|OWENS, SHIRLEY - MICHIGAN STATE UNIVERSITY
Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2001
Publication Date: N/A
Technical Abstract: The ability of dry seeds of common bean (Phaseolus vulgaris L.) to imbibe water and retain their color during thermal processing is essential to providing a quality cooked product to consumers. Color leaching in black beans is especially noticeable and makes a large impact on a consumer's acceptance of varieties. Four black bean varieties that differ in seed coat glossiness and ability to imbibe water and retain color (leaching) during thermal processing were examined by Scanning Electron Microscopy (SEM) and light microscopy. The Asp gene, when dominant, causes structural changes in the seed coat to make the bean appear glossy or shiny. 'Shiny Crow' with its dominant Asp gene has a smooth, waxy cuticle, and palisade cells of a greater length than the other three varieties. Of the four varieties, 'Shiny Crow' imbibed water at the slowest rate and retained most of its black color during thermal processing. 'Raven' with its dull seed coat, imbibed water at the fastest rate and lost most of its seed coat color during thermal processing. The palisade cells of 'Raven' were shortest in length and appeared to have the thinnest waxy cuticle. 'Black Jack' and 'Black Magic' both have dull seed coats and are intermediate between 'Raven' and 'Shiny Crow' with regards to leaching and water uptake. All three of the dull seed coat varieties showed extensive texturing of the waxy cuticle. Our data suggests a relationship between the Asp gene and morphological differences in the seed coat which affect a seed's ability to imbibe water and retain seed coat color even after heat treatment.