• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.443-447
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• 2016

The microalgae have cellulose as a main structural component of their cell wall and the lignin content in microalgae is much lower than other lignocellulosic biomass. Therefore, fermentable sugar production from microalgae (Tetraselmis KCTC 12236BP) can be carried out under pretreatment without high temperature and high pressure. It was investigated that the effect of hot-water pretreatment using sulfuric acid for lipid extracted algae which is expected to be a next generation biomass. The effects of three major variables including extraction temperature, acid concentration and time on the enzymatic hydrolysis were investigated. Among the tested variables, temperature and acid concentration showed significant effects and optimum pretreatment conditions for the economic operation criteria were obtained as follows: reaction temperature of $120^{\circ}C$, sulfuric acid concentration of 2 mol and pretreatment time of 40 min. Under the optimum conditions of acidic hot water pretreatment, experimentally obtained hydrolysis yield were 95.9% which showed about 2.1 fold higher compared with enzymatic hydrolysis process. Therefore, acid pretreatment under mild condition was proven to be an effective method for fermentable sugar production from lipid extracted microalgae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1543-1549
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• 2015

Black rice bran, a by-product from rice milling process, is a good natural source of anthocyanin pigment. The purpose of this study was to determine the optimum conditions for anthocyanin extraction from black rice bran as well as the stability of anthocyanin extract according to different storage temperatures. The main anthocyanin in 'Heugkwang' rice bran was identified as cyanidine-3-glucoside (C3G) by HPLC and LC-MS/MS. The yield and C3G content of black rice bran extract were investigated with various extraction solvents, temperatures, and times. The results indicate that the optimum extraction solvent, temperature, and time were 50% ethanol, $70^{\circ}C$, and 2 h, respectively. The stability of anthocyanin extract was studied during a storage period of 168 days at various temperatures ($-20^{\circ}C$, $4^{\circ}C$, and room temperature). Hunter's values (L, a, and b) of anthocyanin extract increased, whereas C3G content continuously decreased up to 168 days. Variations in Hunter's values and C3G content become larger as storage temperature increased. Anthocyanin extract from black rice bran was very stable, as C3G content after storage at all temperatures was maintained at more than 90% of initial content. These results suggest that anthocyanin extract from black rice bran may be useful as a natural food colorant.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.579-588
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• 2014

In this study, three signal control strategies such as Bike box, Hook-turn, and 6-phase were assessed for various traffic conditions at signalized intersections incorporating bicycle left-turn traffic. Results showed that the size of a waiting zone mainly affected the performance of signal control in both Bike box and Hook-turn. Both Bike box and Hook-turn yielded an identical vehicle delay, but Bike box produced less bicycle delay than Hook-turn by 2.5~29.9 sec/veh for undersaturated traffic conditions. For saturated traffic condition, Bike box produced less vehicle delay than Hook-turn and 6-phase strategies, but bicycle delay was found to increase at the 700 vph of bicycle traffic compared to 6-phase. Bicycle delay was greatly increased under Hook-turn and Bike box strategies when bicycle traffic was greater than 300 vph and 500 vph, respectively. It was also shown that bicycle delay could be significantly reduced by providing appropriate size of queueing space. In addition, Bike box was likely to yield less vehicle and bicycle delay than Hook-turn for traffic volume patterns investigated in this study.

• Horticultural Science & Technology
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• v.35 no.3
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• pp.381-386
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• 2017

'Jangha' is a new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2014. The 'Jangha' cultivar originated in 2008 from a cross between 'Goha' and 'Elsinore' that showed excellent ever-bearing characteristics, including continuous flowering habit and high soluble-solids contents under long-day and high temperature conditions. This cultivar was initially named 'Saebong No. 6' after examining its characteristics and productivity in summer culture from 2010 to 2012. After two regional adaptability tests in 2013-2014, 'Jangha' was selected from Saebong No. 6 as an elite cultivar. The general characteristics of 'Jangha' include semi-spreading type, elliptical leaves, and moderately vigorous growth. The fruit are conical in shape, and red in color. 'Jangha' plants have 21.4 leaves, 55.8 fewer than 'Flamenco' plants. The soluble-solids content of 'Jangha' was 8.9%, which was 1.2% higher than that of 'Flamenco'. The average fruit weight of 'Jangha' was about 11.7g and the marketable yield was $19,013kg{\cdot}ha^{-1}$, 141% higher than 'Flamenco'. 'Jangha' is suitable for summer season cultivation as a high soluble solids contents cultivar, because it shows continuous flowering habit under long-day and high temperature conditions.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.123-130
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• 1980

Thiamine derivatives of thiamine tetrahydrofurfuryl disulfide (TTFD) and thiamine propyl disulfide (TPD) were obtained in a good yield and purity by use of thiothiamine $(SB_1)$ and also described in details for the preparing sodium tetrahydrofurfuryl thiosulphate (Bunte's salt) with and without KI. The optimum reaction conditions for the preparation of TTFD was set in which the Box-Wilson plan was applied. The reaction conditions are as follows; 1. pH value of aqueous solution of thiol type of $B_1{\cdot}HCl;12.09$ 2. Quantity of Bunte's salt (to $B_1{\cdot}HCl\;20G$); 35.01g 3. Reaction temperature; $15.59^{\circ}C$ Studies on ultraviolet absorption were made at various pH and showed that the absorption maxima are shifted with change of pH. The absorption maxima are at $244{\sim}246nm,\;234{\sim}235nm$ in TTFD, and $245{\sim}246nm,\;233{\sim}235nm$ in TPD. The structure was proved by the infrared spectral evidence. Quantitative determination was studied.

• Journal of Mushroom
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• v.10 no.4
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• pp.160-166
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• 2012

The effects of fixed and variable temperatures on fruiting body formation and characters of mushrooms were investigated with normal and thinning treatment plots. In fixed temperature, as temperature was lower, period of harvest was longer as well as days for pinheading in the both of normal and thinning plots. Harvest rate were 91.0, 90.3, and 95.8% at $13^{\circ}C$, $17^{\circ}C$, and $15^{\circ}C$. In the thinning plot, qualities of mushrooms were 7.5, 8.1, and 7.7, and yields were 86.0, 105.9, 104.0g at 13, 15, and $17^{\circ}C$ respectively. In variable temperature with a variable temperature plot, condition II($17^{\circ}C$ for pin-heading(before reverting, 7-8 days)${\rightarrow}16^{\circ}C$ for extending primodia(before thinning, 4-5 days)${\rightarrow}15^{\circ}C$ for extending (after thinning)) was the best for yield which was better than other conditions by 17.4% and 4.0% and quality of mushroom was highest 8.1 among all conditions.

• Applied Biological Chemistry
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• v.44 no.1
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• pp.24-29
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• 2001

Extracts of Acanthopanax koreanum Nakai were decreased as the ethanol concentration was increased, but eleutherosides were increased. Extracts were increased as the extraction time was prolonged. Compared to 15 hrs extraction, extract yield and eleutherosides for 5 hrs extraction were 90.6% and 96%, respectively. Yields of extract and eleutherosides were 6.5% and 75% at $100^{\circ}C$. The optimum extraction conditions were obtained from the samples of 4 years' tree harvested at September, which were water and 50% ethanol as solvents, and $90^{\circ}C$ for 5 hrs extraction. Soluble solids, minerals, free sugars, free acids, free amino acids and total eleutherosides in the extract of Acanthopanax koreanum were $48.2{\sim}47.4%$, $4.5{\sim}5.3%$, 11.2711.80%, $3.02{\sim}3.18%$, 185.33 mg/100 $g{\sim}$ 348.14 mg/100 g and 990.84 mg/100 $g{\sim}$l,416.10 mg/100 g, respectively. The extract was viscous and yellowish brown liquid.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.313-318
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• 2007

In greenhouse farming, a variety of humic acids have been applied to improve soil conditions and plant growth. However, it is still unclear that how humic acids combined with chemical fertilizers affect growth and quality of fruit vegetable crops. This study was conducted to determine the combination effect of humic acids and chemical fertilizers on the growth and fruit quality of tomato (Lycopersicon esculentum MILL.) grown under greenhouse conditions. Three different formulation types of humic acid were used: liquid type A, liquid type B and solid type C. The tomato plants were grown in three treatment combination plots and in conventional fertilizer (CF) plot with recommended levels of nitrogen, phosphorus and potassium: HA combined with CF (HA+CF), HB combined with CF (HB+CF) and HC combined with CF (HC+CF). For most of growth characteristics (i.e. leaf number, internode length, maximum leaf length, leaf width and chlorophyll contents) determined in this experiment, no significant differences were observed between all combination treatments and CF. However, integrated fruit qualities (i.e. averaged weight, sugar contents and acidity) were slightly improved in the humic acid combined with CF treatments when compared with CF alone treatment. No phytotoxicity was observed with humic acid treatments. However, further studies will probably be needed to use widely and safely these humic acids, in order to ensure a maximizing growth, fruit yield and quality of tomato.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.334-340
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• 2020

In this study we developed an enrichment medium and lysis buffers to detect Listeria monocytogenes in meat and processed meat products under various lysis conditions. The enrichment efficiency of L. monocytogenes medium listed in the Food Standards was compared, and thus, Listeria Enrichment Broth (LEB) was modified by adding supplements such as carbon source and minerals. The lysis buffers were developed to extract L. monocytogenes DNA quickly and efficiently under various lysis conditions. L. monocytogenes was most rapidly grown in LEB containing 0.1% pyruvate and 0.1% ferric citrate. A lysis buffer mixed with 0.5% or 1% N-lauroylasrcosine sodium salt, 0.5 N NaOH and 0.5 M EDTA for 30 min at room temperature was found to be the best in terms of DNA purity and yield. These results indicate that developed enrichment medium and lysis buffer can be used to detect L. monocytogenes in meat and processed meat products rapidly and efficiently.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.329-335
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• 1999

The yield of oleoresin content and functionality of fresh garlic were compared according to varying extraction conditions by microwave-assisted extraction (MAE) and conventional extraction (CE) methods. When different extracting conditions were applied, there was no significant difference of extraction methods in the oleoresin content. However, in the case of the CE, the optimum extraction time was two hours, while the other was about five minutes which meant that the extraction time was shortened drastically. The electron donating abilities showed a similar level which was 64% by both methods, using water. And, in the case of ethanol extraction, it resulted 63% and 51% by CE and MAE, respectively. The nitrite scavenging effect diminished while pH was increasing and especially, in the case of pH 1.2, it showed a high elimination effect of more than 90%. There was no difference of extraction methods. The tyrosinase inhibitory effect was 47% and 60% by CE and MAE, respectively in the case of the water extract. The ethanol extract showed similar or a slight lower inhibition of 45% and 39%. The angiotensin I-converting enzyme inhibitory effect showed more powerful activity in the case of MAE extract than CE extract, but there was not an increase relating to reaction time of enzyme. Also, pyruvic acid content was $44.8\;and\;36.0{\mu}moles$ per one gram of a garlic by CE and MAE, respectively when water was used, and was $28.6\;and\;32.0{\mu}moles$ by CE and MAE when ethanol was used. Again, there was no big difference between CE and MAE methods.