Essential Oil from Hibiscus Flowers through Advanced Microwave-Assisted Hydrodistillation and Conventional Hydrodistillation

Abstract

Due to the increased demand and importance of essential oils in medicinal applications, advanced essential oil extraction techniques have been employed. Both conventional hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) were employed to extract the essential oils from the hibiscus flower. Extraction time and solvent polarity were the most critical factors. Scanning electron microscopy (SEM) was used to investigate the surface morphologies of raw powdered hibiscus flowers (not exposed to any pretreatment) and pretreated powdered hibiscus flowers (exposed to methanol absorption for 60 minutes prior to extraction). Extractive chemistry analysis utilizing Fourier transform infrared (FTIR) spectroscopy was performed on the volatile oil obtained by MAHD. Different peaks in the gas chromatography/mass spectrometry (GC/MS) analysis indicated the presence of thirty-seven different compositions. MAHD was more energy efficient, had higher yield production, and was environmentally friendly, reducing HD’s overall carbon footprint by 40%. Oxygenated monoterpene, sesquiterpene, and sesquiterpene hydrocarbons were found in the hibiscus flower’s crude extract. Moreover, the methanolic extract of Hibiscus rosa-sinensis has potent antioxidant properties. A hibiscus flower extract had scavenging activities of 51.2% at 0.2 mg/mL, 0.3% at 0.6 mg/mL, 0.8% at 1.0 mg/mL, and 68.5% at 1.2 mg/mL against DPPH free radicals. Therefore, the MAHD method is well-suited to extracting essential oils from hibiscus flowers, and the resulting oil has the potential to provide significant therapeutic advantages.

A comprehensive review of Patchouli plant: Comparison of microwave-assisted hydro-distillation and hydro-distillation methods

“…Because it has higher yields of essential oils, shorter extraction time [35], environmentally friendly as it emits less CO2 [36], uses less energy and has lower extraction costs than other methods [37], the microwave-assisted hydrodistillation method has been identified as an alternative approach for extracting essential oils from plants [38]. Plant essential oils typically reside inside of cells, thus extra work is required to obtain them.…”

Green Synthesis of Magnetite Nanoparticles Mediated Fumaria officinalis L. Plant as Sustainable and Renewable Adsorbing Materials

“…As a positive control, BHT and ascorbic acid were utilized. The samples' radical-scavenging activities were estimated as inhibition ratio using Equation (1) [37]:…”

Steps to achieve carvone-rich spearmint (Mentha spicata L.) essential oil: a case study on the use of different distillation methods

“…MAHD is a popular technique due to its short process times, increased EO quality and quantity, and lower energy consumption (Moradi et al, 2018;Elyemni et al, 2019;Fardhyanti et al, 2019;Mollaei et al, 2019). MAHD can produce the purest oil with minimally damaged sebaceous glands and a chemical profile similar to HD in hibiscus flower processing (Rassem et al, 2022). MAHD has increased the thymoquinone content in the EO of Nigella sativa L. (Abedi et al, 2017).…”