) and solar (9.13) salts. Contents of [$OH^-$] were measured by using the FT-IR spectra. Bamboo salt exhibited higher reduction potential and contained more OH groups than purified and solar salts. The reduction peak of bamboo salt was observed to be about three times broader than that of solar salt in terms of redox potential amperometry. At a salt concentration of 25%, bamboo salt showed higher radical scavenging activities (81.4%) than solar (5.0%) and purified (2.0%) salts, as evaluated by DPPH assay. Bamboo salt revealed alkaline property, more OH groups and antioxidative activity.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.801-804
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• 2013

The glutathione contents of the selected mutants were investigated and found to be 6.1-15.8 mg/g-DCW. The glutathione content positively correlated with the antioxidant activity of the mutant strains ($R^2$=0.488). Furthermore, the glutathione content of the mutant S. cerevisiae Sa-59 was approximately 38% greater than that of the wild type strain and, therefore, this mutant strain was selected for glutathione production. The volumetric glutathione content in a shaking culture was increased by about 70% compared to the static culture. In addition, the specific glutathione content was increased by ~19%. The volumetric glutathione content and specific glutathione content were increased by approximately 16% and 66%, respectively, when 0.04% glutamate, 0.04% cysteine and 0.04% glycine were added. Furthermore, the highest antioxidant activity was 0.52 as absorbance unit at 700 nm.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.214-219
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• 1993

Properties of the antioxidative fraction isolated from browning reaction product (BRP) that were obtained from 2 M L-ascorbic acid (AsA) solution (adjusted to pH 7.0) by heating for 25 hrs at $85^{\circ}C$ were investigated. Both of dialyzable and nondialyzable fraction isolated from BRP showed antioxidative effect. Dialyzable fraction has stronger antioxidative activity than nondialyzable. Dialyzable fraction was divided into the three fractions (A, B, C) by gel filtration. Among these fractions, the fraction (A) that had the highest reducing power and lowest browning drgree had lowest antioxidative activity. The fraction (C) that had lowest reducing power and highest browning degree showed strongest antioxidative effect. In the UV-visible spectrum of these fractions, the maximum absorption wavelengths of fraction A and B were 266.1 and 257.4nm, respectively, and fraction C showed a weaker absorption peak at 274.8nm. Infrared (IR) spectrum results showed that all fractions (A, B, C) had both hydroxy and carboxylic groups, and fraction B and C had carboxylic ester group.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.38-46
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• 2005

This study was carried out to quantify the rates of anaerobic mineralization and sulfate reduction, and to discuss the potential effects of benthic fauna on sulfate reduction in total anaerobic carbon respiration in Ganghwa intertidal flat in Korea. Anaerobic carbon mineralization rates ranged from 26 to 85 mmol $C\;m^{-2}\;d^{-1}$, which accounted for approximately 46 tons of daily organic matter mineralization in the intertidal flat of southern part of the Ganghwa Island (approximately $90\;km^2$). Sulfate reduction ranged from 22.6 to 533.4 nmol $cm^{-3}\;d^{-1}$, and were responsible for $31{\sim}129%$ of total anaerobic carbon oxidation, which indicated that sulfate reduction was a dominant pathway for anaerobic carbon oxidation in the study area. On the other hand, the partitioning of sulfate reduction in anaerobic carbon mineralization in October decreased, whereas concentrations of Fe(II) in the pore water increased. The results implied that the re-oxidation of Fe(II) in the sediments is stimulated by macrobenthic activity, leading to an increased supply of reactive Fe(II), and thereby increasing Fe(III) reduction to depress sulfate reduction during carbon oxidation.