Comparative analysis of non-thermal technologies and solvent systems for the extraction and characterization of phytochemicals and antioxidants in Pandanus amaryllifolius

Pandanus amaryllifolius leaves (PAL) are known for their aroma and are also a rich source of natural phytochemicals. The purity, yield, and stability of phytochemicals depend upon the efficiency and selectiveness of the extraction method and the solvent used. In this study, the phytochemical and antioxidant activity of PAL were evaluated by using non-thermal extraction techniques, i.e., ultrasound (US) and cold plasma (CP). The extraction was evaluated using two different solvents: petroleum ether and 30 % ethanol. Face-centered central composite design was used to design the experimental parameters. The process parameters used were amplitude (30, 45, and 60 %) and treatment time (15, 30, and 45 min) for US, and voltage (10, 20, and 30 kV) and time (10, 20, and 30 min) for CP. The extraction efficiency of both the treatment methods and solvents was evaluated based on the quantification of total phenolics, flavonoids, terpenoids, chlorophyll content, and antioxidant activity. The damaged cell structure as observed from SEM images, confirmed the extraction of phytochemicals. The presence of phenolic and flavonoid compounds in the extract of PAL was confirmed from the FTIR analysis, revealing its nutritional and medicinal properties. Antioxidant activity was higher in case of 30 % ethanol as compared to petroleum ether. In the case of phenolic compounds, CP along with ethanol, had higher extraction efficiency. The use of non-thermal technology along with a suitable solvent can extract phytochemicals and antioxidants from PAL that can be further utilized for value-added product development.