61B-1 |
Optimization of solid phase microextraction (SPME) on the headspace volatile compounds in Kimchi |
J. H. LEE1, J. H. Kang1, D. B. 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, 132-714 Flavor is one of the most important factors determining quality of Kimchi, a traditional Korean fermented vegetable product, according to Codex. The development of a simple, reproducible and sensitive analytical method to evaluate headspace volatile compounds is important. The objective of this study was to optimize the condition of SPME for the reproducible and sensitive analysis of the headspace volatile compounds in Kimchi. Three mL of filtered Kimchi broth was prepared in a 10-mL bottle with a magnetic stirring bar and sealed air-tightly with a Teflon-coated rubber septum and an aluminum cap. The headspace volatile compounds in sample were isolated by 5 different SPME solid phases and analyzed by gas chromatography (GC). Samples were held for 5, 15, 30, 45 or 60 min to study the effect of isolation time and were kept at 25, 40, 55 or 70°C to study the effect of isolation temperature. The quantification ability of SPME was tested by adding dimethyl disulfide, one of sulfur compounds in Kimchi, to 3 mL of centrifuged and filtered Kimchi broth or deionized water to make 0, 25, 50, 75 or 100 ppb in a 10-mL bottle. Dimethyl disulfide was isolated by 100 mm PDMS and analyzed by GC. Reproducibility of SPME was 5% coefficient of variation in total peak area by the combination of 100 mm polydimethylsiloxane as solid phase, 40°C of isolation temperature and 30 min of isolation time and stirring. SPME could detect dimethyl disulfide quantitatively ranging from 25 to 100 ppb (R2=0.99) in Kimchi broth and in water sample. SPME is a reproducible and sensitive technique for the analysis of the headspace volatile compounds in Kimchi and can be used as a quality control method for industrial scale production.
Session 61B, Food Chemistry: Flavor and aroma chemistry
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