Optimization of Ultrasonic-Assisted Extraction and Purification of Zeaxanthin and Lutein in Corn Gluten Meal

Zeaxanthin and lutein have a wide range of pharmacological applications. In this study, we conducted systematic experimental research to optimize antioxidant extraction based on detection, extraction, process amplification, and purification. An ultrasonic-assisted method was used to extract zeaxanthin and lutein with high efficiency from corn gluten meal. Firstly, the effects of solid-liquid ratio, extraction temperature, and ultrasonic extraction time on the extraction of zeaxanthin were investigated in single-factor experiments. The optimization extraction parameters of zeaxanthin and lutein with ethanol solvent were obtained using the response surface methodology (RSM) as follows: liquid–solid ratio of 7.9:1, extraction temperature of 56 °C, and extraction time of 45 min. The total content of zeaxanthin and lutein was 0.501%. The optimum extraction experimental parameters were verified by process amplification, and we confirmed that the parameters of the extraction process optimized using the RSM design are reliable and precise. Zeaxanthin and lutein from crude extract of corn gluten were separated and purified using silica gel column chromatography with the purity of zeaxanthin increasing from 0.28% to 31.5% (about 110 times) and lutein from 0.25% to 16.3% (about 65 times), which could be used for large-scale industrial production of carotenoids.