Variation for Dietary Fiber Content In Dry Edible Beans.

Dietary fiber has been shown to be an important component in the human diet and related to reducing incidence of the four major chronic diseases, namely heart disease, cancer, obesity, and type 2 diabetes. Dry edible beans (Phaseolus vulgaris L.) are known to be an excellent source of dietary fiber. Seed from 33 varieties of common dry bean were obtained through the Common Bean Coordinated Agricultural Project (Bean CAP). These seeds were grown under greenhouse conditions in Michigan and Idaho. Modified total dietary fiber (MTDF= dietary fiber without oligosaccharides) varied from 23.2 to 15.5% (SE ± 0.7%) among entries grown in one location and from 21.6 to 16.6 % grown at two locations. Mean MTFC was higher for seed produced in Michigan compared to Idaho (19.7 vs 17.8%; P<0.05), suggesting that the environment had an influence on MTFC. Bean market classes differed for MTDF. In general, Andean beans were higher than Mesoamerican navy or black beans.  These results suggest that the genetic diversity exists for MTFC and may be related to domestication events. Furthermore, the levels of genetic diversity seen in these results suggest that plant breeders should be able to modify fiber content by selection.