Changes of volatile compounds, lactic acid bacteria, pH, and headspace gases in Kimchi, a traditional Korean fermented vegetable product

Headspace volatiles of Kimchi stored at 5 degreesC increased over a 7 d period by 20.0% and then decreased from 7 to 27 d by 8.3%. Forty volatile compounds including 18 sulfur compounds were identified in Kimchi. Lactic acid bacteria in Kimchi increased from 3.1 to 4.5 (1 X 10(8) cfu/mL) over a 17-d period and decreased by 40% from 17 to 27 d. As the storage time increased from 17 to 27 d, pH decreased from 4.3 to 3.8, headspace oxygen decreased from 14.3 to 1.3%, and headspace carbon dioxide increased from 27.7 to 45.3%. Enzymatic reactions and chemical oxidations in Kimchi explained the changes of volatile compounds, lactic acid bacteria, pH, headspace oxygen and carbon dioxide.