• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.230-238
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• 2016

This study examined the effects of freezing and thawing conditions on quality of Hanwoo bottom round. The beef samples were frozen by air blast freezing at $-20^{\circ}C$ or ethanol immersion freezing at $-70^{\circ}C$ and then stored at $-20^{\circ}C$ for 10 days. After 10 days of storage, the frozen samples were thawed with air blast thawing at $4^{\circ}C$ or water immersion thawing at $4^{\circ}C$ and subjected to subsequent analyses of drip loss, water holding capacity, thiobarbituric acid reactive substance (TBARS), volatile basic nitrogen (VBN), total aerobic bacteria, and microstructure. Drip loss significantly increased in samples treated with air blast freezing compared to ethanol immersion freezing, whereas freezing and thawing processes had no significant impact on water holding capacity of the samples. Thawing conditions had a much stronger influence on the TBARS and VBN of the samples than freezing conditions. There was no significant difference in the population of total aerobic bacteria among the four samples subjected to one freeze-thaw cycle. In addition, to analyze the effects of freeze-thaw cycle on the quality of beef, three freeze-thaw cycles were performed during storage. Multiple freeze-thaw cycles increased drip loss, TBARS, and VBN and decreased water holding capacity, accelerating microstructural damage. These data indicate that Hanwoo bottom round can be rapidly frozen and thawed by using ethanol immersion freezing and water immersion thawing methods with minimal impact on meat quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.619-624
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• 2016

Chlorine dioxide ($ClO_2$) gas treatment (75 ppmv, 30 min) has been suggested to improve the microbial safety of postharvest paprika in a previous study. Based on these results, in this study, an additional combined treatment using low-concentration $ClO_2$ gas-generating sticks (3 ppmv) in paprika samples during storage was carried out at $8^{\circ}C$ and 90% relative humidity to further enhance the quality and reduce the decay rate of paprika for the purpose of lengthy storage. After the combined treatment, the initial populations of total aerobic bacteria as well as yeast and molds in the paprika samples decreased by 3.04 and 2.70 log CFU/g, respectively, compared with those of the control samples, and this microbial inactivation was maintained by the low-concentration $ClO_2$ gas-generating sticks during storage. In particular, the decay rate of samples with combined treatment was significantly lower than that of the control. Vitamin C content, hardness, and color quality parameters of paprika samples were not altered by treatment, while weight loss of the samples treated with the combined $ClO_2$ gas was lower than that of the control during storage. These results indicate that the combination of two different $ClO_2$ gas treatments is effective for retaining the quality of paprika during prolonged storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.2019-2027
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• 2013

In this study, we tried to develop a coating agent for the fresh-cut fruits used in cakes. First, the coating agent mixing ratios of sugar, pectin, sodium alginate, carrageenan, xanthan gum, vitamin C, and purified water were selected to be 55, 2, 2, 0.04, 0.1, 0.05, and 40.81% (w/w), respectively. In a freeze-thaw stability of the coating agent, the viscosity remained constant for 3 cycles of freezing and thawing repetition process, but showed a slightly decreasing trend in the 4th repetition process (P<0.05). On the other hand, the sugar content, pH, and chromaticity remained constant even in the 4th repetition process. Pineapple coated with the coating agent had smaller weight loss, hardness changes, and total bacteria distribution compared to the uncoated pineapple (P<0.05). In the chromaticity, both of the two pineapples experienced browning with increasing storage duration, as L value decreases and b value increases. However, when the color difference was compared, the progress of browning for the uncoated pineapple was faster than the coated pineapple. Also, the progress of browning at $4^{\circ}C$ was found to be slower than the progress of browning at $25^{\circ}C$. Therefore, the storage stability of the fresh-cut fruits could be improved by coating the fresh-cut fruits for cakes with the coating agent and storing at a low temperature, which would contribute to extending the shelf-life of cakes.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.395-402
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• 2014

BACKGROUND: Azadirachta indica Extract(AIE) containing azadirachtin as active ingredient have been used worldwide as environment-friendly organic material having pest control properties. However, the extracts prepared with different solvent and from different plant site is very diverse and have different toxicity. METHODS AND RESULTS: In this study, the four week repeated oral dose toxicity test of aqueous AIE in Sprague-Dawley rats was carried out to investigate the toxic effect of liver, main toxicity target organ of AIE. The male and female rats were divided into 4 groups, respectively; control(0 g/Kg bw), low-dose group(0.5 g/Kg bw), middle-dose(1.0 g/Kg bw) and high-dose group(2.0 g/Kg bw). As a results, relative liver weight increased with dose-dependent of AIE(p<0.05). Serum LDH in all AIE-treated groups were significantly lower than the control in male rats(p<0.05). However, serum GOT and GPT were significantly increased in all male AIE-treated groups in male rats(p<0.05) and, in particular, increase of serum GPT in dose-dependent manner raise the possibility of liver damage. Even through serum GLU was increased significantly in high-dose group in male rats compared to control, there were no significant differences of urinary GLU among all groups(p<0.05). In addition, histopathological examination of the liver did not reveal any lesions in all AIE-treated groups. CONCLUSION: In conclusion, 4 weeks of the repeated oral administration of AIE 2.0 g/Kg to rats has resulted no toxic response in liver. Therefore, AIE was no indicated to have any toxic effect in the SD rats, when it was orally administrated below the dosage 2.0 g/Kg/day for 4weeks.

• Korean Journal of Poultry Science
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• v.12 no.1
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• pp.31-38
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• 1985

To learn more about the productivity of edible meat and its functional properties of spent hen, 60 White Leghorn fowls at 20 month of age were randomly divided into 6 groups, 10 hen for each group, and processed. As the productivity of edible meat, the yield of dressed carcass, giblets, cut-up meat, and breast and leg (thigh and drustick) muscles were determined. The approximate chemical composition, the content of salt-soluble protein, the emulsifying capacity and W.H.C. of breast and leg muscle were measured as the functional properties. The results were summarized as follows. 1. The average live weight of spent hen was 1,576.7g from which the yield of dressed carcass and giblets were 998.9g(63.4%) and 75.3g(4.8%) respectively. It means the yield of ready-to-cook form was 1,074.2g(68.2%) and the inedible byproducts was 502.5g (31.8%). 2. The average, weight of each part of cut-up chicken were: neck 41.0g(4.1%), wings 135.9g (13.6%), breast 276.7g (27.7%), legs 323.6g (42.4%). back 176.1g(17.6%) and the cutting-loss was 45.6g(4.6%). 3. The average weight of total edible muscle from breast and leg was 51.5g(85.86% of breast and leg cut weight) and the percentages based on the carcass and live weights were 51.6% and 32.7%, respectively. 4. The contents of H$_2$O, protein, fat and water-protein ratio of breast muscle were 72.95%, 20.54%, 1.59% and 3.55, respectively and those of leg muscle were 71.9%, 19.12%, 3.96% and 3.76%, respectively. 5. The salt-soluble protein contents of breast and leg muscle were 7.97% and 6.26% and their concentrations based on the total protein content were 38.8% and 32.74%, respectively. 6. The emulsifying capacity of breast and leg muscle was 43.23$m\ell$and 43.23$m\ell$, respectively. 7. The W. H. C- of breast and leg muscle was 54.23% and 52.61%, respectively.

• Journal of Korea Foresty Energy
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• v.19 no.2
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• pp.93-101
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• 2000

Wood of Robinia pseudoacacia and bark of Populus alba$\times$P. glandulosa, Fraxinus rhynchophylla and Ulmus davidiana var. japonica were collected and extracted with acetone-water(7:3, v/v) in glass jar to examine whether its bioactive compounds exist. The concentrated extracts were fractionated with hexane, chloroform, ethylacetate and water, and then freeze-dried for column chromatography and bioactive tests. The isolated compounds were sakuranetin-5-O-$\beta$-D-glucopyranoside from Populus alba $\times$Pl glandulosa, 4--ethyoxy-(+)-leucorobinetinidin frm R. pseudoacacia and fraxetion from F. rhynchophylla and were characterized by $^1H$ and$^{13}C $ NMR and positive FAB-MS. Decay-resistant activity was expressed by weight loss ratio and hyphae growth inhibition in the wood dust agar medium inoculated wood rot fungi. R. pseudoacacia showed best anti-decaying property in both test and its methanol untreated samples, indicating higher activity than methanol treated samples in hyphae grwoth test. In antioxidative test, $\alpha$-tocopherol, one of natural antioxidants, and BHT, one of synthetic antioxidants, were used as references to cmpare with the antioxidant activities of the extacted fractions. Ethylacetate fraction of F. rhynchophylla bark indicated the hightest activity in this test and all fractions of R. pseudiacacia extractives also indicated higher activities compared with the other fractions. In the isolated compounds, aesculetin isolated from F. rhynchophylla bark showed best activity and followed by robonetinidin from R. pseudoacaica.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.507-512
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• 2006

Purpose : Early detection and intervention of hearing impairment is believed to improve speech and language development and behavior of children. The aim of this preliminary study was to determine the prevalence of hearing impairments, and to identify the association of risk factors relating to refer response in high risk neonates who were screened using distortion product otoacoustic emissions (DPOAE). Methods : The subjects included 871 neonates who were admitted to the neonatal intensive care unit of the Pediatric Department in Soonchunhyang University Bucheon Hospital from May, 2001 to December, 2004. They were screened using DPOAE. Based on DPOAE, we divided the neonates in two groups : 'Pass' and 'Refer'. The differences in risk factors between the pass group and the refer group were analyzed. Results : The incidence of the refer group was 12.1 percent(106 out of 871). The bilateral refer rate was 5.4 percent(47 out of 871). And the unilateral refer rate was 6.7 percent(59 out of 871). Gender, birth place, family history of hearing loss, small/large for gestational age, obstetrical factor, hyperbilirubinemia and use of gentamicin were not statistically related to the refer rate. Statistically related to refer rate were birth weight, resuscitated neonates, Apgar score, craniofacial anomaly, mechanical ventilator application, sepsis, using of vancomycin(P<0.05). The prevalence of hearing impairment (${\geq}60dB$) in this study was 2 percent(18 out of 871). Conclusion : This study showed a higher prevalence of hearing impairment in high-risk neonates. Thus neonatal hearing screening should be carried out in high-risk neonates.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.69-80
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• 2010

Hypocholesterolemic effect of soy protein was examined in comparison with casein and three other dietary protein sources in chicks. In two feeding trials, 40 (Expt.1) or 50 (Expt. 2), three-day-old, male chicks were forced-fed each of five semi-purified-type diets containing isolated soy protein (ISP, cp 82%), casein (cp 92%), rice protein (RP, cp 70%), corn gluten meal (CGM, cp 65%) or fish meal (FM, cp 70%) for two weeks. The diets for Expt. 2 were supplemented with 0.3% cholesterol by replacing glucose. Each protein source was the only source of protein of each diet. Essential amino acids were added to the diets to satisfy their requirements according to NRC. The diets were forced-fed to equalize the intake of all nutrients except the amino acids which were inherently variable in the diets. Chicks fed casein showed lower body weight gain than those fed the other proteins in both experiments. Birds fed ISP and FM gained better body weight than the others. Chicks fed casein showed significantly higher levels of plasma total cholesterol, non-HDL cholesterol and triacylglycerol (TG) than those fed ISP and the other protein sources. Meanwhile, the chicks fed ISP, RP, CGM and FM showed comparable levels of plasma total cholesterol, non-HDL cholesterol and TG. In Expt. 2, the birds fed casein and FM showed markedly elevated plasma total cholesterol and non-HDL cholesterol levels. Liver weight and levels of total lipids and cholesterol of chicks fed casein appeared significantly higher than those of the other protein diets, whereas those of the chicks fed ISP, RP, CGM and FM appeared comparable except cholesterol in FM group. In conclusion, only the chicks fed casein diets in both experiments always showed significantly higher levels of plasma cholesterol and TG compared to those fed ISP and the other protein sources. These results support the views that casein, which has unique lysine-arginine ratio, is inherently hyper-cholesterolemic, and ISP is hypocholesterolemic only when compared to casein.

• Food Science and Preservation
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• v.16 no.2
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• pp.179-185
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• 2009

To develop an Enoki mushroom packaging method, mushrooms were stored at $1^{\circ}C$ for 12 days after passive MAP packaging(PM), vacuum packaging(VM), and gas flushing packaging(AM), after investigation of film thickness influences on respiration rates and gas compositions(LDPE films 20, 40, and 60 m in thickness were tested). Enoki mushrooms had respiration rates of 26.4 mL $CO_2/kg/hour$ at $0^{\circ}C$, 80.0 mL $CO_2/kg/hour$ at $10^{\circ}C$, 130.9 mL $CO_2/kg/hour$ at $20^{\circ}C$, and 130.9 mL $CO_2/kg/hour$ at $30^{\circ}C$. A film thickness of 20 m was chosen for further tests to maintain the oxygen concentration above the minimum growth level; the thinnest film offered a higher gas transmittance rate than did the thicker films. No anaerobic respiration was evident over 12 days of storage using any packaging method, with the exception of VM. AM, using a high concentration of $CO_2$, restricted respiration rate. Mushrooms packaged using the VM method showed the greatest weight loss and extent of discoloration among the packaging methods tested, followed by AM mushrooms using 50% $CO_2/10%\;O_2/40%\;N_2$. Mushrooms packaged by the VM and PM methods developed a serious off-flavor after 2 days of storage, and a high stipe elongation rate after 5 days of storage, respectively. However, AM using 50% $CO_2/10%\;O_2/40%\;N_2$ of various gas ratios tested, allowed Enoki mushrooms to be maintained for up to 12 days without development of off-flavor, discoloration, or moldiness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.175-182
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• 2001

The main focus of this study was set to help college students in Kangwon province to improve and correct dietary habits and to maintain healthy life. The nutritional status and food preference of college students were examined from May to July, 1999. The collection of the research data has been made on the basis of questionnaries for 184 college students residing in Kangwon province. Statistical analysis of the data was performed using SAS package program for descriptive frequency and statistical significance. The meal skipping ratio of the subjects were 2% and for the reasons of meal skipping 45% responded "lack of time". As for main dishes, cooked rice turned out to be the most preferred by the subjects and the second and third favored by female students were bread and noodle respectively. Most preferred side-dishes were meat soup, kimchi, laver Kui,squid Bockeum, fried squid, beef Chon, squid Chorim, soy Namul, Dubuk Changachi and squid Muchim. Less preferred side-dishes include radish soup, white kimchi, mugwort fry, liver Bockeum, liver sheon and egg plant Kui. No one-plate food was disliked by the subjects. Male liked Manndukuk and female liked cuttle fish rice. The intakes of nutrient except for energy, iron and calcium for female students were the same or above the Recommended Dietary Allowances (RDA) for Koreans.