Mechanical properties and integrity of stored corn grains after continuous and intermittent drying

Abstract

This study aimed to evaluate the influence of continuous and intermittent drying during the storage time on mechanical properties and integrity of corn. For intermittent drying, five rest times (0, 4, 8, 12, and 16 h) and four storage times (0, 90, 180, and 270 days) were used. The corn grains harvested at a moisture content of 0.34±0.001 kg kg-1 dry basis (db) were dried in a fixed-layer experimental dryer set at a temperature of 100 °C and an air flow rate of 1.5 m3 min-1 m-2 until they reached a moisture content of 0.16±0.03 kg kg-1 db. For intermittent drying, the process was interrupted at a moisture content of 0.22±0.02 kg kg-1 db and resumed after resting. Tests for electrical conductivity, rupture force, deformation, energy required for rupture, and modulus of toughness and hardness were conducted. Grain integrity is better maintained when the grain has been dried with a longer rest time and stored for short periods; compressive strength exhibits the same behavior as integrity, but hardness, energy for rupture, and the modulus of toughness are not influenced by storage time, and grain deformation was not affected by the rest and storage times.