• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.173-178
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• 2009

Epidemiological studies showed that high trans-fat consumption is closely associated with getting the risks of cardiovascular disease. The objective of this study was to produce trans-free fat through lipase-catalyzed interesterification, as a substitute for the cream margarine commonly used in industry. Optimum conditions for interesterification in a packed bed enzyme bioreactor (PBEB) were determined using response surface methodology (RSM) based on central composite design. Three kinds of reaction variables were chosen, such as substrate flow rate (0.4-1.2 mL/min), reaction temperature (60-70$^{\circ}C$), and ratio of fully hydrogenated canola oil (FHCO, 35-45%) to evaluate their effects on the degree of interesterification. Optimum conditions from the standpoint of solid fat content (SFC) were found to be as follows: 0.4 mL/min flow rate, 64.7$^{\circ}C$ reaction temperate, and 42.8% (w/w) ratio of FHCO, respectively. The half-life of immobilized lipase in PBEB with two stages at 60$^{\circ}C$ ($1^{st}$ stage) and 55$^{\circ}C$ ($2^{nd}$ stage) was about more than 30 days as estimated by extrapolating the incubation time course of tristearoyl glycerol (TS) conversion, whereas the half-life of the enzyme in PBEB with single stage at 65$^{\circ}C$ was only about 15 days. Finally, the results from SFC analysis suggest that trans-free fat produced in this study seems to be a suitable substitute for the cream margarine commonly used in industry.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.233-239
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• 2015

This study determined the optimum extraction conditions based on five response variables (yield, total phenolics, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavanging activity, oxygen radical absorbance capacity (ORAC), and ${\beta}$-1,3-glucan content) in chaga mushroom (Inonotus obliquus) using the response surface methodology, where three independent variables (ethanol concentration, extraction temperature, and extraction time) were optimized using a central composite design. The optimum ethanol concentration, extraction temperature, and extraction time were 50% (w/w), $88.7^{\circ}C$, and 14.5 h; 9.2%, $92.7^{\circ}C$, and 14.5 h; 50.8%, $92.7^{\circ}C$, and 14.5 h; 9.2%, $92.7^{\circ}C$, and 1.5 h; and 90.8%, $92.7^{\circ}C$, and 1.5 h for yield, total phenolics, ABTS, ORAC, and ${\beta}$-1,3-glucan content, respectively. The predicted values of the response variables were compared with those of the extracts under the optimal extraction conditions to verify the models. The optimum extraction condition for the five response variables was predicted to be 81.4% ethanol at $92.7^{\circ}C$ for 14.5 h.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.135-142
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• 2011

A feather-degrading bacterium Elizabethkingia meningoseptica CS2-1 was isolated from compost in a chicken farm. Cultured on a basal medium containing 2% chicken feather, the bacterium showed 729.7 ${\mu}mol/mL$ of amino acid. Optimal culture conditions for feather degradation by E. meningoseptica CS2-1 were $25^{\circ}C$, pH 7.5, and 180 rpm. The optimal pH and temperature for protease activity were 8.0 and $40^{\circ}C$, respectively. The composition of an optimal medium for amino acid production was 0.05% NH4Cl, 0.05% NaCl, 0.03% $K_2HPO_4$, 0.03% $KH_2PO_4$, 0.01% $MgCl_2{\cdot}6H_2O$, 0.1% urea, and 2% chicken feather. Characteristics of amino acids extracted from the optimal medium under the optimal culture conditions of E. meningoseptica CS2-1 were analyzed. The total amino acid content of strain CS2-1 was 1063 ${\mu}mol/mL$, which was 46% higher compared to the basal condition (729.7 ${\mu}mol/mL$). The essential amino acid content in the total amino acid was 315.9 ${\mu}mol/mL$, which was 44% higher than that of the basal condition. Major amino acids were proline (14%), aspartic acid (12%), glutamic acid (11%), serine (10%), alanine (10%), glycine (9%), and tyrosine (7%) by strain CS2-1. These results suggest that strain CS2-1 can be used as a potential microbial resource for the production of amino acid using chicken feathers.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.762-767
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• 2009

In this study, the feasibility of using vegetable oil extracted from tropical crop seed as a biodiesel feedstock was investigated by producing biodiesel and analysing the quality parameters as a transport fuel. In order to produce biodiesel efficiently, two step reaction process(pre-treatment and transesterificaion) was required because the tropical crop oil have a high content of free fatty acids. To determine the suitable acid catalyst for the pre-esterification, three kinds of acid catalysts were tested and sulfuric acid was identified as the best catalyst. After constructing the experimental matrix based on RSM and analysing the statistical data, the optimal pre-treatment conditions were determined to be 26.7% of methanol and 0.982% of sulfuric acid. Trans-esterification experiments of the pre-esterified oil based on RSM were carried out, then discovered 1.24% of KOH catalyst and 22.76% of methanol as the optimal trans-esterification conditions. However, the quantity of KOH was higher than the previously established KOH concentration of our team. So, we carried out supplemental experiment to determine the quantity of catalyst and methanol. As a result, the optimal transesterification conditions were determined to be 0.8% of KOH and 16.13% of methanol. After trans-esterification of tropical crop oil, the produced biodiesel could meet the major quality standard specifications; 100.8% of FAME, 0.45 mgKOH/g of acid value, 0.00% of water, 0.04% of total glycerol, $4.041mm^2/s$ of kinematic viscosity(at $40^{\circ}C$).

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.642-649
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• 2011

Ginseng growth is largely affected by characteristics of soil in Ginseng field. In this study, we determined the critical ranges of physico-chemical properties of soil for optimization of ginseng growth by analyzing the soils from Anseong and Pocheon regions in Gyeonggi province. Fresh weight of ginseng was 2 to 5 fold higher in good growth field compared to poor growth field within Anseong region. In the case of Pocheon region, 1.5 to 2 fold differences of fresh weight of ginseng was observed between good and poor growth field. These results indicate the difference of ginseng growth even in the same region. Based on these results, critical ranges of physico-chemical properties of soils were determined by comparing the good and poor growth field of each regions, which are follows; more than 50% of soil porosity, 2.0~2.8 g/kg of total nitrogen, 500~900 mg/kg for Av. $P_2O_5$, 2.3~3.5 $cmol_c\;kg^{-1}$ for Exch. Ca in Anseong; less than 13% of liquid phase, 400~650 mg/kg for Av. $P_2O_5$, 4.0~4.7 $cmol_c\;kg^{-1}$ for Exch. Ca, less than 0.8 and 0.5 $cmol_c\;kg^{-1}$ for Exch. Mg and K, respectively, in Pocheon. Interestingly, we found that ginseng growth was affected by exchangeable base ratio (Ca:Mg:K) especially in Anseong region, which were 6:2:1 in good growth field while 4:2:1 in poor growth field. Critical ranges for nutrient contents of ginseng leaves were also characterized, which are less than 0.2% and 0.22% of each P and Mg, respectively, in Anseong, while less than 1.8% and 0.18% of each N and P, respecively, and 1.5~3.0% of K in Pocheon. In addition, we determined critical ranges for inorganic nutrient contents in the current study.

• Culinary science and hospitality research
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• v.16 no.4
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• pp.286-296
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• 2010

The purpose of this study is to develop fresh pasta added with mulberry leaf powder as functional fresh pasta. Through previous research, the mixture of 40% of flour and 60% of rice powder was optimum for making noodles with mulberry leaf powder. Making fresh pasta with 40% of wheat flour, 60% of rice powder (optimum moo for making noodles) and mulberry leaf powder(0.5% 1.0% 1.5% 2.0%) was done, followed by the mechanical test(moisture content, color value, texture, tension) and the sensory analysis(quantitative descriptive analysis, preference test). Moisture contents of raw pasta and cooked pasta were the highest in control; scores for moisture contents of cooked pasta were higher than those of raw pasta. The result indicated that the more mulberry leaf powder was, the lower L-value and a-value were in raw pasta and cooked pasta. While the b-vale(yellowness) of raw pasta was the highest in control(9.81), 1.0% of mulberry powder addition sample was the highest in cooked pasta. For hardness, the 2.0% of mulberry leaf powder addition sample has high scores, and adhesiveness and chewiness were no significant difference. The 0.5% of mulberry leaf powder addition sample was the longest in tension distance, which was resulted from the lack of water contents in mulberry leaf powder. In cooked pasta, tension distance had no significant difference between the samples, and force showed the highest score in control. The quantitative descriptive analysis showed that color intensity, savory taste, bitterness were the highest in the 2.0% of mulberry leaf powder addition sample. Gloss and chewiness were no significant difference between the samples. Grassy flavor, savory flavor, bitterness and grainess were intense as mulberry leaf powder was added The preference test showed that MRP 1.5 containing 1.5% of mulberry leaf powder was the most preferable for color, texture and overall quality. In conclusion, 40% of wheat flour, 60% of rice powder and 1.5% of mulberry leaf powder made the best formula of fresh pasta with mulberry leaves.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1708-1714
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• 2015

Fermented red ginseng concentrate is known as a healthy food source, whereas it has off-flavor such as bitterness and sour flavor based on fermentation. ${\beta}$- and ${\gamma}$-cyclodextrin (CD) were used to encapsulate the off-flavor of fermented red ginseng concentrate by using response surface methodology design on ${\beta}$- and ${\gamma}-CD$ combination. The reducing effects were analyzed by sensory evaluation for bitter and sour tastes, ginsenoside Rb1, and total acidity. The optimized mixing ratio of ${\beta}$- and ${\gamma}-CD$ for reducing bitterness was the least expected value of 2.07 at ${\beta}-CD$ 3.74% versus the soluble solid content of fermented red ginseng concentrate and the ${\gamma}-CD$ 20.63% mixture. The encapsulation effects of ginsenoside Rb1 were the most expected value of 96.75% at ${\beta}-CD$ 3.47% and ${\gamma}-CD$ 19.89% mixture. The encapsulation effects of sour taste were the least expected value of 5.63 at ${\beta}-CD$ 9.34% and ${\gamma}-CD$ 9.96% mixture. The encapsulation effects of lactic acid were the most expected value of 67.73% at ${\beta}-CD$ 16.0% and ${\gamma}-CD$ 13.18% mixture. Based on encapsulation and each optimized combination, the most effective entrapping ${\beta}$-and ${\gamma}-CD$ combination ratio was ${\beta}-CD$ 10% and ${\gamma}-CD$ 13%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1206-1212
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• 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
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• v.44 no.5
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• pp.767-774
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• 2015

In recent decades, health concerns related to sodium intake have caused an increased demand for salt or sodium-reduced foods. Umami substance can enhance taste sensitivity to NaCl and may offer a unique approach to replace and reduce the sodium content in foods. In this study, hot water extraction conditions of Wando sea tangle with high umami taste were investigated. Wando sea tangle harvested in June was selected for hot water extraction based on its free amino acids composition. The quality properties of sea tangle extract were investigated at various extraction temperatures ($60^{\circ}C$, $80^{\circ}C$, and $100^{\circ}C$) and times (1 h, 2 h, and 3 h). Sea tangle extracts at the extraction temperature of $100^{\circ}C$ contained the highest soluble solids (35.47%~36.93%), and crude protein (3.75%~4.00%). Viscosities of sea tangle extracts decreased with increasing extraction temperature. Umami amino acids (glutamic acid and aspartic acid) and sensory characteristics were best at extraction conditions of $100^{\circ}C$ for 2 h. Saltiness enhancement of sea tangle extract powder was determined. Saltiness intensities of NaCl solution after adding 1% sea tangle extract powder were enhanced (1.84~4.25-fold). At the same saltiness intensity, sodium contents of NaCl solution with 1% sea tangle extract powder were 12.24~24.33% lower than that of NaCl solution. These results suggest that it is possible to reduce sodium in foods with sea tangle extract as a natural salt enhancer without lowering overall taste intensity.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.215-221
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• 2008

Effects of light generated by LEDs on shoot growth and rooting of Tsuru-rindo(Tripterospermum japonicum) were evaluated. Apical shoots(one or two node with 3-4 leaves) were cultured on MS basal medium with 3% sucrose and maintained for four weeks under five different light qualities: fluorescent lamp(F), 100% red LED(R), 70% red LED+30% blue LED(R7B3), 50% red LED+50% blue(R5B5), or 100% blue LED(B). Rooting was promoted by both red light and fluorescent lamp, and the effect was further promoted under the ventilation. Red light enhanced shoot node elongation, whereas blue light appeared to suppress it. Growth of shoots and leaves were enhanced under the ventilation irrespective of the different light qualities. Under the ventilated condition, total fresh weight of plants was highest in R7B3 LED as 257.7 mg per plant. Dry matters, which are used for index of plant growth, were lowest under red light, whereas it was highest under blue light. The dry matter was inclined to getting higher by ascending the ratio of blue light and red light. Total chlorophyll content was highest in both R7B3 LED and R5B5 LED under ventilation as 29.5 and 31.2, respectively. Above results suggest that light quality optimization could be an important factor to foster in vitro growth of the species. Ventilation treatment appeared to be another important factor to induce normal shoot growth and rooting.