• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.141-146
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• 2005

The objective of this study was to determine the characterisics of quality and antioxidant with various sweet potato(SP) varieties. The differences of skin color between general and colored SP was not significant. The flesh color of steamed SP was the lower than flesh of raw SP, and especially steamed purple SP(5.24) was lower than flesh SP(22.0). In physical characteristics, the hardness of raw SP showed the low values and the springness, gumness and hardness among steamed SP varieties was not significant. The total phenol content(TPC) of purple, yellow-fleshed and general SP had 13.1, 6.22 and 3.02 mg/g, respectively. In DPPH, the purple-fleshed SP had the highest free radical scanvering. Also, shingunmi$(88.5\%)$, Saengmi$(80.9\%)$ and Shinchunmi$(78.9\%)$ show the high antioxidant activities. The redness of SP was positively correlated with TPC in raw and steamed. However, the yellowness of flesh SP was negatively correlated with DPPH.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.655-658
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• 2006

This study was conducted to investigate the potential use of tomato ketchup as an ingredient to improve color and taste in kimchi with reduced red pepper content about 40%. The quality characterisics were studied for kimchi with or without tomato ketchup during fermentation for 25 days at $10^{\circ}C$. The pH of kimchi with tomato ketchup (KWT) decreased with increasing tomato ketchup content from 5% to 20%. The pH of KWT was lower than that of kimchi without tomato ketchup (KWOT) in the early stage of fermentation and did not show any difference after 10 days of fermentation at $10^{\circ}C$. The tendency of titratable acidity changes in KWT and KWOT was the same as the pH changes. The growth of lactic acid bacteria was more inhibited in KWT than in KWOT until 5 days fermentation and the significant difference between KWT and KWOT did not show after 10 days fermentation at $10^{\circ}C$. In sensory evaluation, the hot taste of the kimchi was decreased but the flavor and overall acceptability were increased significantly by addition of 5 to 10 % tomato ketchup (p<0.05).