• 한국축산식품학회지
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• 제30권1호
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• pp.66-72
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• 2010

Pediococcus pentosaceus SA131 was isolated from jeotgal, is the bacteriocin producer against bovine mastitis pathogens, Streptococcus uberis E290, Enterococcus gallinarum E362, and Staphylococcus epidermidis ATCC 12228. The medium composition for pediocin SA131 production by P. pentosaceus SA131 was optimized using response surface methodology. Component of medium was studied as carbon source (glucose, fructose, lactose, glycerol, sucrose, maltose, and mannitol), nitrogen source (beef extract, yeast extract, peptone, malt extract, and tryptone), mineral and surfactant ($MgSO_4$, $KH_2PO_4$, $(NH_4)_2SO_4$, $MnSO_4$, NaCl, sodium acetate, and Tween 80). Through one factor-at-a-time experiment, glucose, fructose, yeast extract, malt extract, NaCl, $MgSO_4$, and Tween 80 were determined as the good ingredient. The effects of major factors for pediocin SA131 production were investigated by two-level fractional factorial designs (FFD). By a $2^4$ FFD, fructose, yeast extract, and $MnSO_4$ were found to be the important factors for the bacteriocin production. Subsequently, a $2^3$ central composite design (CCD) was adopted to derive a statistical model for optimizing the composition of the fermentation medium. The estimated optimum composition for the production of pediocin SA131 by P. pentosaceus SA131 was as follows; 0.13% fructose, 1% glucose, 1.8% yeast extract, 2.58% $MnSO_4$, 0.2% NaCl, and 0.2% Tween 80. The pediocin production under optimized medium was increased to 1,000 AU/mL, compared to the 400 AU/mL in MRS medium.

• 한국식품조리과학회지
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• 제26권5호
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• pp.575-585
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• 2010

This study was performed to determine the optimal composition of a muffin administered dried burdock powder and oligosaccharide. The experiment was designed base on CCD (Central Composite Design), and evaluation was carried out by means of RSM (Response Surface Methodology), which included 10 experimental points with 3 replicates for the two independent variables burdock powder and oligosaccharide. The experimental muffin was made according to a traditional recipe, except that the flour was partially replaced with dried burdock powder (5%, 15%, 25%) and the sugar was partially replaced with oligosaccharide (25%, 50%, 75%). The compositional and functional properties of the prepared products were measured, and these values were applied to the mathematical models. Using the F-test, volume, height, pH, yellowness, chewiness, resilience, springiness, cohesiveness, taste, and overall quality were expressed as a linear model, whereas lightness, redness, adhesiveness, color, flavor, and overall quality were expressed as a quadratic model. The polynomial models developed by RSM for sensory evaluation, color, flavor, texture, taste, and overall quality were highly effective in describing the relationships between the factors (p<0.01). The estimated response surfaces confirmed that the amount of burdock powder had significant effects on color, taste, texture, flavor, and overall quality (p<0.01), whereas and the amount of oligosaccharide had significant effects on color and texture (p<0.01). Increased amount of burdock powder led to reductions of the sensory scores for color, taste, texture, flavor, and overall quality at all oligosaccharide levels. The optimal mixing percentage of burdock powder and oligosaccharide muffin were determined to be 5.00% and 46.25%, respectively.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1527-1532
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• 2016

Strain SPF4211, having hyaluronidase (HAase) inhibition activity, was isolated from P. davidiana (Carriere) Franch fruit (PrDF) sugar extract. The phenotypic and biochemical properties based on 16S rDNA sequencing and an API 50 CHB kit suggested that the organism was B. subtilis. To optimize the HAase inhibition activity of PrDF extract by fermentation of strain SPF4211, a central composite design (CCD) was introduced based on three variables: concentration of PrDF extract (X₁: 1-5%), amount of starter culture (X₂: 1-5%), and fermentation time (X₃: 0-7 days). The experimental data were fitted with quadratic regression equations, and the accuracy of the equations was analyzed by ANOVA. The statistical model predicted the highest HAase inhibition activity of 37.936% under the optimal conditions of X₁ = 1%, X₂ = 2.53%, and X₃ = 7 days. The optimized conditions were validated by observation of an actual HAase inhibition activity of 38.367% from extract of PrDF fermented by SPF4211. These results agree well with the predicted model value.

• Korean Chemical Engineering Research
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• 제54권3호
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• pp.315-319
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• 2016

아마란스 종실 생산의 부산물인 아마란스 잎으로부터 폴리페놀 추출 증대를 위해 열수추출의 주요 공정조건인 추출시간, 추출온도와 에탄올 농도 중심합성법을 이용해 최적화하였다. 폴리페놀의 추출은 추출온도와 시간이 증가함에 따라 증가하였으며 추출에 에탄올 농도와 추출시간이 유의한 효과를 보였다(p<0.05). 열수추출의 에탄올 농도는 61.6 (v/v%)에서 최대 폴리페놀 추출성능을 보이며 농도 증가에 따라 감소하는 경향을 보였다. 중심합성법에 의해 제시 된 2차 회귀방정식의 예측값과 실험값을 비교했을 때 매우 높은 합치도($R^2=0.9566$)를 보였으며 추출온도 $90.1^{\circ}C$, 추출시간 50 min과 에탄올 61.6 (v/v%) 공정조건에서 최대 농도인 12.6 mg GAE/g DM 폴리페놀을 얻을 수 있었다.

• 한국식품영양과학회지
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• 제38권1호
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• pp.116-120
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• 2009

포도즙의 알코올 발효 시 당 농도와 교반속도, 발효시간이 알코올함량과 총산도에 미치는 영향을 알아보기 위해 반응 표면분석을 이용하여 알코올발효 조건을 최적화하였다. 알코올함량은 10%, 총산도는 최소화되는 것을 목적으로 하여 알코올 발효조건을 최적화한 결과 $19.98^{\circ}Bx$로 농축한 국내산 Campbell early 포도즙에 효모를 접종시킨 후 교반속도 104.1 rpm으로 89.67시간 동안 발효시켰을 때 목적값에 가장 근접한 결과를 나타내었다. 알코올 발효 시 포도즙의 당도가 증가할수록 알코올함량과 총산도는 증가하는 경향을 나타내었고, 교반속도는 알코올함량과 총산도에 큰 영향을 주지 않는 것으로 나타났다. 또한 발효시간이 길어질수록 알코올 함량과 총산도가 증가하는 경향을 나타내었다.

• 한국식생활문화학회지
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• 제34권6호
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• pp.779-784
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• 2019

The purpose of this study was to optimize the rice protein extracted using a response surface methodology. The experiment was designed based on a CCD (Central Composite Design), and the independent variables were the high pressure (X₁, 0-400 MPa) and processing time (X₂, 0-10 minutes). The results of the extraction content (Y₁), residue content (Y₂), and recovery yield (Y₃) were fitted to a response surface methodology model (R²= 0.92, 0.92, and 0.93, respectively). Increasing the pressure and processing time has a positive effect on the extraction content (Y₁), residue content (Y₂), and recovery yield (Y₃). Therefore, these high-pressure conditions (independent variables) can significantly affect the improvement in rice protein extraction efficiency. Thus, the optimal conditions of X₁ and X₂ were 400 MPa and 10 min., respectively. Under these optimal conditions, the predicted values of Y₁, Y₂, and Y₃ were 62.93, 57.53 mg/g, and 91.76%, respectively.

• 한국축산식품학회지
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• 제34권6호
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• pp.836-843
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• 2014

Obesity, a condition in which an abnormally large amount of fat is stored in adipose tissue, causing an increase in body weight, has become a major public health concern worldwide. The purpose of this study was to optimize the process for fermented milk for the production of a functional product with an anti-obesity effect by using Lactobacillus plantarum Q180 isolated from human feces. We used a 3-factor, 3-level central composite design (CCD) combined with the response surface methodology (RSM). Concentration of skim milk powder (%, $X_1$), incubation temperature ($^{\circ}C$, $X_2$), and incubation time (h, $X_3$) were used as the independent factors, whereas pH (pH, $Y_1$), anti-lipase activity (%, $Y_2$) and anti-adipogenetic activity (%, $Y_3$) were used as the dependent factors. The optimal conditions of fermented milk for the highest anti-lipase and anti-adipogenetic activity with pH 4.4 were the 9.5% of skim milk powder, $37^{\circ}C$ of incubation temperature, 28 h of incubation time. In the fermentation condition, the predicted values of pH, anti-lipase activity and anti-adipogenetic activity were 4.47, 55.55, and 20.48%, respectively. However, the actual values of pH, anti-lipase activity and anti-adipogenetic activity were 4.50, 52.86, and 19.25%, respectively. These results demonstrate that 9.5% of skim milk powder and incubation at $37^{\circ}C$ for 28 h were the optimum conditions for producing functional fermented milk with an anti-obesity effect.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.933-941
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• 2008

An extracellular $\beta$-glucosidase produced by Monascus purpureus NRRL1992 in submerged cultivation was purified by acetone precipitation, gel filtration, and hydrophobic interaction chromatography, resulting in a purification factor of 92-fold. A $2^2$ central-composite design (CCD) was performed to find the best temperature and pH conditions for enzyme activity. Maximum activity was observed in a wide range of temperature and pH values, with optimal conditions set at $50^{\circ}C$ and pH 5.5. The $\beta$-glucosidase showed moderate thermostability, was inhibited by $HgCl_2$, $K_2Cr_O_4$, and $K_2Cr_2O_7$, whereas other reagents including $\beta$-mercaptoethanol, SDS, and EDTA showed no effect. Activity was slightly stimulated by low concentrations of ethanol and methanol. Hydrolysis of p-nitrophenyl-$\beta$-D-glucopyranoside (pNPG), cellobiose, salicin, n-octyl-$\beta$-D-glucopyranoside, and maltose indicates that the $\beta$-glucosidase has broad substrate specificity. Apparently, glucosyl residues were removed from the nonreducing end of p-nitrophenyl-$\beta$-D-cellobiose. $\beta$-Glucosidase affinity and hydrolytic efficiency were higher for pNPG, followed by maltose and cellobiose. Glucose and cellobiose competitively inhibited pNPG hydrolysis.

• 한국식생활문화학회지
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• 제34권5호
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• pp.637-644
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• 2019

The purpose of this study was to optimize the mandarin dry chip manufacturing using a response surface methodology. The experiment was designed based on a CCD (Central Composite Design), and the independent variables were the drying temperature ($X_1$, $50-90^{\circ}C$), drying time ($X_2$, 12-36 hours), and microwave pretreat time ($X_3$, 0-4 minutes). The results of appearance ($Y_5$), color ($Y_6$), taste ($Y_8$) and overall acceptance ($Y_{10}$) were fitted to the response surface methodology model ($R^2=0.86$, 0.88, 0.89, and 0.84, respectively). Increasing the drying temperature and microwave treatment time were negatively evaluated for consumer acceptance. On the other hand, a high value of consumer acceptance was evaluated when the drying time was more than 24 hr. Therefore, the optimal conditions of $X_1$, $X_2$, and $X_3$ were $52.989^{\circ}C$, 24 hr, and 1 min, respectively. Under these optimal conditions, the predicted values of $Y_5$, $Y_6$, $Y_8$, and $Y_{10}$ were 5.066, 5.338, 5.063, and 5.339, respectively.

• Earthquakes and Structures
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• 제17권5호
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• pp.511-519
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• 2019

The concrete gravity dam is one of the most important parts of the nation's infrastructure. Besides the benefits, the dam also has some potentially catastrophic disasters related to the life of citizens directly. During the lifetime of service, some degradations in a dam may occur as consequences of operating conditions, environmental aspects and deterioration in materials from natural causes, especially from dynamic loads. Cumulative Absolute Velocity (CAV) plays a key role to assess the operational condition of a structure under seismic hazard. In previous researches, CAV is normally used in Nuclear Power Plant (NPP) fields, but there are no particular criteria or studies that have been made on dam structure. This paper presents a method to calculate the limitation of CAV for the Bohyeonsan Dam in Korea, where the critical Peak Ground Acceleration (PGA) is estimated from twelve sets of selected earthquakes based on High Confidence of Low Probability of Failure (HCLPF). HCLPF point denotes 5% damage probability with 95% confidence level in the fragility curve, and the corresponding PGA expresses the crucial acceleration of this dam. For determining the status of the dam, a 2D finite element model is simulated by ABAQUS. At first, the dam's parameters are optimized by the Minitab tool using the method of Central Composite Design (CCD) for increasing model reliability. Then the Response Surface Methodology (RSM) is used for updating the model and the optimization is implemented from the selected model parameters. Finally, the recorded response of the concrete gravity dam is compared against the results obtained from solving the numerical model for identifying the physical condition of the structure.