61B-3 |
Changes of headspace volatile compounds, oxygen, carbon dioxide and microorganisms in Kimchi stored at 5°c for 25 days |
J. H. KANG1, J. H. Lee1, D. B. Min1, S. Min1, and Y. T. Ko2. (1) Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Court, Columbus, OH 43210-1007, (2) Department of Food and Nutrition, DukSung Women’s University, 419 Ssangmundong, Dobonggu, Seoul, Korea, 132-714 The quality of Kimchi, a traditional Korean fermented vegetable product, varies depending on ingredients, fermentation and storage conditions. A better understanding on the changes of headspace volatile compounds, headspace gas compositions, and microorganisms is needed to improve the quality of Kimchi. The objective was to study the relationships among the changes of headspace volatile compounds, oxygen, carbon dioxide, and microorganisms in Kimchi stored at -5°C. Three mL of 2, 7, 12, 17, 22 and 27 day old filtered Kimchi broth were prepared in 10-mL bottles and sealed air-tightly with Teflon-coated rubber septa and aluminum caps. The headspace volatile compounds were isolated by 100 mm polydimethylsiloxane and analyzed by gas chromatography (GC) and GC-mass selective detector. The headspace oxygen and carbon dioxide of Kimchi in pouch was determined every 5 day for 25 days by GC with a thermal conductivity detector. Colony forming units of lactic acid bacteria in Kimchi were determined every 5 day for 25 days by standard spread plate methodologies. Total volatile compounds of 7, 12, 17, 22 and 27 day samples were more than that of 2 day Kimchi by 20.0, 16.5, 14.5, 12.2 and 11.7%, respectively. As the storage time increased from 2 to 27 day, headspace oxygen decreased from 14 to 1% and headspace carbon dioxide increased from 27 to 45% due to the microorganisms. As the storage time increased from 2 to 17 days, the number of microorganisms in Kimchi increased by 45% and then decreased after 17 days by 40%. Forty volatile compounds including 18 sulfur-containing compounds were identified in Kimchi. The changes of headspace volatile compounds, oxygen and carbon dioxide in Kimchi are related with that of microorganisms. SPME is a simple analytical method for the qualitative and quantitative evaluation of headspace volatile compounds in Kimchi.
Session 61B, Food Chemistry: Flavor and aroma chemistry
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