Physical and Viscoelastic Properties of Different Moisture Content Highland Barley Kernels

Abstract

Abstract: The study is conducted to investigate the physical and viscoelastic properties of the highland barley kernels in different moisture content range from 10.1 %% to 20.5 %% (w.b.). Highland barley kernel samples were selected with physical properties in terms of length, width, thickness, 1000-kernel weight, volume, geometric and arithmetic mean diameter changing in linear trends. By using a dynamic mechanical analyzer, the 4-element Burgers model was found to adequately represent the creep behavior of the highland barley kernels (R 2 > 0.977). The creep behavior of the ventral groove and dorsal side was also matched perfectly with Burgers model (R 2 > 0.946). The creep behavior of these kernels at long-time frame was studied applying time-temperature superposition (TTS). TTS method was successfully used to predict the creep behavior of these kernels at longer frame of time. The Tg values for the kernels decreased with increasing moisture content. The Tg values for the kernels at the moisture contents of 10.1 %%and 20.5 %% were 114.33 °C and 67.95 °C, respectively. The magnitude of the storage modulus, loss tangent and their change rates with frequency were maximum at 10.1 %% and minimum at 20.5 %% moisture contents.