Fatty Acids Of Different Degree Research Articles

Effect of different rumen-inert fatty acids supplemented with a dietary antioxidant on performance and antioxidative status of early-lactation cows

The objective of the study was to evaluate the effect of diets supplemented with fatty acids of different degrees of saturation, in the absence or presence of an antioxidant (AOX; Agrado Plus, Novus International Inc., St. Charles, MO), on dairy cow lactation performance. Calcium salts of long-chain fatty acids were supplemented as a source of lower saturation fatty acid, and a palm acid product was supplemented as the higher saturation fatty acid source. Sixty early-lactation Chinese Holstein cows (100±23 d in milk) were randomly allocated to 4 dietary treatments in a 2 × 2 factorial design: (1) lower saturation fatty acid (LS), (2) LS and AOX, (3) higher saturation fatty acid (HS), and (4) HS and AOX. The Ca salts of long-chain fatty acids and palm acid product were supplied at 1.8 and 1.5% on a dry matter basis, respectively, to form isoenergetic diets. The AOX was added at 0.025% in the ration. The experiment lasted 9 wk, including 1 wk for adaptation. Lactation performance was recorded and milk was sampled and analyzed weekly. Blood samples were taken from the coccygeal vein to determine metabolism parameters on d 16, 36, and 56 during the experiment. Neither fatty acid type nor AOX supplementation showed a significant effect on dry matter intake during the study. Milk yield was lower in the LS-fed cows compared with the cows fed HS. Milk fat and milk protein concentrations were not affected by fatty acid type or AOX supplementation. Adding AOX increased the yield of milk in the LS-fed cows, but did not affect those fed HS. Activity of plasma superoxide dismutase was significantly lower, plasma glucose tended to be lower, and plasma malondialdehyde was higher in the LS-fed animals compared with those fed HS. Addition of AOX decreased both plasma nonesterified fatty acids and hydrogen peroxide contents and increased total antioxidant capacity across the fatty acid types. Plasma β-hydroxybutyrate was not affected by fatty acid type or AOX treatment. Cows fed LS had higher cis-9C18:1 and trans-10, cis-12C18:2 in milk at the expense of C18:0, whereas AOX addition increased milk cis-9C18:1 at the expense of milk C12:0, C16:0, and trans-10, cis-12C18:2. It is inferred that feeding LS resulted in inferior lactation performance, whereas addition of antioxidant partially alleviated these negative effects.

Oxidative stability of structured lipids containing C18:0, C18:1, C18:2, C18:3 or CLA in sn2-position – as bulk lipids and in milk drinks

In this study, we compared the oxidative stability of a specific structured lipid (SL) containing conjugated linoleic acid (CLA) in the sn2-position with SL containing other C18 fatty acids of different degree of unsaturation (stearic, oleic, linoleic or linolenic acid). SL was produced by enzymatic interesterification with caprylic acid. Oxidative stability was compared in the five lipids themselves and in milk drinks containing 5% of the different SL. During storage, samples were taken for chemical and physical analyses. Moreover, sensory assessments were performed on milk drinks. The oxidative stability of our SL was very different when comparing (a) bulk lipids and milk drink and (b) the five different batches of each product. SL based on oleic acid was the most unstable as bulk lipid, while SL based on linoleic acid was the most unstable in milk drink. SL based on CLA was the second most unstable in both products.

Oxidative stability of structured lipids containing C18:0, C18:1, C18:2, C18:3 or CLA in sn2-position ? as bulk lipids and in milk drinks*1

In this study, we compared the oxidative stability of a specific structured lipid (SL) containing conjugated linoleic acid (CLA) in the sn2-position with SL containing other C18 fatty acids of different degree of unsaturation (stearic, oleic, linoleic or linolenic acid). SL was produced by enzymatic interesterification with caprylic acid. Oxidative stability was compared in the five lipids themselves and in milk drinks containing 5% of the different SL. During storage, samples were taken for chemical and physical analyses. Moreover, sensory assessments were performed on milk drinks. The oxidative stability of our SL was very different when comparing (a) bulk lipids and milk drink and (b) the five different batches of each product. SL based on oleic acid was the most unstable as bulk lipid, while SL based on linoleic acid was the most unstable in milk drink. SL based on CLA was the second most unstable in both products.

Free Radical-Mediated Lipid Peroxidation in Cells: Oxidizability Is a Function of Cell Lipid bis-Allylic Hydrogen Content

Oxidizability of lipids in homogeneous solution varies linearly with the extent of their unsaturation. In vitro cellular, as well as in vivo, studies of oxidizability have generally relied upon chemical indicators of peroxidation such as thiobarbituric acid-reactive substances. To examine the oxidizability of lipids in cells, we have measured oxygen uptake and, using electron paramagnetic resonance spin trapping with alpha-(1-oxo-4-pyridyl)-N-tert-butylnitrone (POBN), the real time generation of lipid-derived free radicals. We have used our experimental in vitro cellular lipid modification model to examine the rate and extent of lipid peroxidation versus the degree of lipid unsaturation in L1210 murine leukemia cells. Lipid peroxidation was stimulated using the prooxidants iron, ascorbate, and the ether lipid compound 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine. We did a total cellular lipid analysis to determine the number of lipid carbon-carbon double bonds contained in L1210 cells enriched with eight fatty acids of different degrees of unsaturation. We found in cellular lipids that (i) lipid chain length had no apparent effect on the rate or extent of radical formation; (ii) the maximum amount of lipid radical generated increases with the total number of bis-allylic positions in the cellular lipids; and, most importantly, (iii) the rate of cellular lipid peroxidation increases exponentially with the number of bis-allylic positions. Our quantitative results clearly demonstrate, for the first time, that the number of bis-allylic positions contained in the cellular lipids of intact cells determines their susceptibility, i.e., oxidizability, to free radical-mediated peroxidative events.

Heightened susceptibility of fish oil polyunsaturate-enriched neoplastic cells to ethane generation during lipid peroxidation.

We have studied the generation of volatile hydrocarbons by fatty acid-modified L1210 leukemia cells in tissue culture as a measure of lipid peroxidation. There was considerable generation of ethane, and this was dependent on cell number and Fe2+ concentration; it was eliminated by antioxidants and augmented by ascorbic acid. The assay was sensitive and reproducible; ethane was detected when as little as 0.03% of the cellular n-3 (omega-3) fatty acids were peroxidized. To gain further understanding we used a lipid modification model that allows study of cells enriched with fatty acids of different degrees of unsaturation. The quantity of ethane generated was greatest by cells modified with fatty acids of the n-3 family, and there was a high direct correlation of percentage of n-3 fatty acids contained in cellular lipids with peroxidation as measured by ethane generation. Ethane generation was more sensitive in detecting peroxidation than loss of polyunsaturated fatty acids. We conclude that lipid-supplemented leukemic cells produce ethane, and that the rate of generation is a sensitive, quantitative, and highly useful measure of lipid peroxidation when small amounts of iron are present.

Different metabolism of saturated and unsaturated long chain plasma free fatty acids by intestinal mucosa of rats.

AbstractDuring fat absorption, unsaturated long chain fatty acids are esterified at a higher rate than saturated fatty acids of similar chain length. This phenomenon has been attributed to differences in the binding affinity of fatty acids to a cytosolic fatty acid‐binding protein. As intestinal mucosa utilizes plasma free fatty acids as well, we investigated whether long chainplasma free fatty acids of different degree of saturation are metabolized also at different rates.3H‐Palmitic and14C‐linoleic acid complexed to rat serum were injected rapidly into a tail vein of fasting rats. One, 2 and 4 min later there was no difference between3H and14C‐radioactivity in intestinal mucosa, suggesting equal initial uptake of the two labeled fatty acids from plasma. Despite their equal uptake, the incorporation of the isotopes into ester lipids was significantly different, however: at 2 min, 53.1±3.9% of3H and 73.8±4.6% of14C were recovered in ester lipids. Phospholipids and triglycerides accounted for most of the mucosal3H and14C. At 4 min, a similar distribution of isotopes in intestinal mucosal metabolites was found. These data show that despite equal initial uptake by intestinal mucosa unsaturated long chain fatty acids taken up from plasma are esterified to a higher and oxidized to a lower extent than saturated plasma free fatty acids. Unsaturated plasma free fatty acids, therefore, may provide a more important source of fatty acids for endogenous intestinal lipoprotein lipids than saturated plasma free fatty acids. It is speculated that the fatty acid binding protein might be operative not only in the intracellular transport and metabolism of luminal fatty acids but of plasma free fatty acids as well.

Gas chromatographic separation of cholesteryl esters of fatty acids of different degrees of unsaturation.

Cholesteryl esters prepared from the fatty acid methyl esters of linseed oil, pig liver lipids, and Japanese anchory oil have been separated on the basis of their chain lengths and number of double bonds by gas liquid chromatography on a cyanosiloxane SILAR 10C column. The equivalent chain lengths of cholesteryl esters having acyl groups with 14-22 carbons and 0-6 double bonds are presented. A significant influence of the column temperature on the equivalent chain lengths of the polyenoic fatty acid cholesteryl esters has been found. Separation of the cholestanyl and epicholestanyl esters of linseed oil fatty acids, respectively, under the same conditions is also described.

Incorporation of stearate-1-C 14 and oleate-1-C 14 into phosphatidyl choline and phosphatidyl ethanolamine of rat liver mitochondria

Total liver phospholipids containing fatty acids of different degrees of unsaturation have been demonstrated by P 32 incorporation studies to be synthesized at different rates (1, 2). Since the individual phospholipid species each have a characteristic fatty acid composition, the addition to the diet of some fatty acids may stimulate the synthesis of some types of phospholipids more than others. The addition of cholesterol to the diet, particularly with unsaturated fat, has been found to decrease the rate of incorporation of P 32 into the liver total phospholipids and to produce marked alterations in liver phospholipid fatty acid composition (2, 3). Of the individual phospholipid classes, mitochondria have been demonstrated to contain and synthesize primarily phosphatidyl choline and phosphatidyl ethanolamine (4). The purpose of the present study was to determine the rates of incorporation of exogenous stearate and oleate into these two phospholipids and to determine the effects and possible mode of action of cholesterol on these incorporation rates.

The influence of exogenous cholesterol on hepatic lipid composition of the rat

Rats were fed diets containing cottonseed oil and/or cholesterol, cholic acid, methyl esters of long-chain fatty acids, and tocopherol. Livers, hearts, and aortas were examined histologically; liver lipids were fractionated by silicic acid chromatography; and the fatty acid composition of the sterol esters, triglycerides, and phospholipids was determined by gas-liquid chromatography. The degree of deposition of liver sterol esters seemed to be related to the availability of dietary fatty acids for esterification with exogenous cholesterol. No differences in sterol ester deposition were noted among the groups in which the dietary cholesterol was supplemented with methyl esters of fatty acids of different degrees of unsaturation. Fatty acid analysis revealed an accentuation by cholesterol feeding of the increase in monoenoic fatty acids and the decrease of linoleic and arachidonic acids characteristic of essential fatty acid deficiency. Two eicosatrienoic acids, occurring primarily in the phospholipids, were identified. The 5,8,11-eicosatrienoic acid appears to be related to essential fatty acid deficiency, whereas the 8,11,14-isomer is probably an intermediate in the conversion of linoleic to arachidonic acid and is increased when exogenous cholesterol induces an increased arachidonic acid synthesis.

Binary freezing‐point diagrams for alpha‐ and beta‐eleostearic acids with each other and with acetamide

SummaryComplete binary freezing‐point data have been obtained for each of the polymorphic modifications of acetamide with alpha‐eleostearic acid and beta‐eleostearic acid and for alpha‐eleostearic acid with beta‐eleostearic acid. In the light of previously published data the fact that all of these systems are of the simple eutectic type suggests that the tendency of the long‐chain fatty acids to form 1∶1 molecular compounds with acetamide and with each other decreases as the degree of unsaturation increases.The fact that the heat of fusion of beta‐eleostearic acid, 13.2 kcal. per mole, calculated from the freezing‐point data is greater than that for the alpha acid, 10.5 kcal. per mole, corroborates the conclusion that the beta acid is the trans‐trans‐trans modification. Calculations of heats of fusion have been made, based upon all the available freezing‐point data in the literature for binary systems between pairs of C18 fatty acids of different degrees of unsaturation, and certain trends have been dsicussed.