• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.97-106
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• 1984

The Antarctic krill, Euphausia superba, is drawing attention over the world as the largest source of unutilized proteins in the ocean. For the use of krill as a human food, processing conditions of krill sauce by autolysis and/or commercial proteolytic enzyme digestion were examined. The krill was chopped and mixed with equal weight of water, and hydrolyzed by autolysis and/or commercial proteolytic enzyme digestion. The optimal conditions for hydrolysis of krill were $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by autolysis, $52.5^{\circ}C$, pH 6.3, 3hours by bromelain (0.5 %) digestion, and $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by commercial complex enzyme (5 %) digestion, respectively The maximum hydrolyzing rate of protein were 83.2 % by autolysis, 89.7 % by bromelain digestion, 92.7 % by commercial complex enzyme digestion. After krill meat hydrolyzed by autolysis at optimum condition, inactivated at $100^{\circ}C$ for 20 minutes and filtered with Buchner funnel. Two kinds of products were prepared with krill hydrolysate and preservatives: one contained 10 % of sodium chloride and 0.06 % of benzoic acid and the other 10 % of sodium chloride and 3 % of ethyl alcohol. These products were filled in the sterilized glass bottle and sealed. The pH, volatile basic nitrogen, amino nitrogen, color value (L, a and b values) and viable counts of bacteria were determined during storage at $37^{\circ}C$. The results showed that the products could be preserved in good condition during one month at $37^{\circ}C$. As a method to reduce the sodium level in krill sauce, it is convinced that sodium chloride could be replaced half in partially by potassium chloride. In the products prepared from krill by autolysis, bromelain or commercial complex enzyme digestion, hypoxanthine and 5'-IMP were abundant among the nucleotides and their related compounds as 15.3-20.4 ${\mu}mole/g$, dry solid, 2.2-2.5 ${\mu}mole/g$, dry solid, respectively. The abundant free amino acids were lysine, leucine, proline, alanine and valine. The contents of these amino acids were 67.4 %, 69.4 %, 69.8 % of the total free amino acids of each products. And TMAO, betaine and total creatinine were low in contents. The flavor of krill sauce prepared from krill by autolysis or enzyme digestion was not inferior to that of traditional Kerean soy sauce by sensory evaluation.

• Food Science and Preservation
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• v.21 no.2
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• pp.163-169
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• 2014

The effect of the combined argon (Ar) gas packaging treatment on the browning of fresh-cut potatoes was studied. Fresh-cut potatoes were prepared for the following six groups: dipping distilled water for 1 minute and air packaging (Cont); dipping in distilled water for 1 minute and argon gas packaging (AR); dipping in 1% ascorbic acid for 1 minute and air packaging (AA); dipping in 1% ascorbic acid for 1 minute and argon gas packaging (AAR); blanching at $35^{\circ}C$ for 30 minutes and air packaging (BL); and blanching at $35^{\circ}C$ for 30 minutes and argon gas packaging (BAR). The potatoes were washed, peeled, and sliced ($1.5{\times}1.5{\times}1.5$ cm) before treatment. The samples were packed with a 0.04-mm-thick OPP film and were stored at $5^{\circ}C$ for 9 days. During the storage, the $O_2$ concentration decreased in Cont but increased in the AR, AA, AAR, BL, and BAR groups. The $CO_2$ concentration increased during storage. The AR, AAR, and BAR groups showed high $L^*$ and low $a^*$, $b^*$ values (browning index). The growth of the total aerobic bacteria was also inhibited in the AR group. During storage, the PPO activity gradually increased, and the AR group showed lower PPO activity. The AA and AAR groups showed high DPPH radical scavenging activity. It was demonstrated that the argon gas packaging is effective in the quality maintenance of fresh-cut potatoes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.379-389
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• 2008

This study was conducted to assess the microbiological quality of raw and cooked foods served in the elementary school food service. Raw and cooked food samples were collected from 11 selected elementary schools in both June to July and September to October of 2005. Petrifilm plates were used to determine (in duplicate) total aerobic colony counts (PAC), Enterobacteriaceae (PE), coliform counts (PCC), and E. coli counts (PEC). Heavy contamination of Enterobacteriaceae (from 0.08 to 7.40 log CFU/g) and total coliform (0.50 to 6.52 log CFU/g) were observed in raw materials and cooked foods. Escherichia coli (E. coli) were detected in the sample of currant tomato (3.70 log CFU/g), sesame leaf (3.59 log CFU/g), dropwort (0.20 log CFU/g), crown daisy (3.15 log CFU/g), parsley (3.00 log CFU/g), peeled green onion (1.74 log CFU/g), frozen pork (0.65 log CFU/g), frozen beef (0.20 or 1.50 log CFU/g), chicken (1.78 log CFU/g), and young radish leaf seasoned with soybean paste (1.24 log CFU/g). Multiplex PCR system was used to determine the food-borne pathogens: Salmonella spp., Bacillus cereus (B. cereus), E. coli O157:H7, Staphylococcus aureus, Listeria monocytogenes (L. monocytogenes), Vibrio parahaemolyticus, Campylobacter jejuni (C. jejuni), Shigella spp., B. cereus was detected in 19 samples of raw materials and 8 samples of cooked foods. With regard to quantitative analysis, B. cereus counts exceeded 5.46, 3.48 and 1.79 log CFU/g in sesame leaf, peeled green onion and seasoned mungbean jelly, respectively. E. coli O157:H7 was detected on 2 samples of frozen beefs, and its biochemical characteristics of one beef sample was confirmed with API 20E kit (93.7%). L. monocytogenes was detected in fried rice paper dumpling, but the presumptive colonies were not detected onto the conventional plate. C. jejuni was detected in peeled & washed onion.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.345-350
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• 2014

The aim of this study was to investigate the effect of high temperature on the viability of probiotic organisms (Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae) mixed with animal feed under controlled conditions by simulating a farm feed bin in the summer. Following inoculation of probiotics into the feed, the pH and probiotic viability were monitored during an 8-day incubation at room temperature. Sterile and non-sterile feeds displayed different patterns of pH changes, with increased pH in non-sterile feed at 2 days, but a pattern of decreasing pH at 4 days. The viabilities of S. cerevisiae and B. subtilis after mono/co-inoculation were maintained without substantial changes during the incubation, whereas L. plantarum viability tended to decline. In both non-sterile and sterile feeds, the probiotics were maintained or grew without any antagonistic effects. Probiotic viability was also tested upon a shift to high temperature ($60^{\circ}C$). There was no distinct change in pH between sterile and non-sterile feeds after the temperature shift. L. plantarum and S. cerevisiae could not survive at the high temperature, whereas B. subtilis displayed normal growth, and it inhibited the growth of contaminant microbes. Fungal growth was not observed in non-sterile feed 2 days after supplementation with B. subtilis. Therefore, heat resistant B. subtilis could be safely used in feed bins to inhibit microbial contamination, even at high temperatures. The prevention of elevated temperature in feed bins is necessary for the utilization of L. plantarum and S. cerevisiae during the summer season.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.850-856
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• 2005

The sensory and safety of cook-chilled Buchu-jeon were evaluated to provide to foodservice operation during chilled storage for 5 days. The sensory evaluations of cook-chilled Buchu-jeon were conducted according to 3 reheating methods which was frying pan, steam/convection oven and microwave oven. The sensory evaluations were made on 4 sensory attributes (taste, odor, color, and texture) by a 9-member panel using quantitative descriptive analysis (QDA). The Buchu-jeon reheated in the steam/convection oven, after 1 day storage at $3^{\circ}C$, obtained higher score in taste, odor and texture than the ones reheated in a frying pan and microwave oven. Three reheating methods didn't show any difference in taste, odor, color, and texture of Buchu-jeon at $3^{\circ}C$ for 3 days. The Buchun-jeon reheated in microwave oven at $3^{\circ}C$ for 5 days had a significant $(p\leq0.05)$ lower score odor and color than the ones reheated in frying pan and steam/convection oven. The safety of Buchu-jeon was also evaluated by measuring total count, coliform count, psychrotrophic count, acid value and peroxide value during 5 days of storage periods at $4^{\circ}C$C. Total counts of Pajeon was ranged from $5.0\times10^{1}$ CFU/g to $2.2\times10^{2}$ CFU/g and the coliform and psychrotroph were not detected at most experiments. The acid values were ranged from 1.80 to 2.18 mg of KOH/g of fat until 5 days at $4^{\circ}C$. And the peroxide values were ranged from 4.44 to 17.87 meq of peroxide/kg of fat until 5 days of storage period. Therefore, these results demonstrated that the cook-chilled Buchu-jeon is microbiologically and chemically safe during 5 days of storage period at refrigeration temperature.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.411-418
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• 2012

This study was conducted to investigate the effect of calcinated calcium (CC) alone or combination with heat treatment on storage quality and microbial growth in fresh-cut broccoli. Fresh broccoli samples were cut into small pieces and washed in normal tap water (TW), $50{\mu}L{\cdot}L^{-1}$ chlorinated water (pH 6.5), $1.5g{\cdot}L^{-1}$ CC, heat treatment in TW at $45^{\circ}C$, and CC dissolved in TW at $45^{\circ}C$ for 2 minutes separately. Samples were then packaged in $50{\mu}m$ polyethylene bags and stored at $5^{\circ}C$. Results revealed that like $50{\mu}L{\cdot}L^{-1}$ chlorine, washing in CC at normal water temperature was effective in reducing microbial population in fresh-cut broccoli samples. Washing with CC combined with heat treatment increased an electrical conductivity of fresh-cut broccoli. Combined heat treatments with TW and CC reduced aerobic plate count on fresh-cut broccoli, only in initial period of storage. But, later on heat treatment induced injury of fresh-cut broccoli resulting more microbial population compared to non heat treatment. However, samples treated with CC alone had good quality with low off-odor at the end of storage. Results suggest that CC, an environment-friendly sanitizer could be an alternative to chlorinated water for washing of fresh-cut broccoli without affecting sensorial quality.

• Korean Journal of Environmental Agriculture
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• v.9 no.2
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• pp.83-95
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• 1990

This study was conducted to estimate influences of pesticides such as carbofuran[2,3-dihydro-2,2-dimethylbenzofuran-7-yl methyl carbamate] as an insecticide, and pyrazolate [4-(2,4-dichlorobenzolyl)-1,3-dimethyl-5-pyrazolyl-1,3-dimethyl-5-pyrazolyl-p-toluensulfonate], pyrazolate+pretilachlor [2-chlor-2,6-diethyl-N-(n-propoxyethyl) acetanilied] as herbicides on change in numbers of soil microorganisms and pH in planted and unplanted flooded rice paddy soils. The results of weekly investigated change of pH and populations of total bacteria, gram negative bacteria, anaerobic bacteria and fungi after treatments of pesticides were as follows : The change of pH in rice-planted soil gradually decreased in a matter of weeks after treatment with pesticide and the pH increased again from the sixth week, but no change of pH could be observed in nonplanted soil. The total numer of bacteria in the treated plots were slightly less than in the control plot, and the numbers decreased with increasing application rates of pesticides. But the microbial population increased in a matter of days after treatment with pesticide. Number of the gram negative bacteria until the sixth week after treatment of pesticide were fewer than control. The number in the carbofuran-treated plot decreased after a weeks after treatment, but numbers in plots treated with pyrazolate and pyrazolate+pretilachlor increased. The number of anaerobic bacteria in the treated plots were few by comparison with the untreated control, but the number increased after a weeks after treatment with pesticides. The populations of fungi in the carbofuran-treated plot were similar by comparison with the untreated control. The populations in the plots treated with pyrazolate and pyrazolate+pretilachlor decreased in 4 to 5 weeks with increase of application rate, but afterwards increased.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.456-464
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• 2014

Kimchi was prepared with three types of salt (4-year-aged solar salt, FS; 1-year-aged solar salt, OS; and purified salt, PS), using Leuconostoc citreum GJ7 as the starter culture. The prepared kimchi was fermented (up to 0.5-0.6% of acidity) and stored for 5 months at $-1^{\circ}C$. During the storage period, the acidity of FS kimchi increased gradually, whereas that of PS kimchi increased sharply. The yellowness (b) color value of PS kimchi (63.4) was higher than that of other kimchis with solar salts (55.6-60.3). Hardness of FS kimchi (1,912.6 gf) was greater than that of the other kimchis (1,554.4-1,650.2 gf) during the storage period. Moreover, sensory evaluation showed higher scores for FS kimchi than for other kimchis. These results suggest that FS is more suitable salt than PS for long-term storage of kimchi.

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.55-60
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• 2011

To work out quality control methods of environmental-friendly organic materials (EFOMs), the reason and basis for EFOM-selection and farmer's favorite formulation type of EFOMs, etc were investigated on farmers who had been practicing environmental-friendly agriculture. EFOMs used were soil amendments, control agents of plant diseases and insect pests, plant growth promotion formulations, in turns. In EFOMs application time, 22.7% of farmers sprayed EFOMs without delay after they were bought, in other hand, 77.3% of farmers used EFOMs which had been bought and stored for some period. Microbial density on seventeen environmental-friendly microbial formulates (EFMFs) including microbial pesticides, a microbial fertilizer, and environmental-friendly organic materials was investigated at different storing temperature and shelf life. When the microbial density of EFMFs was investigated without delay after they were bought, all used microbial pesticides and a microbial fertilizer was confirmed to be optimal for the certified density but two of environmental-friendly organic materials was confirmed not to be optimal. When microbial density of 17 EFMFs were investigated after storing them for six months at $4^{\circ}C$, only one of 9 microbial pesticides was confirmed not to be optimal, the other hand four of seven environmental-friendly organic materials not to be optimal, which each of their microbial density was less than the certified density. Population dynamics of microbial agents was much more influenced in fluctuated temperature (room temperature) than in static temperature condition ($5^{\circ}C$ and $25^{\circ}C$). Shelf life of microbial agents according to microbial formulation type were high in granule type, liquid wettable type and liquid type in turns.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.15-21
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• 2005

This Study was conducted to investigate the effects of microbial phytase in low phosphirus and calcium level diet on the performance and nutrient digestibility in laying hens. One hundred ninety two, 50 wks old, ISA brown commerical layers were used for 12 weeks feeding trial after 7-d adjustment period. Four dietary treatments included CON(control; Co.), P2 ($0.06\%$ Natuphos, BASF) and P3 ($0.06\%$ PHOSMAX, GENOFOCUS). Ca and available P concentrations of P1, P2 and P3 were 90 and $50\%$ of NRC recommecdations to accentuate difference in response to phytase availability. In whole period, egg production was not affected by treatments. At 12 weeks, egg weight was significantly increased in adding phytase treatments (P<0.05). Egg shell thickness was increased in P1, P2 and P3 treatments compared with control (P<0.05) at 9 weeks. Ca concentration of serum tended to decrease in P1 treatment without significant difference (P>0.05). Ca and P concentrations of tibia were higher in layers fed dietary phyrase than those fed control diet without significant difference (P>0.05). Digestibilities of DM, N and ash were improved in P1 treatment compared with P2 and P3 treatments (P<0.05). Ca and P digestibilities were the highest in P2 treatment (P>0.05), but was not significant difference between control and P1 treatments.