• Asian-Australasian Journal of Animal Sciences
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• v.14 no.6
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• pp.844-849
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• 2001

This study was carried out to determine the optimum conditions for cholesterol removal from homogenized milk by treatment with saponin using a response surface methodology (RSM). The effects of temperature, reaction time, and amounts of celite or saponin added on cholesterol removal from milk were investigated. The level of cholesterol removal from milk increased with saponin concentration and varied from 57.4 to 73.3%. The optimum reaction time, amount of celite addition determined by a partial differentiation of the model equation, and amount of saponin addition were 30min, 0.95% and 1.5%, respectively. Under these conditions, the predicted cholesterol removal by RSM was estimated to be 73.4%. The experimental removal value was 73.7%. Thus, there was no appreciable difference between the experimental value and the predicted value based on RSM.

• Journal of Life Science
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• v.27 no.1
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• pp.38-43
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• 2017

Glycosyl aesculin, a potent anti-inflammatory agent, was synthesized by transglycosylation reaction, catalyzed by Thermotoga neapolitana ${\beta}-glucosidase$, with aesculin as an acceptor. The key reaction parameters were optimized using response-surface methodology (RSM) and $2{\mu}g$ of the enzyme. As shown by a statistical analysis, a second-order polynomial model fitted well to the data (p<0.05). The response surface curve for the interaction between aesculin and other parameters revealed that the aesculin concentration and reaction time were the primary factors that affected the yield of glycosyl aesculin. Among the tested factors, the optimum values for glycosyl aesculin production were as follows: aesculin concentration of 9.5 g/l, temperature of $84^{\circ}C$, reaction time of 81 min, and pH of 8.2. Under these conditions, 61.7% of glycosyl aesculin was obtained, with a predicted yield of 5.86 g/l. The maximum amount of glycosyl aesculin was 6.02 g/l. Good agreement between the predicted and experimental results confirmed the validity of the RSM. The optimization of reaction conditions by RSM resulted in a 1.6-fold increase in the production of glycosyl aesculin as compared to the yield before optimization. These results indicate that RSM can be effectively used for process optimization in the synthesis of a variety of biologically active glycosides using bacterial glycosidases.

• Journal of Microbiology and Biotechnology
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• v.7 no.5
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• pp.345-351
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• 1997

An aqueous/organic two-phase reaction system was applied to the production of catechol using immobilized resting cells of Pseudomonas putida CY 400. Water/ethyl ether system was used because of high partition coefficient of catechol and thus to reduce the product inhibition and degradation. Among the tested immobilization carriers, polyacrylamide gel gave the highest catechol productivity. The immobilization seemed to protect the cells against solvent toxicity. From the simulation of reaction conditions based on two-phase models, it was found that there was an optimum acetate concentration at fixed benzoate and cell concentrations for the catechol productivity. A lower phase volume ratio (lower fraction of organic phase) gave a higher productivity. However, the substrate conversion was low at low phase volume ratio.

• Environmental Engineering Research
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• v.23 no.3
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• pp.309-315
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• 2018

Chlortetracycline (CTC) is one of the most important compounds in antibiotic production, and its distribution has been widely investigated due to health and ecological concerns. This study presents systematic approach to optimize the high-performance liquid chromatography-tandem mass spectrometry for analyzing CTC in a multiple reaction monitoring mode ($479{\rightarrow}462m/z$). One-factor-at-a-time (OFAT) test with response surface analysis (RSA) was used as optimization strategy. In OFAT tests, the fragmentor voltage, collision energy, and ratio of acetonitrile in the mobile phase were selected as major factors for RSA. The experimental conditions were determined using a composite in cube design (CCD) to maximize the peak area. As a result, the partial cubic model precisely predicted the peak area response with high statistical significance. In the model, the (solvent composition) and (collision $energy^2$) terms were statistically significant at the 0.1 ${\alpha}$-level, while the two-way interactions of the independent variables were negligible. By analyzing the model equation, the optimum conditions were derived as 114.9 V, 15.7 eV, and 70.9% for the fragmentor voltage, collision energy, and solvent composition, respectively. The RSA, coupled with the CCD, offered a comprehensive understanding of the peak area that responds to changes in experimental conditions.

• Journal of Ginseng Research
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• v.34 no.1
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• pp.68-75
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• 2010

This study sought to optimize the extraction and enzymatic treatment conditions of Panax ginseng leaves, stems, and roots for the production of fermented ginseng. The optimization enhanced the extraction of total saccharide, a nutrient and growth-activating factor for Lactobacillus bacteria. The hydrolysis of ginseng leaves, stems, and roots was tested with eight enzymes (Pentopan, Promozyme, Celluclast, Ultraflo, Pectinex, Ceremix, Viscozyme, and Tunicase). The enzymatic hydrolysis conditions were statistically optimized by the experimental design. Optimal particle size of ginseng raw material was <0.15 mm, and optimal hydrolysis occurred at a pH of 5.0-5.5, a reaction temperature of 55-$60^{\circ}C$, a Ceremix concentration of 1%, and a reaction time of 2 hr. Ceremix produced the highest dry matter yield and total saccharide extraction. Ginseng leaves were found to be the most suitable raw material for the production of fermented ginseng because they have higher carbohydrate and crude saponin contents than ginseng roots.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.87-99
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• 2013

Waste paper stands for the major biodegradable organic fraction of most of municipal solid waste. The potential of waste paper for glucose production was investigated in this current work. The pretreatment was accomplished by first subjecting waste paper to disintegration time (30 s), followed by ink removal of disintegrated waste paper using an deinking agent. Concentrated acid hydrolysis of waste paper with sulfuric acid was optimized to maximize glucose conversion. The concentrated acid hydrolysis conditions for waste paper (disintegrated time: 30 s, deinking agent loading : 15 ml) were optimized by using central composite design and response surface methodology. The optimization process employed a central composite design, where the investigated variables were acid concentration (60~80%), loading sulfuric acid (1~5 ml) and reaction time (1~5 h). All the tested variables were identified to have significant effects (p < 0.05) on glucose conversion. The optimum concentrated acid hydrolysis conditions were acid concentration of 70.8%, loading sulfuric acid of 3.2 ml and a reaction time of 3.6 h. This research of concentrated acid hydrolysis was a promising method to improve glucose conversion for waste paper.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.511-516
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• 2005

Sorbitan methacrylate was synthesized from sorbitan dehydrated from D-sorbitol using an immobilized lipase. To optimize the enzymatic synthesis of sorbitan methacrylate, response surface methodology was applied to determine the effects of five-level-four-factors and their reciprocal interactions on sorbitan methacrylate biosynthesis. A total of 30 individual experiments were performed, which were designed to study reaction temperature, reaction time, enzyme amount and substrate molar ratio. A statistical model predicted that the highest conversion yield of sorbitan methacrylate was 100%, at the following optimized reaction conditions: a reaction temperature of 43.06 $^{\circ}C$, a reaction time of 164.25 mins., an enzyme amount of 7.47%, and a substrate molar ratio of 3.98:1. Using these optimal factor values under experimental conditions in four independent replicates, the average conversion yield reached 98.7%${\pm}$1.2% and was well within the value predicted by the model.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.904-909
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• 2005

To optimize the removal of free fatty acid in crude vegetable oil, response surface methodology was applied to determine the effects of five level-four factors and their reciprocal interactions on removal of free fatty acid. A total of 30 individual experiments were performed, which were designed to study reaction temperature, reaction time, catalyst amount and methanol amount. A statistical model predicted that the highest removal yield of free fatty acid was 99.8%, at the following optimized reaction conditions: a reaction temperature of 64.99$^{\circ}C$, a reaction time of 36.20 mins., an catalyst amount of 13.01% (w/v), and a methanol amount of 15% (v/v). Using these optimal factor values under experimental conditions in three independent replicates, the average removal yield was well within the value predicted by the model.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.600-612
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• 2015

We investigated the optimization of the organosolv pretreatment of yellow poplar for bioethanol production. Response surface methodology was used to determine the optimal conditions of three independent variables (reaction temperature, reaction time, and sulfuric acid (SA) concentration). Reaction temperature is the most significant variable in the degradation of xylan and lignin in the presence of an acid catalyst, and ethanol production increased with a decrease in the lignin content. The highest ethanol concentration ($42.80g/{\ell}$) and theoretical ethanol yield (98.76%) were obtained at $152^{\circ}C$ (2.5 bar) with 1.6% SA for 16 min. However, because of excessive degradation of the raw material, the overall ethanol yield was less than under other pretreatment conditions which has approximately 50% of WIS recovery rate after pretreatment. The optimal conditions for the maximum overall ethanol yield ($146^{\circ}C$ with 1.22% SA for 15.9 min) were determined with a predicted yield of 17.11%, and the experimental values were very close (17.15%). Therefore, the quadratic model is reliable.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.70-79
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• 2022

Biodiesel production has attracted attention as a sustainable source of fuel and is a competitive alternate to diesel engines. The glycerol that is produced as a by-product is generally discarded as waste and can be converted to green chemicals such as acetins to increase bio-diesel profitability. Acetins find application in fuel, food, pharmaceutical and leather industries. Batch experiments and analysis have been previously conducted for synthesis of acetins using glycerol esterification reaction aided by sulfated metal oxide catalysts (SO₄^2-/CeO₂-ZrO₂). The aim of this study was to optimize process parameters: effects of mole ratio of reactants (glycerol and acetic acid), catalyst concentration and reaction temperature to maximize glycerol conversion/acetin selectivity. The optimum conditions for this reaction were determined using response surface methodology (RSM) designed as per a five-level-three-factor central composite design (CCD). Statistica software 10 was used to analyze the experimental data obtained. The optimized conditions obtained were molar ratio - 1:12, catalyst concentration - 6 wt.% and temperature -90 ℃. A packed bed reactor was fabricated and column studies were performed using the optimized conditions. The breakthrough curve was analyzed.