• Journal of the East Asian Society of Dietary Life
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• v.23 no.5
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• pp.654-661
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• 2013

The current research is designed to analyze sterilization effects on mulberries in terms of storage temperature and storage period after treating with tap water (TW), electrolyzed water (EW) and aqueous chlorine dioxide ($ClO_2$). The treated $ClO_2$ concentrations are 10, 50, 100 and 200 ppm. In each concentration, the mulberries are soaked for 30 seconds respectively. The sterilization effects are being compared at room temperature ($25^{\circ}C$) and at $4^{\circ}C$, respectively. And the enzyme activity related to quality is also being investigated and analyzed about for browning inhibition effects. Microbial sterilizing power increases more in treating plots with EW and $ClO_2$ than treating plot with TW. Futhermore sterilizing power of $ClO_2$ increased sharply on high concentration treatment plot as well. Sterilization effects of $ClO_2$ during storage time are better at cold temperature. Pictures taken from scanning electron microscope reveal that there are no microbes in sterilizing solutions treatment plots. From measurement of the enzyme activity, it is concluded that activities decrease more in sterilizing solutions treatment plots as comparing with TW treated plot during the time. The amount of total polyphenolics decrease with the time passing and EW and $ClO_2$ treatment shows less contents than TW treatment. Thus, EW and $ClO_2$ treatment of mulberris are considered as method to improve safety by reducing total plate count and to contribute to quality maintenance and to extend storage time.

• Korean journal of applied entomology
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• v.55 no.1
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• pp.27-33
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• 2016

Chlorine dioxide has been used as a disinfectant against microbial pathogens. Recently, its insecticidal activity has been known against stored insect pests by oxidative stress. However, any molecular target of the oxidative stress induced by chlorine dioxide has been not known in insects. This study assessed an enzyme activity of acetylcholinesterase (AChE) as a molecular target of chlorine dioxide in the Indianmeal moth, Plodia interpunctella. AChE activities were varied among developmental stages of P. interpunctella. Injection of chlorine dioxide with lethality-causing doses significantly increased AChE activity of the fifth instar larvae of P. interpunctella. Exposure of the larvae to chlorine dioxide fumigant also significantly increased AChE activity. The fifth instar larvae of P. interpunctella exhibited a negative phototaxis. However, chlorine dioxide treatment significantly interrupted the innate behavior. These results suggest that AChE is one of molecular targets of oxidative stress due to chlorine dioxide in P. interpunctella.

• Food Science and Preservation
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• v.13 no.4
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• pp.421-426
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• 2006

Preservation stability of the extract from dried green tea produced in Jeju, extracted at $55^{\circ}C$ for 15 min and bottled in PET container after filtration and then settled at $4^{\circ}C$, indoor at room temperature and outdoor, respectively, was estimated. Color L-value was almost constant but color of the extract became darkened during storage, especially in indoor storage. Main catechins of green tea extract were (-)-epigallocatechin, (-)-epigallocatechin gallate, epicatechin, (+)-catechin, epicatechin gallate in order, and the content of epigallocatechin was 53.8%. Nevertheless total catechin content was not changed in cold storage, and $4.7\sim10%$ of total catechins were reduced in outdoor or indoor storage after 14 weeks. Caffeine content were increased but total polyphenols were not changed largely during storage. Election donating abilities (EDA) showed more than 60% without influence of storage conditions and periods. Nitrite scavenging abilities (NSA) showed more than 90% at pH 1.2, but those were decreased gradually as pH increased, and then disappeared at pH 6.0. Color, polyphenols, antioxidant activities of extract were not so changed for more than 3 months. Microbial growth was not shown during same periods, due to heat treatment of the extracts at $95^{\circ}C$ for 10 min.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.147-151
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• 2005

Retort pouch is widely used in food industry for a long-term preservation and safe food production. By applying retort pouch technique to waxycorn storage, the quality of waxycorn could be maintained and the storage expense could be saved during storage. Water activities(Aw) of retort waxycorn were below 0.80 except blanching treatment, and it is known that microbial propagation is subdued below 0.80. Commercial value of waxy corn was deteriorated when it was frozen quickly at $-40^{\circ}C$ before treating Retort due to obscurity of chromatocity, while the color change was not noticeable when it was treated with Retort at $121^{\circ}C$ for 10min. For all treatments, very small amounts of free sugar were detected, however, there were no significant differences between treatments. As storage period was longer, shelf lifes of waxy corn in control and waxy corn treated with blanching were more shortened when waxy corn was stored at $15,5^{\circ}C$ before Retort, while waxy corn with boiling treatment was not significantly different compared with that in storage in freezer.

• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.177-182
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• 2020

Copper possesses antimicrobial properties against certain bacteria and fungi. In this study, changes in microbial population, color and the antioxidant properties of dried red pepper powder (RPP) by contact with the surface of a copper plate were investigated. Lightness of RPP increased after treatment on the copper plate for 2 h at 55℃. The numbers of total aerobic mesophilic bacteria in RPP increased by 0.61 and 0.50 log on the surface of stainless steel and copper plates during 24 h at 37℃, respectively. The population of yeast and mold was reduced by 90% in the RPP treated on both copper and stainless steel plates under the same condition. Yeast and mold were significantly reduced on the copper plate during 2 h at 55℃. Scavenging activities of RPP treated on the copper plate for 24 h at 37℃ against DPPH radical were decreased; those for 2 h at 55℃ against ABTS radical were rather enhanced. The results suggest that copper might be applied in the processing and storage equipment in relation to RPP products for antimicrobial purposes.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.357-364
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• 2014

The study evaluated replacement of Egyptian berseem clover (BC, Trifolium alexandrinum) with spent rice straw (SRS) of Pleurotus ostreatus basidiomycete in diets of lactating Baladi goats. Nine lactating homo-parity Baladi goats (average BW $23.8{\pm}0.4$ kg) at 7 d postpartum were used in a triplicate $3{\times}3$ Latin square design with 30 d experimental periods. Goats were fed a basal diet containing 0 (Control), 0.25 (SRS25) and 0.45 (SRS45) (w/w, DM basis) of SRS. The Control diet was berseem clover and concentrate mixture (1:1 DM basis). The SRS45 had lowered total feed intake and forages intake compared to Control. The SRS25 and SRS45 rations had the highest digestibilities of DM (p = 0.0241) and hemicellulose (p = 0.0021) compared to Control which had higher (p<0.01) digestibilities of OM (p = 0.0002) and CP (p = 0.0005) than SRS25 and SRS45. Ruminal pH and microbial protein synthesis were higher (p<0.0001) for SRS25 and SRS45 than Control, which also had the highest (p<0.0001) concentration of TVFA, total proteins, non-protein N, and ammonia-N. All values of serum constituents were within normal ranges. The Control ration had higher serum globulin (p = 0.0148), creatinine (p = 0.0150), glucose (p = 0.0002) and cholesterol (p = 0.0016). Both Control and SRS25 groups had the highest (p<0.05) milk (p = 0.0330) and energy corrected milk (p = 0.0290) yields. Fat content was higher (p = 0.0373) with SRS45 and SRS25 groups compared with Control. Replacement of BC with SRS in goat rations increased milk levels of conjugated linoleic acid and unsaturated fatty acids compared with Control. It was concluded that replacing 50% of Egyptian berseem clover with SRS in goat rations improved their productive performance without marked effects on metabolic indicators health.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.313-318
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• 2010

Deinococcus radiodurans RecA protein, when bound to DNA, exhibits a DNA-dependent ATPase. In the absence of DNA, the rate of RecA protein-promoted ATP hydrolysis drops 1,000-fold under the physiological concentrations of salt. This DNA-independent activity can be stimulated to levels approximating those observed with DNA by adding high concentrations (approximately 1.6 M) of a wide variety of salts. This effect was characterized by varying salt concentration and comparing the effects of different ion types. The higher concentrations of salt stimulated the ATP hydrolysis by RecA protein in the absence of DNA. At 1.6 M chloride, the observed stimulation showed the following cation trend $K^+{\geq}Na^+$ > $NH_4^+$ and the following anion sequence was observed: $glutamate^- \; > \; C1^- \;> \; acetate^-\; > \;PO_4^-$ at 1.6 M $K^+$. The catalytic properties of the salt-stimulated ATP hydrolysis reaction was optimal between pH 7.0 and 8.0, which was similar to the double stran nded DNA-dependent ATPase activities of Deinococcus radiodurans RecA protein. In the absence of DNA the active species for ATP hydrolysis by RecA protein was shown to be an aggregate of three RecA protein molecules.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.32-40
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• 2009

To understand contribution of thermophilic microorganisms in decomposition of litter deposits on shore of lakes, we surveyed a lakeshore litter deposit for bacteria growing at $60^{\circ}C$. Ten thermophilic isolates were selected for in-depth characterization, based on their high capacity to degrade high molecular weight organic compounds. Based on phylogenetic analysis on their 16S rRNA gene sequences, all isolates were identified as Geobacillus. The optimal growth temperature and pH of the strains ranged $55{\sim}60^{\circ}C$ and 6.0${\sim}$8.0, respectively. Salinity was inhibitory to the growth of the isolates, showing marked decrease of growth rates at 3% salinity. Based on activities of hydrolytic enzymes and profiles of carbohydrate utilization (determined by API 50 CHB kit), three G. stearothermophilus strains showed patterns clearly distinctive from other isolates. Two G. kaustophilus strains also demonstrated distinctiveness in their metabolic pattern and ecological parameters. However, ecological and metabolic profiles of the other five isolates were more variable and showed some degree of digression from their phylogenetic classification. Therefore, it could be concluded that endospore-forming thermophilic bacteria in lakeshore litter deposits contribute to degradation of organic materials with diverse ecological niches while having successions similar to microbial flora in compost. We propose that the thermophilic isolates and/or their thermo-tolerant enzymes can be applied to industrial processes as appropriate mixtures.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.350-357
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• 2013

Lichens are symbiotic organisms composed of fungi, algae, or cyanobacteria which are able to survive in extreme environmental conditions ranging from deserts to polar areas. Some lichen symbionts produce a wide range of secondary metabolites that have many biological activities such as antibacterial, antifungal, antiviral, antitumor, antioxidant and anti-inflammatory etc. Among the symbionts of lichens, of the bacterial communities of lichen symbionts little is known. In this study, we isolated 4 microbial species from the Arctic lichen Stereocaulon spp. and evaluated their antioxidant properties using 1,1-diphenyl-2-picryl-hydrazyl assay as well as 2,2'-azino-bis(3-ethyl benzothiazoline-6-sulphonic acid) assay. Total phenolic contents and total flavonoid contents were also measured. A potent radical scavenging activity was detected in a number of the lichen extracts. Among the 4 species tested in this study, the ethyl acetate extract of Bosea vestrisii 36546(T) exhibited the strongest free radical scavenging activity, with an inhibition rate of 86.8% in DPPH and 75.2% in ABTS assays. Overall, these results suggest that lichen-bacteria could be a potential source of natural antioxidants.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.301-301
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• 2009

겨울철 농경지 이용율 제고 및 자연경관 조성을 위하여 녹비작물을 재배하는 면적이 지속적으로 증가하고 있는 추세이다. 그 동안 녹비작물에 대한 연구는 주로 파종적기, 작물에 대한 양분공급효과 및 타감 효과 등에 집중되어왔다. 본 연구에서는 토양 중 양분공급 및 미생물활성의 경시적 변화, 잡초억제 및 작물생육에 대한 녹비작물의 투입효과를 알아보기 위하여 수행하였다. 국립농업과학원 구내포장에서 2007년 9월 하순에 헤어리베치(8kg/10a)와 호밀(10kg/10a) 종자를 파종한 후, 이듬해 4월 하순에 수확하여 토양에 환원하였다. 질소공급량은 화학비료(15.2kgN/10a) 대비 헤어리베치(32.2kg/10a, 212%), 호밀(9.2kg/10a, 60%) 및 헤어리베치+호밀(15.5kg/10a, 102%)로 헤어리베치의 질소공급효과가 매우 높았다. 토양 무기태질소 함량은 녹비 처리 후 30일경에 최대에 도달하였으나, 호밀 처리구는 조사기간 동안 큰 변화가 없었다. 토양 유기물 함량의 변화는 시험 전(10DBI)과 비교하여 큰 차이를 보이지 않았으나, 녹비환원 후 10일경에 일시적으로 감소하는 경향을 보였는데 이는 녹비환원 후 토양경운에 의한 영향으로 판단되며, 무기태질소와는 달리 호밀처리구의 유기물함량이 지속적으로 증가하는 경향을 보였다. 토양 탄수화물(수용성 당)은 시험 전에 가장 높았으며, 시간의 경과와 함께 서서히 감소되는 양상을 보였으며 토양 미생물탄소 및 미생물질소의 양은 녹비처리구가 화학비료 처리구에 비해 높았으며 녹비환원 후 50일 까지는 증가하다가 그 이후에 감소하는 경향을 보였는데 이는 토양의 무기태질소 및 탄수화물과 밀접한 관계가 있는 것으로 판단되었다. 녹비처리 후 85일경에 잡초발생량을 조사한 결과, 화학비료 처리구에 비하여 헤어리베치 처리구는 40%, 호밀 처리구는 68%, 헤어리베치+호밀 처리구는 40%의 잡초억제효과가 있었다. 고추과의 수량은 화학비료 처리구(702kg/10a)>헤어리베치(694kg>10a)>헤어리베치+호밀(361kg/10a)>호밀(179kg/10a)의 순으로 나타났다.