Effect of microfluidization on bioaccessibility of carotenoids from Chlorella ellipsoidea during simulated digestion

This study focused on the bioaccessibility of carotenoids from Chlorella ellipsoidea using a simulated digestion model. To increase the bioaccessibility of carotenoids, C. ellipsoidea was pulverized by microfluidization at pressures up to 20000 psi. The microfluidization treatment significantly reduced mean microalga particle size from 2463 to 361 nm. The major carotenoid in C. ellipsoidea was zeaxanthin, with two minor carotenoids, antheraxanthin and β-carotene. After microfluidization, the zeaxanthin and β-carotene contents in C. ellipsoidea were not changed in comparison to the untreated group, whereas the antheraxanthin content was significantly reduced. The bioaccessibility of carotenoids in untreated C. ellipsoidea was very low (zeaxanthin, 2.60%; β-carotene, 1.69%). Approximately 95% of total C. ellipsoidea carotenoids could not be released and micellized by simulated digestion. The microfluidized microalga (at 20000 psi) was 10 times more effective for zeaxanthin and β-carotene micelle formation compared with untreated C. ellipsoidea, showing higher bioaccessibility of carotenoids (zeaxanthin, 32.60%; β-carotene, 18.19%). These results indicate that microfluidization may be useful for disrupting C. ellipsoidea cell walls and improving zeaxanthin and β-carotene bioaccessibility from C. ellipsoidea during the digestion process.