• Journal of Food Hygiene and Safety
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• v.4 no.2
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• pp.119-132
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• 1989

Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.452-458
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• 2010

This study aimed at improving the packaging technology of Yukwa to improve the quality and extend the shelflife using secondary packaging. After packaging the Yukwa using an OPP film, P2, P3, and P4 packaging materials were applied secondarily. Various films including (1) P1: OPP (oriented polypropylene), (2) P2: P1+OPP/LLDPE (linear low density polyethylene), (3) P3: P1+PET (polyethylene terephthalate)/NY (nylon)/CPP (cast polypropylene) and (4) P4: P1+PET/AL (aluminum)/NY/CPP (P4) were used for packaging Yukwa. The experiment was conducted at $25^{\circ}C$ for 12 weeks. P1 showed the highest acid value score (1.26 mg KOH/g), and P3 had the highest peroxide value score (32.91 meq/kg) among all packaging groups. Nevertheless, these values did not exceed the guideline values of 2.0 g KOH/g and 40 meq/kg specified in the Korean food code. The overall color difference showed a tendency for decreasing Hunter 'L' values and increasing 'a' and 'b' values; however, no noticeable difference in the outer appearance was observed in any of the packaging treatments except in the P1 for greater than 10 weeks of storage. Some texture defects were observed in the Yukwa when the moisture contents dropped below 5%. The P4 packaging treatment had the lowest moisture permeability and showed the least rheological deterioration change, followed by P3 and P2. In conclusion, the use of a secondary packaging with less gas and moisture permeability was more effective for maintaining the quality and extending the shelf-life of Yukwa than other types of packaging material.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.383-389
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• 2010

The aim of this study was to determine the methylmercury (MeHg) levels in abyssal fish species. The MeHg in the fishes was extracted with hydrochloric acid and toluene and then purified using an L-cysteine solution. The extract was analyzed with a gas chromatography-electron capture detector (GC-${\mu}ECD$) with a thermon Hg-capillary column. The detection limit and the recovery of the method were 0.002 and 84.2-98.5% (mean, 93.4%), respectively. The MeHg content in 492 abyssal fishes ranged from 0.037 to 2.009 mg/kg. The levels of MeHg [range, mg/kg (mean)] were significantly dependent on fish species and presented as the following; 0.157-2.009 (0.546) in Scalloped hammerhead shark, 0.211-0.878 (0.501) in Blue shark, 0.121-0.993 (0.482) in Spiny dogfish, 0.243-0.658 (0.397) in Salmon shark, 0.074-1.958 (0.353) in Blacktip shark, 0.038-0.807 (0.302) in Southern hake, 0.099-0.511 (0.300) in Scorpion fish, and 0.037-0.133 (0.067) in Ling. The monitoring results showed that the estimated weekly intake of MeHg from sharks, Southern hake, and Ling were lower than the provisional tolerable weekly intake recommended by the Joint FAO/WHO expert committee on food additives.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.100-106
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• 2011

The physicochemical characteristics of chicken breast were determined to identify the optimal ratio of $CO_2$ and $N_2$ to maintain chicken breast quality during cold storage for 6 d. The mixing ratios of $CO_2$ and $N_2$ were 20:80, 40:60, 60:40, and 80:20, respectively. The pH of the chicken breast packed with 80% $CO_2$ and 20% $N_2$ was lower than that of the control on day 1 (p<0.05). The lightness ($L^*$) of the breast increased with increasing $CO_2$ during storage (p<0.05), whereas no difference was found for redness ($a^*$) and yellowness ($b^*$). A lower volatile basic nitrogen level was found for chicken breasts exposed to higher $CO_2$ levels. Furthermore, lipid oxidation of the chicken breast packed with $CO_2$ decreased with increasing $CO_2$ level, and 40% $CO_2$ significantly reduced 2-thiobarbituric acid reactive substances (TBARS) values on days 1 and 6. The total number of microbes was reduced in chicken breast exposed to more than 40% $CO_2$ during storage days 3 and 6 (p<0.05); however, Escherichia coli was not affected by $CO_2$ level. Coliforms of chicken breast were reduced in the 40% $CO_2$ level on storage day 3. Moreover, tray-packed chicken breast exposed to 40% $CO_2$ did not collapse. These results suggest that 40% $CO_2$ and 60% $N_2$ were the optimal conditions for packaging chicken breasts during cold storage.

• Journal of Animal Science and Technology
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• v.53 no.5
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• pp.409-418
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• 2011

This study was conducted to investigate the effects of dietary probiotics and immunomodulator on growth performance, carcass characteristics, fecal $NH_3$ content and pathogenic bacteria counts in ileum and cecum and ileum of broiler chicken (Korean native chicken, HanHyup No. 3). A total of 120 (day-old) chicks were randomly divided into 5 treatments with 3 replicates and there were 8 birds per replicate. Dietary treatments consisted of five diets; the corn-soybean based control diet (C), the diet containing antibiotics (Avilamycin) 10 ppm (T1), the diet containing probiotics 1 [(Lactobacillus ($4.45{\times}10^6$) + yeast ($1.51{\times}10^6$) + Bacillus subtilis ($3.50{\times}10^5$)] at 0.5% level (T2), probiotics 2 [(Lactobacillus ($6.70{\times}10^7$) + yeast ($3.10{\times}10^6$)] at 0.5% level in diet (T3), and the diet containing probiotics 3 [T2 + ${\beta}$-glucan + organic acid] (T4) and raised for 9 weeks. There were no significant differences among treatments in weight gain, feed intake and feed conversion. Carcass ratios of broilers were higher in T3 and T4 than other treatments, however, the differences were non-significant. Internal organs and liver, heart weight were significantly increased in T4 (p<0.05) compared to other treatments. The fecal $NH_3$ gas content was decreased (p<0.05) in antibiotics fed group than others. However, probiotic fed groups were not different when compared with control. The number of Salmonella and E. coli in cecum were reduced in the group supplemented with probiotics and immunomodulator compared to the antibiotics (p<0.05). In this experiment, we showed that diets containing pro-biotics and immunomodulator were capable of an alternative to antibiotics.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.284-289
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• 2017

Oxidized polyethylene wax (OPEW) is, one of the food additives, used as a coating agent in citrus fruits and nuts. OPEW is authorized to quantum satis in EU, USA, and is acceptable less than 250 mg/kg in Australia and New Zealand. But OPEW is unauthorized as a food additive in Korea. This study was to establish the analytical method of OPEW and demonstrate the effective application of various food samples. We first conducted to compare the various analytical method including acid value (AV), high temperature gel permeation chromatography (HT-GPC), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS), gas chromatography flame ionization detector (GC-FID) and fourier transform infrared spectroscopy (FT-IR). This result indicated that FT-IR spectrum of OPEW treated food sample displayed absorption bands for carbonyl group (C=O, $1714cm^{-1}$), ester group (C-O, $1463cm^{-1}$), aliphatic group (C-H, $2916cm^{-1}$). Furthermore, IR spectrum of OPEW treated food sample showed similar tendency with IR spectrum of OPEW standard. Therefore, it is confirmed that analytical method using FT-IR can be detected on analysis of OPEW in food. As a result of monitoring of 111 samples using established analytical method, OPEW was not detected in the food samples.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.308-314
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• 2017

This study was conducted with two ruminally cannulated Holstein steers to examine the effect of micronized and steam flaked corn on ruminal fermentation characteristics. The in situ dry matter degradability after 48 h incubation was the highest (P<0.05) at micronized corn (2.5 mm thickness) compared with steam flaked corn treatments. The steam flacked corn (3.3 mm thickness) was degraded lower (P<0.05) than the 2.9 and 3.1 mm thickness of steam flacked corn. Effective dry matter degradability and the rate of constant were the highest (P<0.05) at micronized corn (2.5 mm thickness) compared with steam flaked corns as well. The in vitro dry matter degradability after 48 h incubation was tended to higher (P=0.088) at micronized corn (2.5 mm thickness) than steam flaked corns, whereas there is no significantly difference between steam flaked corn treatments. Total volatile fatty acid concentration was higher at steam flaked corn (2.9 mm thickness) than micronized corn (2.5 mm thickness) and steam flaked corn (3.1 and 3.3 mm thickness). The acetate : propionate ratio was the highest (P=0.008) at steam flaked corn (2.9 mm thickness) and the lowest (P=0.008) at micronized corn (2.5 mm thickness). Total gas and methane production after 48h ruminal incubation was the highest (P=0.001) at micronized corn (2.5 mm thickness) compared with steam flaked corns. According to these results, the thickness of steam flaked corn as resulted corn processing is believed to do not affect methane production. However, further study is needed to better understand the present results to verify the correlation between corn processing method and their thickness on methane production using the same thickness corns by difference processing methods.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.285-292
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• 2008

To investigate the effect of tillage methods on the silage barely growth and the soil environment in paddy field, liquid pig manure(LPM) was applied after harvesting rice at Jisan series soil for 2 years. Five plots, a LPM applied rate as N%; 0, 100, 150, 200(basal dressing) and 100(basal dressing)+50(additional fertilizer) were divided by tillage methods; non-tillage, non-tillage+rice straw and rotary tillage method. Emission amounts of $NH_3$ gas highly decreased in the rotary tillage and the non-tillage+rice straw plot compared to non-tillage plot. The contents of soil organic matter and exchangeable cation were increased in the applied LPM plot. $NH_4-N$ and $NO_3-N$ contents in soil were the highest in the non-tillage+rice straw plot and followed by the rotary tillage and highly decreased along with the growth of plant. Run-off rate of mineral components were higher in order of the rotary tillage plot£æthe non-tillage plot£æthe non-tillage+rice straw plot and then leached to $SO_4$, $NO_3-N$, K plentifully. The yield of silage barley in dry weight was higher in order of the non-tillage+rice straw plot>the rotary tillage plot>the non-tillage plot. To estimate the feed value of silage barley, crude protein, acid detergent fiber(ADF) and neutral detergent fiber(NDF) contents were analyzed. Crude protein and ADF contents were the highest at rotary tillage N150% plot as 9.7 and 29.4%, respectively. NDF contents was the highest at non-tillage+rice straw N150% plot as 56.7%. In conclusion, we recommend not to incinerate rice straw and to apply LPM at non-tillage status in cultivating the silage barley. This may prevent water pollution and increase barley yields.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1523-1528
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• 1999

The consumer's demands for minimally processed fruits and vegetables have been increased rapidly because of its convenient handling, fresh-like quality as well as producing less wastes from the environmental point of view. Asian pears which are one of the main fruits widely produced and consumed in Korea easily lost their characteristics due to browning and softening after cutting. The objective of this study is to investigate the effects of various treatments on delaying deterioration of sliced Asian pears. 'Shingo' pear slices were treated with various solutions $(1%\;NaCl,\;0.2%\;L-cysteine,\;1%\;CaCl_2\;or\;1%\;calcium\;lactate)$ and were packaged with low density polyethylene $(LDPE,\;60\;{\mu}m)$, ceramic $(CE,\;60\;{\mu}m)$ or vacuum $(Ny/PE,\;80\;{\mu}m)$ film at $20^{\circ}C\;and\;0^{\circ}C$. In order to evaluate the quality of packaged sliced pears, quality index was determined in terms of color, firmness, soluble solids, titratable acidity. ascorbic acid, changes of gas composition, microbial test, and sensory quality. The results showed that sliced 'Shingo' pears packaged with CE and vacuum film maintained better quality than with LDPE at $0^{\circ}C\;and\;20^{\circ}C$. To retard browning and softening. 0.2% L-cysteine and 1% NaCl solutions applied for 1 minute were effective to reduce surface browning of sliced pears, and 1% $CaCl_2$ was the most effective to prevent softening.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.63-73
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• 2009

Recently, the use of lightweight panels in building structures has been increasing. Of the various lightweight panel types, styrofoam sandwich panels are inexpensive and are excellent in terms of their insulation capacity and their constructability. However, sandwich panels that include organic material are quite vulnerable to fire, and thus can numerous casualties in the event of a fire due to the lack of time to vacate and their emission of poisonous gas. On the other hand, lightweight foamed concrete is excellent, both in terms of its insulation ability and its fire resistance, due to its Inner pores. The properties of lightweight concrete is influenced by foaming agent type. Accordingly, this study investigates the insulation properties by foaming agent type, to evaluate the possibility of using light-weight foamed concrete instead of styrene foam. Our research found thatnon-heating zone temperature of lightweight foamed concrete using AP (Aluminum Powder) and FP (animal protein foaming agent) are lower than that of light-weight foamed concrete using AES (alkyl ether lactic acid ester). Lightweight foamed concrete using AES and FP satisfied fire performance requirements of two hours at a foam ratio 50, 100. Lightweight foamed concrete using AP satisfied fire performance requirements of two hours at AP ratio 0.1, 0.15. The insulation properties were better in closed pore foamed concrete by made AP, FP than with open pore foamed concrete made using AES.