Ultrasound-Assisted Extraction of Bioactive Compounds From Fresh Ripened Chillies

Abstract

Red chillies (Capsicum annuum) are a globally significant crop valued for a rich profile of bioactive compounds, including capsaicinoids, carotenoids, and phenolics. Conventional extraction methods, such as maceration and Soxhlet, are often inefficient, energy-intensive, and can lead to the thermal degradation of heat-sensitive compounds. In response to these limitations, this study was conducted to optimize the Ultrasound-Assisted Extraction (UAE) process for fresh ripened red chillies using acetone as a solvent. The experimental design employed a Central Composite Design (CCD) within a Response Surface Methodology (RSM) framework to investigate the effects of ultrasonic power (60–100%), treatment time (10–50 min), and solvent temperature (30–60 °C) on extraction yields. The results of this investigation demonstrated the superiority of the UAE method over conventional techniques. The optimized UAE process with acetone achieved a capsaicin concentration of 2.310 mg/mL, a total flavonoid content of 0.540 mg/mL, a β-carotene yield of 0.127 mg/mL, a total phenolic acid content of 0.336 mg/mL, and an oleoresin yield of 184.7 mg. These yields represent significant increases compared to conventional methods, which produced 2.049 mg/mL for capsaicin, 0.411 mg/mL for total flavonoid, 0.090 mg/mL for β-carotene, 0.285 mg/mL for total phenolic acid, and 44.5 mg for oleoresin. Optimal conditions for extracting a diverse range of compounds with acetone were determined, highlighting the non-linear relationship between process parameters and yield. This study confirmed that UAE with acetone is a highly effective, rapid, and efficient method for recovering a broad spectrum of bioactive compounds, offering a superior and more sustainable alternative to traditional extraction methods for the production of high-quality extracts.