Ultrasound pretreatment combined with supercritical CO2 extraction of Costus spicatus leaf extract

This work aimed to obtain extracts from Costus spicatus leaves through ultrasonic pretreatment in supercritical CO2 extraction (UAE+SFE). A central composite design was used to evaluate the influence of temperature (36–64 °C), pressure (8–20 MPa), and cosolvent (0–20 %w) in terms of overall yield and chemical composition. Morphology using scanning electron micrograph (SEM), total phenolic content, content of total flavonoid, antioxidant (DPPH and ABTS), and antibacterial activities were evaluated. UAE+SFE showed a more notable overall yield, with 6.97 %. In the SEM, the sample treated with UAE+SFE significantly impacted tissue structures, improving the selectivity of SFE regarding linolenic acid, leading to a maximum composition value of 62.5 % area according to GC-MS. Furthermore, the UAE+SFE extract exhibited strong antimicrobial activity compared to the extract obtained by the SFE technique. Based on the pioneering results, the bioactives obtained are promising and interesting for application in the cosmetic, pharmaceutical, and food industries. [Display omitted] •Pioneering study in obtaining extracts from Costus spicatus leaves through UAE+SFE.•Ultrasound improved the yield and quality of the extract.•UAE+SFE is efficient for extracting linolenic acid.•TPC, TFC, DPPH, and ABTS were significantly affected by extraction conditions.•Strong bacterial activity was observed in UAE+SFE extracts.