Extraction of favism-inducing agents from whole seeds of faba bean (Vicia faba L var major)

The objective of the present study was to establish a suitable procedure by which favism-inducing glycosides vicine and convicine could be completely removed from whole seeds of faba beans without distorting their shape or reducing their nutritive value. Detoxification procedures carried out were extraction by water or, 10 g l(-1) acid solutions (acetic, citric and phosphoric acid) using stepwise or continuous soaking procedures. Three cultivars of the beans were used in the study. In the stepwise soaking procedures, the seeds were soaked in either water or acid solution at 40 degrees C for different periods while in the continuous flow techniques, the solutions were constantly passed through a seed reservoir under different time-temperature-flow rate conditions. Extraction of vicine and convicine increased with increasing temperature and period of soaking and/or continuous flow of soaking solutions. Neither stepwise soaking nor autoclaving could effectively remove the favism factors from the whole seeds. The best results were obtained with continuous flow soaking in tap water, giving vicine- and convicine-free seeds. The protein contents of treated seeds were only slightly affected and their physical structure remained intact. Thus, it was concluded that the latter procedure was the method of choice for detoxification of dry whole seeds. (c) 2005 Society of Chemical Industry.