Multi-satge Solvent Extraction of soybean isoflavones

Soya (max Glycine) is one of the enrich source of phytoesterogenes. Isoflavones have a similar structure and function like estrogen in reducing menopausal symptoms and their positive impact have been proved. In the present study extraction of isoflavones from soybeans with ethanol 96% by four different techniques including soxhlet, multi-satge solvent extraction, pre-treated sample by ultrasound and microwave proir to multi-satge solvent extraction carried out and efficient parameters in each methods were optimized. The results showed Soxhlet extraction of 50 g the sample with 150 ml ethanol 96%, during 6 h the maximum extraction yield of phenolics and isoflavanoids were obtained 68.62% and 62.02% respectively. Multi-stage solvent extraction performed by experimental conditions the ratio of solids to solvent extraction 3/10 mg.ml-1, 45C temperature and extraction time 60 min (per extraction), so in this conditions the extraction yield were same as Soxhlet method. In pretreated samples by ultrasound proir to three-stage solvent extraction (for 40 min in cycle 1 and amplitude 60) and microwave-pretreated samples (time leaching of 120 min and radiation time of 5 min), the maximum extraction yield compare to soxhlet method was obtained in solid to solvent ratio of 3.10 mg.ml-1, temperature of 40ºC, extraction time of 15 min. Also Qualitative and quantitative analysis of flavonoids genistein and daidzein in alcoholic dry extract was determined by HPLC.