• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.17-22
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• 1977

In the present paper, the effect of sodium sulfite treatment on tile inhibition of browning reactions occurring in the storage of dried oyster was tested and the supplementary effect of antioxidantsaddedwasalsomentioned. Dried oysters treated with sodium sulfite solutions as described in the previous paper(Lee and Choi, 1977) were stored in the bottles with silica gel bags at room temperature with or without the application of antioxidants. The ethanol solution of an antioxidant mixture(BHA, BHT, plus, synergists) was sprayed on the surface of cooked oyster before drying. The density of brown pigment was determined spectrophotometrically by measuring the absorbance at 420 and 440 nm of both fractions of pigment extract, namely chloroform-methanol and water soluble fractions, which represent the brown color developed by fat oxidation and Maillard reactions respectively. TBA value was also measured for the oxidative rancidity in oysters during the storage. It appeared from the results that the 0.5 M sodium sulfite-60minute treated samples showed better effect after 150 day storage at room temperature. Controlling tile pH of treating solutions, did not reveal so much different in inhibitory effect in the aspect of color but a more reduction of tyrosine and reducing sugar was resulted with acidic solution than with alkaline solution. The development of brown color in dried oyster seemed to be leaded rather by the oxidative rancidity of lipids than sugar-amino reactions particularly in a long-term storage since the browning of chloroform-methanol fraction progressed more rapidly than of water. soluble fraction. The application of antioxidant, therefore, could largely retard the browning of the product as appeared in the results that sodium sulfite treated oyster with addition of antioxidant kept the best color during the storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.198-204
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• 1988

This study was aimed at obtaining elementary data on enzymatic browning of potato and potato products and examining the inhibitory method of browning. Therefore, we extracted polyphenol oxidase from potatoes(Solanum tubersum L.), and investigates its general properties and inhibiting effects of its activity with the different concentrations of sulfites($Na_2S_2O_4,\;Na_2SO_3{\cdot}7H_2O,\;NaHSO_3$). The optimum pH and temperature of polyphenol oxidase were observed to be 6.5 and $37^{\circ}C$ respectively. The polyphenol oxidase at PH5 was very stable, and the activity of polyphenol oxidase between pH $5.0{\sim}9.0$ was estimated to be relatively high, showing $72{\sim}75%$ of its activity at pH5. The polyphenol oxidase was very stable when heated at $40^{\circ}C$ for one hour, and almost 50% of enzyme activity was decreased when heated at $70^{\circ}C$ for twelve minutes. At 0.1mM concentrating of sulfites the relative activity of polyphenol oxidase was 98% in all the three cases of sulfites. Thus sulfites at 0.1mM concentration was found to have little inhibiting effect on polyphenol oxidase activity. At 1mM concentration of sulfites $NaHSO_3$ showed the lowest 36% relative activity among the three. At 5mM concentration of sulfites, the relative activity of $Na_2SO_3{\cdot}7H_2O$ was the lowest 14%.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.274-277
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• 1998

The study was focused to investigate the effect of nitrosodimethylamine (NDMA) formation due to nitrosamine (NA) precursor and/or inhibitor addition to Kimchi during the fermentation of Kimchi at room temperature ($16{\pm}2^{\circ}C$). The addition of nitrite and dimethylamine (DMA) to Kimchi showed the average 32-fold ($21.3{\sim}113.9\;\mu\textrm{g}/kg$) and 9-fold ($1.3{\sim}40.3\;\mu\textrm{g}/kg$) higher NDMA formation than control ($O{\sim}5.6\;\mu\textrm{g}/kg$), respectively. Also, the addition of both nitrite and DMA resulted in the increase of NDMA formation to average 42-fold ($39.4{\sim}155.7\;\mu\textrm{g}/kg$) higher than control. On the other hand, the addition of 4 ruM ascorbic acid to Kimchi with nitrite and DMA inhibited the formation of NDMA down to 71.3% of control. However, the addition of cysteine and erythorbic acid affected no inhibition to NDMA formation during the test. The addition of sodium sulfite increased NDMA formation. Accordingly, this showed that the amount of ascorbic acid generated during Kimchi fermentation played an important inhibition role for NA formation.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1028-1032
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• 2003

To assess accurate methods for measuring sulfur dioxide residue in pickles, the acid distillation HPLC-UV method and Monnier Willams modified method were examined. By the acid distillation HPLC-UV method, sulfites released from pickles by acid distillation were absorbed in 1% triethanolamine solution and detected as sulfite ion by HPLC with UV monitoring at 240nm. An anion exchange column was employed with 1.8mM $Ma_2CO_3-1.7mM\;NaHCO_3$ solution as a mobile phase, $84.0{\sim}91.7%$ of sulfite added to pickled radish were recovered. Total sulfite levels from 48 kinds of pickles analyzed by acid distillation HPLC-UV was compared with those analyzed by the Monnier Williams modified method. The Monnier Williams modified method showed higher levels of sulfur dioxide than the acid distillation HPLC-UV method due to the presence of volatile acids in pickles. The concentration of sulfur dioxide was in the range of $N.D{\sim}173.05ppm$ in pickled radish and over 30ppm of sulfur dioxide from 3 samples by the acid distillation-HPLC-UV method.

• Applied Biological Chemistry
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• v.19 no.1
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• pp.51-56
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• 1976

Chemical changes of dissolved $SO_2$ were followed in vitro system. Varying concentrations of sulfite solution reached similar Eh values 20 hours after preparation. No further increase of Eh values occurred in acidic solutions. Eh values were more greatly increased in neutral solutions than in alkaline solutions, and slightly higher in light than in dark. The decrease of measurable $SO_2$ content tended to be greater with increasing concentrations of sulfite, on exposure to light, and at higher pH values. A larger amount of hydrogen atoms was produced with higher concentrations of $SO_2$ and in neutral to alkaline solutions than in acidic solutions.

• Cross-Cultural Studies
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• v.37
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• pp.185-209
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• 2014

This paper is a study on The Korea Magzine. The magazine has a series. One of them is KOREA'S NOTED WOMEN. This is the women who are all Chinese women. They are Yo-WHA-SI(여와씨), A-WHANG, YU-YUNG(아황과 여영), T'AI-IM AND T'AI-SA(태임과 태사), WANG SO-KOON(왕소군), Su Wang Mo(서왕모), Yang Kwi-pi(양귀비), SU-SI(서시), TAK MOON-KOON(탁문군). The story of the women in the magazine were studied in a series of articles of reasons. First, it is because the Chinese women living in the hearts of Koreans. Second, the Koreans because these women want to love passionately, and be like. Third, because the Chinese women was also well-known in Korea as well known in East Asia. Was This series is used in any way. Features shown in the description was investigated. It explains how to understand what they Korea. Deliberately omitted, and were also added. I also used the analogy and comparison. This does not make sense but were accepted. Finally, we fully understand and take advantage of the literature.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.50-55
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• 2005

New fast proton-conducting organic-inorganic nanocomposite membranes were successfully fabricated using polymer matrix obtained through proper oxidation of thiol ligands in (3-Mercaptopropyl) trimethoxysilane (MPTS) and hydrolysis/condensation reaction of (3-glycidoxypropyl) trimethoxysilane (GPTS). The obtained nanocomposite membranes showed relatively hirh proton-conductivity over $10^{-2}S/cm$ at $ 25^{circ}C$. The proton conductivities of the fabricated composite membranes increased up to $3.6{\times}10^{-1}$ S/cm cm by increasing temperature and relative humidity to $70^{circ}C$ and 100 $100RH\%$. The high proton conductivity of the composites Is due to the proton conducting path through the GPTS-derived 'pseudo-polyethylene oxide 'network in which sulfonic acid ligands work as a proton donor.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.805-813
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• 1994

Zucchini slices, sweet potato stems, taro stems, and platycodon treated with various methods such as dipping in citric acid solution, sulfite solution, or sulfur fumigation were dried by the natural sun drying method or the forced air drying method at 50, 70, 90, or $105^{\circ}C$. Mold growth of the dried vegetables and sensory quality of the dried and rehydrated vegetables were investigated. Limiting moisture contents to prevent mold growth over 3 month storage under room temperature were 15, 20, 25, and 15% for zucchini slices, sweet potato stems, taro stems, and platycodon, respectively. The chlorophyll containing vegetables dehydrated by the forced hot air showed better sensory quality than those by the natural sun. Among the pretreatments, dipping in the sulfite solution provided the best sensory quality to the dried vegetables. The sensory quality of dried platycodon was improved to a small extent by sulfur fumigation and sulfite solution treatment. The sensory quality of the dried platycodon was not found to be affected by the drying methods. All the tested vegetables dried at $105^{\circ}C$ had the worst sensory quality. Except drying temperature of $105^{\circ}C$, the lower the drying temperature, the better the sensory quality and the rehydration rates were obtained for the tested vegetables except platycodon. The sensory quality of the platycodon was little affected by the drying temperature tested in the range of $50{\sim}90^{\circ}C$.

• Journal of Korean Society of Forest Science
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• v.53 no.1
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• pp.44-55
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• 1981

Neutral sulfite precooked fir chips were refined in the Asplund Laboratory Defibrator at various temperature ($20^{\circ}C$, $120^{\circ}C$ and $180^{\circ}C$). The effects of refining temperatures on the physical property and morphological structure of the resulting pulps were discussed. Yields of precooked chips (84%, 92% and 100%) and refining temperature affected remarkably the yield of refined pulp, its beatability, sheet strength and morhphological characteristics. Pulp yield and beatability decreased with increasing refining temperature. Fiber surface of unbeaten pulp from precooked chips of 84% yield was to some extent covered by the secondary wall, while that of the pulp form precooked yield of 92% by the compound middle lamella. In the case of uncooked chips, fibers were damaged heavily, and the exposed fiber surface resulted from the equal amount of the secondary wall and the compound middle lamella. In the case of pulps prepared from precooked chips of higher yields (92% and 100%), sheet strength increased linearly as sheet density increased. But at the same sheet density, pulp from lower precooked yield (84%) had better sheet strength after open discharge refining as compared to pressurized refining, because pulp from the former had much amounts of fines fraction of higher water retention value than the latters. And there was observed a little difference in fiber length distribution but nearly similar in its morphology with increasing refining temperature.

• Journal of Food Hygiene and Safety
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• v.16 no.4
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• pp.308-314
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• 2001

This study was conducted to determine the content of heavy metals in canned foods and soft drinks available on the Korean markets. Trace metals (Pb, Cr, Cd, and Sn) were detected in 24 kinds, 120 samples by Atomic Absorption Spectrophotometer. The average concentration of heavy metals in canned foods was in the order of Sn (6.930 ppm)>Cr (0.050 ppm)>Pb (0.030 ppm)>Cd (0.008 ppm), which was the same order in soft drinks as Sn (3.519 ppm)>Cr (0.080 ppm)>Pb (0.024 ppm)>Cd (0.001 ppm). The total contents of heavy metals in canned fruits and fruit juices were relatively higher than those in cans and drinks made of vegetable and fish. It can be supposed that the high acidity owing to the organic acid of fruit itself promotes to extract metals from can materials, and although fish usually contains more heavy metals than vegetables, canned fish revealed low level because internal organs and most of skin which had more heavy metals than meat were removed throughout canning process. Because processed foods such as canned foods and soft drinks are very popular with the children and adolescence according to the change of life style and eating habit, and the possibility of exposure to heavy metals by the habitual intake of these is increasing simultaneously, it is suggested that more practical study about the process of exposure and the amount in each step is needed fur the assessment of safety.