Optimization of accelerated solvent extraction of paprika oleoresin and its effect on capsaicinoid and carotenoid composition

Accelerated solvent extraction (ASE) is an automatic extraction technology that performs at elevated temperature and pressure to achieve efficient extraction of compounds from solid or semisolid samples in a very short time. In this study, the response surface method (RSM) was used to establish an efficient ASE method for rapid extraction of high-quality paprika (Capsicum) oleoresin with American Spice Trade Association (ASTA) color value as the response variable. The ASTA color values and pungency levels of paprika oleoresin obtained by ASE, maceration extraction (ME) and ultrasound-assisted extraction (UAE) were further compared. The optimal conditions for ASE procedure are a static time of 28 min, an extraction temperature of 78 °C, and 2 cycles. Under these optimal conditions, the ASTA color value of extracted paprika oleoresin reached 847 and the scoville heat unit (SHU) reached 57,200 ± 362. These values were significantly higher than those obtained by ME (ASTA color value: 607, SHU: 42,800 ± 144) or UAE (ASTA color value: 750, SHU: 50,500 ± 1690). These results were also reflected by total carotenoid and capsaicinoid content. There was little difference in carotenoid distribution in ASE, ME and UAE samples. In addition, ASE did not promote additional trans/cis transformation of carotenoids.