Akademik Veri Yönetim Sistemi
SIGMA JOURNAL OF ENGINEERING AND NATURAL SCIENCES, cilt.42, sa.3, ss.739-746, 2024 (ESCI)
Blueberry is a small fruit, which has a very high amount of antioxidant substances. It is consumed either in fresh or dried form. In this study, the effect of vacuum on the oven thin-layer
drying of blueberries was investigated. The kinetic parameters of effective moisture diffusivity
(Deff) and activation energy (Ea) values were calculated. Moreover, the drying curves were
modelled with the most known mathematical modelling equations given in the literature. For
oven and vacuum oven drying, the drying temperatures were selected as 60, 70 and 80°C. The
drying times were seen to decrease by increasing the drying temperature and with the effect
of vacuum. The highest drying time was observed as 420 minutes in oven drying at 60°C. The
effect of vacuum decreased this drying time to 240 minutes. Deff values were calculated to
elucidate the underlying mass transfer mechanisms by using Fick’s 2nd law, which were found
to be between 1.14-2.83×10-9 m2
/s for oven drying and increased to 2.54-4.33×10-9 m2
/s by
the addition of vacuum. Likewise, activation energy was increased from 25.93 to 43.98 kJ/mol
by vacuum addition. Twelve mathematical models were applied to the drying curve data and
among them, Alibas model for both oven drying and vacuum-assisted oven drying gave the
coefficient of determination (R2
) values that were higher than 0.997. As a result, the vacuum
addition was seen to yield lower drying times and higher kinetic parameters for the oven
drying of blueberries.