Ultrasonic-assisted extraction of carotenoids using cottonseed oil: Optimization, physicochemical properties, and flavor studies

Vegetable oils are ideal alternative solvents for extracting fat-soluble substances. Here, response surface methodology, conventional analysis, and headspace-gas chromatography-mass spectrometry were used to evaluate the effect of an extraction process on the carotenoid yield, changes in physicochemical parameters, and flavor quality of cottonseed oil (CSO). An optimal carotenoid recovery rate of 80.3 % was obtained when the ultrasonic power was 213 W, the extraction time was 36.0 min, and the temperature was 44.6 ℃. Although acid (0.25 mg KOH/g), peroxide (9.90 meq/kg), and p-anisidine (0.11) values of carotenoid-enriched cottonseed oil (CECSO) increased relative to the corresponding values for CSO, its 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, carotenoid and total phenolic content also increased, reaching 64.2 %, 49.1 μg/mL, and 320 mg gallic acid equivalent (GAE)/100 g oil, respectively. Additionally, 14 compounds, including nine aldehydes (84.7–103 µg/g), three alcohols (9.41–10.8 µg/g),one acid (0.37–1.24 µg/g), and one heterocycle (4.19–5.32 µg/g), were identified as characteristic compounds in CSO and CECSO. Further, significant differences between the two types of oils were observed in aroma-related substances . This study provides a reference for the application of carotenoid-enriched cottonseed oil in food, health products and cosmetics.