Akademik Veri Yönetim Sistemi
Journal of New Results in Engineering and Natural Science, cilt.9, sa.2019, ss.1-10, 2019 (Hakemli Dergi)
Lemon balm ( Melissa officinalis L.), one of commercially important medicinal and aromatic plants,
must be dried immediately after harvest because of its high initial moisture content (72.99% to
80.11%, wb). Its quality parameters such as its color and essential oil conditions are very sensitive to
drying conditions. The most important factor of drying conditions is the drying air temperature
profile. Five different drying air temperature profiles were used to maintain the quality parameters of
lemon balm samples while reducing the drying time as much as possible. Drying trials with the
constant low temperature (35 °C) and the increasing temperature profile gave the most closest color
values of dried samples to the ones of fresh samples. The maximum color changes occurred with the
constant high temperature (60 °C) and the triangle temperature profile. The drying trials with the
constant low temperature gave the lowest essential oil loss (24.28% loss) while the drying trials with
the constant high temperature gave the highest essential oil loss (63.95% loss). The increasing
temperature profile in which the drying air temperature increased from 35 °C to 60 °C in 8 hours
became the most convenient drying air temperature profile for drying lemon balm when the results
obtained in this study were evaluated altogether.