• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.312-320
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• 1996

This study was to investigate the changes of phytotoxicity of food waste during composting at an aerated static pile for 80 days. The concentration of sodium in the final compost increased by more than 30% and almost of the sodium was a water soluble type which corresponds to about 94% of the total concentration. Major volatile fatty acid(VFA) produced during the composting was acetic acid and also somewhat of butyric acid. High concentration of acetic acid during the composting was kept up for a month and then decreased progressively. It suggests that the phytotoxicity by the VFAs produced during composting of food waste could be removed through a stabilization process in a period of about 40 days. From the statistical analysis between germination index(G.I.) and VFAs. or G.I. and sodium, the phytotoxicity of food waste samples was more dependent in the changes of acetic acid concentration than that of sodium concentration. Considering low G.I. value in the final food waste compost which is matured completely, however. the agricultural utilization of the food waste compost may be to have a big problem due to excess sodium of the compost which is impossible to remove by composting and seriously inhibits growth of plants.

• Food Engineering Progress
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• v.15 no.4
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• pp.388-397
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• 2011

The purpose of this study was to determine the optimum ethanol extraction conditions for maximum extraction of functional components such as ferulic acid, oryzanol, and toopherol from black rice bran using Response Surface Methodology (RSM). A central composite design was applied to investigate the effects of the independent variables of solvent ratio ($X_{1}$), extraction temperature ($X_{2}$) and extraction time ($X_{3}$) on the dependent variables such as total phenol components ($Y_{1}$), total flavonoids compounds ($Y_{2}$), electron donating ability ($Y_{3}$), $\gamma$-oryzanol ($Y_{4}$), ferulic acid ($Y_{5}$) and $\alpha$-toopherol components ($Y_{6}$). ANOVA results showed that coefficients of determination (R-square) of estimated models for dependent variables ranged from 0.8939 to 0.9470. It was found that solvent ratio and extraction temperature were the main effective factors in this extraction proess. Particularly, the extraction efficiency of ferulic acid, $\gamma$-oryzanol and $\alpha$-toopherol components were significantly affected by extraction temperature. As a result, optimum extraction conditions were 20.35 mL/g of solvent ratio, 79.4$^{\circ}C$ of extraction temperature and 2.88 hr of extraction time. Predicted values at the optimized conditions were acceptable when compared with experimental values.

• KSBB Journal
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• v.4 no.1
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• pp.48-56
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• 1989

Fermentation characteristics of Jerusalem Artichoke of yeast K.fragilis CBS 1555 were investigated experimentally and quantitatively according to the change of initial sugar concentrations and initial PHs of fermentation broth. Initial sugar concentrations employed were 26, 45, 65, 105, 180, and 215g/1. And initial PHs of fermentation broth were 3, 5.5, 7 and 9. The maximum specific growth rate was observed as 0.4hr-1 at 65g/1 of initial sugar concentration. The maximum specific alcohol production rate was 1.68g/ghr at 105g/1 of initial sugar concentration Cell yield and ethanol yield represent the maximum values such as 0.14 and 0.49 respectively when the initial sugar concentration was 25g/1. The maximum of ethano1 fermentability, 97% was obtained at the initial concentrations, 26 and 45g/1. However, the maximum of total ethanol yield productivity was 2.78g/1hr when the initial concentration was 215g/1. And also the optimum PH was found 5.5 for both specific growth rate and specific alcohol production rate.

• KSBB Journal
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• v.20 no.4
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• pp.271-277
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• 2005

The polyunsaturated fatty acids (PUFAs) are mostly synthesized by the marine original microorganisms. In this study, the effect of concentrations of glucose, NaCl, and $MgSO_4{\cdot}7H_2O$ on both the growth and the production of lipid and Docosahexaenoic acid (DHA) was investigated using Thraustochytrium aureum ATCC 34304. $Y_{Lipid/X}\;and\;Y_{DHA/Lipid}$ increased according to the increase of initial glucose concentration until 15 g/L of glucose. The maximum values of $Y_{Lipid/X}\;and\;Y_{DHA/Lipid}$ were 0.18 g/g and 0.41 g/g respectively at 15 g/L of glucose. The biomass yield, $Y_{x/s}$, however, was constant as 0.378 g/g regardless of initial glucose concentrations in the range of 5 g/L to 25 g/L. The specific growth rate of T. aureum increased also with initial glucose concentration from 5 g/L and 15 g/L. The maximum value was $0.79\;day^{-1}$ at 15 g/L of glucose, and the growth rate decreased to $0.57\;day^{-1}$ and remained constant according to initial sugar concentration in the range of higher than 15 g/L of glucose. The concentration of NaCl was changed from 0 g/L to 48 g/L, in order to study the characteristics of the growth and the production of lipid and DHA according to NaCl concentration. The growth and the production of lipid as well as DHA stopped all at 0 g/L of NaCl and the maximum values of all the three variables occurred at 24 g/L. The effect of $MgSO_4{\cdot}7H_2O$ concentration was also investigated not to find the growth and the production of lipid and DHA at 0 g/L. However, the growth and the Production with $MgSO_4{\cdot}7H_2O$ concentration increased to reach the maximum values at 18 g/L of $MgSO_4{\cdot}7H_2O$.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.127-127
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• 2001

Chitosan에 Ttichoderma viride 유래의 cellulase를 처리하여 효소분해함으로써 고분자량 chitooligosaccharides를 얻었다. 생산된 올리고당을 HPLC로 분석한 결과 octamer 이상의 것이 전체 올리고당 중 49.3%에 달하는 비교적 고분자 화합물로 구성된 chitooligosaccharides의 혼합물이었다. MTT검색법에 의하여 고분자량 chitooligosaccha- rides의 정상세포주와 암세포주에 대한 세포독성을 실험하였다. 정상세포주인 아프리카 초록원숭이의 신장세포에 대한 $IC_{50}$/(50% 저해농도)값은 1,107.95$\mu$g/ml로 정상세포에 대한 독성은 거의 없었다. 폐암세포주인 A549, 방광암세포주인 J82, 대장암세포주인 SNU-C4, 위암세포인 SNU-1, 유방암세포주인 ZR75-1에 대한 $IC_{50}$/값은 각각 421.06$\mu$g/ml, 417.99$\mu$g/ml, 445.54$\mu$g/ml, 380,65$\mu$g/ml, 460.49$\mu$g/ml로 in vitro 종양세포 증식억제 활성을 나타내었다.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.149-152
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• 2003

This experiment was carried out to obtain the optimal liquid culture conditions for the mycelial growth and the polysaccharide production of Tricholoma matsutake. For the mycelial growth and polysaccharide production, the synthetic medium was optimized with containing glucose 40 g/L, yeast extract 30 g/L, $KH_2PO_4$ 1.5 g/L and $MgSO_4.7H_2O$ 1 g/L. The effects of agitation and aeration were investigated for the cell growth and the polysaccharide production in batch culture. The biomass and polysaccharide concentrations were 21.87 g/L at 150 rpm and 8.86 g/L at 300 rpm, respectively. And the biomass concentration and the polysaccharide production were 20.85 g/L at 0.5 vvm and 8.83 g/L at 1.5 vvm, respectively.

• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.135-141
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• 1982

The gamma radiolysis of C$O_2$, in the presence of organic additives, was studied at the total absorbed dose of 6.7 Mrad. Considerable quantity of CO was produced by adding these additives to $O_2$, though no CO was found without them. The maximum G(CO) values of 4.1 and 4.6 were obtained by addition of 0.5% methanol and 0.25% ethanol, respectively. The G(CO) values of 6.3 and 8.4 were noted by the addition of 1% acetaldehyde and 1% formaldehyde, respectively. The maximum CO concentration of 0.65% was obtained by the addition of 1% acetaldehyde at the dose of 40 Mrad.

• Food Science and Preservation
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• v.23 no.6
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• pp.839-847
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• 2016

The changes of approximate composition, antioxidant activity and melatonin content in rapeseed were monitored during 10 days germination to choose the optimum sprouts with beneficial functionalities. The moisture content of seeds increased from 3.23% to 17.50% during 10 days germination period, while ash content was similar (4.03~4.91%). The fat content was reduced from 38.18% to 22.65%, however, protein content increased from 21.43% to 26.72%. The carbohydrate content increased from 32.71% to 35.84% at 8th day. The reducing sugar and fiber contents reached 10.47% and 15.12% at 6th day from 4.04% and 12.82%, respectively. Eighth day sprouts contained highest level of polyphenol (gallic acid equivalent, 19.2 g/kg). Germination increased antioxidant activities (trolox equivalent, mmol/kg) of seeds with slight difference depending on assay. That is, antioxidant activity was highest at 6th day in DPPH radical scavenging (55.9), 10th day both in ABTS radical scavenging (71.6) and Fe(III) reducing (125.3), and 4th day in peroxy radical scavenging (116.7) assay. Melatonin content of seeds ($0.85{\mu}g/kg$) also increased and reached up to $14.93{\mu}g/kg$ at 6th day. In conclusion, germination more than 4 days raised antioxidant activity of seeds highly, and 6th day sprouts had additional benefit in terms of melatonin, reducing sugar and crude fiber contents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.435-441
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• 2017

The present study was carried out to evaluate the applicability of Tenebrio molitor larvae (mealworm) as a health functional food material in order to contribute to the development of the domestic insect industry and health functional food industry. Protein hydrolysates were prepared from mealworm powder by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain), and the hydrolysates were then tested for their antioxidant activities. Based on available amino group contents and sodium dodecyl sulphate-polyacrylamide gel electrophoresis analyses, mealworms treated with alcalase ($4,781.39{\mu}g/mL$), flavourzyme ($5,429.35{\mu}g/mL$), or neutrase ($3,155.55{\mu}g/mL$) for 24 h showed high degree of hydrolysis (HD) value, whereas HD values of bromelain ($1,800{\mu}g/mL$) and papain-treated ($1,782.61{\mu}g/mL$) mealworms were much lower. Protein hydrolysates showing high HD values were further separated into > 3 kDa and ${\leq}3kDa$ fractions by a centrifugal filter system and then lyophilized, and the production yields of the low molecular weight protein hydrolysates (${\leq}3kDa$) by alcalase, flavourzyme, and neutrase were 42.05%, 26.27%, and 30.01%, respectively. According to the RC_{50} values of the protein hydrolysates (${\leq}3kDa$) obtained from three different antioxidant analyses, all three hydrolysates showed similar antioxidant activities. Thus, alcalase hydrolysates showing the highest production yield of low molecular weight protein hydrolysates were further tested for their inhibitory effects on peroxidation of linoleic acid by measuring thiobarbituric acid values, and the results show that peroxidation of untreated linoleic acid increased dramatically during 6 days of incubation. However, pretreatment with the hydrolysates ($100{\sim}800{\mu}g/mL$) significantly inhibited linoleic acid peroxidation in a dose-dependent manner over 6 days.

• The Korean Journal of Ecology
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• v.24 no.1
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• pp.19-26
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• 2001

Tributyltn, triphenyltin and their degradation products were quantitatively determined in sediments, seawater, and oysters (Crassostrea gigas) collected from Okpo Bay, Korea where a huge shipyard was located. The concentrations of TBT in sediment and oyster were in the range of 5∼2,050 ng/g and 387∼1,190 ng/g (astin on a dry weight basis), respectively. In seawater, it ranged from 19 to 84 ng/ℓ The distribution of TBT compound showed negative gradient from inner to outer bay, which indicates that the shipyard is the point source of TBT contamination in the bay. The contribution of TBT to butyltin concentration in sediment was above 57%. The pattern of TBT distribution was influenced by waterbreak transected the bay. TPhT concentration in oyster ranged from nd (not detected) to 52 ng Sn/g dry wt., whereas that in sediment and seawater was below detection limit. The biological concentration factor (BCF) in oyster was 1.1×10⁴.