• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.152-164
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• 2018

Fermented seasoning pastes were prepared by Aspergillus oryzae and Bacillus subtilis using three edible insects, Tenebrio molitor larvae (TMP), Gryllus bimaculatus (GBP), and Bombyx mori pupa (SPP), with soybean (SBP) as a negative control. Volatile compounds were extracted by the headspace solid-phase microextraction (HS-SPME) method and confirmed by gas chromatograph-mass spectrometry (GC-MS). In total, 121 volatiles from four samples were identified and sub-grouped as 11 esters, 18 alcohols, 23 aldehydes, 5 acids, 10 pyrazines, 2 pyridines, 7 aromatic hydrocarbons, 10 ketones, 19 alkanes, 9 amides, 4 furans and 3 miscellaneous. TMP, GBP, SPP and SBP had 48, 54, 36, and 55 volatile compounds, respectively. Overall, 2,6-dimethylpyrazine and trimethylpyrazine were found by a high proportion in all samples. Tetramethylpyrazine, a main flavor of doenjang, a Korean fermented seasoning soybean paste, was identified as one of the major compounds in TMP, SPP, and SBP. SBP had benzaldehyde, hexanal, n-pentanal, and aldehydes and SPP with pyrazines.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1079-1085
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• 2003

Modified atmosphere packaging was applied to oyster mushrooms (Pleurotus ostreatus) to study the effect of storage temperatures and packaging materialso. Whole mushrooms (200g) were package with polyethylene film $(PE,\;60{\mu}m\;thickness)$, ethylene vinyl acetate (EVA), or ceramic film (containing 5% zeolite) and stored at 0, 5, 10 and $20^{\circ}C$. Weight loss, color, firmness, gas composition $(O_2,\;CO_2)$ inside the film package and ethanol content in the tissue of MA packaged mushrooms were examined. Mushroom that were packed unwrapped in a conventional hardboard box (2 kg) lost marketability at a very early stage of storage due to weight loss, shrinkage, browning, and spore formation. During storage, film packaging prevented or retarded the deterioration of the mushrooms in the aspects of appearance, texture, and discoloration. Firmness slightly decreased with storage time. Total color difference was much higher in the control than in the film-packaged mushroom and rapidly increased at the early of storage. Correlation analysis showed a high correlation between total color difference and b values. These results were characterized by the reduced respiration rate resulting from elevated carbon dioxide and reduced oxygen levels in the package. At all storage temperatures, ethanol content in the tissue increased slightly at the early part of storage and rose considerably towards the end of the storage period. Ethanol content in the oyster mushrooms was higher in the stipe than in pileus tissues. The shelf life of the oyster mushrooms was about $8{\sim}11$ days at $0^{\circ}C$, about $4{\sim}6$ day at $5^{\circ}C$, about $2{\sim}3$ days at $10^{\circ}C$, and about $1{\sim}2$ days at $20^{\circ}C$.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.100-106
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• 2011

The physicochemical characteristics of chicken breast were determined to identify the optimal ratio of $CO_2$ and $N_2$ to maintain chicken breast quality during cold storage for 6 d. The mixing ratios of $CO_2$ and $N_2$ were 20:80, 40:60, 60:40, and 80:20, respectively. The pH of the chicken breast packed with 80% $CO_2$ and 20% $N_2$ was lower than that of the control on day 1 (p<0.05). The lightness ($L^*$) of the breast increased with increasing $CO_2$ during storage (p<0.05), whereas no difference was found for redness ($a^*$) and yellowness ($b^*$). A lower volatile basic nitrogen level was found for chicken breasts exposed to higher $CO_2$ levels. Furthermore, lipid oxidation of the chicken breast packed with $CO_2$ decreased with increasing $CO_2$ level, and 40% $CO_2$ significantly reduced 2-thiobarbituric acid reactive substances (TBARS) values on days 1 and 6. The total number of microbes was reduced in chicken breast exposed to more than 40% $CO_2$ during storage days 3 and 6 (p<0.05); however, Escherichia coli was not affected by $CO_2$ level. Coliforms of chicken breast were reduced in the 40% $CO_2$ level on storage day 3. Moreover, tray-packed chicken breast exposed to 40% $CO_2$ did not collapse. These results suggest that 40% $CO_2$ and 60% $N_2$ were the optimal conditions for packaging chicken breasts during cold storage.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.280-286
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• 1999

This studies were conducted to evaluate efficiency of microbial inoculator for active composting of food wastes. The Microbial inoculators used in this studies were purchased from different comparise to evaluate their effectiveness for composting of food waste in Korea. The number of bacteria growing at $30^{\circ}C$ in commercial inoculator collected were below $91.0{\times}10^8\;CFU/g$ which were counted from well cured compost made by animal manure. The number of bacteria in commercial microbial inoculator, such as FL, VP, B9, CM and GE were higher than that of composted at $50^{\circ}C$ or $60^{\circ}C$ of incubation temperature. Fungi were counted in GR, VP and B9 as over $10^3CFU/g$ at $30^{\circ}C$ of incubation temperature, while fungi of all the commercial inoculator collected could not grown at $50^{\circ}C$ and $60^{\circ}C$. Actinomycetes in most of the these had higher number($10^5CFU/g$) than that of compost : however, it was not detected at $60^{\circ}C$ incubation temperature from all the samples collected. The amount of carbon dioxid production was order to VP>HU>B9>GE>CM>Control>Compost in the lab scale composting test with or without inoculation of commercial inoculators, however, but the difference in carbon dioxide production was similar among each treatments. The effect of inoculation on composting parmeter such as pH changes, temperature increasing and change of chemicals properties were a little among each treatments, with or without inoculation of commercial inoculator in active composting of food waste. Using commercial inoculator did not show any statistical difference in food waste composting process under various condition such as pH changes, temperature changes, etc.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.13-20
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• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.13-20
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• 2008

The flow rate measurements in a multi-phase flow pipeline were evaluated quantitatively by means of a clamp-on sealed radioisotope based on a cross correlation signal processing technique. The flow rates were calculated by a determination of the transit time between two sealed gamma sources by using a cross correlation function following FFT filtering, then corrected with vapor fraction in the pipeline which was measured by the ${\gamma}$-ray attenuation method. The pipeline model was manufactured by acrylic resin(ID. 8 cm, L=3.5 m, t=10 mm), and the multi-phase flow patterns were realized by an injection of compressed $N_2$ gas. Two sealed gamma sources of $^{137}Cs$ (E=0.662 MeV, ${\Gamma}$ $factor=0.326\;R{\cdot}h^{-1}{\cdot}m^2{\cdot}Ci^{-1}$) of 20 mCi and 17 mCi, and radiation detectors of $2"{\times}2"$ NaI(Tl) scintillation counter (Eberline, SP-3) were used for this study. Under the given conditions(the distance between two sources: 4D(D; inner diameter), N/S ratio: $0.12{\sim}0.15$, sampling time ${\Delta}t$: 4msec), the measured flow rates showed the maximum. relative error of 1.7 % when compared to the real ones through the vapor content corrections($6.1\;%{\sim}9.2\;%$). From a subsequent experiment, it was proven that the closer the distance between the two sealed sources is, the more precise the measured flow rates are. Provided additional studies related to the selection of radioisotopes their activity, and an optimization of the experimental geometry are carried out, it is anticipated that a radioisotope application for flow rate measurements can be used as an important tool for monitoring multi-phase facilities belonging to petrochemical and refinery industries and contributes economically in the light of maintenance and control of them.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.492-507
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• 2010

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.

• Food Science and Preservation
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• v.19 no.2
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• pp.249-256
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• 2012

The changes in the volatile organic compounds in plum after its electron beam irradiation and storage were determined using the simultaneous distillation extraction method and gas chromatograph-mass spectrometry. There were 44, 46, 45, 47, and 38 volatile compounds in the 0-, 0.25-, 0.5-, 0.75-, and 1 kGy irradiated samples, respectively. Also, the volatile flavor components of the plum that was stored for 30 days were identified as 48, 40, 40, 39, and 40 components. The compositions of the volatile compounds of the control and irradiated samples showed a similarity after the storage. Especially, the more important volatile flavor of the plum was identified as hexanal of the C6compounds, (E)-2-hexenal and (Z)-3-hexenal. In particular, hexanal, (E)-2-hexenal, and (Z)-3-hexen-1-ol increased in all the doses, where as hexanol and (E)-2-hexen-1-ol decreased. Among the lactone compounds, ${\gamma}$-hexalactone, ${\gamma}$-octalactone, and ${\gamma}$-decalactone were identified during the storage period in the raw samples. Hexanonic acid and 2-hexenoic acid were not identified during the storage of the samples, and 2-methylprrole was detected only when the storage samples were irradiated at a dose higher than 0.5kGy. Therefore, it was shown that there was no effect on the variation of the volatile organic component suntil 1 kGy in the plum was irradiated with an electron beam.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.390-399
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• 2016

Purpose: The objective of this study was to examine the effect of plant scale and cooking conditions on the quality characteristics of sausages during refrigerated storage. Methods: Sausages used in this study were classified into two groups: those submitted to $1^{st}$ cooked treatments and those submitted to $2^{nd}$ cooked treatments. The pH, volatile basic nitrogen (VBN), gas production ratio, and microorganisms were measured in triplicate. Results: The change of quality in the products was assessed every 7 days by measuring pH, VBN levels, total microbes, coliform bacteria, Escherichia coli, and pathogenic bacteria in the products. Pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens, and E. coli were not detected in the sausages with $1^{st}$ cooked treatments. The results showed that the pH of the sausages decline as storage time increased. The pH value of the sausages with $2^{nd}$ cooked treatments changed gradually. VBN levels were generally lower in products with $2^{nd}$ cooked treatments than in those with $1^{st}$ cooked treatments, but they varied with the type of products. On the $35^{th}$ day, the number of total microbes ranged between 6.13-7.12 log CFU/g in products with $1^{st}$ cooked treatments and 3.44-6.92 log CFU/g in products with $2^{nd}$ cooked treatments, showing fewer bacteria in the latter products. Conclusions: $1^{st}$ cooked treatments were effective in microbial control, but $2^{nd}$ cooked treatments could prolong the shelf life of the sausages, indicating a need for differential management of each product.

• Food Science and Preservation
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• v.8 no.3
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• pp.239-245
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• 2001

The CA(Controlled Atmosphere) storage of cherry tomatoes were carried out under seven gas compositions including air. The weight loss of cherry tomatoes progressively increased with storage time. In the case of cherry tomatoes stored under CA conditions, increment of weight loss was reduced. However, cherry tomatoes (in air) tut about 15% weight at the end of storage. In CA stored cherry tomatoes lost about 10% weight at the same time. General trend was a decrease in titratable acidity with storage time. In air md 6.4% O$_2$, 4.2% CO$_2$, titratable acidity was lower than that in other storage conditions. During storage of cherry tomatoes, soluble solids increased till 8 days of storage, and then decreased. Stored cherry tomatoes in air and 6.4% O$_2$+4.2% CO$_2$ have lower values. Lycopene contents of cherry tomatoes with 6% O$_2$ storage condition increased and cherry tomatoes with 1% O$_2$+6% CO$_2$ and 3% O$_2$+3.1% CO$_2$maintained s initial contents. In air, flesh firmness decrease till 8 days, and then increase. At 1% O$_2$+6% CO$_2$ ethanol contents were ten times to that of other experimental conditions. Air and 6% O$_2$+7.8% CO$_2$ condition had lowest value for the ethanol content. In changes of organic acid and citric acid decreased slowly during storage, malic acid in air and below 3% O$_2$was disappeared at 8 days. Above 4% O$_2$concentration malic acid contents were maintained till 16 days. In over all acceptability, air and 6.4% O$_2$+7.8% CO$_2$ condition took a good score from the panel. Quality of stored cherry tomatoes was not edible condition in 1% O$_2$+6% CO$_2$. CA storage cherry tomatoes took a good score in firmness and juiciness where as control received good score in color and sweetness. This result was explained that in air ad 6.4% O$_2$+7.8% CO$_2$stored cherry tomato was ripened and full color development, but in CA was break stage because of suppressed ripening.