• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.116-120
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• 2009

Response surface methodology (RSM) was applied to optimize alcohol fermentation of concentrated grape juice. Sugar concentration ($X_1$), agitation rate ($X_2$) and fermentation time ($X_3$) were chosen as the independent variables of the central composite design (CCD). Dependent variables were alcohol content ($Y_1$) and total acidity ($Y_2$). To optimize two dependent variables, desirability function was defined as $Y_1$=10.0% and $Y_2$=minimum. The optimum conditions for alcohol fermentation were $19.98^{\circ}Bx$ (sugar concentration), 104.1 rpm (agitation rate) and 89.67 hr (fermentation time). The predicted responses were 10.0% in alcohol content and 0.86% in total acidity. The coefficients of determination ($R^2$) were 0.948 and 0.958, which indicate that the model fit was highly significant (p<0.001). The experimental values were 10.1% for alcohol content and 0.88% for total acidity. These values were similar to the predicted values from RSM.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.783-788
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• 2012

The aim of this study was to optimize the manufacturing condition of spreadable modified butter by RSM. Based on the central composite design, the degree of optimization was expressed as a SFC as a dependent variable (Y, %) determined by NMR with 23 experimental groups. Three independent variables were the contents of butter ($X_1$, 35-75%), the contents of grape seed oil ($X_2$, 15-35%), and the contents of hydrogenated soybean oil ($X_3$, 0-4%). As the result, SFC at $10^{\circ}C$ was ranged from 32.37 to 42.76%. In addition, the regression coefficients were calculated for SFC at $10^{\circ}C$ by RSREG. The regression model equation for the SFC was $Y=39.18-0.04X_1X_3$. Consequently, the optimal contents for manufacturing spreadable modified butter were determined as 55.18% for butter, 40.78% for grape seed oil, and 4.08% for hydrogenated soybean oil, respectively. The predicted response value for SFC at $10^{\circ}C$ was 30.20%, comparable to the actual experimental SFC value as 29.85%. Finally hardness and spreadability in reference butter and spreadable modified butter produced under the optimal conditions was measured. The hardness in spreadable modified butter was 31.80 N as compared to 69.92 N in reference butter. The spreadability in spreadable modified butter was 5.6 point as compared to reference butter. This difference may be due to the contents of solid fat by butter and hydrogenated soybean oil. This study showed that the SFC value at $10^{\circ}C$ could be a suitable indicator for the manufacturing spreadable modified butter to predict important attributes such as mouth feel, hardness and spreadability.

• Journal of the Korean Society of Food Culture
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• v.34 no.6
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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.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.231-236
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• 2008

Response surface methodology (RSM) was used for the analysis and optimization of the production process of strawberry Kochujang. Experiments were carried out according to a central composite design, selecting strawberry puree content and red pepper powder content as independent variables and soluble solids content, moisture content, water activity, color characteristics ($L^*-$, $a^*-$, and $b^*$-values) as response variables. The polynomial models developed by RSM were highly effective for describing the relationships between the study factors and the responses. Kochujang containing a higher amount of red pepper powder had a higher soluble solids content; on the contrary, soluble solids content decreased with the increase in the strawberry puree content in the sample. Moisture content increased with increased strawberry puree content but decreased with increased red pepper powder content. Water activity increased with the increase in strawberry puree content in the sample but was less affected by the amount of red pepper powder content. Decreases in $L^*$-values with increasing amount of red pepper powder were noted. $a^*$-values decreased with the increases in red pepper powder content but increased with the increase in strawberry puree content in the Kochujang formulation. $b^*$-values decreased with the increases in red pepper powder content but was less affected by the strawberry puree content. Overall optimization, conducted by overlaying the contour plots under investigation, was able to point out an optimal range of the independent variables within which the six responses were simultaneously optimized. The point chosen as representative of this optimal area corresponded to strawberry puree content=14.36% and red pepper powder content=11.33%, conditions under which the model predicted soluble solids content=$59.31^{\circ}Brix$, moisture content=45.30% (w.b.), water activity=0.758, $L^*$-value=24.81, $a^*$-value=7.250, and $b^*$-value=10.19.

• Food Science and Preservation
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• v.10 no.3
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• pp.314-319
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• 2003

This study was conducted to the optimize salting process of eggplant for development new product and enhancement quality for export. Three variables by five level central composite design and response surface methodology were used to determine optimum conditions for salting time, temperature and salt concentration. Optimization of the process was conducted using the combination of the moisture content, salinity and color of surface and inside of salted eggplant. The regression polynomial model was suitable (P>0.05) by Lack-of-Fit analysis with highly significant. To optimize the process, based on surface response and contour plots, the individual contour plots of the response variables were superimposed. The optimum conditions for this process were 6 days and 15$^{\circ}C$ at 30％ concentration under the optimum of restricted variables as moisture content was below 84％, salinity was below 14％, L and b value of surface were 10 to 20 and below 0, L value and b value of inside were 70 to 75 and 16 to 18.

• Journal of the Korean Society of Food Culture
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• v.34 no.5
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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.

• Korean Journal of Materials Research
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• v.34 no.2
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• pp.85-94
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• 2024

The optimization of deacetylation process parameters for producing chitosan from isolated chitin shrimp shell waste was investigated using response surface methodology with central composite design (RSM-CCD). Three independent variables viz, NaOH concentration (X₁), radiation power (X₂), and reaction time (X₃) were examined to determine their respective effects on the degree of deacetylation (DD). The DD of chitosan was also calculated using the baseline approach of the Fourier Transform Infrared (FTIR) spectra of the yields. RSM-CCD analysis showed that the optimal chitosan DD value of 96.45 % was obtained at an optimized condition of 63.41 % (w/v) NaOH concentration, 227.28 W radiation power, and 3.34 min deacetylation reaction. The DD was strongly controlled by NaOH concentration, irradiation power, and reaction duration. The coefficients of correlation were 0.257, 0.680, and 0.390, respectively. Because the procedure used microwave radiation absorption, radiation power had a substantial correlation of 0.600~0.800 compared to the two low variables, which were 0.200~0.400. This independently predicted robust quadratic model interaction has been validated for predicting the DD of chitin.

• Journal of Korean Society for Quality Management
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• v.51 no.4
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• pp.619-632
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• 2023

Purpose: The main function of INS (Inertial Navigation System) is to measure the position of an armed vehicle and its performance is confirmed through the positioning accuracy test of Korean Defense Standards (KDS). The current standards, however, do not provide clear test methods and the conditions for performing positioning accuracy tests. Accordingly, the purpose of this study is to develop a new method for positioning accuracy test which would be effective. Methods: In this study, a new INS positioning accuracy test method is suggested based on the analysis of test data collected through a statistical experiment known as central composite design. For the positioning accuracy experiment of K105A1, a self-propelled artillery, two factors of driving velocity and driving distance are considered. Results: Based on the analysis of experimental data, a regression model for the positioning error is fitted and the positioning accuracy test of INS is so developed to maximize the positioning error. The standard proximity rate is used as an additional test criterion to evaluate the performance level of INS. Conclusion: The proposed new positioning accuracy test for INS has the advantage of finding the nonconforming items effectively. It is also expected to be utilized for the other similar INS positioning accuracy tests.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.1982-1992
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• 2019

The alkaliphilic, calcium carbonate precipitating Bacillus sp. strain AK13 can be utilized in concrete for self-repairing. A statistical experimental design was used to develop an economical medium for its mass cultivation and sporulation. Two types of screening experiment were first conducted to identify substrates that promote the growth of the AK13 strain: the first followed a one-factor-at-a-time factorial design and the second a two-level full factorial design. Based on these screening experiments, barley malt powder and mixed grain powder were identified as the substrates that most effectively promoted the growth of the AK13 strain from a range of 21 agricultural products and by-products. A quadratic statistical model was then constructed using a central composite design and the concentration of the two substrates was optimized. The estimated growth and sporulation of Bacillus sp. strain AK13 in the proposed medium were 3.08 ± 0.38 × 10⁸ and 1.25 ± 0.12 × 10⁸ CFU/ml, respectively, which meant that the proposed low-cost medium was approximately 45 times more effective than the commercial medium in terms of the number of cultivatable bacteria per unit price. The spores were then powdered via a spray-drying process to produce a spore powder with a spore count of 2.0 ± 0.7 × 10⁹ CFU/g. The AK13 spore powder was mixed with cement paste, yeast extract, calcium lactate, and water. The yeast extract and calcium lactate generated the highest CFU/ml for AK13 at a 0.4:0.4 ratio compared to 0.4:0.25 (the original ratio of the B4 medium) and 0.4:0.8. Twenty-eight days after the spores were mixed into the mortar, the number of vegetative cells and spores of the AK13 strain had reached 10⁶ CFU/g within the mortar. Cracks in the mortar under 0.29 mm were healed in 14 days. Calcium carbonate precipitation was observed on the crack surface. The mortar containing the spore powder was thus concluded to be effective in terms of healing micro-cracks.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.701-708
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• 2017

This study was conducted to evaluate the hyaluronidase (HAase) inhibition activity of Asparagus cochinchinesis (AC) extracts following fermentation by Weissella cibaria through response surface methodology. To optimize the HAase inhibition activity, a central composite design was introduced based on four variables: the concentration of AC extract ($X_1$: 1-5%), amount of starter culture ($X_2$: 1-5%), pH ($X_3$: 4-8), and fermentation time ($X_4$: 0-10 days). The experimental data were fitted to quadratic regression equations, the accuracy of the equations was analyzed by ANOVA, and the regression coefficients for the surface quadratic model of HAase inhibition activity in the fermented AC extract were estimated by the F test and the corresponding p values. The HAase inhibition activity indicated that fermentation time was most significant among the parameters within the conditions tested. To validate the model, two different conditions among those generated by the Design Expert program were selected. Under both conditions, predicted and experimental data agreed well. Moreover, the content of protodioscin (a well-known compound related to anti-inflammation activity) was elevated after fermentation of the AC extract at the optimized fermentation condition.