Regiospecific Distribution of Highly Unsaturated Fatty Acids in Triacylglycerols of Artemia Nauplii Enriched with Marine Oils.

Abstract

Brine shrimp Artemia nauplii, an important live food used in aquaculture, were enriched with five marine oil triacylglycerols (TAG) in order to enhance n-3 highly unsaturated fatty acids (HUFA) essential for fish larvae. Positional distribution of fatty acids in TAG was determined for both of the enriched Artemia nauplii and dietary marine oils. In all of the enriched Artemia nauplii, docosahexaenoic acid was preferentially located in the sn-1,3 position followed by the sn-2 position. Icosapentaenoic acid was preferentially located in the sn-2 position. Distribution patterns of these fatty acids were not similar to those in dietary TAG of fish oil origin. Positional distribution of HUFA characteristic of marine fish TAG does not appear to hold for Artemia TAG during the HUFA enrichment.Artemia TAG and marine oil TAG were subjected to regiospecific analysis. Experimental 1 Marine Oil TAG Used for ArtemiaEnrichment TAG of fish oils [bonito head oil, tuna orbital oil, sardine oil, and HUFA-concentrated fish oil (Larodan Fine Chemicals, Malmö, Sweden)] and marine mammal oil (seal oil) were used for enrichment of Artemia nauplii. The TAG were isolated from the oils by column chromatography on Silicagel 60 (Merck, Darmstadt, Germany) with hexane/ethyl ether for elution. Enrichment of Artemia NaupliiThe marine oil TAG were given to Artemia nauplii in the form of gelatin-acacia microcapsules (7). The microcapsules were prepared by the method described by Kondo (8) as follows. TAG (0.9 g) were added to a mixture of 10% (wt/wt) solution of gelatin (3 mL; Kanto Chemical Co. Inc., Tokyo), 10% (wt/wt) solution of acacia (3 mL; Wako Pure Chemical Industries, Ltd., Osaka) and 10% (wt/wt) solution of acetic acid (0.5 mL) maintained at 43 . After the mixture was homogenized for 1 min, distilled water (14 mL) was added with homogenizing at 43 and then the homogenate was immediately cooled down to 10 in a ice-water bath. Resulting microcapsules were hardened in a refrigerator overnight in the presence of formalin (0.3 mL) at about pH 9 adjusted by adding 10% (wt/wt) sodium hydroxide. The microcapsules were neutralized by repeated centrifugation at 3,200 rpm for 5 min and resuspension in cold water, and then used in suspension for Artemia enrichment.Enrichment was carried out with 24-h-old Artemia nauplii (total length, about 1 mm) at a density of 150 nauplii/mL in 10 L tanks containing 9 L of well-aerated 2% (wt/wt) salinity artificial seawater at 20 (6). After the TAG-containing microcapsule suspensions were added to the tanks, enriched Artemia nauplii samples were taken on a nylon mesh at 18 h, washed in distilled water, and stored at 35 for lipid analysis. An initial sample was also taken just before start of the enrichment.

Characterization of Triacylglycerol Composition of Fish Oils by Using Chromatographic Techniques

“…This result agrees with recent studies in the regiospecific analysis of fish oil triacylglycerols 19,20 .…”

Enriched on-grown Artemia metanauplii actively metabolise highly unsaturated fatty acid-rich phospholipids

“…Moreover, changes in the positional distribution of FA of dietary TAG were also observed in Artemia nauplii enriched with fish oil ethyl esters and TAG (Ando and Narukawa, 2002;Ando and Oomi, 2001;Ando et al, 2004;Shiozaki and Ando, 2004).…”

Production of omega-3 fatty acids acylglycerides by lipase-catalyzed glycerolysis of sardine oil in different reaction media

“…Table A Table A.2, it can be observed that docosahexaenoic acid is mostly found at sn-2 position. This result agrees with recent studies in the regiospecific analysis of fish oil triacylglycerols (Ando & Narukawa 2002;Jayasinghe et al 2012).…”