Essential oil yield and antioxidant activity in diseased and healthy betel leaves: A comparative study of bioactive compounds using GCMS and FTIR profiling

This study focuses on the extraction of essential oils from healthy and diseased betel leaves (Piper betle L.), revealing novel insights into the potential value of diseased leaves, which are often discarded. The findings demonstrate that diseased betel leaves retain a substantial amount of essential oil content, challenging the conventional practice of disregarding them in favour of healthy leaves. Using hydrodistillation, the oil yield from healthy leaves was 1.52%, whereas the yield from diseased leaves was 1.23%. Despite this reduced yield, the chemical composition of the oils revealed unique stress responses in diseased leaves. GC-MS analysis revealed that healthy Betel Leaf Essential Oil (BLEO) contained higher concentrations of key compounds, including copaene (40.91%) and chavibetol (31.85%). At the same time, diseased BLEO contained elevated levels of stress-related compounds such as gamma-muurolene and eucalyptol. This increase in gamma-muurolene and eucalyptol suggests that the diseased leaves undergo biochemical changes in response to stress, adding significant value to their oil content. FTIR analysis confirmed these compositional differences, with diseased BLEO showing reduced peak intensities for critical aromatic and phenolic compounds. Antioxidant activity assays (DPPH and ABTS) indicated that while healthy BLEO exhibited slightly better antioxidant properties (IC50 values: 4.04 µL/mL and 3.41 µL/mL), diseased BLEO retained considerable antioxidant potential (IC50 values: 4.79 µL/mL and 3.73 µL/mL). This research highlights the importance of reconsidering diseased betel leaves as a valuable source of essential oil, offering opportunities for sustainable resource utilization and increased economic benefits by utilizing generally discarded leaves.