Improved extraction of saturated fatty acids but not omega-3 fatty acids from sheep red blood cells using a one-step extraction procedure.
ABSTRACT Several methods are available to extract total lipid and methylate fatty acids from a range of samples including red blood cells (RBC). Fatty acid analysis of human RBC can be undertaken using a two-step extraction and methylation or a combined one-step extraction and methylation procedure. The lipid composition of sheep RBC differs significantly from that of humans and may affect their extraction. The purpose of the current study was to examine the efficiency of extraction of lipid and detection of fatty acids from sheep RBC using a one-step procedure. Fatty acids were analysed using a one-step extraction and methylation procedure using methanol:toluene and acetyl chloride in comparison with a two-step procedure involving extraction of lipid using chloroform:methanol and separate methylation. Concentrations of saturated fatty acids including C16:0 and C18:0 were significantly higher (42.6 and 33.9 % respectively) following extraction using the one-step procedure compared with the two-step procedure. However, concentrations of some polyunsaturated fatty acids, including C20:5n-3 and C22:6n-3 were not significantly different between either procedure. The improved detection of fatty acids may be related to the ability of different solvents to extract different lipid fractions. The differential extraction of lipids and detection of fatty acids from sheep RBC may have important implications in studies examining the effect of dietary treatment on the possible health benefits of fatty acids.
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ABSTRACT: The phenotypic and phylogenetic diversity of micro-algae capable of accumulating triacylglycerols provides a challenge for the accurate determination of biotechnological potential. High-yielding strains are needed to improve economic viability and their compositional information is required for optimizing biodiesel properties. To facilitate a high-throughput screening programme, a very rapid direct-derivatization procedure capable of extracting lyophilized material for GC analysis was compared with a scaled-down Folch-based method. This was carried out on ten micro-algal strains from 6 phyla where the more rapid direct-derivatization approach was found to provide a more reliable measure of yield. The modified Folch-based procedure was found to substantially underestimate oil yield in one Chlorella species (P < 0.01). In terms of fatty acid composition however, the Folch procedure proved to be slightly better in recovering polyunsaturated fatty acids, in six out of the ten strains. Therefore, direct-derivatization is recommended for rapid determination of yields in screening approaches but can provide slightly less compositional accuracy than solvent-based extraction methods.Journal of Applied Phycology 08/2013; 25(4):961-972. · 2.33 Impact Factor
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ABSTRACT: The current study examined the effect of supplementing lambs with algae. Forty, three month old lambs were allocated to receive a control ration based on oats and lupins (n=20) or the control ration with DHA-Gold™ algae (~2% of the ration, n=20). These lambs came from dams previously fed a ration based on either silage (high in omega-3) or oats and cottonseed meal (OCSM: high in omega-6) at joining (dam nutrition, DN). Lamb performance, carcase weight and GR fat content were not affected by treatment diet (control vs algae) or DN (silage vs OSCM). Health claimable omega-3 fatty acids (EPA+DHA) were significantly greater in the LL of lambs fed algae (125±6mg/100g meat) compared to those not fed algae (43±6mg/100g meat) and this effect was mediated by DN. Supplementing with algae high in DHA provides a means of improving an aspect of the health status of lamb meat.Meat Science 05/2014; 98(2):135-141. · 2.75 Impact Factor
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ABSTRACT: Algae high in docosahexaenoic acid (DHA) may provide a source of long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) for inclusion in the diet of lambs to improve the LCn-3PUFA status of meat. The effect of background LCn-3PUFA status on the metabolism of high DHA algae is, however, unknown. The aim of the current study was to determine whether the response to a high in DHA algae supplement fed to lambs for six weeks prior to slaughter was mediated by a maternal periconceptional diet. Forty Poll Dorset × Border Leicester × Merino weaner lambs were allocated to receive either a ration based on oat grain, lupin grain, and chopped lucerne (control) or the control ration with DHA-Gold™ algae included at 1.92 % DM (Algae) based on whether the dams of lambs had previously been fed a diet high in n-3 or n-6 around conception. LCn-3PUFA concentration was determined in plasma and red blood cells (RBC) prior to and following feeding. The concentrations of EPA and DHA in the plasma and RBC of lambs receiving the control ration were significantly (p < 0.001) lower when lambs received the ration for 14 days compared with pre-feeding concentrations. The concentrations of EPA and DHA were also significantly (p < 0.001) higher when lambs consumed the Algae ration compared with the control ration for 42 days. The increase in EPA and DHA was, however, significantly (p < 0.05) lower if lamb dams had previously been fed a diet high in n-6 at conception. Assessing the previous nutrition and n-3 status of lambs may allow producers to more accurately predict the likely response to supplements high in LCn-3PUFA, particularly, DHA.Lipids 07/2014; · 2.56 Impact Factor