title: Effect of Fermentation Temperature on the Volatile Composition of Kimchi.
abstract: This study was conducted to evaluate the effect of fermentation temperature on the volatile composition in Kimchi. Kimchi was fermented at 2 temperature conditions (4 and 20 °C). Volatile compounds of Kimchi samples were analyzed during the fermentation periods using the dynamic headspace gas chromatography-mass spectrometry method. The optimum ripening time for the Kimchi fermented at 4 °C was 35 d, and that of 20 °C was 2 d. The pH at the optimum ripening time was 4.97 and 4.41, and the titratable acidity was 0.59% and 0.76% for the Kimchi fermented at 4 and 20 °C, respectively. Forty different types of volatile compounds, including alcohol, aldehyde, ester, and sulfur compounds, were identified. The Kimchi fermented at 20 °C produced greater amounts of volatile compounds than that at 4 °C. The amounts of most volatiles increased as the fermentation time increased, but those of aldehydes decreased rapidly during both 4 and 20 °C fermentation. Organic acids, ester, and nitriles were detected only in Kimchi fermented at 20 °C. The amounts of dimethyl disulfide, methyl-2-propenyl disulfide, and di-2-propenyl disulfide produced from the Kimchi fermented at 20 °C were more than 2-times of those at 4 °C. Therefore, it is concluded that the strong pungent odor of Kimchi fermented at 20° C is probably due to the high amount of organic acids (low pH) and sulfur compounds (dimethyl disulfide, methyl-2-propenyl disulfide, and di-2-propenyl disulfide) between the 2 Kimchi.
authors.affiliation: Div. of Strategic Food Research, Korea Food Research Inst. (KFRI), 1201-62 Anyangpangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-746, Republic of Korea.
authors.forename: Sang Pil
authors.initials: SP
authors.lastname: Hong
authors.affiliation: Dept. of Food and Nutrition, Univ. of Wisconsin-Stout, Menomonie, WI, 54751, U.S.A.
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Div. of Strategic Food Research, Korea Food Research Inst. (KFRI), 1201-62 Anyangpangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-746, Republic of Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Dept. of Animal Science, Iowa State Univ, Ames, IA, 50011, U.S.A.
authors.forename: Dong Uk
authors.initials: DU
authors.lastname: Ahn
keywords: Kimchi; fermentation temperature; pungent odor; volatile compounds