• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.406-414
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• 2009

The purpose of this study was to examine the effect of hydrogen peroxide at different application time and concentrations on the microtensile bond strength of resin restorations to the deep and the pulp chamber dentin. A conventional endodontic access cavity was prepared in each tooth, and then the teeth were randomly divided into 1 control group and 4 experimental groups as follows: Group 1, non treated; Group 2, with 20% Hydrogen peroxide ($H_2O_2$); Group 3, with 10% $H_2O_2$; Group 4, with 5% $H_2O_2$; Group 5, with 2.5% $H_2O_2$; the teeth of all groups except group 1 were treated for 20, 10, and 5min. The treated teeth were filled using a Superbond C&B (Sun medical Co., Shiga, Japan). Thereafter, the specimens were stored in distilled water at $37^{\circ}C$ for 24-hours and then sectioned into the deep and the chamber dentin. The microtensile bond strength values of each group were analyzed by 3-way ANOVA and Tukey post hoc test(p < 0.05). In this study, the microtensile bond strength of the deep dentin (D1) was significantly greater than that of the pulp chamber dentin (D2) in the all groups tested. The average of microtensile bond strength was decreased as the concentration and the application time of $H_2O_2$ were increased. Analysis showed significant correlation effect not only between the depth of the dentin and the concentration of $H_2O_2$ but also between the concentration of H202 and the application time(p < 0.05), while no significant difference existed among these three variables(p > 0.05). The higher $H_2O_2$ concentration, the more opened dentinal tubules under a scanning electron microscope(SEM) examination.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.171-176
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• 2006

The effect of storage temperature on the quality and antioxidative activity Whangseoke sauce was studied over a period of 240 days. Fermented Whangseoke with $25\%$ salt were stored at $25^{\circ}C$. The quality change and antioxidant activity of Whangseoke in linoleic acid emulsion was evaluated with various parameters including acids values, peroxide values, TBA values, reducing sugar, brown color intensity, electron donating ability and reducing power at various time intervals for 240 days of storage. In general, it was observed, in all sample, that peroxide values, brown color intensity, electron donating ability and reducing power gradually increased, while reducing sugar decreased during storage at $25^{\circ}C$. The antioxidative activities of fermented Whangseoke were determined on tile linoleic acid emulsion system. The results showed that Whangseoke had antioxidant activity. These results suggest that antioxidant activity of Whangseoke seemed to influence by Maillard reaction products during the storage periods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.853-858
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• 2010

The purpose of the study was to determine fat contents and fatty acid compositions of the lipids in sweetfish cultured in Korea and lipid oxidation during storage at refrigeration temperature ($2^{\circ}C$). Whole or minced sweetfish were vacuum-packaged or treated with ascorbic acid. Changes in thiobarbituric acid (TBA) values, peroxide values (PV) and free fatty acid (FFA) in the fish were determined. Sweetfish contained 72.5% moisture, 5.3% lipid and 1.1% ash. Palmitic acid was the highest (27.4% (w/w) of the total fatty acids) among the saturated fatty acids. Total monounsaturated fatty acids (MUFA) were 33.9% and oleic acid (21.0%) was the highest, followed by palmitoleic acid (7.8%). Total PUFA were 28.2%. Predominant PUFA were linoleic acid (8.1%), EPA (5.7%) and DHA (12.1%). TBA values and PV of the whole sweetfish treated with ascorbic acid and vacuumpackaged were not different from the control. TBA values of the minced sweetfish treated with ascorbic acid were significantly lower than the other groups (p<0.05). PV of the fish treated with ascorbic acid and vacuum packaging were significantly lower than the other groups (p<0.05). The result of this study suggests that cultured Korean sweetfish may be a good source of unsaturated fatty acids including EPA and DHA, and vacuum packaging and addition of ascorbic acid may protect lipids from oxidation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.758-765
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• 2016

This study investigated the quality, sensory characteristics, and commercialization potential of a rice snack made from dried anchovy Engraulis japonicus. Mild and spicy snacks were produced using a single extruder, with an oil coating or seasoning, respectively. The approximate respective compositions of the mild and spicy snacks were as follows: moisture 5.20% and 4.71%; crude protein 8.71% and 8.59%: crude lipids 21.14% and 28.5%; ash 1.57% and 1.82%; salt 1.5% and 1.5%; water activity 0.18 and 0.19; and pH 6.31 and 6.28. The peroxide values increased for 30 days after preparation and then decreased from 30 to 90 days. The thiobarbituric acid values increased slightly during storage at $27{\pm}2^{\circ}C$. During storage at $27{\pm}2^{\circ}C$, the lightness and yellowness values were lower for the spicy snack than for the mild snack, while the redness value was higher for the spicy snack. The hardness values of both samples decreased slightly during storage at $27{\pm}2^{\circ}C$. The sensory score of the spicy snack was slightly higher than that of the mild snack. The spicy snack had a higher score than the mild snack in the sensory test, which suggested that the spicy snack made from dried anchovy has more commercial potential.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.443-451
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• 2007

In order to better understand the quality of Korean cactus, Opuntia humifusa, as the functional foodstuffs, it's seeds, stems and fruits were analyzed. In addition, we performed quality evaluation on cookies manufactured with cactus powder added. The results showed the soluble nitrogen-free component levels in the cactus to be very high. The highest component levels were crude fiber(48.75%) and crude fat(7.38%) in the seeds, crude ash(15.39%) in the stems, and moisture(11.26%) and crude protein(8.79%) in the fruits. The antioxidant activities of the cactus were evaluated based on peroxide values(POV), thiobarbituric acid reactive substances(TBARS value), and electron donating ability(EDA) using the DPPH method. The POVs for soybean oil containing a 0.05% concentrated water extract from each part of the cactus revealed a remarkable antioxidant effects on peroxidation as storage time increased. The TBA values were 63.65% in BHT, 60.67% in the stems, 57.31% in the fruits and 49.16% in the seeds. The EDAs were 30.26% in the stems, 25.89% in the fruits, and 25.65% in the seeds. The total polyphenol contents of the water soluble materials from the cactus were 3.14 g/100 g in the fruits, 2.93 g in the stems and 2.11 g in the seeds. For the cookies, as the amounts of fruit and stem powder increased, the spreadness was significantly lowered, but moisture content was increased compared to the control. The color degree of the cookies changed from dim to intense as more fruit powder was added, resulting from a decrease in the L- and b-values and a significantly increased a-value. With the addition of stem powder, the L- and a-values revealed no significant differences, while the b-value was lowered compared to the control as more stem powder added. For texture changes of the fruit cookies, there were significant differences in hardness, gumminess, cohesiveness, springiness and brittleness. The stem cookies, however, showed only differences in hardness, gumminess, and brittleness, and not in cohesiveness and springiness. Finally, an overall sensory preference was found with the 1% fruit powder and 3% stem powder additions.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.849-859
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• 2016

Edible insects have gained recognition worldwide as complementary protein sources. Recently, four edible insects were newly allowed to be used as food materials in Korea: the mealworm (Tenebrio molitor), the cricket (Velarifictorus asperses), the white-spotted flower chaffer beetle larva (Protaetia brevitarsis seulensis), and the rhinoceros beetle larva (Allomyrina dichotoma). In this study, we evaluated the oxidative stabilities of these four edible insects during cold storage. The insects were sacrificed by blanching for 3 minutes in boiling water. The blanched insects were then stored at $4^{\circ}C$ in an incubator for 42 days. The color values, titratable acidity, peroxide values, acid values, TBARS, contents of VBN, and total plate counts of the insects were measured at days 0, 2, 4, 7, 10, 14, 21, 28, 35, and 42, respectively. Blanching decreases oxidative stresses during storage. At day 0, the white-spotted flower chaffer beetle larva showed the highest values for acid value, TBARS, VBN, and microbial counts. Most of the oxidative indicators were significantly changed at day 14 in all four insects, possibly related with the growth on all microbial plates. Based on microbial safety and the oxidative stabilities of lipids and proteins, optimal storage conditions for the cricket, the white-spotted flower chaffer beetle larva, and the rhinoceros beetle larva were 10~14 days at $4^{\circ}C$. Likewise, the mealworm showed rapid oxidation after day 14, but poor qualities were not observed until day 28.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.485-491
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• 1986

Gulbi were made by salting fresh Yellow corvenia (Pseudosciaena manchurica) in three ways; the dry salting method with bay-salt, the dry salting method with purified salt or the abdominal brine injection method with purified salt. Half of the sample was dried by controlling temperature and relative humidity and the other part was dried under the natural condition. The moisture content of the samples were decreased more rapidly by the controlled system than by the natural condition. The lipid content and the iodine values of the muscle and skin of the Gulbi were decreased slowly with laps of drying period. The peroxide values of the sample were increased to its peak after 10 days of drying, and were decreased rapidly thereafter. Both acid values and the thiobarbituric acid values were increased. The deterioration of lipids during Gulbi processing was not notable depending on the salting method, but the natural drying condition affected more severely in their deterioration.

• Korean Journal of Food Science and Technology
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• v.11 no.2
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• pp.93-98
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• 1979

An attempt was made to investigate the antioxidant activity of methylene chloride extracts of a glucose-ammonia browning reaction mixture, which contain pyrazines, important intermediate prod ucts of Maillard-type browning reactions. Methylene chloride extracts were obtained from a glucose-ammonia(1M+8M) browning reaction mixture, which had been heated at $100^{\circ}C$. for 4 hours. The molar ratio of the reactants and the reaction time were reported to be the optimum ratio and time for the maximum formation of pyrazines. The methylene chloride extracts and furfural (for comparison purpose) were added to edible rapeseed oil substrates, and the resulting substrates and the control were stored at $37.0{\pm}1.0^{\circ}C$. Peroxide values (POV), thiobarbituric acid values (TBA-values) and acid values (AV) of the substrates and the control were determined regularly during a 34-day storage period. The antioxidant activity of the methylene chloride extracts and furfural was estimated on the basis of POV, TBA-value and AV-development of the substrates and the control. It was found that the methylene chloride extracts of the glucose-ammonia (1M+8M) browning mixture possessed considerable antioxidant activity. Furfural also showed some activity.

• Korean journal of food and cookery science
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• v.30 no.5
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• pp.509-516
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• 2014

This study aimed to investigate the quality characteristics of iced pumpkin paste cookies prepared using different fat and fatty oils (butter, olive oil, soybean oil, and grape seed oil). The pH, density, and moisture content were the highest in the cookies prepared with butter dough, and the lowest in the cookies prepared with grape seed oil dough. The spread factor of the cookies prepared using with butter was the highest, and the cookie with olive oil, soybean oil and grape seed oil showed lower values. The L values of olive oil cookies, a values of soybean oil cookies, b values of grape seed oil cookies were the highest. The hardness of the cookies prepared using soybean oil was the highest. The overall sensory evaluation showed high overall acceptability for grape seed oil cookies, whereas butter cookies showed lower overall acceptability. The acid value (AV) and peroxide value (POV) were lower in the grape seed oil cookies than in the butter cookies as the storage period of the cookies had passed.

• Korean Journal of Medicinal Crop Science
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• v.8 no.3
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• pp.194-200
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• 2000

The main objective of this study was to characterize physico-chemical properties, sensory property and oxidative stability of safflower seed obtained by various roasting temperature and time. The contents of water soluble solids decreased in the higher roasting temperature and time. Sensory evaluation of safflower seed roasted in various conditions showed significant differences in taste, color, flavor and palatability. The safflower seed roasted at $190^{\circ}C$ for 20min had the best palatability. At the change of Hunter's values, L values were decreased, and a, b and ${\Delta}E$ values were increased in the higher roasting temperature and time. The content of free sugars such as sucrose and raffinose were reduced significantly in higher roasting time of $190^{\circ}C$ and $210^{\circ}C$. During the storage period after roasting treatment, peroxide values (POV) were highly increased after eight months at the all treatment except for $150^{\circ}C$. Therefore, it is inadequate over eight months after roasting treatment.