The main objective of the research was to study the effect of drying
temperatures using infrared irradiation and electric heating convection on
dehydration and was to investigate the effect of drying conditions on the
quality of the shrimp. Two sizes of fresh shrimp (100 shrimp/kg and 200
shrimp/kg) with initial moisture content of 270 - 350 % dry-basis were dried
under various conditions while the final moisture content of dried shrimp
was in ranges between 20 and 25 % dry-basis. Hot air flow rates of 1.0 -
1.2 m/s, drying temperatures of 40 - 90 °C and infrared intensities of 1,785.7
- 3,571.4 W/m2 were used in these experiments. The experimental results
showed that the rate of moisture content transfer of both sizes of shrimps
decreased exponentially with drying time while increasing drying
temperature significantly affected to the drying kinetics and quality of the
shrimps. Effective diffusion coefficients of both shrimps were determined
by a diffusion model forming a finite cylindrical shape was in order of 10-7
m2/s and this effective diffusion coefficient value was relatively dependent
on the drying temperature compared to the initial moisture content. The
quality analysis of dried shrimp using an infrared source and electric heating
source found that the redness value (Hunter a-value) of dried samples using
hybrid infrared radiation and electric heating had a higher colour uniformity
than other drying methods. Additionally, shrinkage and rehydration
properties were insignificantly different for all drying strategies (p < 0.05)
and drying using infrared radiation had higher drying rates compared to
electric heat convection, corresponding to relatively low drying times.