• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.313-320
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• 2008

Efficiency of a far-infrared radiation (FIR) dryer for drying of citrus by-products (CBPs) was evaluated through their antioxidant activities. The CBPs dried through FIR were enzymatically digested by six carbohydrases (AMG, Celluclast, Pectinase, Termamyl, Ultraflo and Viscozyme) to prepare digests for evaluation of the activities. The total polyphenolic and total flavonoid contents of the digests were determined by colorimetric assays. The AMG digest was selected for the further experiments. The antioxidant potential of the digests were evaluated by DPPH, superoxide, hydroxyl and alkyl radical scavenging activities, $H_2O_2$ scavenging activity, metal chelating, lipid peroxidation inhibition and the reduction of DNA damage. The AMG digest from CBPs dried through FIR at $50^{\circ}C$ showed strong antioxidant activities in DPPH, superoxide, hydrogen peroxide, alkyl and metal chelating assays while all the digests showed strong lipid peroxidation activities. Further, enzymatic digests showed remarkable inhibitory activities against $H_2O_2$-induced DNA damage. Hence, the data obtained using different in vitro models clearly established the antioxidant potential of enzymatic digests from CBPs dried through FIR. Furthermore, they can be used as a source of natural antioxidants; hence, far-infrared radiation drying is a viable method for transforming wet CBPs into a dried form without destroying the bioactive components.

• Mycobiology
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• v.46 no.4
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• pp.382-387
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• 2018

The entomopathogenic fungus Cordyceps militaris is a valuable medicinal ascomycete, which degenerates frequently during subsequent culture. To avoid economic losses during industrialized production, scratching stimuli of mycelia was introduced to improve the fruiting body production. The present results indicated that higher yields and biological efficiency were obtained from two degenerate strains (YN1-14 and YN2-7) but not from g38 (an insertional mutant in Rhf1 gene with higher yields and shorter growth periods). Furthermore, the growth periods of the fruiting bodies were at least 5 days earlier when the mycelia were scratched before stromata differentiation. Three ROS-scavenging genes including Cu/Zn superoxide dismutase (CmSod1), Glutathione peroxidase (CmGpx), and Catalase A (CmCat A) were isolated and their expression profiles against scratching were determined in degenerate strain YN1-14 and mutant strain g38. At day 5 after scratching, the expression level of CmGpx significantly decreased for strain g38, but that of CmSod1 significantly increased for YN1-14. These results indicated that scratching is an effective way to promote fruiting body production of degenerate strain, which may be related at least with Rhf1 and active oxygen scavenging genes.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.43-51
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• 2019

The effects on the radical scavenging activities and hepatic lipid levels in rats fed a high-fat diet (HFD) in the 70% ethanolic extract from Acer tegmentosum Maxim (ATM) were evaluated. Total phenol content of ATM was 168.60 mg catechin/g in the 70% ethanolic extract of Acer tegmentosum. The DPPH and ABTS radical scavenging activities were 18.32 mM TE/g and 32.25 mM TE/g, respectively. Food efficiency ratio was lower significantly in supplemented group with 150 mg/kg BW/day during 5 weeks (HFD+ATM) compared to HFD. Total cholesterol and triglyceride contents in liver tissue of HFD+ATM were lower significantly compared to those of the HFD. Supplementation of ATM significantly decreased lipid peroxide contents and increased radical scavenging activity in the liver tissue compared with that of HFD group. Moreover, the hepatocytes of HFD rats showed a typical fatty liver morphology showing the presence of cytoplasmic lipid droplets, whereas administration of ATM attenuated the number and the size of lipid droplets. In the liver tissue of ATM administrated HFD group, the mRNA levels of SREBP-1c, $PPAR{\gamma}$, and FAS were decreased. Therefore, these results suggest that Acer tegmentosum extracts could have antioxidant activities and the hypolipidemic effects in liver tissue by its phenolic compounds.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.52-57
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• 2006

Metallothioneins(MTs) belong to the class of low molecular weight proteins. Recently, it has been suggested that MTs may playa direct role in cellular defense against oxidative stress by functioning as antioxidants. Oxidative damage to different cellular components makes a major contribution to many pathogenenesses. Several studies have demonstrated that MT is able to quench a wide range of reactive oxygen species at a higher efficiency than other well known antioxidants such as superoxide dismutate(SOD). The present study was designed to evaluate the effect of MT on the activities of the reactive oxygen species removal system. MT showed the scavenging of superoxide in the SOD assay system in the presence or absence of SOD. When MT was added to nicotinamide adenine dinucleotide phosphate(NADPH) oxidation system in presence of fixed amount of SOD increase the breakdown rate of superoxide. When MT was added to the system that form nitrite from hydroxylammonium chloride, the formation of nitrite was inhibit. We concluded that the function of MT as antioxidant might have an effect on the level of superoxide scavenging.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.193-193
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• 2008

Wearable and ubiquitous micro systems will be greatly growing and their related devices should be self-powered in order to avoid the replacement of finite power sources, for example, by scavenging energy from the environment. With ever reducing power requirements of both analog and digital circuits, power scavenging approaches are becoming increasingly realistic. One approach is to drive an electromechanical converter from ambient motion or vibration. Vibration-driven generators based on electromagnetic, electrostatic and piezoelectric technologies have been demonstrated. Among various generator types proposed so far, piezoelectric generator possesses considerable potential in micro system. To overcome low mechanical-to-electric energy conversion, the piezoelectric device should activate in resonance mode in response to external vibration. Normally, the external vibration excretes at low frequency ranging 0.1 to 200 Hz, whereas the resonant frequencies of the devices are fixed as constant. Therefore, keeping their resonant mode in varying external vibration can be one of important points in enhancing the conversion efficiency. We investigated the possibility of use of multi-bender type piezoelectric devices. To match the external vibration frequency with the device resonant frequency, the various devices with different resonant frequency were chosen.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.1
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• pp.55-66
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• 1993

The characteristics of the flow processes in the cylinder of the two-stroke cycle engines have become the subject of increasing and attention owing to the simplicity and the higher power per unit weight of the two-stroke cycle engine. Among the many factors which influence on the scavenging flow, the port angle is important factor. Hence, four different type models with one inlet-port and two side-ports are studied to show the effect of port angle on the laminar scavenging flow. When the inlet-port axial is relatively larger than the side-port axial angle, it is showed that the fresh charge penetrate into the burned gas and displace it first toward the cylinder head and then toward the exhaust port. When the inlet-port axial angle is much less than the side-port axial angle, the fresh charge through the inlet-port directly move toward the exhaust port. The result showed that the model A may suppress the generation of vortices in the vicinity of inlet and side prots which restrict the sufficient supply of fresh charge and obstruct the perfect displacement of all combustion products.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.47-57
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• 2023

In this study, the bioactive activities (antioxidant activity, whitening activity, and anti-wrinkle effect) of dried tapioca-unhulled barley grain residue (TUDDG) obtained after alcohol fermentation, were measured. In the case of DPPH radical scavenging activity, the 50% ethanol extract of TUDDG showed the highest level of about 83% at the concentration of 100 mg/ml, and the ABTS radical scavenging activity was also about 98% of the 50% ethanol extract of TUDDG even at the concentration of 10 mg/mL. In the case of mushroom tyrosinase inhibitory activity, the 50% ethanol extract of TUDDG showed the highest activity at 100 mg/ml concentration of 37%. As a result of collagenage activity inhibition and elastase analysis, the 50% ethanol extract of TUDDG showed high activity with 4.2 mg/mL (IC₅₀) and 26.1 mg/mL (IC₅₀), respectively. Therefore, considering the physiological activity as well as the extraction efficiency of physiologically active substances, the 50% ethanol extract of TUDDG is judged to be highly effective.

• Korean Journal of Veterinary Service
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• v.38 no.2
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• pp.117-125
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• 2015

This study was investigated the effects on the radical scavenging activities and hepatic lipid levels in rats fed a high-fat diet (HFD) by the 70% ethanolic extract from Rubus coreanus. The Rubus coreanus extract (RCE) was administered through the gastrointestinal tract at 150 mg/kg BW/day for 5 weeks (HFD+RCE). Total phenol content was 157.93 mg gallic acid/g in the RCE. Scavenging activities to DPPH, ABTS, an d hydroxyl radicals by RCE significantly increased in a does-dependent manner of $50{\sim}500{\mu}g/mL$ concentration. DPPH and ABTS radical scavenging activities were over the 70% in the $500{\mu}g/mL$ concentration. During the five weeks study, the food efficiency ratio was no significant differences between the HFD and HFD+RCE. Liver weight of HFD+RCE (3.75 g/100 g BW) was significantly decreased compared to those of the HFD. Hepatic triglyceride and total cholesterol levels of HFD+RCE were significantly lower compared to those of the HFD. The hepatic TBARS contents in the HFD+RCE was significantly decreased to the HFD, radical scavenging activity was markedly increased in HFD+RCE as normal group. In histological observation of liver tissues, the hepatocytes of HFD+RCE appeared the reduced aspects on the size and numbers of lipid droplets in cytoplasm compared to the HFD. Our results suggest that RCE could have antioxidant activities and hepatic hypolipidemic effects by its phenolic compounds.

• Journal of Mushroom
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• v.15 no.4
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• pp.195-201
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• 2017

We measured the antioxidant activities of Oak mushroom (Lentinula edodes) in browned sawdust medium under conditions of varying LED sources and amounts of light. Consequently, exposure to 200Lx blue LED resulted in highly efficient browning; the most efficient browning was shown at 200Lx, regardless of the type of luminous source. We identified that quantities obtained with the blue luminous source increased compared to those in other treatment plots. The DPPH radical scavenging test conducted to examine antioxidant activity revealed that the red luminous source caused high radical scavenging compared to efficient browning. The fruiting body for Nongjin-go, as a treatment plot with the highest scavenging, under a 400Lx red luminous source was $34.3{\pm}1.80%$ and that for 'Sanjo 701' at a 300lx red luminous source was $32.99{\pm}1.58%$. The polyphenol content, reported to be correlated with DPPH radial scavenging, showed no similar correlation in the 'Nongjin-go' variety. By contrast, 'Sanjo 701' showed a similar association.

• Journal of Life Science
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• v.23 no.8
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• pp.1019-1024
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• 2013

The aims of this study were to determine antioxidation effect and neuroblastoma cell protection effect of donkey's bone and skin extracts (DBSE). DBSE was extracted by a pressure-cooker for 48 h and lyophilized. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was significantly increased with increased doses of DBSE and 40 mg/ml of DBSE showed 95.43% of the DPPH scavenging effect, which was equivalent to 1 mg/ml of vitamin C. The 2,2'-azino-bis (3-ethylbenzothiazoline-6- sulphonic acid) (ABTS) radical scavenging activity was also increased in a dose-dependent manner, and 20 mg/ml of DBSE showed 88.73% of the ABTS scavenging effect. The oxygen radical absorbance capacity (${\mu}M$ Trolox equivalent) of DBSE was significantly increased at a concentration of 10 mg/ml, which showed $132.53{\mu}M$ TE. The viability of oxidatively stressed brain cells induced by $500{\mu}M\;H_2O_2$ was protected by DBSE at concentrations greater than $50{\mu}M$. Cell viability after DBSE treatment at 50 and $100{\mu}g/ml$ was 53.78 and $54.34{\mu}M$ TE, respectively. There was no significant difference between both doses; however, 200 and $500{\mu}g/ml$ of DBSE showed 59.74 and 66.08% of cell viability, respectively indicating that DBSE protected SK-N-SH from oxidation stress. These results suggest that DBSE may have potential to be used as natural antioxidants in food industry, while in vivo evidence is necessary to support DBSE's in vitro-based antioxidative efficiency.