COOKING QUALITY OF LENTILS - THE ROLE OF STRUCTURE AND COMPOSITION OF CELL-WALLS

Good- and poor-cooking samples of Eston lentil, grown under field conditions, were compared for physical (microscopic) and chemical composition of seed, cell walls (CW), and pectin isolated from the CW. Hulled and dehulled, good- and poor-cooking samples of the lentil generally had similar hydration coefficients (water uptake). The poor-cooking sample had 44.1% lower seed phytic acid (PA) than the good-cooking sample. The CW were isolated in similar yields (3.8-4.2%) from the good- and poor-cooking samples and contained 5.8-6.5% protein, 0.5-1.2% starch, 1.2-1.7% lignin, and 17.7-18.1 % galacturonic acid. Arabinose, glucose, galactose, and xylose were the major CW monosaccharides. Transmission electron micrographs of cotyledons and CW of uncooked poor-cooking lentil stained with KMn04showed some evidence of a “lignification-like” mechanism at the cell junctions in the middle lamella. The CW of poor-cooking lentil appeared multilayered under a scanning electron microscope. Pectic substances of the two samples had similar methoxyl content, degree of esterification, and galacturonic acid content (colorimetric) and were thus of the low-ester variety. Seed PA content seemed to play a critical role in affecting the cooking quality of lentil. © 1990, American Chemical Society. All rights reserved.