• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.789-794
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• 2012

For the purpose of development of the latex suitable for polymer cement mortar, experiments on the preparation of carboxylated styrene butadiene latex by the method of the two-step emulsion polymerization were performed. Methyl methacrylate, methacrylic acid and acrylic acid were selected as carboxylic co-monomer, styrene and butadiene as monomer, sodium dodecylbenzene sulfonate and sodium salt of lauryl sulfonate as anionic emulsifiers, and nonylphenoxy poly (ethyleneoxy) ethanol (n=10, 20, 40) as latex stabilizer. Potassium persulfate and sodium bisulfite were also used as redox initiator, and sodium monohydrogen phosphate and potassium carbonate as electrolytes. The effects of categories and concentration of carboxylic co-monomer, molecular weight control agent, crosslinking agent, and styrene/butadiene monomer ratio on the characteristics of latex were investigated. Polymerization recipes for preparation of polymer cement mortar could be proposed. The prepared latexes were tested for the physical properties such as compressive and flexural strength when latexes were mixed with cement mortar. The results showed that the latex could be adapted to polymer cement mortar. Also, it was recognized that the compressive and flexural strength were exhibited 25.4% and 45.3% respectively higher improvement than the quality standards at 28 days curing time.

• The Plant Pathology Journal
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• v.36 no.4
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• pp.335-345
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• 2020

Tomato grey mould has been one of the destructive fungal diseases during tomato production. Ten mM of menadione sodium bisulfite (MSB) was applied to tomato plants for eco-friendly control of the grey mould. MSB-reduced tomato grey mould in the 3rd true leaves was prolonged at least 7 days prior to the fungal inoculation of two inoculum densities (2 × 10⁴ and 2 × 10⁵ conidia/ml) of Botrytis cinerea. Protection efficacy was significantly higher in the leaves inoculated with the lower disease pressure of conidial suspension compared to the higher one. MSB-pretreatment was not effective to arrest oxalic acid-triggered necrosis on tomato leaves. Plant cell death and hydrogen peroxide accumulation were restricted in necrotic lesions of the B. cinereainoculated leaves by the MSB-pretreatment. Decreased conidia number and germ-tube elongation of B. cinerea were found at 10 h, and mycelial growth was also impeded at 24 h on the MSB-pretreated leaves. MSB-mediated disease suppressions were found in cotyledons and different positions (1st to 5th) of true leaves inoculated with the lower conidial suspension, but only 1st to 3rd true leaves showed decreases in lesion sizes by the higher inoculum density. Increasing MSB-pretreatment times more efficiently decreased the lesion size by the higher disease pressure. MSB led to inducible expressions of defence-related genes SlPR1a, SlPR1b, SlPIN2, SlACO1, SlChi3, and SlChi9 in tomato leaves prior to B. cinerea infection. These results suggest that MSB pretreatment can be a promising alternative to chemical fungicides for environment-friendly management of tomato grey mould.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.435-440
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• 1989

The present study was attempted to investigate the mutagenicities of carbonyl compounds(methyl glyoxal, glyoxal, diacetyl, dihydroxyacetone, glycolaldehyde, glyceraldehyde and furfural) derived from Maillard reaction toward Salmonella typhimurium TA 100(base-substitution mutant) without metabolic activation . And for further Investigation of mutagenicity mechanism including desmutagenicity, active oxygen scavengers (cysteine, ${\alpha}-tocopherol$, tris (hydroxymethyl) aminomethane, catalase, ascorbic acid) and reducing agents (glutathione, sodium bisulfite) were also used. Among carbonyl compounds tested, methyl glyoxal, glyoxal, dihydroxyacetone, glycolaldehyde and glyceraldehyde exhibited mutagenicities, and methyl glyoxal showed the strongest mutagenic activity. On the other hand , the mutagenicities of carbonyl compounds were significantly suppressed by cysteine, tris (hydroxymethyl) aminomethane, glutathione and sodium bisulfite. Also, these active oxygen scavengers and reducing agents alone did not show mutagenicity in the present study.

• Tuberculosis and Respiratory Diseases
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• v.39 no.2
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• pp.159-166
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• 1992

Background:Sulfiting agents are widely used as preservatives and antioxidants in foods, beverages and drugs including bronchodilators. There have been reports of sulfite-related reactions such as anaphylaxis, urticaria, angioedema, abdominal discomfortness as well as bronchospasm. Several investigators reported that sulfite-sensitive asthmatic patients comprised from 3.9% to 8.2% of all asthmatic patients and its prevalence was higher in steroid-dependent group than in steroid-independent group. Subjects and Method:We performed oral provocation test with sodium bisulfite and aspirin in 17 asthmatic patients who have experienced aggravation of their symptoms after administration of drugs or foods. All of them were steroid dependent asthmatics. We observed clinical symptoms and steroid requirements from 1 to 18 months. Result:Ten of them showed severe bronchoconstriction after the ingestion of sodium bisulfite (50 to 200 mg) within 30 minutes. Concurrent aspirin intolerance was noted by oral provocation test in four cases (40%). Three of them showed positive responses on skin prick test with sulfite (10 or 100 mg/ml). Mean total eosinophil counts was $844/mm^3$ at asthmatic attack. And there was no significant responses on skin prick test and IgE-RAST to common inhalant allergens. After complete avoidance from sulfite containing foods and drugs as well as antiasthmatic medication for 1 to 18 months, nine of them (90%) could stop or reduce the steroid requirements. ConcIusion:It was suggested that severe steroid dependent and intrinsic type of asthmatic patients should be evaluated for sulfite-sensitivity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.309-309
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• 1994

DA-125에 당류로서 Inositol, Dextrose, Iactose, Mannitol 및 Sorbitol을 첨가하여 DA-125 단독으로 용해한 시료와 비교 평가하였을 때 DA-125의 안정성에 큰 영향이 없었으며, 아미노산 중 L-lysine첨가시 안정성이 향상되는 컷으로 나타났다. 염류를 사용하였을 때는 NaCl, MgSO$_4$첨가시 안정성이 크게 증가하였으며, NaCl의 첨가 농도에 따른 안정성을 시험한 결과 NaCl의 농도 증가에 따라 DA-125의 안정성이 증가하는 것으로 나타났다. 또한 기타 안정화제로 Sodium Bisulfite 첨가시 안정성이 증가되었다. 안정성 시험 중 pH및 용액상태는 변화하지 않았다.

• Journal of the Korean Applied Science and Technology
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• v.18 no.2
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• pp.95-102
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• 2001

Recently, there has been considerably interested in the development to new functional gemini type anionic surfactant, sodium bis-n-alkyl sulfonatosuccinate, had been synthesized through the addition reaction of sodium bisulfite to bis-n-alkyl maleate, in which water was azeotropically distilled by adding benzene to the reaction system, gave a good yield. All the surface activities including krafft point, surface tension, emulsion power and foaming were measure and cmc was evaluated in dilute solution. This results showed a lower ability in $27{\sim}30dyne/cm$ than single-chain surfactant with $32{\sim}35dyne/cm$ to surface tension. Also its cmc value much smaller in $(6.5{\sim}10){\times}10^{-4}mca{\ell}/{\ell}$ than single-chain surfactant with $(40{\sim}45){\times}10^{-4}mca{\ell}/{\ell}$ concentration. In foaming ability and foam stability of gemini surfactant had especially a good ability in approximately $100{\sim}150ml$, and in emulsing power they exhibited a good emulsing phase and stability, and Krafft points were $0{\sim}10^{\circ}C$.

• Food Science and Preservation
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• v.15 no.6
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• pp.791-795
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• 2008

In order to establish the method to prepare and use the sulfur dioxide gas generating agent in low temperature storage of grape fruits, the $SO_2$ generation capacity from various sulfite compounds was investigated, and the method to regulate $SO_2$ gas generation and to detect the gas was developed. The conidial germination and mycelium growth of Botrytis cinerea which causes gray mold disease during grape fruit storage was completely inhibited at the $SO_2$ gas concentration of 400 ppm and 3200 ppm, respectively. Sodium hydrosulfite generated the most amount of $SO_2$ gas among the investigated 5 different sulfite or bisulfite compounds. By adjusting the number of pinholes on packaging film of the compound or by adding pH adjusting agent, e.g. citric acid or phosphates, it was possible to regulate the amount and duration of $SO_2$ gas generation from the compound. Because malachite green was quantitatively discolored by $SO_2$ gas, the solution or impregnated paper with the compound could be practically utilized as a indicator detecting $SO_2$ gas. Finally, when Muscat Bailey A grape was stored at low temperature with $SO_2$ gas generating agent, the disease incidence was reduced after storage.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.331-338
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• 1988

Acetone powder was prepared from raw arrowroots and the polyphenol oxidases of crude enzyme prepared from acetone powder were identified 5 isoenzymes by staining with catechol containing 0.05% phenylene diamine. The crude enzyme was passed through the columns of ion exchangers and gel permeation to fractionate the polyphenol oxidases. The main fraction of polyphenol oxidase appeared to be purified by 94-fold, with the activity yield of 45.4%, and its molecular weight was determined as 38,500 by poly acrylamide gel electrophoresis. The optimal pH and temperature for the enzyme activity were pH 7.5 and $50^{\circ}C$, respectively. The purified enzyme showed a high affinity for catechol and pyrogallol. The Michaelis constant for catechol was calculated to be 16.67mM according to the Lineweaver-Burk method. The enzyme activity was strongly inhibited by L-ascorbic acid, sodium bisulfite, EDTA and KCN, and totally inhibited, by $Fe^{3+}$ at a concentration of 1mM. However the enzyme was activated by $Zn^{2+}$ approximately 1.7 times at the same concentration.

• Korean Journal of Microbiology
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• v.29 no.4
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• pp.238-242
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• 1991

Extracellular laccase secreted from Pleurotus ostreatus was activated by $Cu^{2+}$ and $Cu^{+}$ . The enzyme was strongly inactivated by 8-hydroxyquinoline, potassium cyanide, sodium azide, sodium bisulfite and 2-mercaptoethanol. The two ionogenic groups, which have pKa values of 5.60-5.70 and 6.70-6.85 respectively, were found to relate with the active site of this enzyme. The oxidation reactions were brought about by initial single electron transfer process on the active site. The enzyme was found to be a metalloprotein which had about 3.9 cupric ions per molecule of protein as a prosthetic group. The enzyme showed a strong peak at 605 nm and a weak shoulder at 330 nm in UV-Visible absorption spectrum. Both signals disappeated upon treatment of the enzyme with 4 electron equivalent ascorbate. These results indicate that type I Cu peak and type III Cu shoulder are present in laccase.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1048-1056
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• 2002

Quality of fresh ginger deteriorates rapidly during low temperature storage, and its storage life is short due to sprouting and microbial spoilage. The objectives of this research were to develop, using additives, a minced ginger product, which could maintain acceptable quality for over 30 days, and to investigate its quality changes during the cold storage. Storage stability of minced ginger product was investigated from the standpoint of the inhibition of brown discoloration, gas formation and liquid-solid separation. Fresh ginger was peeled and ground to produce minced ginger (control). Sodium bisulfite, L-cysteine, NaCl, sodium benzoate, modified starch, and/or xanthan gum were added to the control to minimize quality loss during storage, and to develop an optimum formula (A) of minced ginger. Samples were packed in Nylon/PE films, stored at $5^{\circ}C$, sampled at a 30-day interval, and subjected to quality evaluations. Changes in pH, surface color, gas formation, liquid-solid separation, contents of free amino acids, free sugars, organic acids, and fatty acids were determined. Gas formation was effectively inhibited in samples with sodium benzoate and/or NaCl. Samples with xanthan gum did not result in liquid-solid separation. L-Cysteine and sodium bisulfite were effective in controlling discoloration. pH decreased during storage in all samples, except sample A. Organic acid contents of all samples increased during storage, with lactic acid content showing the highest increase. Free amino acid content decreased with increasing storage time. Free sugar content of all samples decreased during storage. Sensory results showed sample A maintained acceptable quality until 90 days of storage. These results suggest that quality of minced ginger could be successfully maintained with the additions of selected additives for up to 90 days.