• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.148-156
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• 2008

The purpose of this study was to analyze the changes in physicochemical characteristics and NDMA formation of Orostachys japonicus A. Berger according to harvest times. The results showed moisture, carbohydrate, crude fiber and crude protein contents of <$48.5{\pm}1.4%$, $38.2{\pm}1.2%$, $l5.8{\pm}0.4%$ and $13.2{\pm}0.6%$ respectively. The total mineral content was 4,817.1 mg/100 g, where Ca was highest($2,577.0{\pm}3.2$ mg/100 g), followed by K, Mg, Na, P and Fe. The composition amino acid of O. japonicus A. Berger showed high levels of glutamic acid and aspartic acid. And among the five free sugars detected, galactose and glucose were most abundant at $32.2{\pm}0.02$ mg/100 g and $25.3{\pm}0.1O$ mg/100 g, respectively. Upon comparing O. japonicus A. Berger extracts that came from plants harvested during $August{\sim}October$, total phenolic compound($2,703.l{\pm}5.2l{\sim}2,428.0{\pm}3.52$ mg/100 g) and flavonoid($634.2{\pm}2.33{\sim}1,324.6{\pm}1.87$ mg/100 g) contents were higher in the methanol extract than in the water extract. Also, within a reaction system, nitrite scavenging ability and NDMA inhibition were most effective at pH 2.5, and increased in proportion to the extract concentration. Finally, the methanol extract of O. japonicus A Berger harvested during $August{\sim}October$ had the highest nitrite scavenging and NDMA inhibition effects.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.223-229
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• 2002

For the research of the natural marine antioxidant, several bacteria were isolated from the coast of jin-Hae in Korea. Among the marine bacteria studied, strain HJ-14, a gram-negative, motile, strait rod, aerobic, and $Na^{+}$ required bacterium showed high activity of 1,1-diphenyl-2-picrylhydrazyl radical scav- enging. The morphological, physiological, and biochemical characteristics of the strain HJ-14 were similar to those of the Alteromonas macleodii ATCC $27126^{T}$ . Thus, it was tentatively identified as Alteromonas sp. HJ-14. The compositions of major fatty acids in cell membrane of Alteromonas sp. HJ-14 were $C_{ 14:0}$ , $ C_{15:0}$ , $C_{16:0}$ and $C_{17:1}$ $_{w8c}$ , which also suggest that it is affiliated with Alteromonas sp. The optimum culture conditions for production of antioxidant materials with Alteromonas sp. HJ-14 were at $25$~$37^{\circ}C$ and pH 6~8. The optimum conditions for the production of antioxidant for carbon, inorganic nitrogen, and sodium chloride sources were 2.5%(w/v) dextrin, 0.5%(w/v) ammonium sulfate, and 2~6%(w/v) sodium chloride, respectively. The hydroxyl radical scavenging ability of Alteromonas sp. HJ-14 broth was 90.03%, which is higher than ascor-bic acid(83.28%) and lower than butylated hydroxyanisole(95.46%) and $\alpha$-tocopherol(97.17%).