• Journal of Food Hygiene and Safety
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• v.2 no.1
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• pp.21-27
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• 1987

ABS1'RACT-Comparative effects of gamma irradiation and ethylene oxide treatment on the sterilization, and physicochemical and sensory quality of dried marine products(shrimp, anchovy) were investigated. Population of mesophilic total bacteria, aerobic spores and tolerant bacteria of samples were $10^{3}-10^{7}/g,\;10^{7}\;to \;10^{4}/g\;and\;10^{2}\;to\;10^{6}/g$, respectively. Coliforms and molds were found only in dried shrimp as $10^{2}/g$. Mesophilic total bacteria, aerobic spores and acid tolerant bacteria were reduced by over 2 to 4 log cycles with irradiation of 5 to 7 kGy and they were completely sterilized by irradiation dose of 7 to 10 kGy. $D_{10}$ value of mesophilic total bacteria of samples ranged from 1.53 to 2.73 kGy. Coliforms and molds were sterilized at 5 to 7 kGy irradiation but ethylene oxide treatment proved insufficient to eliminate the microorgainsms. An optimum dose of irradiation was less detrimental than ethylene oxide treatment to phpicochemical properties of the samples, such as the pH, TBA value, TMA-N, amino acids, minerals and color difference. Sensory quality after three months of storage showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as ethylene oxide treated samples.amples.

• Food Science and Preservation
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• v.12 no.6
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• pp.511-515
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• 2005

The responses of 'Tsugaru' apple and 'Baekhyang' peach fruits treated with 1-MCP, the ethylene inhibitor, were compared. In Tsugaru apple fruits, the reduction of flesh firmness and titratable acidity were significantly retarded for 2 weeks by the treating fruits with 1 or 5 ppm of 1-MCP immediately after harvest The respiration decreased continually for 2 weeks and the onset of ethylene production were also retarded severely. However, in Baekhyang peach fruits, the effects of 1-MCP treatment on the respiration and ethylene production were only transient and the firmness reduction was retarded slightly by the repeated 1-MCP treatments. The responsiveness of the Baekhyang peach fruits on ethylene seems to be recovered rapidly after 1-MCP treatment. In case of Baekhyang fruits, the 1-MCP should be treated repeatedly for effective ethylene inhibition, and the ethylene accumulation should be avoided during the 1-MCP treatment.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.577-585
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• 2014

A series of experiments using atmospheric-pressure non-thermal plasma coupled with transition metal catalysts were performed to remove ethylene from agricultural storage facilities. The non-thermal plasma was created by dielectric barrier discharge, which was in direct contact with the catalyst pellets. The transition metals such as Ag and $V_2O_5$ were supported on ${\gamma}-Al_2O_3$. The effect of catalyst type, specific input energy (SIE) and oxygen content on the removal of ethylene was examined to understand the behavior of the hybrid plasma-catalytic reactor system. With the other parameters kept constant, the plasma-catalytic activity for the removal of ethylene was in order of $V_2O_5/{\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ from high to low. Interestingly, the rate of plasma-catalytic ozone generation was in order of $V_2O_5/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$, implying that the catalyst activation mechanisms by plasma are different for different catalysts. The results obtained by varying the oxygen content indicated that nitrogen-derived reactive species dominated the removal of ethylene under oxygen-lean condition, while ozone and oxygen atoms were mainly involved in the removal under oxygen-rich condition. When the plasma was coupled with $V_2O_5/{\gamma}-Al_2O_3$, nearly complete removal of ethylene was achieved at oxygen contents higher than 5% by volume (inlet ethylene: 250 ppm; gas flow rate: $1.0Lmin^{-1}$; SIE: ${\sim}355JL^{-1}$).

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.83-87
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• 2000

Carnation petals exhibit autocatalytic ethylene production and wilting during senescence. The autocatalytic ethylene production is induced by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes, whereas the wilting of petals is related to expression of the cysteine proteinase (CP) gene. Until recently, it has been believed that these two phenomena, autocatalytic ethylene production and wilting, are regulated in concert in senescing carnation petals, since the two phenomena occurred closely in parallel. Our studies with petals of a transgenic carnation harboring a sense ACC oxidase transgene and petals of carnation flowers treated with 1,1-dimethyl-4-(phenylsulfonyl) semicarbazide showed that the expression of ACC synthase and ACC oxidase genes and that of CP are regulated differently in carnation psanetals. Interestingly, in the petals of transgenic carnation, the transcript for CP was accumulated but the transcripts for ACC synthase and ACC oxidase were not accumulated in response to exogenous ethylene. Based on these results, we hypothesized that two ethylene signaling pathways, one leading to the expression of ACC synthase and ACC oxidase genes and the other leading to the expression of CP gene, are functioning in senescing carnation petals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2550-2558
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• 2013

Poly(o-hydroxyamides)(PHAs) copolymers having oligo(oxy ethylene) pendant in the main chain were synthesized by solution polycondensation reaction at low temperature. Copolymer precursors were studied by fourier transform infrared(FT-IR), differential scanning calorimeter(DSC), thermogravimetric analyzer(TGA), universal testing machine(UTM) and limited oxygen index(LOI). The inherent viscosities of the PHAs measured at $35^{\circ}C$ in DMAc or DMAc/LiCl solution were in the range of 0.74~1.42 dL/g. Solubility of the precursors with higher oligo(oxy ethylene) unit was increased, but the PBOs were nearly insoluble in a variety of solvents. The degradation temperature of the copolymer precursors was recorded in the ranges of $408{\sim}664^{\circ}C$ in nitrogen and char yields showed 13~59% values at $900^{\circ}C$. The mechanical properties and flame retardancy of copolymer precursors decreased with higher oligo(oxy ethylene) unit.

• Elastomers and Composites
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• v.36 no.1
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• pp.14-21
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• 2001

To increase the properties of EVA foam such as tensile strength, rebound resilience, and compression set, ethylene-1-butene copolymer (EtBC) was blended with EVA. After that crosslink characteristics of the blends and cell structures and mechanical properties of the foam were studied. As the amount of EtBC increased in EVA/EtBC blends, torque values of oscillating disc rheometer(ODR) increased and the foaming ratio decreased because the viscosity and crosslink density of EVA/EtBC blends increased. Foaming ratio and cell size of the foam increased by increasing the amount of foaming agent. When compared the mechanical properties of the foam which have same densities, tensile strength, rebound resilience, and compression set properties of the foam were improved by increasing the amount of EtBC in the EVA/EtBC blends.

• Journal of Plant Biology
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• v.35 no.4
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• pp.409-414
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• 1992

Effect of quercetin, a kind of natural plant flavonoids, on auxin-induced ethylene production in barley coleoptiles was studied. Auxin-induced ethylene production was apparently stimulated by quercetin. This stimulatory effect of quercetin appeared after 4 h of incubation period. Ethylene production was stimulated 200% over the control after 8 h of incubation by $3{\times}10^{-5}\;M$ quercetin. The quercetin effect was most prominent at $10^{-4}\;M$ of IAA. Ethylene production induced by the synthetic auxin, 2,4-D and NAA, was not significantly affected by quercetin. Also ACC-based ethylene production was unaffected by the flavonoid. In an effort to elucidate mechanisms of quercetin action on auxin-induced ethylene production, the effect of quercetin on 1M metabolism was studied. Data obtained from these experiments indicate that quercetin treatment resulted in about 90% inhibition of IAA oxidase activity. IAA ($3{\times}10^{-5}\;M$) conjugation was found to be not affected by quercetin. This results suggest that the stimulatory effect of quercetin on auxin-induced ethylene production may be due to the fact that quercetin inhibits 1M oxidase activity, thus increasing the free IAA level.

• Tribology and Lubricants
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• v.28 no.6
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• pp.315-320
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• 2012

For proper functioning, general machines usually need lubricant oil as a cooling, cleaning, and sealing agent at points of mechanical contact. The quality of lubricant oil can deteriorate during operation owing to various causes such as high temperature, combustion products and extraneous impurities. In this study, a heavy load stopped during operation, and the oil was analyzed to check whether any impurities were added. Extraction using acetonitrile followed by reaction with BSTFA(bistrimethylsilyl trifluoroacetamide) showed that, trimethylsilylated ethylene glycol was present in the lubricant oil. To quantify the ethylene glycol in the oil, deuterium-substituted ethylene glycol, which acted as an internal standard, was added to the sample and then extracted with the solvent. Next, the extract was reacted with the derivatizing agent(BSTFA) and then analyzed with GC/MS. The detection limit of this method was found to be $0.5{\mu}g/g$ and the recovery of oil containing $20,000{\mu}g/g$ of ethylene glycol was measured to be 94.8%. A damaged O-ring and eroded cylinder liner were found during the overhaul, which implied the leakage of coolant containing ethylene glycol into the lubricating system. The erosion of the cylinder liner was assumed to be due to cavitation of the coolant in the cooling system.

• Molecules and Cells
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• v.41 no.10
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• pp.923-932
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• 2018

Ethylene regulates numerous aspects of plant growth and development. Multiple external and internal factors coordinate ethylene production in plant tissues. Transcriptional and post-translational regulations of ACC synthases (ACSs), which are key enzymes mediating a rate-limiting step in ethylene biosynthesis have been well characterized. However, the regulation and physiological roles of ACC oxidases (ACOs) that catalyze the final step of ethylene biosynthesis are largely unknown in Arabidopsis. Here, we show that Arabidopsis ACO1 exhibits a tissue-specific expression pattern that is regulated by multiple signals, and plays roles in the lateral root development in Arabidopsis. Histochemical analysis of the ACO1 promoter indicated that ACO1 expression was largely modulated by light and plant hormones in a tissue-specific manner. We demonstrated that point mutations in two E-box motifs on the ACO1 promoter reduce the light-regulated expression patterns of ACO1. The aco1-1 mutant showed reduced ethylene production in root tips compared to wild-type. In addition, aco1-1 displayed altered lateral root formation. Our results suggest that Arabidopsis ACO1 integrates various signals into the ethylene biosynthesis that is required for ACO1's intrinsic roles in root physiology.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.9-17
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• 1993

Postharvest treatments such as polyethylene film wrapping, ethylene scrubber, and fruit coatings were compared to find a potential effect on the fruit quality in 'Fuji' apples during storage and simulated marketing. Polyethylene film wrapping appeared to be excellent in preventing weight loss during storage but fruits lost weight at a high rate when exposed to ambient temperature during simulated marketing. Also, surface cracking disorder was observed in parts of film-wrapped fruit under marketing condition after storage of 21 weeks. Ethylene scrubber effectively removed ethylene in polyetheylene bags but this effect reduced along with the increase of storage time. Although Prolong-treated fruits were good in appearance at 12-week storage, no beneficial effect was found on the inhibition of weight loss during storage as well as marketing. In addition, wax-like substances were accumulated on the surface after storage of 21 weeks, resulting in the reduction of marketability. Water soluble wax seemed highly effective on the inhibition of weight loss during storage and marketing. However, parts of fruit were severely injured probably due to the high concentration of wax. Undamaged fruit showed excellent appearance in shape and flesh quality even after 21 weeks of storage. Further study is required to find the proper concentration of wax.