Polygonum minus is a plant rich with bioactive components that contribute to food, pharmaceutical, and perfume industries. However, high moisture content in fresh plants will allow
microbial activity that leads to the degradation of plant quality. This can be prevented by
drying the fresh plants to preserve the characteristics of their bioactive components. The
present work was conducted to determine the effect of different drying methods such as
air-drying, oven-drying (40 and 60°C), and freeze-drying on essential oil (EO) yield and
chemical compounds of P. minus roots. For comparison purposes, all samples were extracted
by maceration with n-hexane at room temperature. Then, the samples were analysed and
identified by using gas chromatography-mass spectrometry (GC-MS). The highest EO yield
extract was obtained from freeze-drying (4.15 ± 0.5), followed by air-drying (3.79 ± 0.19). EO
yield from oven-drying at 40 and 60°C was 3.4 ± 0.14 and 0.86 ± 0.04, respectively. Results
showed that by increasing the drying temperature, the EO yield would decrease and cause a
loss of major chemical compounds in the P. minus root. Air-drying was found to be the best
method in preserving the presence of important chemical compound in P. minus roots such as
β-caryophyllene (1.43%), pentadecane (4.34%), hexadecanoic acid (3.91%) and oleic acid
(3.97%).