Extractability of Thevetia peruviana glycosides with alcohol mixture

The aim of this work was to investigate the most effective extraction conditions for the production of thevetia seed protein concentrate of reduced cardiac glycoside content. Alcoholic extraction of the glycosides was studied as a function of time, solvent to meal ratio and solvent composition. Thevetia seed meal was extracted with 10:1, 15:1 and 20:1 solvent to meal ratios, for 45 min, 24, 48 and 72 h. Varying concentrations - 50 to 100% (v/v) aqueous alcohol - were also used. A concentration of 70 or 80% aqueous alcohol resulted in the lowest glycoside content, while a solvent to meal ratio of 15:1, extracted over a period of 72 h, appears to give the best compromise between glycoside extraction and cost of extraction solvent. All treatments resulted in an increase in the protein content of the samples.