• Title/Summary/Keyword: stored temperature

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THE COMPARATIVE STUDY FOR THE SHEAR BOND STRENGTH OF DENTAL ADHESIVES CURED WITH VARIOUS LIGHT SOURCES (다양한 광원으로 중합한 치과용 접착제의 전단강도에 관한 비교 연구)

  • Choi, Nam-Ki;Cho, Seong-Hoon;Kim, Seon-Mi
    • Journal of the korean academy of Pediatric Dentistry
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    • v.38 no.1
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    • pp.33-41
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    • 2011
  • The objective of this study was to compare the shear bond strengths of five dentin adhesive systems cured with three different light curing sources. Seventy five noncarious permanent teeth were collected and stored in an 0.1% thymol solution at room temperature after extraction. The tested adhesives were: Adper Scotchbond Multi-purpose Plus Adhesive (SM) Adper Single bond 2 (SB), Clearfil SE Bond (SE), Adper Prompt L-Pop (PL), G-Bond (GB). And three light curing unit systems were used: Elipar Free light 2(LED), OptiLux 501 (Halogen), Flipo (PAC). For the shear bonding test, the labial and lingual surfaces of permanent teeth were used. To obtain a flat dentin surface, the labial and lingual surfaces of the teeth were sanded on SiO2 with number 600 grit and then divided into 15 groups of 10 surfaces each. All samples were theromocycled in water $5^{\circ}C$ and $55^{\circ}C$ for 1000 cycles. The results were as follows: 1. When cured with Freelight 2, the shear bond strength of SM was significantly higher than that of PL, GB (p<0.05), whereas no significant difference was found among those of any other bonding agents. 2. When cured with Optilux 501, the shear bond strength of SM was significantly higher than those of any other bonding agents (p<0.05), whereas no singnificant difference was found among those of andy other bonding agents. 3. When cured with Flipo, the shear bond strength of SM was significantly higher than those of SB, SE, GB (p<0.05), whereas no significant differences was found among those of any other bonding agents. 4. For comparison according to three different light cure unit system, except SB and GB, each three dentin bonding agents showed no significant difference. For SB, only Freelight 2 was significantly higher than the others, with no significant difference between Optilux 501 and Flip. For GB, Statistically significant difference was found only between Freelight and Flipo.

Effects of Chitosan on Quality and Shelf-life of Paeksulgis Added Chitosan (키토산 첨가에 따른 백설기의 품질특성 및 저장성)

  • 정현숙;박찬성;노홍균
    • Food Science and Preservation
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    • v.8 no.4
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    • pp.427-433
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    • 2001
  • The purpose of this study was to investigate the effect of chitosan on the shelf-life and quality of Paeksulkis(Korea rice cake). Paeksulgis containing 0-0.5% chitosan were stored at 5$^{\circ}C$ for 4 week and 2$0^{\circ}C$ for 1 week to test the effect of extenting shelf-life of Paeksulgis by chitosan. The pH of Paeksulkis was 5.65 without chitosan and pH of those were about 7.0(6.94-7.01) with 0.05-0.5% level of chitosan. Moisture content of Paekrukis wish or without chitosan was 38-40%. In Hunter’s color values of Paeksulkis of control, the lightness (L) was 84.28, redness(a) was -1.56 and yellowness(b) was 7.68. The lightness (L), redness(a) and yellowness(b) of Paeksulkis were increased by the increasing concentration of chitosan. In mechanical characteristics, cohesiveness concentration of Paeksulkis were the highest in control while obtained the highest score in color, after swallowing and overall quality (p<0.05). The score of flavor and consistency of Paeksulkis with different levels of chitosan wre not significant while the score of moisture in Paeksulkis with 0.05-0.5% level of chitosan was significantly higher than control (p<0.05). The score of flavor and consistency of Paeksulkis with different levels of chitosan were not significant while the score of moisture in Paeksulkis with 0.05-0.5% level of chitosan was significantly higher than control (p<0.05). Total bacterial counts (TBC) of Paeksulgis immediately before storage were 4.2$\times$10$^2$CFU/g in control and those containing 0.3-0.5% of chitosan were 0.5-1.0 log cycle lower than control. TBC of Paelsulgis containing chitosan was lower than increased for 2 weeks, reached at 1.8$\times$10$^{5}$ CFU/g and decreased for 2 weeks, reached at 1.8$\times$10$^4$CFU/g during storage at 5$^{\circ}C$. TBC of Paeksulkis with more than 0.3% of chitosan were 1.9 log cycles lower than that of control during storage at 5$^{\circ}C$. TBC of Paeksulkis with more than 0.3% of chitosan were 1.9 log cycles lower than that of control during storage at 5$^{\circ}C$ for 4 weeks. TBC of Paeksulgis increased to 10$^{8}$ CFU/g in control and 10$^{6}$-10$^{7}$ CFU/g in more than 0.3% chitosan during storage at 20$^{\circ}C$ for 1 week. The shelf-life of Paeksulkis was increased with increasing concentration of chitosan both temperature at 5$^{\circ}C$ and 20$^{\circ}C$.

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The Effect of Hen Age on Egg Quality in Commercial Layer (실용산란계의 산란연령이 계란의 품질에 미치는 영향)

  • Lee, Min Hee;Cho, Eun Jung;Choi, Eun Sik;Bang, Min Hee;Sohn, Sea Hwan
    • Korean Journal of Poultry Science
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    • v.43 no.4
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    • pp.253-261
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    • 2016
  • Egg quality is a very important factor for both consumers and producers. Factors affecting egg quality include strain and age of hens; egg storage temperature, time, and humidity; laying season; and feeding. This study aimed to determine the effect of hen age and egg storage time on egg quality. A total of 700 eggs obtained from Hyline Brown commercial layers were used for this experiment, and they were separated into two hen age groups (30 vs. 60 weeks) with eight treatments and four storage times (day 0, 10, 20, and 30). The egg weight; shell color, thickness, and density; albumen height; Haugh unit (HU); yolk color; and the yolk and albumen pH and viscosity were measured for the egg quality assessment. The results showed that the age of the hen and egg storage time significantly affected almost all parameters of the internal and external egg quality. The shell thickness, albumen height, HU, yolk color, pH of yolk and albumen, and yolk viscosity significantly decreased with increasing hen age. The egg shell color was significantly lighter in eggs from 60-week-old hens than in those from 30 weeks-old hens. The egg weight; shell weight, thickness, and density; albumen height, HU; and albumen viscosity significantly decreased, but the yolk color and pH of the yolk and albumen increased with increasing egg storage time. The interaction effects between the storage time and hen age were significant in shell thickness, albumen height, yolk color, and yolk and albumen pH and viscosity. The eggs obtained from 60-week-old hens showed significantly lower shell thickness, albumen height, and HU values, which are considered typical egg quality measurements, than values of eggs from 30-week-old hens. Therefore, increasing hen age and egg storage time caused the deterioration of egg quality. In conclusion, this study demonstrated that hen age is the major factor affecting the quality of fresh eggs, whereas the storage time is the determinant factor affecting the quality of stored eggs.

Quality change of mini sweet pumpkins (suppress cultivation, fall planting) during storage at different conditions (가을작형 억제재배 미니단호박의 저장조건별 품질 변화)

  • Oh, Bong-Yun;Jo, Gyeong-Suk;Lee, You-Seok;Kang, Jeong-Hwa;Jang, Mi-Hyang;Hwangbo, In-Sik
    • Food Science and Preservation
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    • v.22 no.6
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    • pp.779-787
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    • 2015
  • We stored sweet pumpkins at $8^{\circ}C$, $12^{\circ}C$, $12^{\circ}C$ plasma curing and room temperature (control) for 180 days. During this time, the quality characteristics were analyzed within the different groups. No spoiling occurred in either of the storage conditions for up to 120 days, and the marketability was good. After 120 days, spoiling sharply increased by over 70% in the control group, while in the $12^{\circ}C$ group it decreased to 20~60%. Conversely, spoiling was completely absent in the $8^{\circ}C$ and $12^{\circ}C$ plasma curing groups during the overall 180 days of storage. The lowest moisture content was found in the $8^{\circ}C$ group and the quality of the pumpkins was excellent during the entire storage period. The color of pulp was better in the $12^{\circ}C$ and $12^{\circ}C$ plasma curing groups, with best results were found in the latest. Both the $8^{\circ}C$ and $12^{\circ}C$ plasma curing groups maintained their dark green surface colors, while both the $12^{\circ}C$ and control groups turned from green to yellow. All groups showed a reduction in their initial hardness, with the $8^{\circ}C$ group staying the hardest. Soluble solid and mealiness was increased to the storage during 90 days while decreased, that were long to maintain the mealiness texture in the $8^{\circ}C$ storage pumpkin. The overall acceptability from sensory evaluation was higher in the $12^{\circ}C$ plasma curing group, when compared to those of the $8^{\circ}C$, $12^{\circ}C$ and control groups storage conditions.

FRACTURE RESISTANCE OF THE THREE TYPES OF UNDERMINED CAVITY FILLED WITH COMPOSITE RESIN (복합 레진으로 수복된 세 가지 첨와형태 와동의 파절 저항성에 관한 연구)

  • Choi, Hoon-Soo;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.33 no.3
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    • pp.177-183
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    • 2008
  • It was reported that esthetic composite resin restoration reinforces the strength of remaining tooth structure with preserving the natural tooth structure. However, it is unknown how much the strength would be recovered. The purpose of this study was to compare the fracture resistance of three types of undermined cavity filled with composite resin with that of non-cavitated natural tooth. Forty sound upper molars were allocated randomly into four groups of 10 teeth. After flattening occlusal enamel, undermined cavities were prepared in thirty teeth to make three types of specimens with various thickness of occlusal structure (Group $1{\sim}3$). All the cavity have the 5 mm width mesiodistally and 7 mm depth bucco-lingually. Another natural 10 teeth (Group 4) were used as a control group. Teeth in group 1 have remaining occlusal structure about 1 mm thickness, which was composed of mainly enamel and small amount of dentin. In Group 2, remained thickness was about 1.5 mm, including 0.5 mm thickness dentin. In Group 3, thickness was about 2.0 mm, including 1 mm thickness dentin. Every effort was made to keep the remaining dentin thickness about 0.5 mm from the pulp space in cavitated groups. All the thickness was evaluated with radiographic Length Analyzer program. After acid etching with 37% phosphoric acid, one-bottle adhesive (Single $Bond^{TM}$, 3M/ESPE, USA) was applied following the manufacturer's recommendation and cavities were incrementally filled with hybrid composite resin (Filtek $Z-250^{TM}$, 3M/ESPE, USA). Teeth were stored in distilled water for one day at room temperature, after then, they were finished and polished with Sof-Lex system. All specimens were embedded in acrylic resin and static load was applied to the specimens with a 3 mm diameter stainless steel rod in an Universal testing machine and cross-head speed was 1 mm/min. Maximum load in case of fracture was recorded for each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA) and a Tukey test at the 95% confidence level. The results were as follows: 1. Fracture resistance of the undermined cavity filled with composite resin was about 75% of the natural tooth. 2. No significant difference in fracture loads of composite resin restoration was found among the three types of cavitated groups. Within the limits of this study, it can be concluded the fracture resistance of the undermined cavity filled with composite resin was lower than that of natural teeth, however remaining tooth structure may be supported and saved by the reinforcement with adhesive restoration, even if that portion consists of mainly enamel and a little dentin structure.

Seed Germination, Seedling Grwoth and Optimal Seedling Density of Phellodendron amurense Rupr. in Nursery (황벽나무의 종자발아(種子發芽)와 묘목생장(苗木生長) 및 적정생육밀도(適正生育密度)에 관(關)한 연구(硏究))

  • Goo, Gwan-Hyo;Lee, Kang-Young;Youn, Ki-Sik;Lee, Chong-Kyu
    • Journal of Korean Society of Forest Science
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    • v.86 no.4
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    • pp.443-449
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    • 1997
  • We examined the effect of pretreatments on seed germination, seedling growth, optimal seedling density of Phellodendron amurense. The seeds were carefully purified after collection in late Oct. from natural population at Mt. Chiri. For the evaluation of pretreatment effects, seeds were sowed in an experimental nursery after being stored in open ground($2{\sim}8^{\circ}C$) with soaking in 20% $H_2O_2$, 50-fold pon-pon solution, cold moist stratification in refrigerator($2{\sim}4^{\circ}C$) and dry storage in roam temperature($4{\sim}18^{\circ}C$), respectively, For the effect of growth density of seedlings, seedlings germinated in nursery were precisely controlled with 53, 104, 220, 380 seedlings per $m^2$. Among pretreatments for the promotion of germination rate, pon-pon treatment(68.8%) was highest, the others were higher than that in dry storage(2.3%), and these seed pretreatment methods were significantly different at 1% level. The height growth of seedlings showed the most vigor from Jun.12 to Jul. 8, and from Jul.20 to Aug. 2, and it reached to 72.8% of height growth. In case of 1-0 seedling, although seedling density per $m^2$ was increased, seedling growth was decreased. The optimal seedling density was 104 seedlings per $m^2$. The standard seedlings for plantation were above height 55cm, root collar diameter 8.1mm, and root length 21cm. These results demonstrated that seed of P. amurense requires stratification for the germination promotion.

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Effect of Irradiation, Packaging and Storage on the Oxidation of Cholesterol and Lipid in Pork Longissimus Meat (돈육 등심의 콜레스테롤 및 지질 산화에 전자선 조사, 포장 및 저장기간이 미치는 영향)

  • 신택순;이정일
    • Food Science of Animal Resources
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    • v.22 no.2
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    • pp.137-144
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    • 2002
  • Pork loins that retailed in market were used as experimental samples. Some pork samples in raw state were packaged with PVDC in either aerobic or vacuum condition. The other pork samples were cooked until core temperature reached at 70$\^{C}$ and then packaged immediately in the same way with the raw samples. After these samples were irradiated by electron beam 6 kGy, the samples were stored in a refrigerator (2∼4$\^{C}$). Identification and quantification of cholesterol oxides were performed at 0 and 7 days. The results were following. During the early stage of storage, cholesterol oxides were not produced from the raw meat samples, but with the passage of storage time,7 $\alpha$-hydroxycholesterol, 7$\beta$-hydroxycholesterol, 7-ketocholesterol, 20 $\alpha$-hydroxycholesterol, $\beta$-epoxide and $\alpha$-epoxide, which were not produced during the early stage of storage, were produced. The production of cholesterol and lipid oxidation products were significantly higher (P<0.05) in the meats with aerobic packaging than those with vacuum packaging, Cooked meat after irradiation showed 7 $\alpha$-hydroxycholesterol, 7 $\beta$-hydroxycholesterol, $\alpha$-epoxide and cholestanetriol on the 7th day of storage, although those chemicals were not produced during the early stage of storage. Production of cholesterol oxides was significantly increased (P<0.05) with the passage of storage time for all treatments, and showed significantly lower value (P<0.05) with the vacuum packaging than these for aerobic packaging. Species of cholesterol oxides from irradiated meat after cooking were similar to those from cooked meat after irradiation. Collectively, it was found that the production of cholesterol oxides was more easily affected by packaging condition than irradiation.

Quality Characteristics of Treated with Mild Heat and Minced Ginger during Storage (열처리 조건에 따른 다진생강의 저장 중 품질특성)

  • Kim, Hee-Su;Choi, Jeong-Hee;Lee, Ho-Joon;Jeong, Moon-Cheol;Kim, Byung-Sam;Kim, Dong-Man
    • Food Science and Preservation
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    • v.17 no.6
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    • pp.784-792
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    • 2010
  • Mild heat treatment was applied to ginger rhizomes to achieve shelf-life extension for fresh minced ginger. The rhizomes were treated at 45, 50, 55, or $60^{\circ}C$ for different periods of time, minced, and stored at $10^{\circ}C$ for 9 days. Microbial levels in minced fresh ginger decreased with increases in temperature and duration of heat treatment. The non-treated and treated samples did not significantly differ in color at the initial stage of storage. Changes in color were detected after 3 days, and accelerated after that time. The ${\Delta}E$ value of control samples reached 12.42, whereas that of treated samples (except when $45^{\circ}C$ was applied for 60 min) ranged from 7.67 to 10.96, after 9 days. There was no significant difference in initial pH value between control (pH 6.09) and treated (pH 6,046.20) samples. The pH of control samples increased to 8.02 after 9 days, whereas pH values of samples treated at $50^{\circ}C$ and $60^{\circ}C$ ranged from pH 6.807.83 after 9 days. The percentage of control drip was 25.65% at the initial stage of storage, which was lower than those of treated samples. Drip increased to 38.63% in the control and to 34.20~38.44% in treated samples after 9 days. The sensory characteristics of the control samples were similar to those of treated samples at the initial stage of storage. After 6 days, the control and some treated samples developed off-flavors and discoloration. However, samples treated at $50^{\circ}C$ for 60 min retained favorable quality characteristics for 9 days after storage.

Effects of Molasses and Phellinus linteus Meal Addition on the Quality of Korean Herbal Medicine Meal Silage (상황버섯박과 당밀의 첨가가 한약제박 사일리지의 품질에 미치는 영향)

  • Jang, Seok-Hun;Oh, Hyun-Min;Kim, Sung-Bok;Cho, Chi-Hyun;Park, Noh-Sung;Lee, Bong-Duk;Lee, Hyung-Suk;Lee, Soo-Kee
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.31 no.4
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    • pp.431-440
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    • 2011
  • This experiment was conducted to investigate the effects of molasses and $Phellinus$ $linteus$ meal supplementation on the quality of Korean herbal medicine silage. Herbal medicine meal silages were produced by the addition of 0, 15, and 30% of $Phellinus$ $linteus$ meal and 0, 1, and 2% of molasses ($3{\times}3$ factorial design) and stored for 40 days at room temperature. There were three replicates per treatment. Its quality such as chemical composition, pH, organic acids, the number of microorganisms and $in$ $vitro$ dry matter disappearance were determined. As the $Phellinus$ $linteus$ meal level increased, crude protein and crude fat contents increased significantly, but the acid detergent fiber (ADF) content decreased significantly. As the addition of $Phellinus$ $linteus$ meal decreased, and molasses increased, pH tended to decrease, but the lactic acid content trended to increase. The acetic acid content was lower in a higher level (30%) of $Phellinus$ $linteus$ meal, and higher in a higher level (2%) of molasses. As the $Phellinus$ $linteus$ meal level increased, the butyric acid content decreased, and butyric acid of molasses treatment was higher than that of non-supplemented control. Molasses increased the number of Lactobacillus, but decreased the number of fungi in silage. A lower level of $Phellinus$ $linteus$ meal increased the number of Lactobacillus, but decreased the number of fungi. $in$ $vitro$ dry matter disappearance tended to increase by the addition of $Phellinus$ $linteus$ meal and molasses. It is concluded that the addition of molasses and $Phellinus$ $linteus$ to herbal medicine meal silage could enhance its nutritional quality. It is considered that proper levels of molasses and $Phellinus$ $linteus$ meal in herbal medicine meal silage were 2 % and 15% respectively.

Immune Activity of Mosidae and Quality Characteristics of Brown Rice Dasik Using Mosidae Powder (모시대의 면역 활성 탐색 및 모시대 분말 첨가 현미다식의 품질 특성)

  • Kim, Ae-Jung;Han, Myung-Ryun;Kim, Myung-Hwan;Tae, Ki-Hwan;Lee, Soo-Jung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.5
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    • pp.548-554
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    • 2009
  • The principal objective of this study was to evaluate the immune activity of Mosidae and the physiochemical characteristics of brown rice Dasik prepared with Mosidae (Adenophora remotiflora) powder. We assessed the effects of Mosidae ethanol extract (MEE) on the production of IL-6T, IL-12 and TNF-$\alpha$ by peritoneal exudate macrophages (PEMs) using ELISA. We also determined general compositions, and conducted Hunter's color values, sensory evaluation, and the mechanical characteristics of Mosidae Dasik stored at room temperature ($20^{\circ}C$). With MEE treatment, ILI-6 (75% of LPS: positive control), IL-12 (35.7% of LPS) and TNF-$\alpha$ (27.32% of LPS) were proliferated at a dose of $1000{\mu}g/mL$. In the general compositions of the samples, fat contents of Mosidae Dasik significantly decreased (p<0.05). The more Mosidae powder was added to the samples, the more was the luminance, and Hunter's a and b were significantly decreased (p<0.05). As more Mosidae powder was added to the samples, springiness score was significantly decreased, but the score of hardness, gumminess and chewiness were increased (p<0.05). The results of sensory evaluation showed that there were significant differences in the color, taste and overall quality of the samples (p<0.05), but there was no significant difference in texture. We note that, among the samples evaluated herein, Mosidae stimulates some kinds of cytokines from machrophage and 1% Mosidae Dasik (MPD1) for the best commercial value.