Song Yi Koo

Antiproliferative Effects of Carotenoids Extracted from Chlorella ellipsoidea and Chlorella vulgaris on Human Colon Cancer Cells

The antiproliferative activity of carotenoids separated from marine Chlorella ellipsoidea and freshwater Chlorella vulgaris has been evaluated. HPLC analysis revealed that the main carotenoid from C. ellipsoidea was composed of violaxanthin with two minor xanthophylls, antheraxanthin and zeaxanthin, whereas the carotenoid from C. vulgaris was almost completely composed of lutein. In an MTT assay, both semipurified extracts of C. ellipsoidea and C. vulgaris inhibited HCT116 cell growth in a dose-dependent manner, yielding IC(50) values of 40.73 +/- 3.71 and 40.31 +/- 4.43 microg/mL, respectively. In addition, treatment with both chlorella extracts enhanced the fluorescence intensity of the early apoptotic cell population in HCT116 cells. C. ellipsoidea extract produced an apoptosis-inducing effect almost 2.5 times stronger than that of the C. vulgaris extract. These results indicate that bioactive xanthophylls of C. ellipsoidea might be useful functional ingredients in the prevention of human cancers.

Optimization of pressurized liquid extraction of carotenoids and chlorophylls from Chlorella vulgaris.

Pressurized liquid extraction (PLE) was applied to the extraction of carotenoids and chlorophylls from the green microalga Chlorella vulgaris. Four extraction techniques such as maceration (MAC), Soxhlet extraction (SOX), ultrasound assisted extraction (UAE), and PLE were compared, and both the extraction temperature (50, 105, and 160 degrees C) and the extraction time (8, 19, and 30 min), which are the two main factors for PLE, were optimized with a central composite design to obtain the highest extraction efficiency. The extraction solvent (90% ethanol/water) could adequately extract the functional components from C. vulgaris. PLE showed higher extraction efficiencies than MAC, SOX, and UAE. Temperature was the key parameter having the strongest influence on the extraction of carotenoids and chlorophylls from chlorella. In addition, high heat treatment (>110 degrees C) by PLE minimized the formation of pheophorbide a, a harmful chlorophyll derivative. These results indicate that PLE may be a useful extraction method for the simultaneous extraction of carotenoids and chlorophylls from C. vulgaris.

Characterization of core–shell calcium-alginate macrocapsules fabricated by electro-coextrusion

Spherical macrocapsules, where calcium-alginate shell enclosed olive oil as a model core medium, were fabricated by electro-coextrusion. The effects of three key process factors, including alginate concentration in shell fluid (0.5-4.0%), shell-to-core flow rate ratio (4-12 at a fixed core flow rate of 0.05 mL/min), and applied voltage (0-10 kV), on the morphological and textural characteristics of the macrocapsules were analyzed using response surface methodology. The analysis showed that the diameter, shell thickness, hardness, and breaking energy of the macrocapsules were in the ranges of 0.89-1.61 mm, 17.4-66.4 μm, 1.37-11.01 N, and 0.34-6.90 mJ, respectively, and strongly influenced by all the three factors, except that the surface appearance was only significantly affected by the shell-to-core flow rate ratio. The process factors were also optimized for the practically useful macrocapsules, having non-oily surface and hardness larger than 3 N, using a graphical optimization technique.

Increased sulforaphane concentration in brussels sprout following high hydrostatic pressure treatment

High hydrostatic pressure (HHP) treatment was used to increase the concentration of sulforaphane in Brussels sprout, a cruciferous vegetable known to have health benefits. The highest concentration of sulforaphane was 1021.8 μmol per kg fresh weight of Brussels sprouts after HHP treatment at 500 MPa, which corresponded to a 317% increase compared to the HHP-untreated control.