Isoflavone characterization in different genotypes of soybean

Soy isoflavones are phytochemicals of high interest since consumption of soy products has been linked to a variety of health protective effects including risk reduction of cardiovascular disease, lowering rates of prostate and mammary cancers and improvement of bone health. The aim of this work was to select soybean genotypes which contain a high isoflavone concentration and therefore may enhance the health beneficial effects of soy products. Twenty soybean samples (from USA, Serbia, Ukraine and China) of different genotype origin were screened for their isoflavone content. All samples were cultivated and harvested under the same conditions on experimental fields at the Institute of Field and Vegetable Crops, Novi Sad. After extraction with methanol-water (8:2, v/v), the isoflavone content was determined by C₁₈ reversed phase HPLC, coupled with a photodiode array detector [1]. The highest and lowest isoflavone contents were 8.52 and 2.64mg/g soy, respectively, while the average was 6.01mg/g soy. Analysis of variance showed that there were significant differences between cultivars (P value <0.05). On the other hand, t-test showed that there is no significant difference in content of isoflavones between different countries of origin (P value <0.05). This demonstrates that each of investigated countries has a cultivar that is significantly rich in isoflavones, as well as one that has low isoflavone levels. Considering significant differences among different soy genotypes on the basis of the results of this study, some cultivars with the highest content of isoflavones could be recommended as potential food and supplement ingredients.

References: [1] Lee JH. et al. (2004) J. Agric. Food Chem. 52: 2647–2651.