Quality characteristics of green sea urchin (Strongylocentrotus droebachiensis) gonads as affected by the season and dietary factors

• Main Author: Liyanapathirana, Chandrika M.
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2001
• Subjects: Newfoundland
• Online Access: https://research.library.mun.ca/1638/; https://research.library.mun.ca/1638/1/Liyanapathirana_ChandrikaM.pdf; https://research.library.mun.ca/1638/3/Liyanapathirana_ChandrikaM.pdf

The eating quality of sea urchin gonads from Strongyiocentrotus droebachiensis harvested in the Newfoundland coasts as affected by the season and an artificial diet was assessed. Evaluations were performed on the basis of biochemical and fatty acid composition, total and free amino acid contents, and contents of nucleicacids and pigments, among others. -- Noticeable changes occurred in the biochemical composition of wild and cultured sea urchin gonads. Moisture and lipid contents showed an inverse relationship in all samples examined. Sea urchin gonads had the highest amount of lipid and the lowest amount of moisture in the spring. Lipid content of cultured sea urchin gonads decreased with increased feeding time while the moisture content increased. Protein content, on the other hand, was highest in the fall in the wild sea urchins. The corresponding value for cultured sea urchins was observed 9 weeks after feeding on an artificial diet. Relative proportions of lipid and protein were quite low in the wild as well as cultured sea urchin viscera. -- There were no qualitative differences in the lipid class composition between gonads and viscera of wild and cultured sea urchins. Major non-polar lipid classes were triacylgiycerol (TAG), free fatty acids (FFA) and sterol (ST) while major polar lipid classes were phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Triacylgiycerol content was highest in the spring and fall in gonads and viscera, respectively. On the other hand, TAG content in cultured sea urchins was increased with length of feeding period. Phosphatidylcholine was the dominant polar lipid class in wild sea urchin tissues. However, PE became dominant in cultured urchins on week 9 after feeding on an artificial diet. -- The fatty acids 14:0 and 16:0 were the major saturated fatty acids (SFA) consistently present in total, polar and non-polar lipids of sea urchin gonads and viscera irrespective of their origin while 20:4n-6 and 20:5n-3 were the major polyunsaturated fatty acids (PUFA). However, in ...