Sterols in mollusks and crustacea of the Pacific Northwest

Abstract

There are at least eight major sterols in mollusks and cholesterol predominates in shrimp and crab of the Pacific Northwest. Depending on the analytical method used, significandy different values for total sterols in mollusks are' obtained. Using combined gas liquid chromatography for A s sterols and a modified Liebermann-Burehard reaction for A s ,7 sterols, an average total sterol and cholesterol content in oysters (Crassostrea gigas) of 170 ± 21 mg and 51 ± 10 mg/ 100 g~ respectively were found. Approximately one-half these amounts were found in 7 other mollusks. Dungeness Crab (Cancer magiter) and Pacific shrimp (Pandalus joradani) contain 50 and 144 mg cholesterol/100 g, respectively. For these crustacea, this represents 99% of the total sterols present. In mollusks, the percent nonesterified sterols ranges from 49.6 to 100%, with a mean of 73%. Only free cholesterol is present in Dungeness crab. Proximate composition of all samples, including oysters analyzed over a 9-month period is reported.

Lipid, FA, and sterol composition of New Zealand green lipped mussel (Perna canaliculus) and tasmanian blue mussel (Mytilus edulis)

“…The lipid content results for the TBM and the NZGLM in this study are in agreement with earlier studies of the blue mussel and other molluscs. The main lipid class of NZGLM and TBM was PL (up to 74%), which is consistent with other data for molluscs (7)(8)(9)22). a Data for each species, as determined by Iatroscan, are the mean of nine individual animals, representing three animals from each of three sites (values are expressed as mean ± SD).…”

“…Lipid contents in the TBM and NZGLM (1.2 to 1.8%) were similar to values reported in a study investigating the lipid composition of marine invertebrates of the Pacific Northwest (8). That study found the common blue mussel to have a lipid content of 1.8% in comparison to clams (1.5-1.7%), cockles (0.9-1.7%), horse clams (2%), and fresh oysters (2.5-4%), with crustacea such as crab and shrimp at around 1 and 1.5%, respectively.…”

“…Lipid constitutes around 2% of the wet weight in the blue mussel (7)(8)(9) of which approximately 75% is structural lipids (10). Depending on season and/or the life cycle of the mussel, lipid content and composition may vary.…”

Seasonal Variations of Lipid Content and Composition in Perna viridis

“…Invertebrates have been reported to contain a wide range of sterols [29]. There were 9 sterols identified in the present study, however, the 17 had been identified previously in both the frozen NZGLM and TBM when the authors used GC-MS to identify the sterols, and 14 were identified from frozen and freeze-dried NZGLM [3].…”

Ocorrência do 7-cetocolesterol e efeito de processamentos térmicos sobre sua formação em camarão-rosa ( Penaeus brasiliensis + Penaeus paulensis) ou Efeito de processamentos térmicos sobre ocorrência do 7-cetocolesterol ( Penaeus brasiliensis + Penaeus paulensis)

“…Dentre os esteróis, componentes da fração lipídica neutra, o colesterol é o mais proeminente, correspondendo a 94 a 99% do total (GORDON, 1982;KRZYNOWEK & PANUNZIO, 1989 , 1965;PIKUL et aI., 1984). o maior conteúdo lipídico no produto frito se deveu à absorção do óleo utilizado na fritu ra, conforma consta na literatura (MAl et aI., 1978;AGREN & HANNtNEN, 1993;CANDELA et ai., 1996).…”