Determination of Soybean Isoflavone by HPLC/DAD and Simple UV Spectroscopic Analysis: a Comparative Study.

Validated HPLC and UV analysis were applied for quantitative determination of six isoflavones (daidzin, glycitin, genistin, daidzein, glycitein, and genistein) in soy products. In HPLC analysis, six isoflavones showed satisfactory regression (r² > 0.99) within test ranges, and the recovery was in the range of 91.00 to 117.00%. LOD and LOQ ranged from 0.004–0.016 (µg ml⁻¹) and 0.015–0.035 (µg ml⁻¹), respectively. The quantified isoflavones present in prepared and commercial extracts were then subjected to principal component analysis (PCA), in conjunction with hierarchical cluster analysis (HCA), which showed differences in the isoflavone from soybeans. The employment of a simple and low-cost UV spectrophotometric methodology was also applied in quantification of same compounds in the same soy extracts. Paired t-test confirmed that there is no significant difference between the results obtained for the two methods. Our results revealed that the developed methods have potential perspective for the original discrimination and quality control of isoflavones in soybean-based products employing a rapid, fast, and not-expensive method. [ABSTRACT FROM AUTHOR]