18B-25

K.-S. KIM¹, M.-Y. Baik², K.-H. Park³, and C.-S. Park². (1) Dept. of Food Science and Technology, KyungHee Univ., 1 Seocheon-ri, Kiheung, Yongin, 449-701, South Korea, (2) Dept. of Food Science and Technology, KyungHee Univ., Seochun 1, Yongin, 449-701, South Korea, (3) Dept. of Food Science and Technology, Seoul National Univ., School of Agricultural Biotechnology, San 56-1, Silim-dong, Kwanak-gu, Seoul, 151-742, South Korea

Isoflavones are the most common estrogenic compounds found in plants and have been shown to possess antimicrobial and insecticidal properties and to prevent and reduce the risk of various cancers. HPLC is the most common method for quantitative analysis for isoflavone in various food materials. However, the cost of HPLC analysis is very expensive and HPLC takes relatively longer time. Furthermore, HPLC device is much complex and must consider the physical and chemical interactions within samples, packing material and solvent. The object of this work was to develop the new rapid quantification method of isoflavones using TLC. Solvent systems for TLC analysis were determined using 3 to 4 solvents with different composition. Quantification of isoflavone in TLC method was carried out using densitometric analysis by determining the intensity of spot. The effectiveness of TLC method was compared to HPLC method by determining the amount of isoflavones in various soybeans and Kudzu roots. Rapid and clear separation of isoflavones (genistin and daidzin) was obtained with the solvent system of chloroform : methanol : water: acetic acid (60 : 30 : 10 : 0.5, v/v/v/v). Genistin and daidzin were successfully quantified in the range of 0.15~1.80μg/ml with 99% confidence in TLC method. Quantification of isoflavones in various soybeans and kudzu roots using both TLC and HPLC methods showed no significant differences. This suggests that TLC method can be used to rapidly quantify the isoflavones in various food systems. This work provides the new rapid quantitative analysis method of isoflavone using TLC. The TLC method does not need sample preparation and is very useful when many samples have to be analyzed at the same time.

Session 18B, Food Chemistry: Antioxidant and bioactive agents
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana