Optimization of soy isoflavone extraction with different solvents using the simplex-centroid mixture design

Abstract

The objective of this study was to optimize the extraction of different isoflavone forms (glycosidic, malonyl-glycosidic, aglycone and total) from defatted cotyledon soy flour using the simplex-centroid experimental design with four solvents of varying polarity (water, acetone, ethanol and acetonitrile). The obtained extracts were then analysed by high-performance liquid chromatography. The profile of the different soy isoflavones forms varied with different extractions solvents. Varying the solvent or mixture used, the extraction of different isoflavones was optimized using the centroid-simplex mixture design. The special cubic model best fitted to the four solvents and its combination for soy isoflavones extraction. For glycosidic isoflavones extraction, the polar ternary mixture (water, acetone and acetonitrile) achieved the best extraction; malonyl-glycosidic forms were better extracted with mixtures of water, acetone and ethanol. Aglycone isoflavones, water and acetone mixture were best extracted and total isoflavones, the best solvents were ternary mixture of water, acetone and ethanol.

Keywords::

• soybean
• solvent extraction
• response surface methodology
• HPLC

Acknowledgements

This work was partially funded by CNPq/MCT and FundaçãoAraucária/PR. LYY would like to thank CNPq for a graduate scholarship, and EII is a CNPq Research Fellow.

Declaration of interest : This research was partially funded by ConselhoNacional de DesenvolvimentoCientífico e Tecnológico – ‘National Council of Technological and Scientific Development’, CNPq, Brazil and FundaçãoAraucária/PR. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.