• Food Science and Preservation
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• v.16 no.2
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• pp.223-229
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• 2009

The effects of 0.01%(w/v) chitosan-ascorbate(CA) and 10 ppm morea on the number of total microbes, Escherichia coli levels, and growth of food poisoning bacteria in dombaeki during storage at $10^{\circ}C$ over 6 days were investigated. Total microbes in meat, cartilage, and skin of untreated samples increased by 4.24, 3.81, and 2.20 logs compared to the zero timepoint, respectively, but, in CA-treated samples, counts fell by 2.66, 2.37, and 1.24 logs. Total microbial levels in morea-treated meat, cartilage, and skin showed similar tendencies but the effects were slightly less than seen in CA-treated samples. E. coli numbers in CA-treated meat, cartilage, and skin stored for 6 days decreased by 1.69, 1.25, and 1.52 logs respectively, compared with control samples. Morea-treated samples showed similar falls, but the effects were again slightly less than seen after CA-treatment. Both Salmonella and Vibrio parahaemolyticus were detected in untreated meat stored for 3 or 6 days. Food poisoning bacteria were found in both untreated and morea-treated samples stored over 6 days. However, no such bacteria were detected in CA-treated samples. Also, CA-treated meat, cartilage, and skin showed low degrees of degeneration. Thus, CA treatment enhanced shelf-life and dombaeki quality by inhibiting microorganism growth and tissue breakdown during storage.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.175-183
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• 2010

To understand the variation of macro benthos community according to the installation of structure and topographic placement in the shellfish farm on tidal flat, the practical example of the tidal shellfish growing area at Namsung-ri Goheung was observed. The results of the research for the field observation were summarized as follows. (1) The ground gradient of the shellfish farm was very flat below about $1^{\circ}$. The shellfish farm ground took the shape of $\sqcup$ from the shoreline to the place of 150 m seawards, and the shape of $\sqcap$ from there to the low tide line. During ebb tide, the $\sqcup$ shape ground stored the sea water, and the $\sqcap$ shape ground was supposed to act as the effect factor to leak slowly or to prevent the outflow. (2) The oyster shell bag or the type of riprap wall as the boundary in the shellfish farm was classified into five types. The air exposure time and flooding time were 181 and 434 minutes, respectively. (3) In the numerical experiment, the deep-sea water wave coming in the study area had 0.5 m of maximum wave height to show the very stable conditions and the wave direction pattern of S-direction was dominant at Naro great ridge, and SE, SSW and S-direction were distributed strongly around the shellfish farm. (4) By the grain size analysis, the sediment around tidal flat consisted of gravel 0.00~5.81(average 1.70)%, sand 14.15~18.39(average 13.23)%, silt 27.59~47.15(average 30.84)% and clay 35.79~55.73(average 36.19)%, and the sediment type was divided into (g)M(lightly gravelly mud), sM(sandy mud) and gM(gravelly mud) by Folk's diagram. (5) The macro benthos community survey conducted in this site in January, 2010 showed that 1 species of Mollusca, 8 species of Polychaeta and 2 species of Crustacea appeared, and 11 species occupying over 1% of total abundance were dominant.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.105-115
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• 2012

The detailed proximate, fatty/amino acid, mineral composition, texture, color, chemical and taste compounds of six oysters (four kinds of cultured oysters and two kinds of wild oysters) in Korea were investigated. Length and weight of the shell removed cultured and wild oysters were 4.7~5.1 and 3.0~4.2 cm, and 5.9~9.1 and 2.6~5.5 g, respectively. The proximate compositions were not significantly different between cultured and wild oysters. Amino nitrogen and volatile basic nitrogen content of these ones were 232.8~258.2 and 160.5~213.9 mg/100 g, 9.5~12.0 and 7.8~9.5 mg/100 g, respectively. As a texture characteristic of muscle, shearing force were 95~114 and 105~132 g. Amounts of total amino acids of cultured and wild oysters were 9,004~10,198 and 8,165~8,942 mg/100 g, respectively. Major amino acids and inorganic ions were aspartic acid, glutamic acid, proline, alanine, leucine, phenylalanine, lysine, arginine and K, Na, Ca, Fe, S, P, Zn. Major fatty acids of these ones were 16:0, 18:0, 16:1n-9, 18:1n-9, 22:1n-9, 16:4n-3, 20:5n-3 and 22:6n-3, and there was little difference between the two groups. Amounts of free amino acids of cultured and wild oysters extracts were 1,444~1,620 and 1,017~1,277 mg/100 g, respectively, and major ones were taurine, glutamic acid, glycine, alanine, tryptophan, ornithine and lysine. There is a little difference in glycine, tryptophan, ornithine and arginine contents, but TMAO and TMA contents were low in amount, and were not significantly different between the two groups.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.56-69
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• 2016

Flame resistant treatment has been applied since 1973 for fire prevention in historical wooden buildings, but several problems, such as whitening and discoloration are constantly occurring in some Dancheong, in spite of evaluation criteria. It is supposed that these phenomena are caused by the stability issue of flame retardant, Dancheong production methods, the residue of chemicals, which were applied in the past, building location environments, etc., but no evaluation and cause inspection has been performed. Therefore, this study aims to verify the effect of flame retardant on Dancheong by producing Pseudo-samples and setting spatial and temporal environment conditions. Pseudo-samples of Dancheong were produced using three methods; the method specified in the Standard Specification of Properties; the method, which is generally used in the site and the traditional method. For different environment conditions of pseudo-samples, the areas were classified into a coastal area and an inland area and the places were classified into a sunny place and a wetland. After applying a flame retardant, annual variations were inspected for 12 months and change aspects were observed through scan and regular observation. In annual variation inspection, various variations like whitening, decolorization, dissolution and exfoliation were found and especially, whitening was most dominant. When the effect of flame retardant depending on the production methods was analyzed, whitening occurred in all the three production methods. It is supposed that this is because calcium(Ca) was contained in the coloring material of each production method and it reacted with phosphorous(P) of flame retardant. When the effect of flame retardant depending on the environment conditions was analyzed, whitening occurred more in the coastal area than in the inland area and it reduced in the building in a sunny place, which was constructed using the traditional method. It is supposed that this results from the humidity change and the difference of glue used in each production method. In conclusion, for using a flame retardant containing phosphorous(P), there is a need to check if calcium components including Oyster Shell White were used in Dancheong in advance and to conduct various preliminary studies on place conditions and Dancheong construction conditions.

• Applied Biological Chemistry
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• v.18 no.3
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• pp.145-166
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• 1975

The calcium balance study was carried out to determine the availability of calcium in different sources for chicks and laying hens. The sources of calcium were calcium carbonate (CC), dicalcium phosphate-dihydrate (DCPH), and dicalcium phosphate-anhydride (DCPA) for chicks and calcium carbonate (CC) and oyster shell (OS) for laying hens. The radioisotope dilution method was employed to measure the endogenous excreta calcium during the period of balance study following preliminary feeding. A. Experimental results with chicks: No significant difference was found among feed consumption of chicks fed diets containing different sources of calcium. Body weight gain of chicks was dependent upon the source of calcium. The gain decreased in the order of DCPH, DCPA and CC (P<0.01). The feed conversion efficiency in chicks fed DCPH was better than those in chicks fed CC or DCPA. The average tibia ash contents for chicks fed different sources of calcium were similar. The DCPH was superior to CC or DCPA regarding the calcium content in tibia ash. There were no significant differences among the average calcium contents in plasma trichloracetic acid filtrate in chicks irrespective of calcium sources. The mean apparent retention of calcium by chicks fed DCPH, CC and DCPA were 65.9, 64.0 and 59.9% respectively. The calcium to phosphorus ratios in tibia ash and plasma trichloracetic acid filtrate for chicks fed different sources of calcium were similar. The chicks fed DCPH showed the partition of endogenous excreta calcium in total excreta calcium as 35.6% which was higher than 31.0 or 31.4% for chicks fed CC or DCPA. The endogenous excreta calcium per day per chick in group fed DCPH, DCPA or CC were 17.2, 16.1 and 14.6mg respectively. The true retained calcium per day per chick in group fed DCPH were 109.9 mg which was higher than those observed with CC or DCPA group (P<0.01). The true retention of calcium by the birds fed diets containing DCPH, CC or DCPA were 78.1, 75.1 or 72.6% respectively. B. Experimental results with laying hens: The feed consumption, egg production and feed converion efficiency of laying hens fed diets containing different sources of calcium were similar. Calcium concentration in plasma trichloracetic acid filtrate in laying birds fed CC was equivalent to the value obtained by feeding OS. The apparent calcium retention by laying birds fed CC was 61.6% and it was significantly more than that of hens fed OS of 51.6% (P<0.05). The partition of endogenous excreta calcium in total excreta calcium of laying hens fed CC was 23.5% and this was higher than that of birds fed OS of 15.6%. The laying hens fed CC showed 310 mg of endogenous excreta calcium per day per bird while birds fed OS showed 261mg. The true retention of calcium by layers fed CC was 70.7% against 59.2% for birds fed OS (P<0.05).