Carbohydrate Profile of a Dry Bean (Phaseolus vulgarisL.) Panel Encompassing Broad Genetic Variability for Cooking Time

Dry beans are typically consumed as a whole food, and cooking time is one of the most important processing quality attributes. A panel of eight dry bean entries with variability in cooking time was established, grown in three locations, and used to test the hypothesis that carbohydrate components are major underlying contributors to genetic variability in cooking time. The cooking times ranged from 17 to 160 min. In general, faster cooking bean genotypes had higher levels of soluble dietary fiber in both the raw and cooked samples. Resistant starch levels in the raw beans, although not correlated with cooking time, were of interest because of the large genotypic variability, and they ranged from 1.5 to 35%. One genotype in particular, a yellow bean from Africa, Cebo Cela, had low resistant starch levels in the raw seeds of 1.5–2.5%, whereas average resistant starch levels in the entire panel were 26–30%. Resistant starch levels (3.9–4.2%) in the cooked seed of Cebo Cela were comparable to the other genotypes (3.4–4.3%). Based on light microscopy, the cell walls did not remain intact in the raw milled seed used for the analyses, but they did remain intact in the cooked samples, suggesting the differences in resistant starch in the raw seed are related to starch structure.