ANALYTICAL METHODS FOR THE DETERMINATION OF PHENOLIC PHYTONUTRIENTS IN FOODS
Location: Food Composition and Methods Development Lab
Title: Influence of Extraction Solvents and Delipidation on Assay of Isoflavones from Soybean (Experimental Biology Annual Meeting 2007, Washington DC)
Submitted to: Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: November 3, 2006
Publication Date: April 1, 2007
Citation: Luthria, D.L., Biswas, R., Natarajan, S.S. 2007. Influence of Extraction Solvents and Delipidation on Assay of Isoflavones from Soybean. Experimental Biology, April 25, 2007, Washington, D.C.
Interest in soy based products has grown significantly in the past few decades due to the variety of health protective effects associated with soybean consumption. Soybeans are known to contain a large number of bioactive phytochemicals, such as isoflavones, saponins, phytosterols, and phenolic acids. Isoflavone enriched extracts have been evaluated in the prevention of a wide range of health problems associated with menopause, cardiovascular disease, osteoporosis, and breast, prostate, and colon cancers. The influence of delipidation and extraction solvents and techniques on the assay of isoflavones from soybean was investigated. This systematic study was undertaken to address substantial variations in the solvents and procedures used for the extraction of isoflavones from soybeans by different research groups. Comparison of seven different solvent mixtures used for the extraction of isoflavones from ground soybean with and without lipids was carried out. Assessments of six commonly used extraction techniques (shaking, vortexing, sonication, stirring, Soxhlet, and pressurized liquid extraction (PLE)) with an optimized extraction solvent mixture was also performed. Both, the total isoflavone content and the isoflavone HPLC profiles varied significantly with different extraction solvents and techniques. Optimum total isoflavone recoveries from soybean samples were obtained from delipidated soybeans with dimethyl sulfoxide:ethanol:water (5:75:25, % v/v/v) solvent mixture using a PLE.