Optimization of extraction process for ustiloxins A and B from rice false smut balls using an orthogonal array design

Optimization of four factors, namely methanol concentration (A), extraction pH value (B), material-to-solvent ratio (C) and extraction times (D), for extraction of ustiloxins A and B from rice false smut balls was achieved by using an L18 orthogonal array design with three levels and four factors. The results show that the optimum conditions for ustiloxins A and B extraction should be A1B2C2D3 corresponding to methanol concentration at 10%, extraction pH value at 6, material-to-solvent ratio at 1:30 (g/mL) and extraction times as 3, respectively. Under the optimum extraction condition, the content of ustiloxins A and B in rice false smut balls was analyzed to be 0.80 and 0.57 mg/g, respectively, on a dry weight basis.Keywords: Rice false smut balls, Villosiclava virens, Ustilaginoidea virens, ustiloxins A and B, orthogonal array design, extraction optimization.African Journal of Biotechnology, Vol 13(38) 3912-391