• Applied Biological Chemistry
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• v.37 no.3
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• pp.168-174
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• 1994

Effects of filtration and centrifugation on the oxidative stabilities of sesame oils during storage at $70^{\circ}C$ were studied by combination of determining peroxide values and conjugated dienoic acid values of oils and measuring the hexanal formation using headspace gas chromatography. Crude sesame oil from roasted seeds contained more free fatty acids, conjugated dienes, and metals (Fe, Cu, Mg and Zn); on the other hand, higher contents of moisture and ${\gamma}-tocopherol$ were found in the filtered or centrifuged oil. Only filtered oil contained more peroxides than the crude oil in spite of the color advantage of the highest L and b values among three oils. All the oils showed the tendency of increasing in total color difference during storage at $70^{\circ}C$, fatty acid compositions were relatively constant except for decreasing tendency of linoleic acid in filtered oil. No significant difference at 1% in the oxidative stabilities was observed between centrifuged oil and crude oil with higher susceptibility to the oxidation in the filtered oil. Centrifuged sesame oil was the best in the aspect of both oxidative stability and the oil color.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.476-486
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• 2016

This study investigated the effect of the powder produced by ball-milling the outer layer of annatto (Bixa orellana L.) seeds on the physicochemical properties as well as the antioxidant and antimicrobial activities of pork patties over 14 d of refrigerated storage (4±1℃). Five pork patty treatments were produced containing three different concentrations of annatto seeds, 0.1, 0.25 and 0.5% (ANT0.1, ANT0.25, ANT0.5), 0.1% ascorbic acid (AA0.1), and a control (CTL). Based on the results, annatto seed powder appeared to show antioxidant activity. The Hunter color values of pork patties were affected by the addition of annatto seed powder, which increased the redness and yellowness values, but decreased the lightness of the patties (p<0.05). To evaluate the antioxidative effects of annatto on pork patties, thiobarbituric acid reactive substances (TBARS) and peroxide values (POV) were analyzed over 14 d of refrigerated storage. Treatments containing annatto seed showed lower TBARS and POV than control (CTL) samples (p<0.05). The volatile basic nitrogen (VBN) of the pork patties containing annatto seeds were lower than that of CTL at the end of storage (p<0.05). Although no differences in total bacterial counts were observed between control and treated patties, those containing annatto seeds had lower microbial counts for Enterobacteriacease than CTL or AA 0.1%. Therefore, annatto seed powder might be a good source of natural antioxidants for the production of meat products.

• Korean Journal of Poultry Science
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• v.30 no.3
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• pp.177-182
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• 2003

This study was carried out to investigate the influence of dietary xanthophylls supplementation on the antioxidant and color properties of broiler meat. After raised for 6 weeks, broilers were slaughtered and stored at 3$^{\circ}C$ for 9 days. Experimental treatments were divided into lutein, canthaxanthin, astaxanthin and capsanthin. The supplementation level was adjusted to 30 ppm. The pH values of the thigh was higher(P<0.05) than those of the breast. No differences in pH values were shown among xanthophylls treatments. Xanthophylls supplementation to chick inhibited the formation of TBARS(Thiobarbituric acid reactive substance) and POV(lipid peroxide) of broiler meat during storage. At 9 day storage, the TBARS and POV of xanthophylls treatment decreased as compared to the control(P<0.05). The broiler meats fed astaxanthin had antioxidant effects in both breast and thigh. Dietary xanthophyll supplementation to chick decreased the CIE L(lightness) and increased a(redness) values of broiler meats fed canthaxanthin increased(P<0.05) during storage. These results indicated that broiler meats fed xanthophylls had dark-red color and antioxidant effect during refrigerated storage.

• Korean Journal of Food Science and Technology
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• v.11 no.2
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• pp.86-92
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• 1979

Antioxidants. BHA, BHT and PG were added to a commercial soybean oil at a level of 200 ppm, and the antioxidant-treated oils and a control oil were subjected to 30 min. heating at $150{\pm}2^{\circ}C$ and 23.5 hr. cooling at room temperature for 6 times. Variations of % antioxidant retention and some physical and chemical properties of the oils were investigated. The results of the present study were as follows. 1. The % retention of BHA, BHT and PG after the second heating and cooling was respectively 60.5, 55.7 and 40.5 %. That of BHA, BHT and PG after the 6th heating and cooling was respectively 5.7, 3.0 and 1.8 %. 2. The refractive indices and viscosity of the oils, including the control, increased slowly at first. but after 4th heating and cooling, these values increased rapidly. The color indices of the oils, including the control, increased very rapidly, but after the 2nd heating and cooling, the rates of the increase diminished considerably. 3. The efficiency of each antioxidant in suppressing peroxide, thiobarbituric acid, and acid value development decreased rapidly as the antioxidant contents of the oils decreased. After the 6th heating and cooling, the peroxide. thiobarbituric acid and acid values of the oils treated initially with the antioxidants did not differ appreciably from those of the control.

• Journal of the Korean Society of Food Culture
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• v.7 no.3
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• pp.213-222
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• 1992

This investigation was undertaken for the purpose of studying the quality and acceptability during storage at room or refrigerator temperature of Yackwa containing waxy rice flour substituted for 0,10,30,50,70% of the wheat flour. The storage periods were 0,15,30 and 45 days. Chemical composition, composition of fatty acids, and value, and peroxide values of Yackwa were measured. Sensory evaluation was done by a panel of 5 judges majoring in food and nutrition. The evaluation was repeated 4 times. Objective evaluation was done by rheometer and color difference meter. Chemical composition of Yackwa were $5.9{\sim}6.8%$ for moisture, $3.43{\sim}4.09%$ for crude protein, $22.35{\sim}27.65%$ for crude fat, $0.27{\sim}0.31%$ for ash, $15.6{\sim}18.4%$ for fructose, $10.6{\sim}13.7%$ for glucose, $0.34{\sim}1.0%$ for sucrose, and $0.79{\sim}2.37%$ for maltose, respectively. Fatty acid contents of Yackwa were $10.54{\sim}10.73%$ for palmitic acid, $4.12{\sim}4.18%$ for stearic acid, $25.8{\sim}26.9%$ for oleic acid, $51.6{\sim}52.1%$ for linoleic acid, and $0.27{\sim}0.34%$ for linolenic acid, respectively. Acid value and peroxide value of Yackwa during storage showed little change. As a result of sensory evaluation for Yackwa made various levels of waxy rice flour, there were no significant differences in most of characteristics between the samples supplemented with waxy rice flour to 30% of wheat flour at 0.01% level. By the color difference meter, the value of L (lightness) and b (yellowness) were increased by increasing the amounts of waxy rice flour, however, there were no significant differences at 0.1% level between the samples supplemented with waxy rice flour to 30% of wheat flour, on the other hand, the value of a (redness) was decreased by increasing the amount of waxy rice flour. In the textural characteristics, brittleness, and chewiness were increased by increasing the amounts of waxy rice flour, and by lengthening the storage period, on the other hand, resilience and cohesiveness showed vice versa. In the correlation coefficient between sensory characteristics and mechanical characteristics, overall acceptability in sensory evaluation correlated significantly with cohesiveness, chewiness, and the values of L, a, and b in mechanical test in most of samples(p<0.001).

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1400-1406
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• 2014

This study investigated the quality characteristics of sea salt coated with coffee oil (SCO). Three-year-old salt was used after drying in an oven at $105^{\circ}C$ for 2 hours. Product A was composed of 100 g of sea salt and 8 g of coffee oil, product B was 100 g of sea salt and 16 g of coffee oil, and product C was 100 g of sea salt, 8 g of coffee oil, and 0.3 g of shell powder. The moisture content, ash content, color, peroxide value, acid value, and sensory evaluation of sea salt coated with coffee oil were determined monthly during 5 months of storage at room temperature. The contents of moisture and ash of SCO were 2~3% and 81~83%, respectively, but not significantly different during the storage period. Calcium content of product C was higher than that of product A or B. Coffee flavor in all SCO products was retained for 3 months. Hunter L, a, and b color values in SCO decreased with increasing storage period. However, redness and yellowness of product B were higher than those of other products. The peroxide and acid values of products A and C were lower than those of product B during storage period. Sensory evaluation during the storage period showed that quality of product A and C was maintained for 4 months, whereas product B was preserved for 3 months.

• Restorative Dentistry and Endodontics
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• v.33 no.5
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• pp.463-471
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• 2008

This study investigated the clinical effectiveness and safety of sealed bleaching compared to conventional in-office bleaching using a randomized clinical trial of split arch design. Ten participants received a chairside bleaching treatment on the upper anterior teeth, and each side was randomly designated as sealed or control side. A mixture of Brite powder (PacDent, Walnut, USA), 3% hydrogen peroxide and carbamide peroxide (KoolWhite, PacDent, Walnut, USA) were used as bleaching agent. The control side was unwrapped and the experimental side was covered with a linear low density polyethylene (LLDPE) wrap for sealed bleaching. The bleaching gel was light activated for 1 hour. The tooth shades were evaluated before treatment, after treatment, and at one week check up by means of a visual shade (VS) assessment using a value oriented shade guide and a computer assisted shade assessment using a spectrophotometer (SP). The data were analyzed by paired t-test. In the control and sealed groups, the visual shade scores after bleaching treatment and at check up showed statistically significant difference from the preoperative shade scores (p<.05). The shade scores of the sealed group were significantly lighter than the control immediately after bleaching and at the check-up appointment (p<0.05). Compared to prebleaching status, the ${\Delta}E$ values at post bleaching condition were $4.35{\pm}1.38\;and\;5.08{\pm}1.34$ for the control and sealed groups, respectively. The ${\Delta}E$ values at check up were $3.73{\pm}1.95\;and\;4.38{\pm}2.08$ for the control and sealed groups. ${\Delta}E$ values were greater for the sealed group both after bleaching (p<.05) and at check up (p<.05). In conclusion, both ${\Delta}E$ and shade score changes were greater for the sealed bleaching group than the conventional bleaching group, effectively demonstrating the improvement of effectiveness through sealing.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3543-3548
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• 2023

Shutdown chemistry evolution is performed in nuclear power plants at each refueling outage (RFO) to establish safe conditions to open system and minimize inventory of corrosion products in the reactor coolant system (RCS). After hydrogen peroxide is added to RCS during shutdown chemistry evolution, corrosion products are released and are removed by filters and ion exchange resins in the chemical volume control system (CVCS). Shutdown chemistry evolution including RCS clean-up time to remove released corrosion products impacts the critical path schedule during RFOs. The estimation of clean-up time prior to RFO can provide more reliable actions for RCS clean-up operations and transients to operators during shutdown chemistry. Electric Power Research Institute (EPRI) shutdown calculator (SDC) enables to provide clean-up time by Co-58 peak activity through operational data from nuclear power plants (NPPs). In this study, we have investigated the results of EPRI SDC by shutdown chemistry data of Co-58 activity using NPP data from previous cycles and modeled the estimated clean-up time by EPRI SDC using average Co-58 activity of the NPP. We selected two RFO data from the NPP to evaluate EPRI SDC results using the purification time to reach to 1.3 mCi/cc of Co-58 after hydrogen peroxide addition. Comparing two RFO data, the similar purification time between actual and computed data by EPRI SDC, 0.92 and 1.74 h respectively, was observed with the deviation of 3.7-7.2%. As the modeling the estimated clean-up time, we calculated average Co-58 peak concentration for normal cycles after cycle 10 and applied two-sigma (2σ, 95.4%) for predicted Co-58 peak concentration as upper and lower values compared to the average data. For the verification of modeling, shutdown chemistry data for RFO 17 was used. Predicted RCS clean-up time with lower and upper values was between 21.05 and 27.58 h, and clean-up time for RFO 17 was 24.75 h, within the predicted time band. Therefore, our calculated modeling band was validated. This approach can be identified that the advantage of the modeling for clean-up time with SDC is that the primary prediction of shutdown chemistry plans can be performed more reliably during shutdown chemistry. This research can contribute to improving the efficiency and safety of shutdown chemistry evolution in nuclear power plants.

• Food Science and Preservation
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• v.16 no.2
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• pp.238-245
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• 2009

The antioxidant effects of chungkukjang, a popular fermented soybean paste in Korea, prepared with solar salt were investigated in vitro. DJI chungkukjang(DJIC) was prepared using 3%(w/w) solar salt or 3%(w/w) refined salt, and fermented by Bacillus subtilis DJI. All of DJIC with no salt, DJIC with 3%(w/w) solar salt, DJIC containing 3%(w/w) refined salt, and commercial chungkukjang were extracted with ethanol, hexane, and water. Antioxidative activities were measured by 1,1-diphenyl-2-picryl hydrazyl(DPPH) free-radical generation, nitrite scavenging activity, peroxide value in the presence of linoleic acid, and the Rancimat test, in comparison with the commercial antioxidant butylated hydroxytoluene(BHT). Ethanol chungkukjang extracts showed the highest antioxdative capacities, whereas DPPH free-radical generation and scavenging activities, and linoleic acid peroxide values of DJIC extracts prepared using solar salt, and salt-free DJIC, showed the greatest values. In addition, extracts of DJIC prepared using solar salt had the highest antioxidant indices. Antioxidative activities were higher in DJIC extracts than in those of commercial chungkukjang. However, the antioxidative capacities of DJIC prepared using solar salt and DJIC with no added salt were less than those of BHT. In conclusion, these results suggest that extracts of chungkukjang prepared using solar salt are useful nutritional antioxidants and that dietary supplementation with such materials would decrease oxidative stress.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.476-487
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• 2021

To prepare acrylic resin coatings containing 70% of solids, we used n-butyl methacrylate(BMA), methyl methacrylate(MMA), 2-hydroxyethyl methacrylate(2-HEMA), and acetoacetoxyethyl acrylate(AAEA), caprolactone acrylate(CLA) as raw materials, the glass transition temperature(T_g) of acrylic copolymer was adjusted around 50 ℃. The viscosity and molecular weight of the acrylic resins was increased with increasing OH values. Di-tert-amyl peroxide was found to be the suitable initiator to get high-solids acrylic resins. The optimum reaction conditions found in the study are 5 wt% of initiator, 4 wt% of chain transfer agent, 4 hrs of dropping time, and 140 ℃ of reaction temperature. The structure of the synthesized resins were characterized by FT-IR and ¹H-NMR spectroscopy. Number average molecular weight of 1900~2600 and molecular wight distribution of 1.4~2.1 were obtained. Crosslinked acrylic urethane clear coatings were obtained by curing reaction between the synthesized acrylic resins and hexamethylene diisocyanate trimer(Desmodur N-3300), the equivalent ratio of NCO/OH was 1.2/1.0. The physical properties from the following studies were carried out: viscosity(Zahn cup #2), adhesion, drying time, pot-life, pensil hardness, and 60° specular gloss. Various properties of the acrylic urethane clear coatings were also evaluated on the coating specimens. Adhesion property to a substrate, drying time, pot-life, pencil hardness, and 60° specular gloss of prepared paint showed quite good properties. Futhermore, prepared paint containing 10% of CLA showed quite good properties for adhesion, low viscosity and high hardness.