Study on the saga-bean (Adenanthera pavonia L.). III. Effect of traditional processing methods on the nutritive value and other physiological consequences

Abstract

Previous studies of traditional processing methods on saga-beans revealed that saponine is the most difficult antinutritive substance to be eliminated and hence still to be found in saga tofu and tcrnpeh. In this study it is shown that the digestibility coefficient of saga products, i.8. boiled cotyledons, tofu and tempeh, significantly lower than that of casein. However, their protein efficiency ratio (PER), biological value (BV) and net protein utilization (NPU) are similar to that of casein. The negative physiological effects of saga products are mainly due to the presence of saponine. It is shown that the relative weights of livers of the rats receiving the tofu, in which the saponine content is the highest, are significantly lower than ohm. Also, there is an indication that the number of red blood cells of the rats receiving the tofu and saga tempeh are lower than those rmiving boiled cotyledons or casein, which may be due to the harmolytic action of saponine. The positive physiological effect of saga products (boiled cotyledons and tempeh) is due to their capacity to reduce the cholesterol level in the plasma, which may be caused by the presence of more fibres and sterols, and higher proportion of arginine/lysine in their protein, than those in the tofu and casein. It is concluded that the saponine contained in the saga-bean has to be eliminated before consumption. One simple method to do this is to boil the cotyledons; however, more studies are needed to devdop effective separation method of cotyledons from the hulls. ' These saies of dtudies on the saga-beans have to be considered as a preliminary study. More studies are needed, not only in the field of food technology but also in agronomy, genetics, agroeconomy, etc., before the utilization of the saga-bean as a source of cheap protein for human consumption can be developed.