• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.66-72
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• 2018

Corn stover is known as a good candidate for a functional food ingredient when the main lignocellulosic material, lignin, is used as bioactive materials as form of polyphenolic compounds. The purpose of this study was to determine the microwave extraction conditions under which total phenolic compounds (TPC) and flavonoid contents of corn stover were maximized. Microwave-assisted extracts using sulfuric acid ranging from 0 to 1.0 mol with extraction time between 40 and 240 sec were conducted by using response surface methodology (RSM). Microwave power showed significant effects (p<0.05) and the concentrations of TPC and flavonoids increased with increased level of microwave power and extraction time. The optimum conditions for corn stover extraction were determined as 698.6 W, 240 sec, and 0 mol sulfuric acid, and the predicted value of TPC and flavonoid is 82.4 mg GAE/g DM and 18.1 mg/g DM, respectively. Microwave extraction was evaluated as an economic process with low energy consumption, short extraction and high extraction yield of bioactive including TPC and flavonoids compared to conventional extractions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.827-835
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• 2022

Commercial boiled frozen ark shell Scapharca subcrenata (BFAS) is generally used as a seasoned seafood products. One problem facing the industry is that quality decreases during thawing. This study investigated ways to improve quality and shelf-stability of BFAS for use as a non-thermally prepared seasoned seafood products. The Viable bacteria were detected in BFAS after thawing under running water, but were not detected after blanching for over 2 min at 95±5℃. Blanching and dewatering times were optimized by response surface methodology (RSM) to reduce the initial number of bacteria and improve BFAS texture. Experimental design was deemed appropriate because no significant difference (P>0.05) was observed between predicted and actual moisture content, hardness, and overall acceptance values. Optimal blanching and dewatering times were 210 s and 80 s, respectively. Optimized blanching and dewatering processes can significantly improve safety and BAFS qualities including texture. These results indicate that BFAS demand as a staple for home meal replacements can be increased by application of optimized blanching and dewatering processes, especially in Korean seafood processing companies where running water thawing is common.

• Applied Chemistry for Engineering
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• v.35 no.3
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• pp.248-254
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• 2024

In this study, functional substances with antibacterial properties were extracted from the needles of Abies holophylla and Pinus koraiensis, and optimized using the central composite design-response surface methodology (CCD-RSM). The optimal extraction conditions for Abies holophylla were an extraction temperature of 59.5 ℃ and an ethanol/ultrapure water volume ratio of 69.5 vol.%, resulting in an extraction yield of 13.5% and inhibition diameters of 11.6 mm against Escherichia coli (E. coli) and 9.3 mm against Staphylococcus aureus (S. aureus). For Pinus koraiensis, the optimal extraction conditions were an extraction temperature of 59.2 ℃ and an ethanol/ultrapure water volume ratio of 67.8 vol.%, resulting in an extraction yield of 4.8% and inhibition diameters of 7.9 mm against E. coli and 12.5 mm against S. aureus. The actual experimental results under these optimal conditions showed that an extraction yield from Abies holophylla needles was 13.0% and an inhibition diameter of 11.7 mm against E. coli and 9.2 mm against S. aureus, indicating an error rate of approximately ± 2.3%. For Pinus koraiensis needles, the extraction yield was 5.1%, with inhibition diameters of 7.5 mm against E. coli and 12.3 mm against S. aureus, indicating an error rate of ± 4.23%.

• Steel and Composite Structures
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• v.34 no.5
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• pp.681-698
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• 2020

The paper addresses contribution to the modeling and optimization of major machinability parameters (cutting force, surface roughness, and tool wear) in finish dry hard turning (FDHT) for machinability evaluation of hardened AISI grade die steel D₃ with PVD-TiN coated (Al₂O₃-TiCN) mixed ceramic tool insert. The turning trials are performed based on Taguchi's L₁₈ orthogonal array design of experiments for the development of regression model as well as adequate model prediction by considering tool approach angle, nose radius, cutting speed, feed rate, and depth of cut as major machining parameters. The models or correlations are developed by employing multiple regression analysis (MRA). In addition, statistical technique (response surface methodology) followed by computational approaches (genetic algorithm and particle swarm optimization) have been employed for multiple response optimization. Thereafter, the effectiveness of proposed three (RSM, GA, PSO) optimization techniques are evaluated by confirmation test and subsequently the best optimization results have been used for estimation of energy consumption which includes savings of carbon footprint towards green machining and for tool life estimation followed by cost analysis to justify the economic feasibility of PVD-TiN coated Al₂O₃+TiCN mixed ceramic tool in FDHT operation. Finally, estimation of energy savings, economic analysis, and sustainability assessment are performed by employing carbon footprint analysis, Gilbert approach, and Pugh matrix, respectively. Novelty aspects, the present work: (i) contributes to practical industrial application of finish hard turning for the shaft and die makers to select the optimum cutting conditions in a range of hardness of 45-60 HRC, (ii) demonstrates the replacement of expensive, time-consuming conventional cylindrical grinding process and proposes the alternative of costlier CBN tool by utilizing ceramic tool in hard turning processes considering technological, economical and ecological aspects, which are helpful and efficient from industrial point of view, (iii) provides environment friendliness, cleaner production for machining of hardened steels, (iv) helps to improve the desirable machinability characteristics, and (v) serves as a knowledge for the development of a common language for sustainable manufacturing in both research field and industrial practice.

• Food Science and Preservation
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• v.17 no.1
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• pp.66-71
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• 2010

In the Joseon Dynasty, various fruit teas were popularized to promote health, with spread of Donguibogam and Hyangyag gugeupbang. As interest in fruit tea has recently increased, studies on its manufacture have become necessary. We used response surface analysis for rediscovery and commercialization of grape tea. Major materials of traditional grape tea are grape juice, pear juice, ginger juice, and honey, and the sugar contents of these materials were 12.3, 14.1, 3.3 and 75 $^{\circ}Brix$, respectively. When sensory examinations were conducted with subjects aged 40-60 years, the difference between dilution ratios of 100% and 150% was not significant, but tea diluted by 150% showed somewhat higher scores than did tea diluted by 100%. Ginger taste and sweetness were found to have the greatest effect on overall acceptance. Regression analysis on color, flavor, taste, and overall acceptance values, with reference to ginger juice and honey as independent variables, revealed that the $R^2$ values were 0.8411, 0.6717, 0.9499, and 0.9015, respectively. Contour maps were superimposed to obtain an optimal combination of ingredients for traditional grape tea, and the indicated levels of ginger juice and honey were 0.46-0.69% and 3.85-5.20%, in combination with grape juice, pear juice, and water concentrations of 28%, 9% and 60% (all w/w), respectively. Thus, it is now possible to prepare traditional grape tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.4
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• pp.499-506
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• 2006

Response surface methodology was used to investigate the cookie manufacturing process with black rice flour. A three- variable, three-level central composite design was employed where the independent variables were the amount of black rice flour ($0{\sim}20%$), baking time ($10{\sim}14 min$), and sugar type (sucrose, aspartame and oligosaccarides). pHs of dough and cookie tended to increase with the addition of black rice flour. Moisture content of dough slightly increased with tile addition of black rice flour but nearly affected by baking time. Spread factor increased with the addition of black rice flour and it was more evident in the samples prepared with sucrose. L*-value decreased but a*-value increased significantly with the addition of black rice flour. Generally the amount of black rice flour in the sample did not affect the textural characteristics of cookie. As the amount of black rice and baking time increased, sensory flavor became stronger. Sensory sweetness as well as hardness increased but sensory color became darker with the addition of black rice flour. In addition, the response surface models developed in this study for most of physicochemical and sensory characteristics of black rice cookie were adequate.

• Journal of Life Science
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• v.29 no.8
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• pp.861-870
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• 2019

This study was undertaken to establish optimum medium compositions for cost-effective mannitol production by Leuconostoc mesenteroides SRCM201425 isolated from kimchi. L. mesenteroides SRCM21425 from kimchi was selected for efficient mannitol production based on fructose analysis and identified by its 16S rRNA gene sequence, as well as by carbohydrate fermentation pattern analysis. To enhance mannitol production by L. mesenteroides SRCM201425, the effects of carbon, nitrogen, and mineral sources on mannitol production were first determined using Plackett-Burman design (PBD). The effects of 11 variables on mannitol production were investigated of which three variables, fructose, sucrose, and peptone, were selected. In the second step, each concentration of fructose, sucrose, and peptone was optimized using a central composite design (CCD) and response surface analysis. The predicted concentrations of fructose, sucrose, and peptone were 38.68 g/l, 30 g/l, and 39.67 g/l, respectively. The mathematical response model was reliable, with a coefficient of determination of $R^2=0.9185$. Mannitol production increased 20-fold as compared with the MRS medium, corresponding to a mannitol yield 97.46% when compared to MRS supplemented with 100 g/l of fructose in flask system. Furthermore, the production in the optimized medium was cost-effective. The findings of this study can be expected to be useful in biological production for catalytic hydrogenation causing byproduct and additional production costs.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.321-327
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• 2015

The optimal condition for preparation of powdered calcium acetate (LCCA) which has high solubility, from calcined powder (LCCP) of the littleneck clam shell by response surface methodology (RSM) was examined. Increased molar ratio of LCCP led to reduced solubility, yield, color values, and overall quality. The critical values of multiple response optimization of independent variables were 2.57 M of acetic acid and 1.57 M of LCCP. The actual values (pH 7.0, 96.1% for solubility, and 220.9% for yield) under the optimized condition were similar to the predicted values. LCCA showed strong buffering capacity between pH 4.89 and 4.92 on addition of ~2 mL of 1 N HCl. The calcium content and solubility of LCCA were 21.9-23.0 g/100 g and 96.1-100.1%, respectively. The FT-IR and XRD patterns of LCCA were identified as calcium acetate monohydrate, and FESEM images revealed an irregular and rod-like microstructure.

• Applied Chemistry for Engineering
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• v.30 no.3
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• pp.337-344
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• 2019

In this study, an antioxidant was extracted from Lonicera japonica and Sophora japonica L, which was optimized by using the central composite design (CDD) model of response surface methodology (RSM). The response value of CDC model establishes the extraction yield and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The extraction time, volume ratio of ethanol/ultrapure water, and extraction temperature were selected as quantitative factors. According to the result of CDC, optimal extraction conditions of Lonicera japonica were as follows; the extraction time of 2.08 h, volume ratio of ethanol/ultrapure water of 41.53 vol.%, and extraction temperature of $55.08^{\circ}C$. At these conditions the expected results indicated that the yield and DPPH radical scavenging activity were estimated as 37.88 wt% and 40.37%, respectively. On the other hand, optimal extraction conditions of Sophora japonica L. could be found as the extraction time of 2.13 h, volume ratio of ethanol/ultrapure water of 62.89 vol.%, and temperature of $50.42^{\circ}C$. Under the conditions, the (possible) maximum values of yield and DPPH radical scavenging activity were found as 35.43 wt% and 55.7%, respectively.

• Culinary science and hospitality research
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• v.22 no.2
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• pp.13-28
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• 2016

This study performed quantitative analysis of isoflavone glycoside contents on Buseoktae, Daewon, Wooram beans and cheonggukjang made of Buseoktae beans from the LC/MS/MS. Also, the experiment carried out by means of RSM(response surface methodology), which included 10 experimental points for the two independent variables addition(40, 55, 70 g) and time(2, 3, 4 min) from the beginning point to boil of cheonggukjang. These were optimized using a Face-centered central composite design. Daidzein contents were $212.16{\mu}g/mL$ in Buseoktae, $212.21{\mu}g/mL$ in daewon, $158.54{\mu}g/mL$ in wooram beans. Genistein contents were $318.84{\mu}g/mL$ in Buseoktae, $310.50{\mu}g/mL$ in daewon, $262.71{\mu}g/mL$ in wooram beans. Total isoflavone contents were $532.50{\mu}g/mL$ in Buseoktae, $524.19{\mu}g/mL$ in Daewon, $422.71{\mu}g/mL$ in Wooram beans. Isoflavone contents of Buseoktae and Daewon were quite similar, relatively contents of Wooram beans were low. Total isoflavone contents of Buseoktae cheonggukjang (for business use) was $430.10{\mu}g/mL$ in A ($32^{\circ}C$, 96 h fermentation), $460.09{\mu}g/mL$ in B ($36{\sim}40^{\circ}C$, 30 h fermentation), $417.46{\mu}g/mL$ in C cheonggukjang($36{\sim}38^{\circ}C$, 72 h fermentation), B cheonggukjang was just a bit more than A, C cheonggukjang. The estimated response surfaces confirmed that the amount and time had significant effects on taste. The optimum condition of Buseoktae cheonggukjang taste was predicted to be 55.20 g addition at 2.92 min.