A Histological Basis for ‘Hard-To-Cook’ Phenomenon in Red Gram (Cajanus cajan) Cultivars

Sections of cotyledons (dhals) and leached starch granules in red gram (Cajanus cajan), were examined microscopically. The average expansion ratios of good cooking (GCD) and poor cooking (PCD) dhals were 1.8 and 1.4 for cotyledons, 2.4 and 2.0 for cells at 30 min cooking, and 6.5 and 5.5 for starch granules at 6 min cooking, respectively. Cells and starch granules of GCD dispersed freely and quickly into the medium while those of PCD tended to disperse slowly and remain in clusters. The variation in expansion, separation and clustering properties of cells and starch granules during cooking caused cookability differences of red gram cultivars.