• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.1062-1069
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximizing the functional properties of roasted Pleurotus eryngii. Based on the central composite design, independent variables were ethanol concentration ($0{\sim}100%$), extraction time ($1{\sim}9$ min) and microwave power ($25{\sim}125$ W). Soluble solid content, electron donating ability and nitrite-scavenging ability were mainly affected by ethanol concentration, but ACE inhibition activity was largely affected by extraction time. The optimum ranges of extraction conditions resulting from superimposing the response surface were predicted to be ethanol concentration ($25{\sim}50%$), extraction time ($3{\sim}9$ min) and microwave power ($80{\sim}125$ W). Total protein and total phenolic compound content of optimal extracts were 45.80 mg/g and 7.42 mg/g, respectively. In phenolic compounds of roasted Pleurotus eryngii extracts, protocatechuic acid was the highest concentration at 1226.32 ${\mu}g/g$, followed by salicylic acid, catechin, p-hydroxybenzoic acid, caffeic acid, coumaric acid and hesperidin.

• Food Science and Preservation
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• v.14 no.5
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• pp.474-480
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• 2007

Response surface methodology (RSM) was employed to optimize extraction conditions preserving valuable functional properties of fluid Cheonggukjang obtained from red ginseng. Based on a central composite design, the study plan was established using variations in microwave power, ethanol concentration, and extraction time. Regression analysis was applied to obtain a mathematical model. A maximum electron donating ability (EDA) of 99.09% was obtained under the specific extraction conditions of microwave power 135.62 W, ratio of solvent to sample contents. 3.60 g/mL, and an extraction time of 11.79 min. The maximum inhibitory effect on tyrosinase activity was 10.02% at 119.16 W, 4.02 g/mL, and 5.57 min. The maximum superoxide dismutase (SOD)-like activity was 63.83% under the extraction conditions of 125.29 W, 4.04 g/mL, and 11.02 min. Based on superposition of four-dimensional RSM data obtained to optimize electron donating ability, nitrite-scavenging ability, inhibitory effect on tyrosinase activity, and SOD-like activity, the optimum ranges of extraction conditions were found to be a microwave power of $l{\sim}85 W$, a ratio of solvent to sample content of $1.4{\sim}2.8\;g/mL$, and an extraction time of $6.5{\sim}11\;min$.

• Food Science and Preservation
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• v.10 no.4
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• pp.547-553
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• 2003

To develop the health and functional food material from oats, this study was conducted to determine the biologiral activities(antibacterial, antioxidative and mtltmor effects) of oat bran's soluble ${\beta}$-glucans obtained from oat bran concentrate(OBC) by central composite experimental design. The antibacterial effect of oat's ${\beta}$-glucans in the concentration of 250, 500$\mu\textrm{g}$/disc was not detected by paper disc method, and no antioxidative effect of them in the concentration of 5％ by electron donating ability. The growth inhibition on tumor cell lines of oat's soluble ${\beta}$ -glucans was significantly higher in the experimental fraction of No. 7(temperature 45$^{\circ}C$, ethanol 15%, pH 6) than the other fractions(p<0.05). The maximal values of growth inhibitions on AGS, Hep3B and A549 cell lines in the cancentration of 1mg/ml are 59%, 58% and 54% respectively. In addition, the inhibition effect on three tumor cell lines of No. 1(temperature 5$^{\circ}C$, ethanol 5%, pH 6) was relatively high. From the results of response surface methodology, as the values of independent variables changed, they influenced the growth inhibition effect on this cell lines. With this on work further research is required to clarify antitumor effects.

• Food Science and Preservation
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• v.18 no.4
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• pp.546-551
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• 2011

Response surface methodology (RSM) was used for the microwave-assisted extraction (MAE) of the effective components of grape seed, such as its antioxidative and nitrite-scavenging abilities. Microwave power (2,450 MHz, 0-160W), ethanol concentration (0-100%), and MAE time (1-5 min) were used as independent variables (Xi) for the central composite design to yield 16 different MAE conditions. The optimum MAE conditions were predicted for the dependent variables of the extracts, such as the total phenolic content ($Y_1$) antioxidative ability ($Y_2$), and nitrite-scavenging ability ($Y_3$), depending on different microwave powers, ethanol concentrations, and MAE times. The determination coefficients ($R^2$) of the regression equations for the dependent variables ranged from 0.8024 to 0.9498. The maximal values of each dependent variable were predicted at different MAE conditions, as follows: 3.19% total phenolic content at 142.32W, 44.30% ethanol, and 4.36 min, and 1.22 antioxidative ability at 84.44W, 56.60% ethanol, and 3.28 min. More than 99.5% nitrite-scavenging ability was predicted at pH 1.2-3.0, 30.80-106.58W, 49.32-55.18% ethanol, and 3.72-4.58min, respectively. The results indicated that the total phenolic content and anti oxidative ability showed a higher correlation with each other in that they were more influenced by microwave power than by the other variables, while the nitrite-scavenging ability was largely influenced by the ethanol concentration.

• Food Science and Preservation
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• v.20 no.4
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• pp.502-509
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• 2013

This study was conducted in order to monitor the extraction conditions for a gel-state beverage development of the Opuntia ficus-indica stem. Moreover, the organoleptic properties of the beverage prepared by the extract were optimized using the response surface methodology (RSM). The determination coefficient ($R^2$) value for the extraction yield of the stem was 0.95 (p<0.01). The maximum extraction yield was obtained at an extraction temperature of $93.02^{\circ}C$, 123 min of extraction time and 22.57 mL/g of water to sample. The beverage was prepared with the addition of xanthan gum, sugar and persimmon vinegar to the extract with a central composite design. The maximum organoleptic color of the beverage was obtained at 0.38% xanthan gum, 7.91% sugar and 0.76% persimmon vinegar. The maximum organoleptic flavor was obtained at 0.30% xanthan gum, 7.06% sugar and 1.26% persimmon vinegar. The maximum organoleptic taste was obtained at 0.22% xanthan gum, 10.36% sugar and 0.90% persimmon vinegar. The maximum overall palatability (3.92 score) of the gel-state beverage was obtained at 0.35% xanthan gum, 10.83% sugar and 1.21% persimmon vinegar.

• Food Science and Preservation
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• v.10 no.2
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• pp.219-223
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• 2003

Response surface methodology was used for monitoring and optimizing the extraction conditions of campesterol, stigmasterol, ${\beta}$ -sitosterol, and total sterols from the safflower seed. The conditions of phytosterol extraction were optimized by using central composite design with the temperature(35∼75$^{\circ}C$, X$_1$), the time (1∼11hr, X$_2$), and the preheating temperature(60∼100$^{\circ}C$, X$_3$) as three variables. The extraction conditions for maximum campesterol content were 59.01$^{\circ}C$(X$_1$), 2.88hr(X$_2$), and 75.04$^{\circ}C$(X$_3$). But stigmasterol, ${\beta}$ -sitosterol and total sterols were not significantly different under designed extraction condition in this study. Besides, oil was extracted from safflower seed at various conditions and yields were 23.44% at 35$^{\circ}C$ and 20.05% at 80$^{\circ}C$, respectively. Total tocopherol content increased from 0.172% to 0.207% as the extraction temperature increased from 35$^{\circ}C$ to 80$^{\circ}C$. A structured lipids(SL) was synthesized enzymatically by extracted safflower oil and conjugated linoleic acid(CLA). After 24hr reaction, 31.79 mol% CLA was incorporated into the extracted safflower oil.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.229-239
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• 2018

The purpose of this study was to effectively produce the biosugar from cell wall of lipid extracted microalgae (LEA) by using microwave-assisted pretreatment without enzymatic hydrolysis process. Response surface methodology (RSM) was applied to optimization of microwave-assisted pretreatment conditions for the production of biosugar based on enzyme-free process from LEA. Microwave power (198~702 W), extraction time (39~241 sec), and sulfuric acid (0~1.0 mol) were used as independent variables for central composite design (CCD) in order to predict optimum pretreatment conditions. It was noted that the pretreatment variables that affect the production of glucose (C6) and xylose (C5) significantly have been identified as the microwave power and extraction time. Additionally, the increase in microwave power and time had led to an increase in biosugar production. The superimposed contour plot for maximizing dependent variables showed the maximum C6 (hexose) and C5 (pentose) yields of 92.7 and 74.5% were estimated by the predicted model under pretreatment condition of 700 w, 185.7 sec, and 0.48 mol, and the yields of C6 and C5 were confirmed as 94.2 and 71.8% by experimental validation, respectively. This study showed that microwave-assisted pretreatment under low temperature below $100^{\circ}C$ with short pretreatment time was verified to be an effective enzyme free pretreatment process for the production of biosugar from LEA compared to conventional pretreatment methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.378-385
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• 2017

This study investigated the design of a snap fit, which is widely used for fastening plastic parts. We analyzed the assembly mechanism of a lock snapfit, measured the assembly force and separation force based on the design of experiments, and derived a regression equation through an analysis of variance. The response surface methodology was also used. Polybutylene terephthalate was used to fabricate specimens, and the assembly force and separation force were measured using a micro-tensile tester. The length, width, thickness, and interference were considered as factors. A second-order regression model was used to derive the regression equation. The assembly force decreased with increasing length and width, but it increased with increasing thickness and interference. The finite element method was used to analyze the assembly mechanics. The width decreased the assembly force by increasing the ductility. The influences of the factors for low assembly force and high release force were shown to be opposite to each other. It was necessary to design a structure that minimized the assembly force while maintaining an appropriate level of separation force.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.92-103
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• 2015

Box-Wilson experimental design method, known as central composite design, is the design of any information-gathering exercises where variation is present. This method was devised to gather as much data as possible in spite of the low design cost. This method was employed to model the effect of mixing factors on several performances of 60 MPa high strength self compacting concrete and to numerically calculate the optimal mix proportion. The nonlinear relations between factors and responses of HSSCC were approximated in the form of second order polynomial equation. In order to characterize five performances like compressive strength, passing ability, segregation resistance, manufacturing cost and density depending on five factors like water-binder ratio, cement content, fine aggregate percentage, fly ash content and superplasticizer content, the experiments were made at the total 52 experimental points composed of 32 factorial points, 10 axial points and 10 center points. The study results showed that Box-Wilson experimental design was really effective in designing the experiments and analyzing the relation between factor and response.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.147-152
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• 2020

In this study, we dedicated to optimize the process for a reactive diluent for epoxy resin of improved chemical resistance by using cardanol, a component of natural oil of cashew nut shell liquid (CNSL). The central composite design (CCD) model of response surface methodology (RSM) was used for the optimization. The quantitative factors for CCD-RSM were the cardanol/ECH mole ratio, reaction time, and reaction temperature. The yield, epoxy equivalent, and viscosity were selected as response values. Basic experiments were performed to design the reaction surface analysis. The ranges of quantitative factors were determined as 2~4, 4~8 h, and 100~140 ℃ for the cardanol/ECH reaction mole ratio, reaction time, and reaction temperature, respectively. From the result of CCD-RSM, the optimum conditions were determined as 3.33, 6.18 h, and 120 ℃ for the cardanol/ECH reaction mole ratio, reaction time, and reaction temperature, respectively. At these conditions, the yield, epoxy equivalence, and viscosity were estimated as 100%, 429.89 g/eq., and 41.65 cP, respectively. In addition, the experimental results show that the error rate was less than 0.3%, demonstrating the validity of optimization.