Starch digestibility of five cooked black bean (Phaseolus vulgaris L.) varieties

Five common bean varieties were cooked and studied regarding starch digestibility. Cooking time of different cultivars ranged between 2.55 and 5.92 h. Available starch (AS) values decreased with the storage time and the bean sample that had the lowest AS content (control sample, without storage) showed the shortest cooking time. A similar pattern was found for resistant starch (RS); the varieties that had the longest cooking time presented the widest range in RS values, measured as the difference between the control sample and the value obtained in the sample stored during 96h. The retrograded RS (RRS) depended on the variety and even more on the molecular structure of each starch. The in vitro a-amylolysis rate decreased with the storage time; the samples with the smallest hydrolysis percentage had the highest RS content. These results suggest that some bean varieties could be recommended depending on the specific dietetic use of beans. (C) 2003 Elsevier Inc. All rights reserved.