• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.547-551
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• 1992

The antioxidative effects of Rhus javanica $Linn{\acute{e}}$ ethanol extract (RE) with or without some synergists were determined by measurement of POV and TBA of oil in ramyun and potato flake fried in palm oil or lard. RE with ascorbic acid and with tocopherol significantly increased the oxidative stability of ramyun. The results obtained from sensory evaluation were similar to those of POV and TBA values. RE with phosphoric acid and with ascorbic acid retarded the oxidation of potato flakes fried in palm oil or lard during storage.

• Clinical and Experimental Reproductive Medicine
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• v.18 no.1
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• pp.81-87
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• 1991

There studies were carried for evaluation of the efficiency of freezing of hamster oocytes for use in a human sperm penetration assay. The hamster oocytes fully equilibrated in various cryoprotectant agents and inseminated with human sperm. After insemination with hamster oocytes, there was no difference in penetrated rates. Cumulus free oocytes equilibrated in 1.5M various cryoprotective agents and slowely cooled to temperature $-30^{\circ}C$ before rapid cooling and storage in nitrozen tank. After rapid thawing, survival rates of frozen oocytes according to cryo-protective agents were examined and the human sperm penetration assay with zona free hamster oocytes was conducted. 1. Survival rates of oocytes after cryoprotectants exposure have no significant difference (range 88-91%) and peneration rate was 51.1%. 2. Recovery and survival rate of frozen-thawed oocytes were 85.1 and 66.8%. There was no significant difference on cryoprotective agents. 3. Penetration rates of the frozen-thawed and intact oocytes were 69.0 and 77.0%, respectively. 4. Hamster oocytes cryopreservation provides a convenient way of supplying and trans-porting hamster oocytes for the assessment of the fertilizing potential of human spermatozoa.

• Korean journal of food and cookery science
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• v.14 no.5
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• pp.560-565
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• 1998

The purpose of this study was to investigate any differences in the efficiency of various antioxidants for the three types of substrates such as corn oil in water (O/W) emulsion, water in com oil (W/O) emulsion, and bulky corn oil. ${\alpha}$-Tocopherol (${\alpha}$-Toc) at 0.01 or 0.02%, ascorbic acid (AsA), ascorbyl palmitate (AP), and BHT at 0.02% were added separately to the prepared O/W emulsion, W/O emulsion, and bulk oil, and their antioxidative effects were compared. The mixture of ${\alpha}$-Toc ind AsA or AP at the level of 0.02% also was tested to observe any synergistic effect. Oxidation was made by storing at 42${\pm}$1$^{\circ}C$ for 25 days and the oxidative stability was determined by peroxide value and conjugated dienoic acid with time fluctuation of storage. The results were as follows: 1. In case of O/W emulsion, the order of antioxidative effect was AP> ${\alpha}$-Toc+AP>${\alpha}$-Toc+AsA>AsA>BHT. 2. In case of W/O emulsion, the order of antioxidative effect was AsA>AP>${\alpha}$-Toc+AsA>BHT. ${\alpha}$-Toc+AP mixture showed the prooxidant effect rather than synergistic effect. 3. In case of bulk oil, the order of antioxidative effect was AsA>AP>${\alpha}$-Toc+AsA>${\alpha}$-Toc+AP\ulcornerBHT. Therefore, AsA, a hydrophilic antioxidant, was more effective in W/O emulsion system than in O/W emulsion system, while the opposite trend was found in AP, a lipophilic antioxidant. AsA, a hydrophilic antioxidant, was more efficient in bulk oil of anhydrous substrate. ${\alpha}$-Toc showed prooxidant effects in all substrates.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.7.1-7.7
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• 2018

Objectives: The aim of this study is to compare the shear bond strengths of ceramic brackets bonded to zirconia surfaces using different zirconia primers and universal adhesive. Materials and Methods: Fifty zirconia blocks ($15{\times}15{\times}10mm$, Zpex, Tosoh Corporation) were polished with 1,000 grit sand paper and air-abraded with $50{\mu}m$ $Al_2O_3$ for 10 seconds (40 psi). They were divided into 5 groups: control (CO), Metal/Zirconia primer (MZ, Ivoclar Vivadent), Z-PRIME Plus (ZP, Bisco), Zirconia Liner (ZL, Sun Medical), and Scotchbond Universal adhesive (SU, 3M ESPE). Transbond XT Primer (used for CO, MZ, ZP, and ZL) and Transbond XT Paste was used for bracket bonding (Gemini clear ceramic brackets, 3M Unitek). After 24 hours at $37^{\circ}C$ storage, specimens underwent 2,000 thermocycles, and then, shear bond strengths were measured (1 mm/min). An adhesive remnant index (ARI) score was calculated. The data were analyzed using one-way analysis of variance and the Bonferroni test (p = 0.05). Results: Surface treatment with primers resulted in increased shear bond strength. The SU group showed the highest shear bond strength followed by the ZP, ZL, MZ, and CO groups, in that order. The median ARI scores were as follows: CO = 0, MZ = 0, ZP = 0, ZL = 0, and SU = 3 (p < 0.05). Conclusions: Within this experiment, zirconia primer can increase the shear bond strength of bracket bonding. The highest shear bond strength is observed in SU group, even when no primer is used.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.331-337
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• 1988

The thermal properties of typical five Indica and five Japonica rice varieties were investigated by Differential Scanning Calorimetry (DSC). There was no significant difference in gelatinization temperature between Indica and Japonica varieties, but the average enthalpy of gelatinization was larger in Indica types than that in Japonica. However, the enthalpy of melting of amylose-lipid complex was larger in Japonica types than that in Indica types. The DSC thermogram of hydrolyzed rice residue included a smaller peak of gelatinization with narrow range of temperature. Retrogradation of gelatinized rice kernel was also determined with DSC theremograms. The endothermic peak areas clearly increased with increasing storage time at $4^{\circ}C$ so that the area could be used as a measure of the relative degree of retrogradation. The results indicated that Samgang variety(Indica) retrograded more rapidly than Chuncheong variety(Japonica).

• Food Science of Animal Resources
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• v.31 no.1
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• pp.27-31
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• 2011

To differentiate between frozen-thawed and fresh broiler breast fillets, different methods such as optical microscopy and measurement of drip loss, pH, torrymeter and K-value were performed. A total of 10 samples of fresh and frozen-thawed breast fillets were stored in a refrigerator ($4^{\circ}C$) for 5 d. Optical microscopy of the frozen-thawed breast fillets found structural changes caused by ice crystals, which may have significantly increased drip loss compared to fresh breast fillet. The pH and K-value could not be distinguished between the two breast fillets during storage. However, the torrymeter values of the fresh and frozen-thawed breast fillets were significantly different (p<0.05). The results indicate that both optical microscopy and torrymeter measurement can be effective methods for differentiating between fresh and frozen-thawed breast fillets. However, optical microscopy may be difficult to implement in the marketplace since it requires much time and effort. Thus, the determination of the torrymeter value is the easiest and most rapid instrumental method among those tested for the differentiation of frozen-thawed chicken breast fillet from fresh one.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.359-365
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• 2014

Oriental pear (Pyrus communis L. cv 'Niitaka') was stored at $0^{\circ}C$ for 5 months and major metabolites involved in blackening of the peel were analyzed by untargeted GC-MS and targeted HPLC methods. In this study, peels of sound and skin-blackened pears were analyzed and compared. Skin-blackened fruit was clearly characterized by a distinctive pattern in changes which included a decrease of malic acid, succinic acid, and ascorbic acid, while an increase of fumaric acid, threonine, and gluconic acid, which indicated both reduced metabolic activity and anti-oxidative capacity of the cells. Chlorogenic acid was a major phenolic compound and the peel of sound fruit showed high levels of free phenolic compounds compared than the peel of skin-blackened fruit which are believed to be related to oxidation of phenolics in skin-blackened tissue. The changes or profiling of major metabolites by targeted or untargeted analysis method could become a useful tool for understanding physiology, disorder mechanism, and identifying metabolic networks connecting primary and secondary metabolism in postharvest research.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.79-86
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• 2013

We investigate the effect of preharvest spray of aminoethoxyvinylglycine (AVG), an inhibitor of ACC synthase activity, on fruit quality of 'Wonhwang' pear (Pyrus pyrifolia Nakai). And the effects were compared with ethephon which releasing ethylene to elucidate treatment efficacy of ethylene biosynthesis inhibitor on Asian pears. Chemicals were sprayed on 30 days before harvest with AVG (75 and 150 mg/L) and ethephon (100 mg/L), respectively. Highest flesh firmness during 21 days of shelf-life at $25^{\circ}C$ after 30 days of cold storage was attained in the fruit treated with 150 mg/L AVG (26.5N) when compared with untreated control (16.7N), while the fruits treated with 100 mg/L ethephon completely lost their marketability within 14 days of shelf-life by mass drop of firmness down to 11.6N. Low incidence of physiological disorders including pithiness and core browning were attained at the fruits treated with 150 mg/L AVG when we compared with untreated control. No occurrence of mealiness found in the fruits treated with AVG but ethephon treated fruits showed 36.4% during 14 days of shelf-life. Consequently, AVG spray at the concentration of 150mg/L on Asian pear 'Wonhwang' fruit regarded as useful preharvest management approach for keeping quality during marketing period after simulated exportation.

• Korean journal of food and cookery science
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• v.15 no.5
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• pp.533-538
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• 1999

${\alpha}$-amylase was investigated as an antistaling agent for Backsulgie, a traditional rice cake. Rice powder was mixed with ${\alpha}$-amylase, fermented for 2 hr at 37$^{\circ}C$, and steamed for 20 min. Rice cake was stored at room temperature or freezer for 4 days, and analyzed to determined the changes of chemical and sensory properties. When ${\alpha}$-amylase was added to rice cake, the content of reducing sugars and the yellow color of the cake were increased, and the water activity was decreased. Soft and moist textural properties were apparent in ${\alpha}$-amylase-added rice cakes by sensory evaluation. X-ray diffraction showed a V pattern after 4 days of storage which indicated the starch of rice cake was not retrograded. However, there was no significant difference in moisture content between enzyme-treated and non-treated rice cakes. Above results suggest that ${\alpha}$-amylase treatment produced dextrins which consequently bound with water and inhibited the retrogradation of rice cake.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.750-757
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• 2016

This study investigated the quality, sensory characteristics and commercial potential of a rice snack prepared with dried oyster. Mild and spicy versions of the snack were produced using an oil coating and a mixed seasoning powder coating, respectively. The approximate compositions of the mild snack and spicy snack were 5.13% and 4.78% moisture, 8.92% and 8.94% crude proteins, 17.58% and 20.35% crude lipids, 1.88% and 1.87% ash, and 2% and 1.8% salt, with water activity values of 0.20 and 0.18 and a pH of 6.11 and 6.10, respectively. The color of the mild snack was lighter with more yellow and less red compared with the spicy snack. Thiobarbituric acid levels increased slightly, and hardness 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. These results suggest that the spicy snack might have more commercial potential than that of the mild snack according to its higher sensory test score.