Concentrations Of Long-chain Fatty Acids Research Articles

Muscular long-chain fatty acid content during graded exercise in humans.

We measured the content of long-chain fatty acids (LCFA) in biopsies obtained from the vastus lateralis muscle in humans at rest and after different exercise intensities. Nine volunteers exercised at 65% of maximal oxygen uptake (VO2 max) for 40 min and at 90% of VO2 max for another 15 min on a Krogh bicycle ergometer. LCFA measured in muscle tissue averaged 76 +/- 5 nmol/g wet wt at rest, decreased significantly after exercise at 65% VO2 max to 48 +/- 4 nmol/g wet wt, and increased to 68 +/- 5 nmol/g wet wt (P < 0.05) after high-intensity exercise. The calculated myocyte LCFA content at rest amounted to 69 +/- 5 nmol/g wet wt, decreased by 43% (P < 0.05) after exercise at 65% of VO2 max, and subsequently increased by 54% after exercise at 90% of VO2 max (P < 0.05) compared with the values obtained at the lower workload. The blood plasma LCFA concentration during the low-intensity exercise (366 +/- 23 nmol/ml) was similar to the values obtained at rest (372 +/- 31 nmol/ml) but decreased significantly during the high-intensity workload (249 +/- 49 nmol/ml). From these data it is proposed that 1) in human skeletal muscle, metabolism rather than cellular availability of LCFA governs the rate of LCFA utilization at rest and during exercise, and 2) consequently reduction in muscle LCFA oxidation during high-intensity exercise (e.g., 90% VO2 max) is due primarily to a decrease in mitochondrial LCFA oxidation rate rather than an insufficient cellular availability of LCFA.

Effect of anatomical location on the composition of fatty acids in double-muscled Belgian Blue cows

Double-muscled cows of the Belgian Blue breed, ranging from ca. 680 to 880 kg live weight were slaughtered and various fat depots sampled for lipid analysis. Subcutaneous fat (SCF), intermuscular fat in m. serratus (IMF1) and m. transversalis (IMF2), kidney fat (KF) and intramuscular fat in m. longissimus thoracis (IMF3) were sampled. In IMF3 samples, polar lipids were separated from other lipid classes by thin layer chromatography. Both the proportions ( w w %) and gravimetric concentrations (mg g −1 of sample) of long-chain fatty acids were determined in total lipids of SCF, IMF1, IMF2, KF and in lipid classes of IMF3 by gas chromatography. The greatest concentration of total fatty acids was found in KF (777.6 ± 82.6 mg g −1), followed by SCF (721.3 ± 92.2 mg g −1), IMF2 (709.8 ± 72.5 mg g −1) and IMF1 (682.1 ± 71.6 mg g −1). Triacylglycerol and polar lipid fatty acid content of m. longissimus thoracis (IMF3) were respectively 8.1 ± 3.3 and 3.1 ± 0.6 mg g −1. Fatty acid content, particularly the triacylglycerol fatty acid content in IMF3, increased ( p < 0.01) with increasing carcass fat content. Polar lipid fatty acids in IMF3 contained a higher proportion of polyunsaturated fatty acids (32.6 ± 4.8 %) and lower proportion of saturated fatty acids (27.4 ± 5.0%) compared to the triacylglycerol fatty acid fraction ( p < 0.01), which may reflect a prerequisite for proper membrane functioning. Internal fat depots were more saturated ( p < 0.01) compared to SCF. The proportion of monounsaturated fatty acids differed ( p < 0.01) between IMF1 and IMF2, possibly reflecting differences in muscle activity and functioning. Oleic (C18:1) and stearic (C18:0) acids comprised more than 60% of the total fatty acids in all anatomical locations.

Stratum corneum lipid composition and structure in cultured skin substitutes is restored to normal after grafting onto athymic mice.

Restoration of an epidermal barrier is a definitive requirement for wound closure. Cultured skin substitutes grafted onto athymic nude mice were used as a model for a long-term study of stratum corneum barrier lipid metabolism and organization. Samples of stratum corneum collected after 12 and 21 d in vitro and 6, 11, and 24 mo postgrafting were examined for their lipid and fatty acid composition, and their lipid organization and structure using electron microscopy and small angle X-ray diffraction, respectively. All of these methods confirm the impaired barrier function of cultured skin substitutes in vitro, as judged from the deviations in lipid composition and from poor organization of the stratum corneum lipids that show no lamellar structure. At 6 mo postgrafting, the total stratum corneum lipid profiles of the epidermal grafts is close to that of the human stratum corneum with the exception of the presence of mouse specific lipids. The increase of ceramides 4-7 in cultured skin substitutes after grafting indicates restored activity of processes involved in the hydroxylation of fatty acids and sphingoid bases. Conversely, the ceramide profile still reveals some abnormalities (elevated content of ceramide 2 and slightly lower content of ceramide 3) and the content of long-chain fatty acids remains below its physiologic level at 6 mo postgrafting, but normalizes by 2 y postgrafting. The ultramicroscopic observations revealed the formation of lamellar extracellular lipid domains by 4 mo postgrafting. Despite these findings, the X-ray diffraction showed differences in the diffraction pattern at 2 y after grafting, suggesting that the organization of stratum corneum lipids in all epidermal grafts differs from that of the native skin.

Development and regulation of glucose-6-phosphatase gene expression in rat liver, intestine, and kidney: in vivo and in vitro studies in cultured fetal hepatocytes.

The mRNA and the activity of glucose-6-phosphatase (Glc-6-Pase) were present in the liver, kidney, and small intestine of 15-day-old suckling rats, but were absent from the stomach, colon, lung, white and brown adipose tissues, muscle, heart, brain, and spleen. The mRNA encoding Glc-6-Pase was present in the liver of 21-day-old fetal rats and increased markedly immediately after birth. From 5 days after birth to the end of the suckling period, it returned to 50% of the level found in the liver of 48-h starved adult rats. When rats were weaned at 21 days onto a high-carbohydrate, low-fat (HCLF) diet, the concentration of liver Glc-6-Pase mRNA was markedly increased. In the fetal rat jejunum, the activity and mRNA of Glc-6-Pase were very low. It increased during the 5 days after birth and then declined to reach very low levels. Neither mRNA nor activity of Glc-6-Pase was present in the fetal kidney. They appeared and increased slowly during the suckling period to reach maximal levels 15 days after birth and then remained constant. Weaning onto the HCLF diet did not change the Glc-6-Pase gene expression, neither in the jejunum nor in the kidney. The regulation of Glc-6-Pase gene expression by hormones and nutrients was studied in cultured hepatocytes from 20-day-old rat fetuses. Bt2cAMP stimulated the Glc-6-Pase gene expression in a dose-dependent manner. This probably resulted from an increased gene transcription since the half-life of the transcript was not affected by dibutyryl cAMP (Bt2cAMP). The Bt2cAMP-induced Glc-6-Pase mRNA accumulation was antagonized by insulin in a dose-dependent manner. Long-chain fatty acids (LCFAs), but not medium-chain fatty acids, induced the accumulation of Glc-6-Pase mRNA and the stabilization of the transcript. The peroxisome proliferator, clofibrate, induced a threefold increase in Glc-6-Pase mRNA concentration. Both stimulation of Glc-6-Pase mRNA by LCFAs and clofibrate were inhibited by insulin. Increasing concentrations of glucose (from 0 to 20 mmol/l) did not affect the Bt2cAMP-induced Glc-6-Pase gene expression. By contrast, high glucose concentration (25 mmol/l) markedly induced the Glc-6-Pase gene expression in fed adult rat hepatocytes. The difference in the response to glucose between fetal and adult rat hepatocytes is discussed. We conclude that the rapid increase in hepatic Glc-6-Pase mRNA levels that accompanies the fetal-to-neonatal transition in the rat is triggered by the reciprocal change in circulating insulin and LCFA concentrations, coupled to the rise in liver cAMP concentration.

Contraction-induced increase in Vmax of palmitate uptake and oxidation in perfused skeletal muscle.

To evaluate the effects of contractions on the kinetics of uptake and oxidation of palmitate in a physiological muscle preparation, rat hindquarters were perfused with glucose (6 mmol/l), albumin-bound [1-14C]palmitate, and varying amounts of albumin-bound palmitate (200-2,200 micro mol/l) at rest and during muscle contractions. When plotted against the unbound palmitate concentration, palmitate uptake and oxidation displayed simple Michaelis-Menten kinetics with estimated maximal velocity (Vmax) and Michaelis-Menten constant (Km) values of 42.8 +/- 3.8 (SE) nmol . min-1 . g-1 and 13.4 +/- 3.4 nmol/l for palmitate uptake and 3.8 +/- 0.4 nmol . min-1 . g-1 and 8.1 +/- 2.9 nmol/l for palmitate oxidation, respectively, at rest. Whereas muscle contractions increased the Vmax for both palmitate uptake and oxidation to 91.6 +/- 10.1 and 16.5 +/- 2.3 nmol . min-1 . g-1, respectively, the Km remained unchanged. Vmax and Km estimates obtained from Hanes-Woolf plots (substrate concentration/velocity vs. substrate concentration) were not significantly different. In the resting perfused hindquarter, an increase in palmitate delivery from 31.9 +/- 0.9 to 48.7 +/- 1.2 micro mol . g-1 . h-1 by increasing perfusate flow was associated with a decrease in the fractional uptake of palmitate so that the rates of uptake and oxidation of palmitate remained unchanged. It is concluded that the rates of uptake and oxidation of long-chain fatty acids (LCFA) saturate with an increase in the concentration of unbound LCFA in perfused skeletal muscle and that muscle contractions, but not an increase in plasma flow, increase the Vmax for LCFA uptake and oxidation. The data are consistent with the notion that uptake of LCFA in muscle may be mediated in part by a transport system.

Biosorption of long-chain fatty acids in UASB treatment process

Biosorption of long-chain fatty acids (LCFA) in the upflow anaerobic sludge blanket (UASB) treatment process was investigated using batch tests and continuous reactor runs. Batch experiments were conducted, for characterization of the biosorption, with two active and one inactivated (autoclaved) sludge granules as sorbents and with a single (oleic acid) or a mixture of LCFA (LCFA m; 50% oleic, 35% palmitic and 15% stearic acid) as sorbates. The LCFA m showed a faster adsorption onto the granules than oleic acid. With the active sludge granules, adsorption was followed by desorption. Methane production increased significantly, either simultaneously (at lower LCFA concentrations) or succeedingly (at higher concentrations) with desorption. The desorption was mediated by biological activity, since it did not prevail with inactivated granules or with active granules inhibited at higher LCFA m concentrations. The inactivated granules had a slightly higher initial biosorption capacity. Increased LCFA concentrations resulted in more LCFA adsorbed and greater inhibition of their biodegradation. A hypothesis is proposed to explicate the relationship between biosorption, desorption and biodegradation of LCFA by sludge granules: adsorption is a prerequisite for biodegradation while desorption is a consequence of biodegradation. Isothermal studies with oleate showed that the apparent biosorption could be described by the physical multilayer adsorption theory and the sorption isotherm derived was consistent with the Freundlich model. The quantitative relation between LCFA biosorption and granular sludge flotation was investigated in a UASB reactor fed with LCFA m. Sludge flotation depended on the LCFA m loading rate rather than on their concentration. The higher the loading implemented, the more flotation occurred and the shorter time required for complete flotation of the sludge bed. Flotation started when the LCFA m loading rate exceeded 0.09 g COD/g VSS·d, while complete flotation occurred at the loading rates exceeding 0.2 g COD/g VSS·d. These results suggest that sludge bed wash-out is likely to be encountered before inhibition of methanogenesis during the treatment of LCFA-containing wastewaters by the UASB process.

Hen age and fatty acid composition of egg yolk lipid

1. Total lipid, total cholesterol, and phospholipid contents per gram of egg yolk were found to be the same for eggs from 21 and 57 week-old hens. 2. In contrast, fatty acid composition of total egg yolk lipid was different for the 2 groups of hens. The contents of long-chain (20 C and 22 C) polyunsaturated fatty acids of n-6 and n-3 series were 20% to 25% higher in egg yolks from the younger hens. 3. This finding is discussed with respect to the nutritional value of eggs from hens of different ages regarding the use of egg yolk lipid in the production of infant formulae.

Training and fatty acid metabolism.

Older studies in humans seem to suggest a correlation between plasma long chain fatty acid (LCFA) turnover and oxidation on the one hand and plasma LCFA concentration on the other hand during submaximal exercise. However, recent studies in man, in which higher concentrations of plasma LCFA have been reached during prolonged submaximal exercise, have revealed a levelling off in net uptake in spite of increasing plasma LCFA concentrations. Furthermore, this relationship between plasma LCFA concentration and plasma LCFA uptake and oxidation was altered by endurance training such that levelling off was not apparent in the trained state. These recent findings in man give support to the notion from other cell types that transport of fatty acids from the vascular compartment to the cytosolic space in the muscle cell is not only due to simple diffusion, but is predominantly carrier-mediated. During prolonged submaximal knee-extension exercise it has been demonstrated that the total oxidation of LCFA was approximately 60% higher in trained compared to nontrained subjects. The training-induced adaptations responsible for this increased utilization of plasma fatty acids by the muscle could be located at several steps from the mobilization of fatty acids to skeletal muscle metabolism in the mitochondria. To what extent triacylglycerol located in the muscle cell contribute to the overall lipid utilisation during exercise is still not clear. However, due to underestimation of the contribution of plasma LCFA and fatty acids liberated from the circulating VLDL-triacylglycerols to the overall fatty acid oxidation during exercise there is increasing understanding that muscle triacylglycerol contributes to a lesser extent as fuel during exercise in man than mostly stated.

Changes in lipids and membrane anisotropy in human spermatozoa during epididymal maturation

Previously it was demonstrated that immature and immotile human spermatozoa from the caput epididymides developed a good progressive motility after in-vitro stimulation with phosphatidylcholine (PC). In order to define the role of PC and membrane anisotropy in epididymal maturation and to determine the exact lipid composition of human spermatozoa during epididymal maturation, spermatozoa from seven epididymides from patients who underwent orchiectomy because of prostatic cancer were investigated. Lipids were determined by high-performance thin-layer chromatography and gas chromatography. Membrane anisotropy was measured by fluorescence polarization. The ratio between PC and phosphatidylserine (PS) plus phosphatidyl ethanolamine (PE) plus sphingomyelin (SM) was significantly higher in spermatozoa from the cauda compared to those from the caput and corpus. This was due to an increase of PC and a decrease of the concentration of PS plus PE plus SM. With regard to fatty acids, those with saturated chains predominated in caput spermatozoa while the highest concentration of unsaturated long-chain fatty acids was in cauda spermatozoa. A lower membrane anisotropy of cauda spermatozoa compared with caput or corpus spermatozoa was found. In conclusion, during epididymal maturation human spermatozoa integrate lipids, particularly PC, which is strongly associated with the induction of progressive motility. A change in the pattern of fatty acids and a decrease in the cholesterol/phospholipid molar ratio cause a decrease in membrane anisotropy in cauda spermatozoa.

Plasma lipids, erythrocyte membrane lipids and blood pressure of hypertensive women after ingestion of dietary oleic acid from two different sources.

To study the effect of a diet rich in mono-unsaturated fatty acids (MUFA), from high-oleic sunflower oil (HOSO) and olive oil, on plasma lipids, erythrocyte membrane lipids (including fatty acid composition) and blood pressure of hypertensive (normocholesterolaemic or hypercholesterolaemic) women. There were 16 participants who were hypertensive women aged 56.2 +/- 5.4 years. The participants ate a diet enriched with HOSO or olive oil for two 4-week periods with a 4-week washout period before starting the second type of MUFA diet. At entry and during study of each diet, plasma lipids and apolipoproteins were measured by conventional enzymatic methods. Erythrocyte membrane lipid and fatty acid compositions were analysed by means of the latroscan thin-layer chromatography/flame ionization detection technique and by gas chromatography, respectively. Blood pressure was also measured. The statistical analysis was conducted by using Student's two-tailed paired t-test. In both groups of hypertensive patients, there was a significant increase in plasma high-density lipoprotein (HDL) cholesterol concentration after the HOSO or olive oil diets, with regard to baseline. Additionally, a significant decrease in plasma HDL2 cholesterol concentration and an increase in plasma HDL3 cholesterol concentration were evident. The membrane free-cholesterol concentration increased significantly and the phospholipid concentration decreased significantly in erythrocytes after the olive oil diet, though both MUFA diets produced a significant decrease in the concentration of membrane esterified cholesterol. Therefore, the molar ratio of cholesterol to phospholipids was raised significantly in the erythrocyte membrane of hypertensive women after the dietary olive oil, but not after the HOSO diet. In the hypertensive and normo-cholesterolaemic group the HOSO diet significantly increased the content in the erythrocyte membrane of oleic, eicosenoic, arachidonic and docosapentaenoic acids, whereas the olive oil diet increased the content of palmitoleic acid and long-chain polyunsaturated fatty acids of the n-3 family besides, compared with baseline. A significant decrease in linoleic acid was also evident. In the hypertensive and hypercholesterolaemic group, the HOSO diet resulted in significant increases in palmitoleic, oleic, eicosenoic and behenic acids, whereas the olive oil diet enhanced the content of arachidonic, docosapentaenoic and docosahexaenoic acids besides, with respect to baseline. In addition, there was a significant decrease in stearic acid, but only after dietary olive oil was there a decrease in linoleic acid. The most important differences between the two MUFA diets were the increase in n-3 fatty acids and the decrease in the n-6; n-3 fatty acids ratio after dietary olive oil in the erythrocyte membranes of hypertensive patients. Interestingly, a significant reduction in systolic and diastolic blood pressures was only evident after the ingestion of olive oil. These data suggest that the beneficial effects of dietary olive oil on the plasma lipids and lipoprotein profile, lipid and fatty acid composition of erythrocyte membrane, and blood pressure in women with untreated essential hypertension are not found equally for the HOSO-rich diet, despite both vegetable oils providing a similar concentration of MUFA.

Characteristics of Milk and Reduced Fat Cheddar Cheese from Cows Fed Extruded Soybeans and Niacin

A control diet and three experimental diets were fed to midlactation Holstein cows to evaluate the effects of dietary unsaturated fatty acids and niacin on milk and reduced fat Cheddar cheese. The diet consisted mainly of rolled corn and soybean meal in the concentrate mixture. Experimental diets consisted of the control diet with added niacin and the control diet but with extruded soybeans substituted for part of the corn and soybean meal, with and without added niacin. Milks from cows fed diets of extruded soybean and extruded soybeans with added niacin contained lower concentrations of short- and medium-chain fatty acids and higher concentrations of long-chain fatty acids. Cheese milks consisted of a control, a homogenized control (3.45MPa), and unhomogenized and homogenized milks (3.45MPa) from cows fed extruded soybeans with added niacin. Reduced fat Cheddar cheeses produced from unhomogenized and homogenized milks from the cows fed extruded soybeans with added niacin contained higher concentrations of unsaturated fatty acids. The reduced fat Cheddar cheeses maintained acceptable flavor, body, and texture during storage. Homogenization of cheese milk had little effect on cheese properties. Cheeses manufactured from milks with high amounts of unsaturated fatty acids were softer; however, this difference was not detected by the sensory panel.

Lactational Responses of Dairy Cows Fed Unsaturated Fat from Extruded Soybeans or Sunflower Seeds

Nine multiparous Holstein cows were used in a replicated 3 x 3 Latin square to evaluate the response to diets containing equal amounts of supplemental fat from extruded soybeans or sunflower seeds. Both fat sources contained about 66% polyunsaturated fatty acids; for soybeans, about 8% was linolenic acid, but sunflower seeds contained mostly linoleic acid. Periods were 5 wk, and data were collected the last 3 wk of each period. Total mixed diets were (DM basis) 25% corn silage, 25% alfalfa hay, and 50% concentrate mix. Control concentrate mix contained primarily corn, barley, and soybean meal; extruded soybeans or rolled sunflower seeds replaced portions of the corn, barley, and soybean meal in isonitrogenous (17% CP) diets. Milk yield was higher for cows fed supplemental fat. Percentages of milk fat and protein and DMI were similar for all three dietary treatments. Milk fat from cows fed soybeans or sunflower seeds contained higher concentrations of unsaturated fatty acids and long-chain fatty acids than did milk fat from cows fed the control diet. Milk yield and composition were similar for cows fed soybeans or sunflower seeds. Soybeans or sunflower seeds can be used as dietary fat supplements to increase milk yield and the proportion of unsaturated fatty acids in milk fat.

Cyclic AMP and fatty acids increase carnitine palmitoyltransferase I gene transcription in cultured fetal rat hepatocytes.

In the rat, the gene for liver mitochondrial carnitine palmitoyltransferase I (CPT I), though dormant prior to birth, is rapidly activated postnatally. We sought to elucidate which hormonal and/or nutritional factors might be responsible for this induction. In cultured hepatocytes from 20-day-old rat fetus, the concentration of CPT I mRNA, which initially was very low, increased dramatically in a dose-dependent manner after exposure of the cells to dibutyryl cAMP (Bt2cAMP). Similar results were obtained when long-chain fatty acids (LCFA), but not medium-chain fatty acids, were added to the culture medium. The effects of Bt2cAMP and LCFA were antagonized by insulin, also dose dependently. In contrast, CPT II gene expression, which was already high in fetal hepatocytes, was unaffected by any of the above manipulations. Bt2cAMP stimulated CPT I gene expression even when endogenous triacylglycerol breakdown was suppressed by lysosomotropic agents suggesting that the actions of cAMP and LCFA were distinct. Moreover, half-maximal concentrations of Bt2cAMP and linoleate produced an additive effect CPT I mRNA accumulation. While linoleate and Bt2cAMP stimulated CPT I gene transcription by twofold and fourfold, respectively, the fatty acid also increased the half-life of CPT I mRNA (50%). When hepatocytes were cultured in the presence of 2-bromopalmitate, (which is readily converted by cells into its non-metabolizable CoA ester) CPT I mRNA accumulation was higher than that observed with oleate or linoleate. Similarly, the CPT I inhibitor, tetradecylglycidate, which at a concentration of 20 microM did not itself influence the CPT I mRNA level, enhanced the stimulatory effect of linoleate. The implication is that induction of the CPT I message by LCFA does not require mitochondrial metabolism of these substrates; however, formation of their CoA esters is a necessary step. Unlike linoleate, the peroxisome proliferator, clofibrate, increased both CPT I and CPT II mRNA levels and neither effect was offset by insulin. It thus appears that the mechanism of action of LCFA differs from that utilized by clofibrate, which presumably works through the peroxisome proliferator activated receptor. We conclude that the rapid increase in hepatic CPT I mRNA level that accompanies the fetal to neonatal transition in the rat is triggered by the reciprocal change in circulating insulin and LCFA concentrations, coupled with elevation of the liver content of cAMP.

The effect of intracellular pH on long-chain fatty acid uptake in 3T3-L1 adipocytes: evidence that uptake involves the passive diffusion of protonated long-chain fatty acids across the plasma membrane.

To understand the mechanism of long-chain fatty acid permeation of the plasma membrane in mammalian cells, the effects of changes in the cytoplasmic pH on the internalization of physiologically relevant, submicromolar concentrations of uncomplexed long-chain fatty acids were investigated in 3T3-L1 adipocytes. The acidification of the cytoplasm upon NH4Cl prepulsing of intact cells was accompanied by a rapid reduction of cellular long-chain fatty acid uptake (measured as the total accumulation of [9,10-3H]oleate). This was followed by a slow recovery to normal levels of uptake as the cytoplasmic pH recovered. Conventional filtration assays do not distinguish between fatty acid movement across the plasma membrane and intracellular steps, such as binding to cytoplasmic fatty acid-binding proteins or metabolism. While the in vitro binding of a photoreactive fatty acid, 11-m-diazirinophenoxy[11-3H]undecanoate, to a cytoplasmic fatty acid-binding protein was insensitive to changes in pH from pH 7.5 to 5.5, the in vitro conversion of oleate into oleoyl-CoA by cellular acyl-CoA synthetase decreased dramatically. Therefore, the labelling of the 15 kDa cytoplasmic fatty acid-binding protein in intact cells by the photoreactive fatty acid was used as a more direct measure of the permeation of the probe across the plasma membrane. Acidification of the cytoplasm resulted in an immediate reduction in the labelling of this protein in intact adipocytes. Its photolabelling recovered, however, upon the recovery of the cytoplasmic pH to normal levels. This was due to effects of the cytoplasmic pH on the permeation of the photoreactive fatty acid across the plasma membrane rather than its binding to the 15 kDa protein or metabolism in vivo. This is the first demonstration that the movement of physiologically relevant, submicromolar concentrations of uncomplexed long-chain fatty acids across the plasma membrane of intact cells is coupled to the cytoplasmic pH and suggests that it occurs by the diffusion of the protonated long-chain fatty acid through the lipid bilayer.

Effect of Fermentation on the Primary Nutrients in Finger Millet (Eleusine coracana)

The effect of fermentation using endogenous grain microflora at 30 °C on the primary nutrients in finger millet (Eleusine coracana) is reported. The fermentation decreases the starch and long-chain fatty acid content. The pH drops by 2.1 units, leading to an increase of about 6.5 and 3.7 times in lactic and acetic acid contents, respectively. These are the major organic acids produced during fermentation. The total fat content decreased by about 42.9%, which favorably agrees with total loss in long-chain fatty acid content. The total microbial flora increased rapidly during the first 24 h of fermentation. Controlled fermentation using a mixed-culture inoculum taken from 18 and 48 h fermented millet decreased the fermentation time markedly as measured in terms of pH and titratable acidity. Keywords: Finger millet; Eleucine coracana; natural fermentation; primary nutrients; biochemical changes; carbohydrates; fatty acids

Composition of ruminal bacteria harvested from steers as influenced by dietary forage level and fat supplementation.

The objective of this study was to examine the effects of dietary forage level and fat supplementation on the chemical composition of mixed ruminal bacteria (MRB). Six ruminally cannulated beef steers (354 kg +/- 18) were given ad libitum access to six diets (13.2% CP; DM basis) that were offered twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage levels (70 vs 30% of dietary DM as corn silage) and three forms of fat supplementation including no canola seed or canola seed added at 10% of dietary DM as whole treated with alkaline hydrogen peroxide or untreated crushed. Canola seed contributed 5% added fat to the total diet. The remaining dietary ingredients were corn, canola meal, molasses, and urea. No interactions (P > .05) between dietary forage level and canola seed supplementation were observed. Concentrations of OM, N, and all amino acids were higher (P < .05) in MRB from steers fed low forage than in MRB from steers fed high forage. Concentrations of purines and GE and the N:purines ratio in MRB were not affected (P > .05) by dietary forage level or canola seed supplementation. Canola seed supplementation did not affect (P > .05) concentrations of OM, N, or most of the amino acids in MRB. Concentrations of four essential amino acids (i.e., isoleucine, leucine, lysine, and phenylalanine) in MRB were decreased (P < .05) due to canola seed supplementation. Dietary forage level did not affect (P > .05) concentrations of long-chain fatty acids in MRB.(ABSTRACT TRUNCATED AT 250 WORDS)

ANALYSIS OF CALCIUM-LIPID COMPLEXES IN FAECES

Calcium is purported to prevent colorectal cancer by forming insoluble complexes with bile acids and long-chain fatty acids in the large bowel. Therefore, a method for analysing calcium-lipid complexes in faeces has been developed to investigate this. The calcium soaps of a long-chain fatty acid (calcium palmitate) and bile acids (calcium deoxycholate, chenodeoxycholate, cholate and lithocholate) were obtained by organic synthesis. Studies with the authentic soaps reveal that they exist in an empirical ratio of calcium-to-lipid of 1:2. On addition to lipid-free faeces, approximately 30% of calcium palmitate could be recovered and quantified in the authentic state by extraction with 72% ethanol and overnight precipitation at 0 degree C. In contrast, the calcium soaps of the bile acids could not be recovered in the authentic state but were quantified entirely as the free acids. The method was applied to the analyses of calcium-lipid complexes in the faeces of adenoma patients partaking in a placebo-controlled calcium-intervention study. The results show that human faeces contain appreciable amounts of calcium long-chain fatty acid soaps predominantly in the form of calcium palmitate and stearate. The faecal concentration of long-chain fatty acid soaps was increased significantly (P = 0.005) during calcium intervention but this did not have a statistically significant effect on the excretion of free long-chain fatty acids (P = 0.4). Calcium long-chain fatty acid soap formation was found by multiple regression to be equally dependent on stool long-chain fatty acid and calcium concentration. Calcium soaps of the bile acids were not detected by this method.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of raw and roasted lupin seeds as protein supplements for lactating cows

Lupin seeds, raw or roasted, were compared with soybean meal as protein supplements for dairy cows by determination of crude protein fractions, rumen fermentation characteristics, digestibility of nutrients, and lactation performance. Roasting increased the estimated undegraded crude protein fraction of lupins from 37.7% to 44.7% compared to that of soybean meal at 36.0%. Acid detergent insoluble nitrogen in roasted lupins did not increase markedly compared to raw lupins, indicating minimal protein damage due to roasting. Isonitrogenous substitution of raw or roasted lupins for soybean meal in lactation diets did not substantially change rumen fermentation characteristics or whole tract digestibility of nutrients. However, cows fed roasted lupins produced more milk than those fed raw lupins. Higher yields of fat, protein and lactose from cows fed roasted versus raw lupins were primarily due to increased milk yield. Milk fat from cows fed lupins had higher concentrations of long-chain fatty acids compared with milk from cows fed soybean meal. Improved lactational performance of cows fed roasted versus raw lupins was probably due to more sustained release of protein in the rumen, increased undegraded protein supply, and increased efficiency of utilization of dietary energy for milk energy output.

Lipid composition of liver peroxisomes isolated from untreated and clofibrate-treated mice and rats

Peroxisomes were isolated from liver tissue of control and clofibrate-treated adult male NMRI mice and Sprague-Dawley rats. Phospholipids, cholesterol, triglycerides and free fatty acids were measured in the peroxisomes. The fatty acid profiles of the phosphatidylethanolamine, the phosphatidylcholine, the triglyceride and the free fatty acid fractions were also analyzed. Phosphatidylethanolamine was the dominating phospholipid in peroxisomes from untreated animals. The fatty acid profiles of phosphatidylethanolamine, free fatty acids and triglycerides were similar for untreated mice and rats but differences between the species were observed in the pattern derived from phosphatidylcholine. Phosphatidylcholine was the most abundant phospholipid after clofibrate treatment. Clofibrate treatment caused an increase in the concentrations of phospholipids and unsaturated long-chain fatty acids and a decrease in the concentrations of triglycerides, free fatty acids, cholesterol and shorter saturated fatty acids.

Detergent extraction and enzymatic analysis for fecal long-chain fatty acids, triglycerides, and cholesterol

We report a procedure for determining fecal long-chain fatty acids (LCFA), triglycerides, and cholesterol after detergent extraction with 10 mL/L Triton X-100, 6 mL/L Brij 30, and 0.1 mol/L HCl in isotonic saline by enzymatic analysis of the extraction supernates. Mean recoveries of calibrators ranged from 105% to 117%. Assays of fecal extracts were linear with concentration from 0 to 1000 mumol/L for LCFA, from 10 to 90 mumol/L for triglycerides, and from 0 to 300 mumol/L for cholesterol. Within-run CVs were < 3% for medium and high concentrations, and 3%, 14%, and 28% for low concentrations of LCFA, cholesterol, and triglycerides, respectively. Correlation with gravimetric determination resulted in coefficients (r2) of 0.72 for total fat, 0.63 for neutral fat, and 0.66 for nonesterified fat. Assays of extracts and residues prepared for gravimetric determination indicated that approximately 90% of triglycerides, cholesterol, and LCFA were extracted by organic solvents and that the extracts contain a significant amount of other fats. The proposed method appears accurate, precise, specific, and suitable for routine analysis.