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.

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& A pressurized liquid extraction (PLE) technique was developed for the extraction of bioactive isoflavonoids including tectoridin (1), iridin (2), tectorigenin (3), iristectorigenin A (4), irisflorentine (5), and irigenin (6) from Belamcanda chinensis using aqueous ethanol as the extraction solvent. The effects of various key factors of PLE, including solvent composition (0-100% ethanol in water), temperature (80-180 C) and extraction time (5-20 min), were evaluated with respect to the extraction efficiency. Only solvent compositions altered the extraction yields of isoflavonoids with 60% ethanol providing the best extraction efficiency. When compared with conventional extraction methods, such as reflux or sonication extraction, PLE resulted in higher extraction efficiency with shorter extraction time and lower solvent consumption. We also tested the thermal stability of tectoridin, isoflavonoid glycoside, at various temperatures (80-180 C) in 60% ethanol for a 20 min extraction time to mimic conditions that could be encountered during PLE. Tectoridin was degraded to tectorigenin (aglycone) at temperatures over 150 C, therefore, care should be taken in the choice of temperature used for PLE.