Eliminating vicine and convicine, the main anti-nutritional factors restricting faba bean usage

Abstract

BackgroundFaba bean (Vicia faba L.) seeds are an excellent source of plant-based protein. In spite of the vast nutritional and environmental benefits provided by faba bean cultivation, its use as a food crop has been restricted, primarily due to the presence of the pyrimidine glycosides vicine and convicine (v-c). Ingestion of v-c can cause favism in individuals with a genetically inherited deficiency in glucose-6-phosphate dehydrogenase (G6PD). In monogastric animals, v-c can cause decreased feeding efficiency. The elimination of these glucosides is a goal of most faba bean breeding programs worldwide. Scope and approachOur review focuses on the current genetic, molecular and biochemical knowledge surrounding the accumulation of v-c in faba beans. The gap between the current knowledge and what remains unknown is discussed. This review also explores historical and obscure information on v-c in faba bean. Key findings and conclusionsA low-v-c faba bean line was identified in the 1980s and this trait has been introduced into several modern cultivars. It has been shown that low-v-c faba beans are safe for G6PD-deficient individuals. A robust molecular marker is now available for marker-assisted breeding to reduce levels of v-c. The biosynthetic pathway of v-c is not yet understood and is currently under investigation. An international coordinated effort, led by the authors of this paper, is making progress towards full elucidation of the pathway. Further efforts in this direction could lead to lower levels of these compounds than the current low v-c genotypes offer, perhaps even complete elimination.