• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1304-1308
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• 2006

The present study describes the preliminary evaluation of the antioxidant activity and the cytotoxic effect of Ceramium kondoi. The antioxidant activities and cytotoxic effect of the water extracts were evaluated by total phenolic contents (TPC), DPPH radical scavenging activity (RSA), reducing power (RP), comet assay, and MTT reduction assay. TPC, DPPH RSA, and RP of the extract at the concentration of $1,000{\mu}g/mL$ was $659.2{\mu}M$, 86.0%, and 1.084, respectively, and those were concentration dependent. The $200{\mu}M\;H_2O_2-induced$DNA damage was inhibited by C. kondoi water extract in a dose dependent manner in human leukocytes. The inhibition was by 62.3, 39.8, 24.8% and 16.4% at the concentration of 5, 10, $25{\mu}g/mL$ and $50{\mu}g/mL$, respectively. Cytotoxic activity on HT-29 cells and MCF-7 cells of the C. kondoi water extract at the concentration of $10{\mu}g/mL$ was 49% and 60%, respectively. These results strongly support the possibility of C. kondoi as a source of natural functional materials.

• Journal of Life Science
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• v.20 no.7
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• pp.1107-1112
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• 2010

In this study, the stable maintenance of bioactivity in alkaline ionized water (AIW) and antibacterial effects of AIW were evaluated to confirm benefits of AIW. As controls, purified water (PW) and tap drinking water (DW) were used. The pH and ORP (oxidation-reduction potential) of AIW, PW and DW used were 9.5 and 120 mV, 7.2 and 144 mV, and 7.3 and 564 mV, respectively. High level of minerals was observed in DW (DW>AIW>PW of mineral contents). Concentrations of $Ca^{++}$ and $Na^+$ in DW were 14.5, and 8.4 mg/l, respectively, while no $Ca^{++}$, $Mg^{++}$, $K^+$, and $Na^+$ were detected in PW. Evaluation of antioxidant activities for AIW, PW and DW showed that the waters did not act as antioxidants. However, the DPPH (1,1-diphenyl-2-picryl hydrazyl) or superoxide radical scavenging activities or reducing power of vitamin C were stably maintained in AIW and PW, though not in DW, against heat treatment ($60^{\circ}C$) or vigorous shaking (120 rpm) at $37^{\circ}C$. Similarly, after aspirin treatment at $60^{\circ}C$ for 1 hr, the antithrombosis activity in PW and AIW was 62.6% and 55.3%, while that of DW was 52.1%. Furthermore, cell growth analysis and viable cell count of Escherichia coli H7:O157 in PW, AIW and DW showed that AIW and DW, not DW, have antibacterial activities. Our results suggest that the state of water, for example pH, ORP and mineral contents of water, should be considered in medicine or food industries, and that AIW has high potential for utilization in various fields.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1481-1486
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• 2010

In this study we investigated the antioxidant activities and quality characteristics of Halocynthia aurantium and Halocynthia roretzi. The pH of H. aurantium was higher than that of H. roretzi. The volatile basic nitrogens of H. roretzi and H. aurantium were 22.41 mg% and 16.80 mg%, respectively. Lightness and yellowness of H. roretzi were higher than those of H. aurantium, but redness of H. aurantium was higher. The results of sensory evaluation showed that the H. aurantium was better for color, odor, taste and acceptability. Total combined amino acid contents of H. roretzi and H. aurantium were $36368.23\;{\mu}mol/g$ and $36500.12\;{\mu}mol/g$, respectively. Our results showed that H. roretzi had relatively higher contents of Asp, Glu, Gly, DPPH radical scavenging activity, ABTS radical scavenging activity and reducing power. Also total phenol content of H. roretzi was higher than that of H. aurantium. The organoleptic properties of the H. aurantium were superior but the antioxidant activities were relatively lower than those of H. aurantium. For commercial usage, additional study would be helpful in the two ascidians to recommend.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.41-50
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• 2012

The study was carried out to analyze the relationship between analysis of antioxidant activity and the level of functional components according to particle size of corn silk. Particle size was classified into 5 groups. By particle size distribution and color difference, the total phenol content and DPPH radical scavenging activity were observed. The particle sizes of corn silk were $199.17{\mu}m$, $178.27{\mu}m$, $85.48{\mu}m$, $27.4{\mu}m$ and $20.97{\mu}m$, respectively. The lightness of colored pigments was increased when the particle size was decreased. The contents of free sugar (fructose, glucose, galactose, sucrose, and maltose) of corn silk were analyzed using a HPLC. The total phenol contents by the particle sizes of corn silk were 2.01 mg/g, 2.02 mg/g, 2.06 mg/g, 2.26 mg/g and 2.26 mg/g, respectively. DPPH radical scavenging activities of samples were 21.00%, 21.75%, 22.90%, 24.35% and 23.67%, respectively. Antioxidative activities of Trolox and Fe(II) in corn silk were measured by ferric reducing antioxidant power (FRAP) assay and Trolox equivalent antioxidant capacity (TEAC) assay. TEAC values of samples were $2.36{\mu}mol$ TE / g dw, $2.81{\mu}mol$ TE / g dw, $3.20{\mu}mol$ TE / g dw, $3.36{\mu}mol$ TE / g dw, and $3.44{\mu}mol$ TE / g dw, respectively. FRAP values of samples were $11.67{\mu}mol$ Fe(II) / g dw, $12.80{\mu}mol$ Fe(II) / g dw, $13.43{\mu}mol$ Fe(II) / g dw, $13.85{\mu}mol$ Fe(II) / g dw and $15.95{\mu}mol$ Fe(II) / g dw, respectively. Total phenolic content and antioxidantive activities based on FRAP assay and TEAC assay were increased with decreasing particle size. In addition, DPPH radical scavenging activity was also increased. A significant correlation was also noted between DPPH radical scavenging activities and the content of phenolic compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.840-846
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• 2015

We investigated blueberry wine made using traditional yeast (Saccharomyces cerevisiae M-5) and Saccharomyces cerevisiae Fermivin which is widely used in wine manufacturing, and measured its fermentative characteristics and antioxidant activity. S. cerevisiae M-5 is a traditional yeast isolated from domestically grown Black raspberry (Rubus occidentalis). Both S. cerevisiae M-5 and Fermivin were inoculated into blueberry juice (BBJ) up to $1{\times}10^9CFU/kg$, followed by incubation at $25^{\circ}C$ for 39 days. Final fermentation products of blueberry fermented with S. cerevisiae M-5 (BBM) presented 13.10% alcohol, $8.42^{\circ}Bx$ of sugar, and 1.183% acidity, and final fermentation products of blueberry fermented with Fermivin (BBF) presented 14.20% alcohol, $8.2^{\circ}Bx$ of sugar, and 1.153% acidity. The contents of total polyphenol and flavonoid compounds of BBM were higher than those of BBF and BBJ. DPPH and ABTS radical scavenging activities and reducing power of BBM were higher than those of BBF. The sensory evaluation revealed that BBM showed excellent flavor, taste, and overall acceptability compared with BBF. Based on these results, the possibility of industrial utilization of S. cerevisiae M-5 as traditional yeast was confirmed by sensory evaluation and antioxidant activity. Fermentation rate of S. cerevisiae M-5 was similar to Fermivin, which is used in the food industry.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.339-346
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• 2022

This study was performed to investigate the quality characteristics and antioxidant activity of black soybean Sunsik product with functional food ingredients and functional labeling system. We prepared black soybean Sunsik (BS) containing black beans, cereals, and vegetables. Black soybean Sunsik with nondigestible maltodextrin and calcium lactate (BSN) was prepared by adding non-digestible maltodextrin and calcium lactate to the base recipe to apply a functional labeling system. The particle size in BS was 118.00 ㎛, whereas BSN was 127.00 ㎛. The respective L, a, and b color values of BS were 73.25, 2.36, and 14.21. The respective L, a, and b values of BSN were 73.21, 2.36, and 14.31. The respective water retention capacities of BS and BSN were 241.67% and 216.33%. No significant difference was observed between BS and BSN in the three physicochemical properties described above. However, the pH of BSN was 5.45, which was significantly lower than that of BS. The total respective phenolic contents of BS and BSN were 1.75 mg GAE/g and 1.61 mg GAE/g, and total respective flavonoid contents of BS and BSN were 6.36 mg RE/g and 5.95 mg RE/g. The antioxidant capacities of BS and BSN were compared via assays of DPPH and ABTS radical scavenging activities, FRAP, and reducing power. The antioxidant activities of BS and BSN increased in a dose-dependant manner. No significant difference between BS and BSN was observed in any measure of antioxidant capacity. These results suggested that the addition of functional food ingredients (non-digestible maltodextrin and calcium lactate) did not affect the quality characteristics and antioxidant activity of black soybean Sunsik.

• Journal of Life Science
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• v.33 no.12
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• pp.1052-1061
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• 2023

This study was carried out to evaluate the effect of fermentation by B. subtilis (BPLE), L. brevis (LPLE), S. cerevisiae (SPLE) and C. militaris (CPLE) on the antioxidant activity of Protaetia brevitarsis larvae fed with mushroom substrates (king oyster mushroom). The total polyphenol content of Protaetia brevitarsis larvae (PLE), BPLE, LPLE, SPLE and CPLE were 58.07±0.67, 83.33±0.98, 79.21±1.32, 61.02±0.87 and 57.90±1.02 mg GAEs/extract g, respectively. The flavonoid contents of the PLE, BPLE, LPLE, SPLE and CPLE were 17.35±1.57, 19.49±0.95, 16.90±1.57, 18.12±0.95 and 16.99±0.95 mg QEs/extract g, respectively. The DPPH radical scavenging activity showed no significant difference between the PLE, BPLE, LPLE, SPLE and CPLE at a concentration of 0.2 mg/ml. However, at a concentration of 0.4 mg/ml or more, the DPPH radical scavenging activity of the BPLE and LPLE was higher than that of the PLE. The reducing power of the BPLE and LPLE was also higher than that of the PLE, and more than twice as high at a concentration of 0.8 mg/ml or more. The ORAC value of the BPLE (79.77±0.82 uM TEs/extract g) was higher than that of the PLE (61.34±0.97 uM TEs/extract g). A WST-1 assay of the RAW 264.7 cells indicated that the PLE, BPLE, LPLE, SPLE and CPLE showed no cytotoxicity.

• Economic and Environmental Geology
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• v.56 no.4
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• pp.421-433
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• 2023

The final disposal of spent nuclear fuel(SNF) from nuclear power plants takes place in a deep geological repository. The metal canister encasing the SNF is made of cast iron and copper, and is engineered to effectively isolate radioactive isotopes for a long period of time. The SNF is further shielded by a multi-barrier disposal system comprising both engineering and natural barriers. The deep disposal environment gradually changes to an anaerobic reducing environment. In this environment, sulfide is one of the most probable substances to induce corrosion of copper canister. Stress-corrosion cracking(SCC) triggered by sulfide can carry substantial implications for the integrity of the copper canister, potentially posing a significant threat to the long-term safety of the deep disposal repository. Sulfate can exist in various forms within the deep disposal environment or be introduced from the geosphere. Sulfate has the potential to be transformed into sulfide by sulfate-reducing bacteria(SRB), and this converted sulfide can contribute to the corrosion of the copper canister. Bentonite, which is considered as a potential material for buffering and backfilling, contains oxidized sulfate minerals such as gypsum(CaSO4). If there is sufficient space for microorganisms to thrive in the deep disposal environment and if electron donors such as organic carbon are adequately supplied, sulfate can be converted to sulfide through microbial activity. However, the majority of the sulfides generated in the deep disposal system or introduced from the geosphere will be intercepted by the buffer, with only a small amount reaching the metal canister. Pyrite, one of the potential sulfide minerals present in the deep disposal environment, can generate sulfates during the dissolution process, thereby contributing to the corrosion of the copper canister. However, the quantity of oxidation byproducts from pyrite is anticipated to be minimal due to its extremely low solubility. Moreover, the migration of these oxidized byproducts to the metal canister will be restricted by the low hydraulic conductivity of saturated bentonite. We have comprehensively analyzed and summarized key research cases related to the presence of sulfates, reduction processes, and the formation and behavior characteristics of sulfides and pyrite in the deep disposal environment. Our objective was to gain an understanding of the impact of sulfates and sulfides on the long-term safety of high-level radioactive waste disposal repository.

• Food Science and Preservation
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• v.20 no.6
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• pp.784-790
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• 2013

The quality characteristics of Campbell grape juice with different extraction processes (AE; autoclave extraction, HWE: hot water extraction, and EE: enzyme extraction) were investigated. The juice yields of the AE, HWE, and EE juices were 79.8%, 82.3% and 92.6%, respectively. The titratable acidity and soluble solids of the EE juice were significantly higher than those of the other extracts. There was no significant difference in the $L^*$ values of the juices, but the $a^*$ and $b^*$ values of the EE juice were higher than those of the other extracts. The viscosity of the HWE and EE juices was higher than that of the AE juice. The major free sugars in the grape juice were identified as glucose and fructose, and the highest organic acid content was found in the EE juice. The total polyphenol content of the EE juice was 55.7 mg% and was higher than those of the AE and HWE juices, which were 31.3 mg% and 39.5 mg%, respectively. Especially, the anthocyanin content of the EE juice was 22.1 mg%, which was two to four times higher than those of the AE and HWE juices, which were 4.5 mg% and 10.5 mg%, respectively. The EE juice showed the highest antioxidant effect, measured from the DPPH free radical scavenging activity and reducing power. In conclusion, we suggest that the enzyme treatment in the grape extraction was more effective than the autoclave and hot water methods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.765-770
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• 2017

Green tea (Camellia sinensis L.) is consumed as a popular beverage worldwide, particularly in Asia. In this study, the effects of green tea powder addition on the antioxidant activities and texture properties of cooked rice were investigated. Texture analysis was carried out by texture profile analysis. Total polyphenols and total flavonoids were determined using spectrophotometric methods, and antioxidative activities were determined based on DPPH and ABTS radical scavenging activities, reducing power, and lipid peroxidation inhibitory activity. Antioxidant contents and antioxidative activities increased with a higher amount of green tea powder. However, there was no difference in texture properties between cooked rice with green tea powder and the control group. In conclusion, addition of green tea powder to cooked rice would be useful to increase antioxidant contents and antioxidative activities without alteration of texture properties.