• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.2
• /
• pp.287-293
• /
• 2010

Regarding the physical properties of wheat flour added with lily's root powder, elasticity in farinograms tended to increase as the ratio of added lily's root powder increased. However, viscoelasticity, absorptivity, absorption time, and stability tended to decrease after an initial increase when a certain ratio of lily's root powder was added to the wheat flour. Results from the rapid viscosity analyzer (RVA) indicated that the retention strength, final viscosity, break down, set back value, $P_{max}$ value of the alveogram, and falling number value decreased. As for gaseous release, measured with a rheofermentometer, the total amount of $CO_2$ gas generated and retained tended to decrease. As for the gelatinizing properties in terms of differences in the granularity and the amount of lily's root powder (bulbs) added to wheat flour, the initial gelatinization temperature had no effect regardless of the type or amount of general grinding and minute (ultra-fine, $10\;{\mu}m$) lily's root powder. Meanwhile, the peak viscosity and peak viscosity time exhibited significant differences in 3, 5% general grinding lily's root powder additive groups. On the other hand, there was no significant difference between 3, 5% minute lily's root powder additive groups. This is likely because the activity of the enzyme in wheat flour decreased relatively and differences in the lily's root powder granularity resulted in a variation in water absorptivity. In the preference test, flavor retention of the functional bread increased according to the granularity of lily's root powder and the ratio of added lily's root powder, thus resulting in significant differences in the mouth feel and flavor; the texture and crumb color, however, did not exhibit significant differences.

• Analytical Science and Technology
• /
• v.13 no.2
• /
• pp.136-150
• /
• 2000

For the identification of unknown drugs in biological samples, we attempted rapid high performance thin layer chromatographic method which is sensitive and selective chromatographic analysis of high performance thin layer chromatography (HPTLC) with automated TLC sampler and ultra-violet (UV) scanner. We constructed HPTLC database (DB) on two hundred five drugs by using the data of Rf values and UV spectra (scan 200-360 nm) as well as gas chromatography/mass spectrometry (GC/MS) DB on ninety six drugs by using the data of relative retention time (RRT) on lidocain and mass spectra. After extracting drugs in biological sample by solid phase extraction (Clean Screen ZSDAU020), we applied them to HPTLC and GC/MS DB. Drugs, especially extracted from biological samples, showed good matching ratio to HPTLC DB and these drugs were confirmed by GC/MS. In conclusion, this DB system is thought to be very useful method for the screening of unknown drugs in biological samples.

• Korean Journal of Food Science and Technology
• /
• v.32 no.3
• /
• pp.507-512
• /
• 2000

The headspace flavors of roasted tea, prepared with steamed and nonsteamed polygonatum roots, were absorbed in solid-phase microextraction(SPME) fiber coated with $65\;{\mu}m$ of carbowax/divinylbenzene(CW/DVB) and analysed by GC-MS. The absorption conditions of SPME fiber for equilibrated headspace were selected as $60^{\circ}C$ and 30 min. In a comparison for both samples roasted at $130^{\circ}C$ for 15 min, gas chromatograms showed a similar pattern in overall profiles between steamed and nonsteamed samples before roasting, but some differences were observed in peak characteristics. From 40 separated peaks, 25 compounds were identified with both GC-MS and retention time comparison. The pyrazines including 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, 2-acetyl-1-pyrroline, etc. were higher in their contents in nonsteamed-roasted sample than steamed-roasted one. In particular, steamed-roasted polygonatum showed higher contents of acetic acid(8.17%) and hexanoic acid(5.43%) than the corresponding compounds of nonsteamed-roasted one, 2.40% and 2.00%.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.6
• /
• pp.731-737
• /
• 1992

The specific attributes of aroma quality of canned tuna meat were investigated before and during refrigerated storage. Fresh, cooked tuna, beefy and meaty flavor notes of canned tuna meat were changed to card-boardy(1 week storage), oxidized fat-like(2 weeks storage), fatty acid-like and heavy oxidized fat-like(3 weeks storage), and then moldy and painty(4 weeks storage) flavor notes during storage in refrigerator at $4^{\circ}C.$ More than 126 peaks of volatile compounds collected from canned tuna meat were separated on Carbowax 20M capillary column of gas chromatographic analysis. Of the peaks, 54 compounds were identified by mass spectral data, matching $I_E$ values, and sniffing the effluent of each peak from GC detector. The contents of many low molecular weight compounds eluted with early retention times were decreased, whereas some other new compounds eluted with longer retention time were formed during storage. The compounds increased up to 3 weeks of storage and then decreased at extended storage time(4 weeks) were 1-penten-3-ol, 3-penten-2-ol, heptanal, limonene, 1-pentanol, octanal, 1-hexanol, nonanal, 2-octanone, 2-nonanone, 1-heptanol, benzaldehytde and some methyl substituted benzenes. p-Thiocresol, 2-chlorophenol, and 2-heptylthiophene were formed after 4 weeks of storage, but not detected in fresh canned tuna. Therefore, these compounds could be used as indicators for the quality changes during refrigerated storage.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.16 no.2
• /
• pp.57-65
• /
• 2008

Wastewater containing strong organic matter is very difficult to treat by utilizing general sewage treatment plant. but the wastewater is adequate to generate biomass energy (bio-gas; methane gas) by utilizing anaerobic digestion. EcoDays Plug Flow Reactor (E-PFR), which was already proved as an excellent aerobic wastewater treatment reactor, was adapted for anaerobic food wastewater digestion. This research was performed to improve the efficiency of bio-gas production and to optimize anaerobic wastewater treatment system. Food wastewater from N food waste treatment plant was applied for the pilot scale experiments. The results indicated that the efficiency of anaerobic wastewater treatment and the volume of bio-gas were increased by applying E-PFR to anaerobic digestion. The structural characteristics of E-PFR can cause the high efficiency of anaerobic treatment processes. The unique structure of E-PFR is a diaphragm dividing vertical hydraulic multi-stages and the inversely protruded fluid transfer tubes on each diaphragm. The unique structure of E-PFR can make gas hold-up space at the top part of each stage in the reactor. Also, E-PFR can contain relatively high MLSS concentration in lower stage by vertical up-flow of wastewater. This hydraulic flow can cause high buffering capacity against shock load from the wastewater in the reactor, resulting in stable pH (7.0~8.0), relatively higher wastewater treatment efficiency, and larger volume of bio-gas generation. In addition, relatively longer solid retention time (SRT) in the reactor can increase organic matter degradation and bio-gas production efficiency. These characteristics in the reactor can be regarded as "ideal" anaerobic wastewater treatment conditions. Anaerobic wastewater treatment plant design factor can be assessed for having 70 % of methane gas content, and better bio-gas yielding and stable treatment efficiency based on the results of this research. For example, inner circulation with generated bio-gas in the reactor and better mixing conditions by improving fluid transfer tube structure can be used for achieving better bio-gas yielding efficiency. This research results can be used for acquiring better improved regenerated energy system.

• Applied Biological Chemistry
• /
• v.27
• /
• pp.3-17
• /
• 1984

Anaerobic digestion has recently attracted all over the world and Korea also shows no exception. The major benefits of anaerobic digestion are energy production, water pollution control, pathogen reduction and effective manure production. In Korea it was recognized in late sixties that there was a positive need to find alternative energy for farmers household. The main traditional energy sources in rural area were crop residues and forestry products. Therefore Office of Rural Development through its Rural Guidance Bureau disseminated about 29,000 household biogas units from 1969 to 1975 to provide cooking fuel for farmers household and to improve the mode of farmers living standards. The units were welcomed by farmers at that time. Now, however, most of them are not using due to a number of reasons associated with cold winter and some techno-economical problems (in those day, fossil fuel was quite expensive to compare with other prices and since then farmers income was quickly increased). The author studied on bag type household biogas plant to solve some technical problems of existing household biogas plants, but this also has little appeal for the farmers. From 1977 author studied on village scale biogas plant with two pilot plants. From the viewpoint of energy production, COD removal, kill rate of pathogen and fertilizer value, the results obtained from the experiments were quite promising, but the construction cost of the village scale biogas plant was too high for the farmers in Korea. To find most suitable biogas plant for farmers in Korea through the simplifying the biogas digester, the author developed batch-load biogas plant. By feeding coarse crop residues and manures, total solids concentrations of the batch-load biogas plant are about 28 percent which is much higher than continous digester of 5-8 percent. The batch-load biogas plant was welcomed by many farmers in Korea when it was reported on TV and newspapers. The plant was disseminated 154 units in 1982, 766 units in 1983 and 812 units in 1984 as a promissing project. Besides these biogas plant experiments, studies were also conducted 1) to determine gas production rate with agricultural wastes, 2) to evaluate the effect of loading rate, dilution, retention time on biogas production, 3) to project the amount of potencial energy from agricultural wastes.

• Journal of Korean Society of Water and Wastewater
• /
• v.11 no.1
• /
• pp.33-41
• /
• 1997

An attempt was made to enhance anaerobic treatment efficiency by adopting the anaerobic sequencing batch reactor(ASBR) process at a thermophilic temperature. Operational characteristics of the ASBR process were studied using laboratory scale reactors and concentrated organic wastewater composed of soluble starch and essential nutrients. Effects of fill to react ratio (F/R) were examined in the Phase I experiment, where the equivalent hydraulic retention time(HRT) was maintained at 5 days with the influent COD of 10g/L. A continuous stirred tank reactor(CSTR) was operated in parallel as a reference. Treatment efficiency was higher for the ASBRs because of continuous accumulation of volatile suspended solids(VSS) compared to the CSTR. However, the rate of gas production and organic removal per unit VSS in the ASBRs was much lower than the CSTR. This was caused by reduced methane fermentation due to accumulation of volatile acids(VA), especially for the case of low F/R, during the fill period. When the F/R was high, maximum VA was low and the VA decreased in short period. Consequently, more stable operation was possible with higher F/R. Effects of hydraulic loading rate on the efficiency was studied in the Phase II experiment, where the organic loading rate was elevated to 3333mg/L-d with the F/R of 0.12. Reduction of organic removal along with rapid increase of VA was observed and the stability of reaction was seriously impaired, when the influent COD was doubled. However, operation of the ASBR was quite stable, when the hydraulic loading rate was doubled and a cycle time was adjusted to 12 hour. It is essential to avoid rapid accumulation of VA during the fill period in order to maintain operational stability of the ASBR.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.241-244
• /
• 2000

Continuous $H_2$ production from CO and water was studied in a trickle bed reactor(TBR) using Rhodopspedomonas palustris P4. To achieve high cell density, R. palustris P4 were cultivated by a fed-batch culture mode under chemoheterotrophic and aerobic condition, and final cell concentration was 13 g/L. TBR could provide sufficient residence time for CO to contact with cell suspension circulating TBR. The maximum CO uptake rate was found to be 16 mmol/L/hr at gas retention time of 50 min and CO partial pressure of 0.4 atm. In our correlation of the experimental data with mathematical model of TBR, the TBR operation with P4 was found to be lie in an intermediate state between mass transfer limitation and kinetic limitation. Due to the high cell density as well as hydrogen production activity in this study, TBR operation showed a superior performance to other previous reports on microbial hydrogen production.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.8
• /
• pp.603-610
• /
• 2009

This research was performed to improve removal efficiency of toluene and methyl ethyl ketone (MEK) using Candida tropicalis, one of the yeast species. An airlift loop bioreactor (ALB) was employed to enhance the capability of mass transfer for toluene and MEK from the gas phase to the liquid, microbial phase. Polymer gel media made from PAC, alginate and PEG was applied for the effective immobilization of the yeast strain on the polymer gel media. The experimental results indicated that the mass transfer coefficient of toluene without polymer gel media was 1.29 $min^{-1}$ at a gas retention time of 15 sec, whereas the KLa value for toluene was increased to 4.07 $min^{-1}$ by adding the media, confirming the enhanced mass transfer of volatile organic compounds between the gas and liquid phases. The removal efficiency of toluene and MEK by using yeast-immobilized polymer gel media in the ALB was greater than 80% at different pollutant loading rates (5, 10, 19 and 37 g/$m^3$/hr for toluene, 4.5, 8.9, 17.8 and 35.1 g/$m^3$/hr for MEK). In addition, an elimination capacity test conducted by changing inlet loading rates stepwise demonstrated that maximum elimination capacities for toluene and MEK were 70.4 and 56.4 g/$m^3$/hr, respectively.

• Journal of Environmental Health Sciences
• /
• v.21 no.4
• /
• pp.1-9
• /
• 1995

This study was carried to investigate the biodegradability of phenol in the wastewater with the two sludge blanket-packed bed reactor in series. Each reactor had a dimension of 0.09 m i.d. and 1.5 m height and consisted of two regions. The lower region was a sludge blanket of 0.5 m height and the upper region was a packed-bed of 1 m height. The packed bed region was charged with ceramic raschig rings of 10 mm i.d., 15 mm o.d. and 20 mm length. The reactors were operated at 35$\circ$C and the hydraulic retention time(HRT) was maintained 24 hours. The synthetic wastewater composed of glucose and phenol as major components was fed into the reactor in a continuous mode with incereasing phenol concentration. In addition, the nutrient trace metals($Na^+, Mg^{2+}, Ca^{2+}, PO_4^{3-}, NH_4^+, Co^{2+}, Fe^{2+}$ etc.) were added for growing anaerobes. The phenol concentration of the effluent, the overall gas production, the composition of product gas, the efficiency of COD reduction and the duration of acclimation period were measured to determine the performance of the anaerobic wastewater treatment system as the phenol concentration of the influent was increased from 600 to 2400 mg//l. Successfully stable biodegradation of phenol could be achieved with the anaerobic treatment system from 600 to 1, 800 mg/l of the influent phenol concentration. The upper level of influent phenol loading was high enough to meet most of the practical requirement. The duration of acclimation increased with the phenol loading. At steady state of the influent phenol concentration of 1800 mg/l, the treatment performance indicated the phenol reduction efficiency of 99%, the COD reduction efficiency of 99% and the gas production rate of 37 l/day. At the influent phenol concentration of 2400 mg/l, however, the operation of the treatment system was noted unstable. While the concentration of methane in biogas decreased with increasing the influent phenol loading, the carbon dioxide was increased. However, the concentration of hydrogen was varied negligibly. The concentration of methane was high enough to be used as a fuel. As a result, it is suggested that anaerobic phenol wastewater treament was economical in the sense of energy recovery and wastewater treatment.