Fatty acid composition of water buffalo meat

The fatty acid composition of intramuscular lipids of Longissimus dorsi (LD), Psoas major (PM), Biceps femoris (BF), Semitendinosus (ST) muscles and liver of water buffalo male calves was determined by capillary gas-liquid chromatography. The content of total lipids in the LD muscle was found to be maximum, followed by PM, BF and ST in decreasing order (1·03, 0·99, 0·66 and 0·55g/100g of fresh muscle). Liver contained 2·65 g of total lipids per 100 g of fresh tissue. Following the anatomical location, intramuscular lipids contained 44-55% of saturated fatty acids, of which the major components were stearic and palmitic acids. Mono-unsaturated fatty acids (31-40%) composed mainly oleic acid (90%). The PUFA contents in PM, LD, ST and BF were, respectively, 11%, 12%, 13% and 16%. The predominant PUFA were linoleic (66%) and arachidonic (25%). The significance of difference of PUFA content between muscles is discussed. Liver contained 48%, 27% and 22% saturated, monosaturated and PUFA, respectively. The PUFA in liver were linoleic (36%), C20 (47%) and C22 (9%).

Aroma of fresh oysters Crassostrea gigas: composition and aroma notes

In contrast to many foods, very little is known about the aroma of fresh oysters. This study deals with the relationship between extracted volatiles of oysters and their olfactory properties. Nearly 50 volatiles were identified: most of them were principally related to fatty acid oxidation (86%) and particularly to n-3 polyunstaturated fatty acid oxidation (66%). Only one volatile arose from amino acid degradation. Panelists detected 42 odors by sniffing. Among them, only 12 odors were definitely attributed to identified volatile. These odors were green/sulfur/crustacean, mushroom/citrus, and marine/cucumber notes and were attributed to dimethyl sulfide, 1-penten-3-one, hexanal, (2,4)-E,E-heptadienal, 1-octen-3-one, 1-octen-3-ol, 6-methyl-5-hepten-3-one, octanal, (E,Z)-2,6-nonadienal, (E)-2-octenal, and decanal, respectively.

Carcase characteristics of a heavy Japanese quail line under introgression with the roux gene

1. The roux plumage sex-linked recessive gene may be used for early sexing of Japanese quail in crossbreeding production systems with wild-type and roux lines. However, associated effects of the gene on carcase and meat composition need to be assessed. 2. Quail carcases from pure Line K males and females (100% K), a heavy meat line which was used as the recipient line for the introgression of the roux gene, and from same-age roux or wild-type females from the second generation of introgression (75% K) were dissected. The effects of sex, line and plumage colour on carcase components and on protein and lipid contents of various tissues were estimated. 3. Expected sex differences in carcase weights were obtained, with marginally higher values for females. However, weights of parts and carcase yield (ratio of empty carcase weight without head, neck and feet over live body weight) were similar for both sexes in pure Line K which had a 68% carcase yield. Lipid contents in leg meat were higher in males (3.1%) than in females (2.7%). 4. The roux gene did not seem to have any major impact on carcase parts or composition. However, in roux birds, leg skin was marginally higher in lipids and pectoralis major lower in proteins than in wild-type ones.

Secreted and intracellular phospholipases A2 inhibition by 1-decyl 2-octyl-glycerophosphocholine in rat peritoneal macrophages

Compounds able to inhibit phospholipases A2 can be considered as potential anti-inflammatory drugs. In this respect, the inhibitory effect of the phospholipid analogue 1-decyl 2-octyl-rac-glycero-3-phosphocholine (decyloctyl-GPC) added to the culture medium of rat peritoneal macrophages stimulated with ionophore A23187 was determined. (a) The substrate of phospholipase A2 1-octadecanoyl 2-[14C]eicosatetraenoyl-sn-glycero-3-phosphocholine ([14C]20:4-GPC) was added to the culture medium. In macrophages + extracellular fluids, its hydrolysis at the 2-position, produced [14C]non-phosphorous lipids which reached 12% of the dose at 0.14 microM, 73% at 0.9 and > 90% at 1.6 microM; in experiments where macrophages and extracellular fluids were analyzed separately, decyloctyl-GPC initially added at 4 microM, significantly inhibited the release of [14C]fatty acids and the eicosanoid synthesis, demonstrating its ability to inhibit secreted and/or intracellular phospholipases A2. (b) Extracellular fluids were separated from the macrophages and incubated with [14C]20:4-GPC: 48% of the dose was hydrolyzed by extracellular fluid-associated secreted phospholipase A2 and decyloctyl-GPC at 3 microM, reduced this hydrolysis by 50%. (c) [3H]arachidonic acid ([3H]20:4) was added to the culture medium and was esterified in the macrophage membrane phospholipids. Activation of intracellular phospholipase A2 induced the release of [3H] fatty acids and eicosanoid synthesis. These releases were inhibited by 50% with decyloctyl-GPC added at 4 microM. (d) [3H]20:4 and [14C]20:4-GPC were added to the culture medium of the macrophages. [3H] and [14C] fatty acids and eicosanoids were released in macrophages or extracellular fluids. They were significantly reduced by the phospholipid analogue added at 4 microM. It is concluded that secreted and intracellular phospholipases A2 were both inhibited by decyloctyl-GPC which extensively reduced the 20:4 release from exogenous and membrane phospholipids and therefore eicosanoid synthesis.

High rate of intestinal absorption of the phospholipid anlaogue 1-dodecyl 2-[1-14C] octanamido-sn-2-deoxy-glycero-3-phosphocholine in the rat

The phospholipid analogue with two short fatty chains, 1-dodecyl-2-[1-14C] octanamido-sn-2-deoxy-glycero-3-phosphocholine ([14C] phospholipid analogue), with a non-hydrolyzable bond at position 2 of the glycerol, is an inhibitor of phospholipase A2. It was obtained after chemical synthesis and 0.5 micromol was solubilized in Na+ taurocholate with an equimolar amount of 1-octadecanoyl 2-[3H]eicosatetraenoyl-sn- glycero-3-phosphocholine which is the current substrate of phospholipases A2. Both molecules were introduced into the duodenum of rats in order to follow their captations by intestinal mucosa cells for 30, 60 or 90 min. The [14C] phospholipid analogue was poorly split by phospholipases A2 (pancreatic juice and intracellular enzymes). It disappeared from the intestinal contents (87% of the dose gone in 90 min) as rapidly as the tritiated lecithin (81%) but this was later split by the phospholipases at a higher rate.

Uptake of the phospholipase A2 inhibitor 1-dodecyl 2-[1-14C] octanamido-sn-2-deoxy glycero-3-phosphocholine by peritoneal macrophages

The [14C] phospholipid analogue 1-dodecyl-2-[1-14C] octanamido-sn-2-deoxy glycero-3-phosphocholine was synthetized. With 2 short fatty chains linked by alkyl and amido bonds to positions 1 and 2 of the glycerophosphate backbone, it was an inhibitor of phospholipase A2 in ionophore A23187-stimulated macrophages. Its uptake by rat peritoneal macrophages and its resistance towards phospholipases A2 were determined at nanomolar or micromolar concentrations in the culture medium. A control substrate for phospholipases A2 activity was established with the lecithin 1-octadecanoyl 2-[3H] eicosatetraenoyl-sn-glycero-3-phosphocholine ([3H] 20:4-GPC), a source of [3H] arachidonic acid after cleavage at position 2. Non-stimulated- or ionophore A23187-stimulated macrophages incorporated extensively the [14C] phospholipid analogue added at 30-4000 nM. At 4000 nM which induced 50% inhibition of the phospholipase, 40% of the dose was found associated with the [14C] phospholipids of 2 x 10(6) stimulated macrophages after 120 min incubation, while only low amounts of [14C] non-phosphorous lipids were detected. It is concluded that the [14C] phospholipid analogue was readily taken up by the macrophages with limited hydrolysis.

Quail egg yolk: a novel cryoprotectant for the freeze preservation of Poitou jackass sperm

For many years, attempts have been made to establish a sperm bank for the Poitou jackass population which is threatened with extinction. Unfortunately, no cryopreservation technique has ever been described for spermatozoa of this species. In an attempt to find a suitable technique, we studied the relative effectiveness of chicken egg yolk and quail egg yolk in preserving the motility and characteristics of movement of Poitou jackass spermatozoa during the freezing-thawing process. Semen was diluted to 60 x 10(6) sperm/ml in a preservation medium containing 4% (v/v) glycerol with 0, 2, 5, 10, 15, or 20% (v/v) of chicken or quail egg yolk. The chemical composition of these two eggs was compared. Effects were assessed using an automated analyzer which measured curvilinear velocity (VCL), straight line velocity (VSL), and the velocity of the average path. Linearity was defined as VSL/VCL x 100. The amplitude of the lateral head displacement was also measured. It was found that after the freeze-thaw process, quail egg yolk improved the percentages of motile and progressively undulating spermatozoa and the movement characteristics compared with chicken egg yolk. The optimal concentration of quail egg yolk was 10%. The general composition of the two types of egg yolk were similar, but quail egg yolk contained significantly more phosphatidylcholine, less phosphatidylethanolamine, and a smaller ratio of polyunsaturated to saturated fatty acids than chicken egg yolk. The improvement of motility for frozen-thawed Poitou jackass spermatozoa using frozen-thawed quail egg yolk compared to chicken egg yolk may be due to the differences in composition of the two yolks.

Dissociate arachidonic acid release from eicosanoid synthesis in rat peritoneal macrophages is possible using concomitantly eicosapentanoic acid as a phospholipid analogue

Activated macrophages exposed to the association of eicosapentanoic acid 20:5 n-3 and a synthetic non hydrolysable phospholipid analogue maintained a discrete synthesis of active eicosanoids. 20:4 n-6 split from the internalized 20:4-GPC was accumulated in cells and extracellular fluids. This combination thus represents a novel approach to reduce the 20:4 n-6 cascade.

Divergent selection for residual food intake in Rhode Island red egg-laying lines: gross carcase composition, carcase adiposity and lipid contents of tissues

1. A sample of 48 hens and cockerels from generation 17 of a divergent selection experiment on residual food intake was examined to determine whether the large food intake differences between those lines were associated with differences of body composition. 2. Adiposity and lipid contents of various parts of the carcase were higher in the low residual food intake line than in the high residual food intake line, both in males and females, with the cockerels of the high residual food intake line markedly lean. 3. On an equal weight basis obtained by linear correction for body weight differences, males had heavier thigh, drumstick and bones, but less adipose tissue and smaller amounts of lipids in the liver, meat, skin and abdominal adipose tissue than females.

Analysis of lipid composition of sarcoplasmic reticulum membranes from normal and malignant hyperthermic pig skeletal muscle

In search of a general membrane defect hypothesis for malignant hyperthermia syndrome, we analysed the lipid profiles of heavy sarcoplasmic reticulum membranes isolated from normal and malignant hyperthermia longissimus dorsi pig muscle. Malignant hyperthermia susceptibility was assessed by halothane challenge of pigs. Sarcoplasmic reticulum membranes from malignant hyperthermia susceptible pigs differed significantly from control ones in the cholesterol content and phosphatidylethanolamine/phosphatidylcholine ratio; both were higher in former membranes. These latter lipid modifications were in agreement with the significant increase of their bulk lipid viscosity, as evidenced by an increase of diphenyl hexatriene fluorescence anisotropy. The increased level of phosphatidylethanolamine associated with the decreased content of phosphatidylcholine in malignant hyperthermic membranes was shown to be a potential consequence of depressed activities of both phospholipid N-methyltransferase I and II activities. Finally, the distribution of fatty acids in these particular phospholipids showed no change in phosphatidylcholine molecules, whereas the percentage of arachidonate and stearate in the phosphatidylethanolamine species were respectively higher and lower in malignant hyperthermic membranes. These differences in major phospholipids content and the enrichment of a metabolically important fatty acyl chains in malignant hyperthermia sarcoplasmic reticulum membranes strongly suggest that the lipid metabolism may contribute to the molecular mechanism of malignant hyperthermia syndrome.

Comparative changes in the lipogenic enzyme activities and in the in vivo fatty acid synthesis in liver and adipose tissues during the post-weaning growth of male rats

Changes in the specific activities of acetyl-CoA-carboxylase (ACX), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G-6-PD) were compared to changes in de novo lipogenesis measured by in vivo incorporation of [3H] of tritiated water into fatty acids of liver and of perirenal and dorsal subcutaneous adipose tissues. In the adipose tissues, the specific activities of the three enzymes rather closely followed fluctuations in the rate of fatty acid synthesis. In the liver, ACX and especially ME activities were satisfactory indicators of de novo lipogenesis; G-6-PD activity did not depend on de novo lipogenesis.

Relative contribution of the main tissues and organs to body fatty acid synthesis in the rat

Tritiated water was used to measure the rate of fatty acid synthesis in the main tissues and organs of 7-week old Wistar male rats in order to determine the relative contribution of each tissue to body fatty acid synthesis. We reached the following conclusions: (a) the liver is the main site of fatty acid synthesis, it alone synthesizes 42% of the newly synthesized fatty acids in the body. (b) The dissectable white adipose tissues synthesize 27% of the fatty acids in the body. This group of tissues is heterogeneous because the mesenteric adipose tissue alone contains 40% of the labeled fatty acids present in the white adipose tissues. (c) Besides the intestines, organs other than the liver play a negligible role (2% of the total) in fatty acid synthesis. (d) The skin contributes 7% of the body fatty acid synthesis. (e) The rest of the carcass, essentially composed of the musculature and the skeleton, contributes 18% of body fatty acid synthesis and accounts for 33% of the extrahepatic tissue fatty acid synthesis.

Lipogenic capacity and relative contribution of the different tissues and organs to lipid synthesis in male rat

The rates of 3H2O incorporation into total lipids and fatty acids were measured in vivo in the different organs and tissues of 7-week old male Wistar rats to compare the lipogenic capacity of those organs and tissues and to determine their relative contributions to body lipid synthesis. Our results were the following; (1) liver was the major site of the synthesis of total lipids and fatty acids (37 and 42%, respectively, of body synthesis); (2) white adipose tissues synthesized about 24% of the total lipids; mesenteric adipose tissue alone synthesizing 40% of the fatty acids produced in dissectable white adipose tissues; (3) skin showed low lipid synthesis but played an appreciable role in that synthesis (8% of the total) due to its large contribution to total body weight; (4) other organs (excluding liver) showed low lipid synthesis; however, that of the small intestine was 1-2% of body synthesis; (5) the rest of the carcass (mainly musculature and skeleton) contributed 25% to body lipid synthesis. The putative roles of the different tissues and organs in adipose tissue development have been discussed.

[De novo lipogenesis: kinetics of in vivo incorporation of tritiated water 3H into fatty acids and total lipids of the liver, plasma, adipose tissue and carcass of the male rat]

Tritiated water 3H, injected by intraperitoneal route into 7-week old male Rats, was incorporated into lipids synthesized de novo. The Rats were killed 0, 3, 7, 10, 15, 30, 60 and 120 min. after tracer injection. The results show that an optimal interval of about 10 min. between tracer injection and animal sacrifice was necessary to obtain a correct estimate of lipogenesis de novo by avoiding intertissue exchanges.