Genetic Diversity and Inter-Relationships of Common Bean (Phaseolus vulgaris L.) Starch Traits

The starch morphology, granule size distribution, apparent amylose content (AAC), pasting properties, textural properties, gelatinization, and retrogradation of 16 common bean varieties are studied. According to the observed phenotypic data, the genetic diversity and inter-relationships of these starch traits are analyzed. Wide diversity in starch quality traits is observed. Both volume mean diameter and area diameter of starch granules range from 21.6 to 32.3 mu m, AAC ranges from 30.6% to 45.7%, and gelatinization temperature (GT) varies from 64.7 degrees C to 76.8 degrees C. AAC is not significantly correlated to GT and other gelatinization parameters or to retrogradation parameters, but is significantly positively correlated to hardness, trough viscosity, final viscosity, and setback. Conclusion temperatures (T-c) and enthalpy of gelatinization (Delta H-g) are significantly negatively correlated to retrogradation percentage. Thus, AAC mainly affects textural and pasting properties, and retrogradation mainly depends on gelatinization (Delta H-g and T-c) rather than AAC. This study provides guidance for the processing and application of these starches.