Near equilibrium moisture content values for hull-less oats

Sorption characteristics of hull-less oats were obtained by thin layer dryi ng (TLD) and equilibrium relative humidity (ERH) methods. For the TLD metho d, oats were at initial moisture contents of 11, 16, and 22% [dry basis (db )] and the air was conditioned to obtain relative humidities of 27, 37, 48, 61, 68, 69, 75, 88, and 93% at temperatures from 15 to 35 degreesC. For th e ERH method, low (7.6 to 8.7% db) and high (19.6 to 21.2% db) initial mois ture content samples were used at temperatures from 15 to 35 degreesC. A si gnificant difference exists between the values of equilibrium moisture cont ent (EMC called 'apparent hysteresis') obtained by two methods. Apparent hy steresis was 0.68 to 1.06 and 0.46 to 3.62 percentage points for the TLD an d ERH methods, respectively. High apparent hysteresis in the ERH method is attributed to the fact that it failed to attain EMC in 20-24 h as is sugges ted in the literature. Additional tests for extended time for ERH method na rrowed the apparent hysteresis, indicating that trite EMC values were not o btained by the ERH method.