• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.8
• /
• pp.1206-1212
• /
• 2010

This study was performed to establish optimum extraction condition of Tricholoma matsutake. A central composite design was applied to investigate the effects of independent variables, extraction temperature ($X_1$), extraction time ($X_2$) and water per sample ($X_3$) on dependent variables such as soluble solids contents ($Y_1$), total phenolics contents ($Y_2$), reducing sugar contents ($Y_3$), electron donating ability ($Y_4$) and nitrite scavenging ability ($Y_5$). The optimum extraction conditions were predicted and monitored by response surface methodology using SAS program based regression analysis. Soluble solids content, electron donating ability and nitrite scavenging ability were highly affected by water per sample. However, the contents of total phenolics and reducing sugar were affected by water per sample and extraction temperature as well. The optimum extraction conditions for soluble solids were 34.84 mL/g (water/sample) at $78.85^{\circ}C$, for 3.33 hr. In contrast, the optimum extraction conditions of electron donating ability were temperature of $91.00^{\circ}C$, time of 1.62 hr and water per sample of 39.42 mL/g. Taken together, the optimum ranges for hot water extraction of Tricholoma matsutake were $70{\sim}90^{\circ}C$, 2~4 hr and 30~50 mL/g.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.3
• /
• pp.381-388
• /
• 2017

This study was performed to evaluate the effects of Liriopis tuber (SLT) extracts on cookie production conditions for reduction of sugar usage through response surface methodology (RSM). The experimental conditions were designed according to the central composite design with 17 experimental points, including three replicates for three independent variables such as the amounts of SLT extracts, butter, and sugar. The experimental data on quality and sensory evaluation of cookies were fitted with various models, and accuracy of the equations was analyzed by ANOVA. Among various responses, spread ratio, sugar content, lightness, redness, hardness, and sensory properties of color, texture, sweetness, appearance, and overall quality showed significant correlations with the contents of three independent variables. From these results, the optimum formulation of cookies for reduced usage of sugar was calculated as SLT extract 6.84 g, butter 47.20 g, and sugar 36.02 g. Optimized cookies showed improved sensory properties but no difference in sweetness compared to control cookies.

• Korean Journal of Microbiology
• /
• v.41 no.2
• /
• pp.105-111
• /
• 2005

Streptomyces produces many kinds of secondary-metabolites including antibiotics. Screening of a new compound and elucidation of a biosynthetic pathway for the secondary metabolites are very important fields of biology, however, there is a main problem that most of the identified compounds are already researched compounds. To solve these problems, a microarray system that is based on the data related to the biosynthetic genes for secondary-metabolites was designed. For the main contents of DNA microarray, the important genes for the bio-synthesis of aminoglycosides, polyenes group, enediyne group, alpha-glucosidase inhibitors, glycopeptide group, and orthosomycin group were chosen. A DNA microarray with 69 genes that were involved in the bio-synthesis for the antibiotics mentioned above was prepared. The usability of the DNA microarray was confirmed with the chromosomal DNA and total RNA extracted from S. coelicolor whose genomic sequence had already been reported.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.4
• /
• pp.586-591
• /
• 2015

To prepare peach wine using peach juice, fermentation properties were monitored, and fermentation conditions (initial sugar concentration, temperature, and time) were optimized by a response surface methodology. Alcohol content for peach wine fermentation ranged from 3.4~9.2% [$R^2=0.9229$ (P<0.01)] and 8.54% (maximum value) at $18.73^{\circ}Brix$, $16.81^{\circ}C$, and 12.99 day. Acidity ranged from 0.30~0.74%, and 0.25% (minimum value) at $15.11^{\circ}Brix$, $17.09^{\circ}C$, and 13.61 day. Residual sugar concentration was $6.67^{\circ}Brix$ (maximum residual sugar content) at $17.79^{\circ}Brix$, $20.63^{\circ}C$, and 3.37 day. Yellow color intensity was 18.92 (maximum Hunter's color b value) at $13.19^{\circ}Brix$, $20.81^{\circ}C$, and 12.81 day. Based on the above study results, optimization conditions for peach wine fermentation were 9 days, below $20^{\circ}C$, and $19^{\circ}Brix$ peach juice.

• Food Science and Preservation
• /
• v.23 no.7
• /
• pp.913-922
• /
• 2016

The aim of this study was to develop a new salting condition that included added maltodextrin (MD) and grape seed extract (GSE) to ensure the microbiological safety and quality of salted shredded Korean cabbage. Response surface methodology (RSM) was used to analyze the effects of four independent variables (NaCl concentration, salting duration, MD concentration, and GSE concentration). The following response variables were evaluated: reduction in total aerobic bacteria, yeast, and mold counts; weight loss and salt content; and taste, texture, and overall acceptability of salted shredded Korean cabbage. The optimal salting conditions include a combination of 10.09~10.32% NaCl, 9.45~10.00% MD, and 234~300 ppm GSE in a ternary salting solution and a salting duration of 5.68~5.94 hr. This optimal combination reduced total aerobic bacterial and yeast/molds counts by 3.33 and 1.45 log CFU/g, respectively, while maintaining high sensory scores for taste, texture, and overall acceptability of the salted shredded Korean cabbage. In addition, the optimal conditions yielded more acceptable weight loss and salt content characteristics. The results suggest that use of the optimized combination of salting conditions can improve the microbiological safety and quality of salted shredded Korean cabbage used for commercial kimchi production.

• Food Science and Preservation
• /
• v.19 no.4
• /
• pp.492-500
• /
• 2012

This study was conducted to develop a sauce prepared with sweet pumpkin and Korea Doenjang. The optimum conditions for manufacturing sweet pumpkin-doenjang sauce were investigated using the response surface methodology, based on the central composition design. The amount of stock added, the thickening agent, and doenjang were used as the independent variables, and the sensory characteristics (taste, flavor, color, and overall acceptability) were used as the dependent variables to evaluate the optimum conditions for the preparation of the sauce. The optimum conditions for the maximized-responses variables in the preparation of the sauce were 448.5 g of sweet pumpkin stock, 331.5 g of the thickening agent, and 20.0 g of doenjang. The quality characteristics of sweet pumpkin-doenjang sauce that was manufactured at optimum conditions were as follow: 89.55% moisture content, 0.70% crude protein, 0.10% crude lipids, and 0.71% crude ash. The pH of the sauce was 5.96; total acidity, 0.08%; and soluble solids, 6.80$^{\circ}Brix$. The total polyphenol content of the sauce was 5.70 mg/L. The electron-donating ability and reducing power of the sauce were, 14.24% and 1.64 OD, respectively.

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.10
• /
• pp.5-11
• /
• 2016

In this study, the factors affecting commercialization of $Pt/TiO_2$ catalyst, which can oxidize HCHO at room temperature, was investigated. In order to determine the optimum noble metal loading, the catalytic activity was evaluated by varying the Pt loadings; the best catalytic activity was achieved for 1 wt% of Pt. In addition, the catalyst prepared under the reduction condition showed an excellent HCHO oxidation conversion at room temperature. Based on these results, it was confirmed that the activity could be changed by oxidation state of active metal, and in case of Pt, metallic Pt ($Pt^0$) species was more active on HCHO oxidation at room temperature. As a result of evaluating an effect of space velocity to determine the optimum operating condition, it was found that in the lower space velocity, conversion rate of HCHO was increased due to increase of catalyst bed. Catalytic activity was greater in the presence of moisture than in its absence. Through above results, the key factors for commercialization of oxidation catalyst, which was operated at room temperature even without any additional energy source was confirmed.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.8
• /
• pp.839-846
• /
• 2008

The flocculation characteristics of polyacrylamide base flocculants were estimated to reduce the moisture content of the dehydrated cakes. The dewaterability for sewage sludge was found to have a marked effect depending on the flocculant type, agitating speed and time, kind of dissolution water, etc. The optimal agitating speed and time were 700 rpm and 3 sec, respectively, in this experimental condition. and the dewaterability was proportion to the agitating speed upto 700rpm. When recycle water as the dissolution water was used, the solution viscosity of all kind of flocculants was decreased. However, the change of its viscosity are not proportioned to the dewaterabilities for each flocculant. Flocculation system of combinations of the first and sencond flocculation using single flocculant was investigated. Effects of the ratio of first and second dosage for dual flocculation on the dewaterability were also investigated. The optimum conditions of dual flocculation system are 75% and 50% as first dosages for low and high viscous flocculant for total dosage of common flocculation, respectively. Based on the results, an overall mechanism of dual flocculation system is proposed and it is envisaged that optimization of flocculation processes in this way can result in considerable savings in cost.

• Korean Chemical Engineering Research
• /
• v.58 no.4
• /
• pp.565-572
• /
• 2020

This study developed a software platform using machine learning of artificial intelligence to optimize the distillation column system. The distillation column is representative and core process in the petrochemical industry. Process stabilization is difficult due to various operating conditions and continuous process characteristics, and differences in process efficiency occur depending on operator skill. The process control based on the theoretical simulation was used to overcome this problem, but it has a limitation which it can't apply to complex processes and real-time systems. This study aims to develop an empirical simulation model based on machine learning and to suggest an optimal process operation method. The development of empirical simulations involves collecting big data from the actual process, feature extraction through data mining, and representative algorithm for the chemical process. Finally, the platform for the distillation column was developed with verification through a developed model and field tests. Through the developed platform, it is possible to predict the operating parameters and provided optimal operating conditions to achieve efficient process control. This study is the basic study applying the artificial intelligence machine learning technique for the chemical process. After application on a wide variety of processes and it can be utilized to the cornerstone of the smart factory of the industry 4.0.

• Korean Journal of Food Science and Technology
• /
• v.45 no.2
• /
• pp.180-190
• /
• 2013

The purpose of this study was to determine the optimal amount of 2 ingredients, i.e., black barley flour ($X_1$), and olive oil ($X_2$), for the production of white pan bread from black barley flour. The experiment was designed according to the central composite design of response surface methodology, which showed 10 experimental points, including 2 replicates for black barley flour and olive oil. Significant differences were found in the results of the physical and mechanical properties analysis of each sample, including weight (p<0.05), volume (p<0.01), specific loaf volume (p<0.01), color L (p<0.01), color a (p<0.001), color b (p<0.05), hardness (p<0.001), springiness (p<0.01), cohesiveness (p<0.01), gumminess (p<0.001) and chewiness (p<0.05). Significant differences in the sensory measurements were observed in color (p<0.01), appearance (p<0.01), texture (p<0.05), taste (p<0.05) and overall quality (p<0.05). The optimum formulation, which was calculated using the numerical and graphical methods, was determined to be 18.00% black barley flour and 1.80% olive oil.