• Korean journal of food and cookery science
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• v.25 no.2
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• pp.243-251
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• 2009

Changes in pH and acidity were investigated in kimchi containing different amounts of added onion and/or pear during fermentation at $10^{\circ}C$. As the fermentation period increase, the pH and sugar contents of the onion and/or pear kimchi were higher compared to the control kimchi. However, the acidity of the kimchi containing onion and/or pear was lower than that of the control. To enhance the acceptance of kimchi, the optimal conditions for the addition of onion and pear were evaluated with the central composite design, ANOVA, and response surface methodology. According to variations in the mixing ratio of onion and pear, smell, taste and overall acceptability differed significantly, but the appearance and texture were not different. The optimal levels of onion and pear, predicted on the basis of each corresponding sensory parameters for kimchi, were $4.55{\sim}5.00%$ and $0{\sim}0.30%$ for smell, 2.61% and 2.38% for taste and 2.78% and 2.57% for overall acceptability, respectively.

• Food Science and Preservation
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• v.17 no.1
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• pp.84-90
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• 2010

We investigated methods to minimize patulin content during processing of apple juice in Korea. Ascorbic acid concentration (100, 200, 300, and 400 ppm) and activated carbon concentration (50, 100, 150, and 200 ppm) were the parameters assessed by response surface methodology. Residual patulin was lowest in the presence of 237.77 ppm ascorbic acid and 106.58 ppm activated carbon, and increased as these levels increased. Sugar content was affected more byascorbic acid concentration than by activated carbon level, and the total phenol content was revealed to be the saddle point. In addition, the expected total flavonoid content was maximized with increased levels of ascorbic acid and activated carbon. The data showed that 246-274 ppm (v/v) ascorbic acid and 93-122 ppm (v/v) activated carbon were optimal for juice extraction, and the $R^2$ quality factor for juice processing was significant and within the range of 1-10% for all tested parameters.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.65-72
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• 2002

This study was to determine the optimum conditions of malt extracting temperature, extracting time of malt in water, ratio of malt to water, and rice volume of malt extract water on saccharification in producing sikhe (sweet rice drink) using central composite design of response surface methodology. Glucose and maltose were analyzed by a biosensor having dual cathode system. The optimum temperatures of malt extracting for glucose and maltose were 60 and $55^{\circ}C$. The saccharification power for the two sugars was highest when malt powder soaked for 6.5 and 5.75 hour, respectively. And ratios of malt to water for optimum saccharification were 1 : 6.3 to 1 : 8.8, respectively. The optimum volumes of malt extracting to rice for the two sugars were 0.48% and 0.6%, respectively. The application of response surface methodology to sikhe processing showed a good correlation with high significance.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.33-37
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• 2003

Sensory quality of pine nut gruel was investigated to determine the effects of processing conditions on its quality. Response surface methodology was applied to investigate effects of water volume and pine nut weight ratios to rice weight and heating time on the preference of pine nut gruel in terms of color, flavor, viscosity, taste, and overall acceptance. Results showed that processing conditions did not affect the color of pine nut gruel. Viscosity and overall acceptance were affected by the ratio of water volume to rice weight and heating time. $R^2$ of response surface regression equations were 0.6954, 0.8333 (p<0.05), 0.9668 (p<0.01), 0.8664 (p<0.05), and 0.8159 (p<0.10) for color, flavor, viscosity, taste, and overall acceptance respectively. No relationship was observed between color and overall acceptance. The relationship between viscosity and overall acceptance was the highest.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1102-1107
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• 2001

The mixing conditions of kochujang added pumpkin extract were optimized by response surface methodology. The organoleptic color of pumpkin kochujang showed the maximum score for the mixing condition of 433.63 g pumpkin extract, 81.76 g red pepper powder and 17.03 g meju powder. The organoleptic aroma of pumpkin kochujang revealed the maximum score for the condition of 437.07g pumpkin extract, 83.65 g red pepper powder and 11.90 g meju powder. The organoleptic taste of pumpkin kochujang showed the maximum score in 382.94 g pumpkin extract, 63.44 g red pepper powder and 13.10 g meju powder. The optimum mixing conditions for overall acceptability of pumpkin kochujang were 442.04 g pumpkin extract, 62.58 g red pepper powder and 16.30 g meju powder.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.202-206
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• 2014

A response surface method based on a central composite design experiment was used to determine the optimum conditions for pretreatment of persimmon peel. It was mathematically predicted that the maximum amount of reducing sugars would be obtained at an $H_2SO_4$ concentration of 1.77% (w/v) and a heat treatment time of 26.4 min. A reducing sugar concentration of 63.23 g/l was obtained under the optimum pretreatment conditions determined by RSM. Under anaerobic growth conditions, Saccharomyces cerevisiae NK28 produced 15.52 g/l of ethanol with a yield of 0.34 g ethanol/g glucose from pretreated persimmon peel, which corresponded to 14% and 26% enhancements in ethanol productivity and ethanol yield, respectively, compared with those obtained in aerobic growth conditions. This study suggests that persimmon peel might be a useful substrate for bioethanol production by yeast fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.654-661
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• 1997

Response surface methodology was applied to monitor dynamic changes in free sugars and free amino acids associated with browning reaction during roasting of Polygonatum odoratum roots. Second-order model for qualities of water- soluble extracts was employed to generate contour maps and response surfaces. Browning color intensity of water-soluble extracts was increased with the roasting time up to around 14$0^{\circ}C$, but decreased in increasing temperature above L6O"C. Free sugars, mainly composed of sucrose and fructose, were remarkably decreased at roasting under the higher temperature and longer time, while glucose linearly increased with the increase of roasting temperature up to 15$0^{\circ}C$. Most of free amino acids was decreased in their amounts in Proportion to the roasting temperature and time, while threonine and lysine were insignificantly increased under the roasting conditions at above 17$0^{\circ}C$ and 60min.0min.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.441-450
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• 2013

The purpose of this study was optimization of the conditions for mixing different amounts of red radish (Raphanus sativus L.) sprout powder, butter, and sugar when baking domestic wheat cookies prepared using red radish sprout powder. Response surface methodology, with a central composite design comprising 5 levels and 3 variables, was used to identify the best possible combination of amounts of red radish sprout powder ($X_1$), butter ($X_2$), and sugar ($X_3$). The physical and mechanical properties of each of the 20 samples analyzed, including color L (p<0.001), color a (p<0.01), color b (p<0.001), spread ratio (p<0.001), and hardness (p<0.01), differed significantly. The results of sensory evaluations, including color (p<0.001), appearance (p<0.001), texture (p<0.001), flavor (p<0.01), taste (p<0.001), and overall quality (p<0.001) also differed significantly among the samples. The optimal compositional ratios were 5.15 g for the red radish sprout powder, 64.84 g for the butter, and 47.18 g for the sugar.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.503-509
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• 2018

In this study, we used the ultrasonic extraction process as a method to extract antioxidant substances from kudzu, and measured the content of iso-flavonoids puerarin, daidzein, daidzin contained in kudzu. The response surface methodology which is a statistical analysis method for optimizing the extraction amount of iso-flavonoids from the kudzu and the process condition for maximizing the yield was applied. It is the final objective of this study to effectively derive the condition of the process that matches the target response with a minimum number of experiments and analyze the effect of each process condition on the response. In the response surface methodology, the central composite design was applied and the optimum condition was analyzed, and the three independent variables were set to ultrasonic irradiation time, volume ratio of ethanol/ultrapure water, ultrasonic irradiation power. Using the response surface methodology, the optimum conditions with the maximum extraction yield and the content of iso-flavonoids were evaluated as ultrasonic irradiation time (24.75 min), ethanol / ultrapure water volume ratio (39.75 vol%), ultrasonic irradiation power (592.36 W). The overall satisfaction level appears as high as 0.8938, which is recognized at a significance level within 5%. As a result of analyzing the optimization process, it was confirmed that the ultrasonic irradiation time is the factor that most affects the responses.

• KSBB Journal
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• v.24 no.3
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• pp.321-326
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• 2009

This study was to optimize the medium components for astaxanthin production in Paracoccus sp. through surface response methodology. A screening test was first conducted on 5 medium components using a Plackett-Burman design, from which $MgSO_4$ and yeast extract were identified as the significant factors affecting astaxanthin production. These significant factors were optimized by central composite design of experiments and response surface methodology, as 2.83 g/L $MgSO_4$ and 7.02 g/L yeast extract, respectively. The expected astaxanthin concentration with these optimized medium compositions were 0.925 mg/L. In flask culture, the experimentally obtained concentration of astaxantin was 1.021 mg/L, where it had been 0.4 mg/L before optimization.