Cereal Chem. 71:423-428   |  VIEW ARTICLE


Moisture Absorption Characteristics of Laird Lentils and Hardshell Seeds.

J. Tang, S. Sokhansanj, and F. W. Sosulski. Copyright 1994 by the American Association of Cereal Chemists, Inc. 

Moisture absorption and water imbibition tests were conducted to investigate the characteristics of moisture uptake in Laird lentils (Lens culinaris Medik.) and to study the role of moisture content in the development of hardshell lentils. The widths of lentil hilum openings at a range of lentil moisture contents were examined using scanning electron microscopy. The initial moisture contents of lentils markedly affected the route of moisture migration, rate of water absorption, imbibition time, and proportion of hardshell lentils. At moisture contents of 16-24% (on a dry basis), moisture diffused mainly through the seedcoat, and the absorption behavior was predicted accurately by a one-dimensional diffusion equation. The permeability of lentil seedcoat decreased with decreasing moisture content because of reduced pore and fissure sizes in the cuticle layer over the seed surface. When lentil moisture content was at 12%, the hilum opening was the dominant route for moisture to enter lentils. The widths of lentil hilum openings also decreased with moisture content, some hila were closed at 12% moisture content. Impermeable seedcoat and concurrent closing of the hilum opening resulted in hardshell lentils. Increasing the soaking temperature from 12 to 22 C resulted in greater seedcoat permeability and reduced the percentage of hardshell lentils by about one half over the 24-hr soaking period.