| The lipids from the gonad of Heliocidaris crassispina (Fujian Province, China) was extracted using enzyme-assisted aqueous extraction method (EAE), and the extraction process was optimized by single factor experiment and orthogonal experiment. By applying gas chromatography-mass spectrometry (GC-MS), Generik Diol solid-phase extraction (SPE), high-performance thin layer chromatography (HPTLC) and differential scanning calorimetry (DSC) technologies, the quality of EAE lipid was comparatively characterized with that of Folch method and Matyash method with the lipid yields, physicochemical properties, fatty acid compositions, nutritional indexes, lipid compositions, melting and crystallization characteristics as indicators. The results showed that the optimal conditions of EAE process were determined as follows: solid-liquid ratio 1∶ 20, neutral protease dosage 7 500 U/g, enzymatic hydrolysis temperature 50 ℃，enzymatic hydrolysis time 5 h, and pH 7. The lipid yield was 23.22% under above conditions, which was significantly lower than that of Folch method (2727%) and Matyash method (27.14%). Compared with Folch method and Matyash method, the lipids from the gonad of Heliocidaris crassispina extracted by EAE had lower peroxide value (0.006 g/100 g), higher iodine value (95.77 gI/100 g), lower content of saturated fatty acids (51.48%), higher content of polyunsaturated fatty acids (34.53%), higher total content of EPA and DHA (15.04%), better nutritional indexes, lower phospholipids content (4.23%) and lower melting temperature and crystallization temperature. In conclusion, though bearing the shortages of low yield, complicated demulsification process and poor selectivity of phospholipids, EAE surpassed Folch method and Matyash method for milder conditions, eco-friendly initiatives, better quality, better nutritional value, lower melting and crystallization temperature of lipids, and suitable for the development of high quality marine dietary lipids. |
