100-8 |
Effect of artificial feed on lipid constituents of gonads of Newfoundland green sea urchins (Strongylocentrotus droebachinensis) |
C. M. LIYANA-PATHIRANA1, F. Shahidi2, A. Whittick1, and R. G. Hooper1. (1) Department of Biology, Memorial University of Newfoundland, St John's, NF A1B 3X9, Canada, (2) Department of Biochemistry, Memorial University of Newfoundland, St. John's, NF A1B 3X9, Canada The gonads of sea urchins are considered to be a delicacy. Green sea urchins are abundantly found in the coastal areas of Newfoundland, but they remain underutilized. The objective of this study was to determine the effect of a grain based feed formulation on total lipid content, lipid class distribution and fatty acid composition of sea urchin gonadal lipids. Sea urchins captured from the wild were initially fed Laminaria sp followed by a grain based feed formulation. Total lipids were extracted from gonads according to the Bligh and Dyer procedure. Lipid classes were identified by thin layer chromatography - flame ionization detection(TLC-FID). Fatty acid composition was determined, following transmethylation, using gas chromatography. The total lipid contents on week 0, 3, 6 and 9 ranged between 3.83±0.17 and 4.73±0.11%.Triacylglycerols contributed 66.7±0.75, 69.07±0.89, 74.63±0.81 and 77.43±0.76% to the total non-polar lipids on week 0, 3, 6 and 9, respectively. Free fatty acids and cholesterol were among other dominant constituents. Major polar lipid classes were phosphatidylcholine(PC), phospahatidylethanolamine(PE) and sphingomyelin/ lysophosphatidylcholine(SM/LPC) . PC contributed the highest amount on week 0 (65.73±1.42%), but its content was reduced by approximately 50% on week 6 and 9. Meanwhile, the content of PE increased from 17.31±0.21 on week 0 to 25.05±1.18, 46.51±1.93 and 53.37±0.33% on week 3, 6 and 9, respectively. Eicosapentaenoic acid (EPA) was dominant on week 0 while linoleic acid (LA) was the major PUFA of sea urchin gonads fed on the artificial diet. The LA content increased from 1.10±0.10 on week 0 to 6.53±0.23, 13.78±0.23 and 15.65±0.09% on week 3, 6 and 9, respectively. The corresponding values for EPA were 16.31±0.14, 15.01±0.11, 9.4±0.23 and 8.39±0.08%. The results signify the importance of feed constituents on lipid composition of sea urchin gonads. The fatty acid distribution of gonads could further be tailor-made to obtain a shelf-stable product.
Session 100, Seafood Technology: Texture, Chemistry
|