Abstract:
Microwave assisted fluidized bed drying is a novel drying techniqu
e which reduces
drying time and yields higher quality products. In this study the effect of this method on
color changes of whole and cut hazelnut kernels was investigated. The parameters of color
and resulting total color change, chroma, Hue angle and bro
wning index were also
calculated during drying in three temperatures (40, 50 and 60°C) and microwave power
levels (0, 450 and 900W). Comparison was made to investigate the effect of drying
condition on browning of hazelnut surface and internal cavity. The
zero and first order
kinetic models were also fitted to whole and cut kernel color parameters. The results
showed similar behavior in color parameters of whole and cut kernels.
L
value and Hue
angle decreased with increasing drying time, drying air tempera
ture and microwave
power but
a, b, ΔE
, chroma and browning index increased.
L
and
b
values of whole
kernels were higher than cut kernels but the
a
value was lower. Zero
-
order model was
selected as the best model for predicting
a, b
and
ΔE
while first order
model best
described the kinetics of color changes of
L
, chroma, Hue angle and browning index.
Keywords:
Color Parameters, Fluidized Bed Drying, Hazelnut, Kinetic Modeling,
Microwav
