Effect of processing on Thevetia peruviana glycoside

Abstract

The nutritional content of the meal of Thevetia peruviana seed is comparable to that of soybean and peanut meals but is rarely consumed due to its toxicity, resulting from high content of cardiac glycoside. This work therefore was designed to investigate suitable method(s) for the effective removal of the cardiac glycoside from seed kernel meal. The various methods of processing employed were: fermentation, boiling in water, soaking in water, autoclaving, acid and alcohol treatments. The results showed that fermentation gave the least reduction in the cardiac glycoside (59.87%); boiling gave better (76.42%) reduction than all methods except alcohol treatment which gave the best reduction (84.97%). Further investigation using combined method (boiling and alcohol treatment) with temperature and time variation showed that boiling with 80% methanol/ethanol solvent mixture (8:2) for 30 minutes at 450C is sufficient to attain the optimum (91.0%) reduction of the toxic cardiac glycoside from the seed meal.