Form Of Linoleic Acid Research Articles

Polyunsaturated Fatty Acid Fractionation from Crude Palm Oil (CPO)

Biodiesel is a fuel derived from vegetable oil. One of the vegetable oils that can be used in the manufacture of biodiesel is Crude Palm Oil (CPO). High-quality biodiesel must have a low iodine number and a high oxidation stability. This can be achieved if CPO does not contain polyunsaturated fatty acids (PUFA). It follows that in order to produce high-quality biodiesel, palm oil that contains high saturated fatty acids but that does not contain PUFA is needed. Therefore, it is necessary to fractionate PUFA with saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA). The purpose of this study was to separate PUFA in the form of linoleic acid from CPO and to determine the best conditions in the separation process to produce fatty acids with low iodine numbers. Fractionation was carried out at temperatures of 30 °C and 35 °C, with an extraction time of 3 h and 4 h, and with ratios of CPO and solvent of 1:2 and 1:3 (v/v). The solvents used were n-heptane and DMSO (dimethyl sulfoxide). The results showed that linoleic acid could be separated from CPO using the fractionation method with the best conditions at a temperature of 35 °C, an extraction time of 4 h, a ratio of CPO and solvent of 1:3, an iodine number of 40.78766, and an oxidation stability of 19.03593 h. GC-MS analysis proved that the fractionated CPO did not contain linoleic acid. The lower the iodine number was, the higher the oxidation stability was.

Linoleate-enriched diet increases both linoleic acid esterified to omega hydroxy very long chain fatty acids and free ceramides of canine stratum corneum without effect on protein-bound ceramides and skin barrier function

Few studies have investigated the influence of increased amounts of dietary linoleic acid on the epidermal lipid biochemistry and TEWL in healthy subject. The influence of dietary linoleic acid on canine stratum corneum (SC) lipids was studied by feeding two groups of five dogs differential amounts of linoleic acid (LA) for three months. SC was harvested by tape stripping and lipids were analyzed by thin-layer chromatography and mass spectrometry. The dogs that were fed the higher concentration of LA showed high increases in the contents of both linoleic acid and free ceramides in the SC, whereas the protein-bound ceramide content was unchanged. Acylacids that represent the esterified form of linoleic acid in omega hydroxy very long chain fatty acids (ω-OH VLCFA) accounted for most of the elevation of LA, whereas the concentration of the free form was not significantly changed. Corroborating the absence of change in the protein-bound ceramides content of healthy dogs SC, TEWL was nearly unaffected by the linoleic acid-enriched diet.

Effect of Dietary Safflower and Canola Oil on Growth Performance, Body, and Fatty Acid Composition of Rainbow Trout (Oncorhynchus mykiss)

The objective of the present study was to evaluate the effects of the diets enriched with safflower and canola oil on growth, feed utilization, body composition, liver, and muscle fatty acid composition of rainbow trout (Oncorhynchus mykiss). Rainbow trout having approximate initial weight of 97.03 ± 0.10 g were fed the experimental diets containing only fish oil (Group 0SFO), safflower oil (50% safflower oil, Group 50SFO and 33% safflower oil, Group 33SFO), and vegetable oil blend (33% safflower and 33% canola oil, Group 66SFCO) for 45 days. Twenty-five fish were randomly assigned for triplicate treatments and offered the test diets two times daily to apparent satiation. At the end of the experiment, survival was 100% in all treatments. No significant differences in the weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio were found between fish fed with the different experimental diets. The highest hepatosomatic index (HIS) and viscerasomatic index (VSI) was obtained in 50SFO and 33SFO groups, respectively. The moisture, protein, lipid, and ash content in the body composition of the fish increased in all experimental groups. The lipid content was not significantly different among the groups (p > 0.05); however, there was a significant difference in ash content between the control and the other groups (p < 0.05). The experimental diets containing vegetable oil (50SFO and 33SFO groups) and vegetable oil blend (66SFCO group) had significantly higher concentrations of n-6 fatty acids, predominantly in the form of linoleic acid (LA). The n-3 fatty acids were present in significantly higher concentration in the control treatment (0SFO). The fatty acid composition of fish fillet and liver were reflective of the dietary lipid source. While the fillet and liver of fish fed the 50SFO diet was high in linoleic acid (18:2 n-6), fish fed the 66SFCO diet had high concentrations of oleic acid (OA; 18:1 n-9). The present study suggests that fish oil can be replaced by up to 50% with safflower oil and by up to 66% with safflower + canola oil blend in rainbow trout diets with no significant effect on growth.

Effects of dietary oil source on growth and fillet fatty acid composition of Murray cod, Maccullochella peelii peelii

The Murray cod, an Australian native freshwater fish, supports a relatively small but increasing aquaculture industry in Australia. Presently, there are no dedicated commercial diets available for Murray cod; instead, nutritionally sub-standard feeds formulated for other species are commonly used. The aim of the present investigation was to assess the suitability of two plant based lipid sources, canola oil (CO) and linseed oil (LO), as alternatives to fish oil for juvenile Murray cod. Five iso-nitrogenous, iso-calorific, iso-lipidic semi-purified experimental diets were formulated with 17% lipid originating from 100% cod liver oil (FO), 100% canola oil, 100% linseed oil and 1 : 1 blends of canola and cod liver oil (CFO) and 1 : 1 blends of linseed and cod liver oil (LFO). Each of the diets was fed to apparent satiation twice daily to triplicate groups of 50 Murray cod with initial mean weights of 6.45 ± 1.59 g for 84 days at 22 °C. Final mean weight, specific growth rate and daily feed consumption were significantly higher for the FO and LFO treatments compared to the LO treatment. Feed conversion and protein efficiency ratios were not significantly different amongst treatments. Experimental diets containing vegetable oil and vegetable oil blend(s) had significantly higher concentrations of n-6 fatty acids, predominantly in the form of linoleic acid (LA), while n-3 fatty acids were present in significantly higher concentrations in LO and LFO treatments. The fatty acid composition of Murray cod fillet was reflective of the dietary lipid source. Fillet of fish fed the FO was highest in EPA (20:5n-3), ArA (20:4n-6) and DHA (22:6n-3). Fish fed the CO diet had high concentrations of oleic acid (OlA) (192.2 ± 10.5 mg g lipid − 1 ), while the fillet of Murray cod fed the LO diet was high in α-linolenic acid (LnA) (107.1 ± 6.7 mg g lipid − 1 ). The present study suggests that fish oil can be replaced by up to 100% with canola oil and by up to 50% with linseed oil in Murray cod diets with no significant effect on growth.

Production of tomato flavor volatiles from a crude enzyme preparation using a hollow-fiber reactor.

In recent years there has been an increase in the interest in the production of compounds by isolation from natural sources or through processes that can be deemed "natural". This is of particular interest in the food and beverage industry for flavors and aromas. Hexanal, organoleptically known to possess "green character", is of considerable commercial interest. The objective of this study was to determine if the enzyme template known to be responsible for the synthesis of hexanal from linoleic acid (18:2) in tomato fruits could be harnessed using a hollow-fiber reactor. A hollow-fiber reactor system was set up and consisted of a XAMPLER ultrafiltration module coupled to a reservoir. The enzyme template was extracted from ripe tomato fruits and processed through an ultrafiltration unit (NMWC of 100 kDa) to produce a retentate enriched in soluble and membrane-associated lipoxygenase (LOX) and hydroperoxide lyase (HPL). This extract was recirculated through the lumen of the hollow-fiber ultrafiltration unit with the addition of substrate in the form of linoleic acid, with buffer addition to the reaction flask to maintain a constant retentate volume. Product formation was measured in the permeate using solid phase microextraction (SPME) developed for this system. At exogenous substrate concentrations of 16 mM and a transmembrane pressure of 70 kPa, hexanal production rates are in the order of 5.1 microg/min. Addition of Triton X-100 resulted in membrane fouling and reduced flux. The reactor system has been run for periods of up to 1 week and has been shown to be stable over this period.

Effect of Dietary Linoleic Acid and Essential Fatty Acid Deficiency on Resting Metabolism, Nonshivering Thermogenesis and Brown Adipose Tissue in the Rat

Rats were fed a diet either deficient (0.05%) in essential fatty acids (EFA), or providing 4% (control) and 10% (surplus) of the total energy intake in the form of linoleic acid. All diets were isoenergetic and provided 13.9% of the energy as fat. The rats were kept at 29 or 5 degrees C. Growth and food intake of rats fed linoleic acid surplus at either temperature for 10 wk were not different from that of controls; basal metabolism, norepinephrine-induced nonshivering thermogenesis (NST) and thermogenic variables in the brown adipose tissue (amount of mitochondria and mitochondrial uncoupling protein) also were not different. The effects of EFA deficiency were drastically enhanced in the cold: After 10 wk of consuming a diet low in EFA at 5 degrees C, the body weight of rats was 75% of that of controls (87% at 29 degrees C); the food intake was 135% of controls at 5 degrees C (120% at 29 degrees C). The resting respiration in deficient rats was 125% of controls at 5 degrees C (110% at 29 degrees C); body temperatures as low as 35.1 degrees C were measured in deficient rats after 3 wk at 5 degrees C; the cold tolerance of the rats was significantly diminished (30% died within 3 wk at 5 degrees C), thus emphasizing the essential role of dietary EFA during cold stress. Norepinephrine-induced NST and the thermogenic parameters in brown fat were not influenced by EFA deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Dietary Menhaden Oil on Tumor Cell Loss and the Accumulation of Mass of a Transplantable Mammary Adenocarcinoma in BALB/c Mice&lt;xref ref-type="fn" rid="FN2"&gt;2&lt;/xref&gt;&lt;xref ref-type="fn" rid="FN3"&gt;3&lt;/xref&gt;

A reduction in the size of transplantable mammary adenocarcinoma IX was achieved when female BALB/c mice were fed isocaloric 10% fat diets containing either hydrogenated cottonseed oil (HCTO) or menhaden oil (MO) as opposed to those mice fed corn oil (CO). Indeed, CO increased the size of the neoplasms when fed alone at 5 or 1% of the diet, although such diets contained less fat calories than did the 10% fat diets containing the other two oils. At the 10% level of dietary fat, enhanced accumulation of tumor mass was observed even when 7.5, 5.0, and 2.5% CO was administered in combination with either HCTO or MO. Although this effect of CO could not be inhibited when nine times as much HCTO was added to the diet, such growth enhancement was abolished when the diet contained nine times as much MO. Hence these experiments emphasized the importance of the type rather than the amount of dietary fat. Whereas MO contained polyunsaturated fatty acids (PUFA's) [approximately 1% as linoleic acid, approximately 16% as 5,8,11,14,17-eicosapentaenoic acid (EPA), approximately 11% as 4,7,10,13,16,19-docosahexaenoic acid (DHA)], HCTO contained none and CO had about 60% of its constituent fatty acids in the form of linoleic acid. The rate of tumor cell loss, determined by the [125I]5-iodo-2'-deoxyuridine method, in the 10% MO-fed or the 10% HCTO-fed mice (54 or 45%, respectively) was more than twice that observed for tumors from the 10% CO-fed mice (22%). These observations were discussed in terms of the influence of the dietary PUFA linoleic acid [C 18:2 (No. of carbons:No. of double bonds), n-6], the PUFA EPA (C 20:5, n-3), and the PUFA DHA (C 22:6, n-3) on the size of mammary tumors and on the involvement of prostaglandins in this process.

INTRAVENOUS LIPID ADMINISTRATION IN THE PREMATURE INFANT. 1. EFFECT ON ESSENTIAL FATTY ACID STATUS (EFAS)

Rapid changes occur in essential fatty acid status (EFAS) during fat-free parenteral nutrition (Pediatr Res 4:309A, 1983). We therefore evaluated the effects of IV Liposyn 20% administration on EFAS and compared them to the control group (group 1). Infants received either 0.34 gm (group 2) or 0.68 gm (group 3)/kg of lipid daily for 5 days providing 2% or 4% of the estimated caloric requirement (120 cal/kg/day) in the form of linoleic acid. Mean birth weight (1410, 1400, and 1470 gm in groups 1, 2, and 3, respectively), gestation (31.2, 31.4, and 30.9), daily caloric intake during the study (51.2, 50.2, and 49.3 cal/kg) and clinical features were similar. EFAS was assessed at 4 ± 1 (#1, before starting PN), at 6 ± 1 (#2), and 8 ± 1 (#3) days of age. Triene/tetraene ratio (T/T; mean, SD) is expressed as weight % of fatty acid in plasma phospholipids. The results are outlined.Baseline (#1) T/T ratio is similar in all groups. T/T ratios in groups 2 and 3 do not change significantly and remain lower than in group 1 (P <.01, 2-way ANOVA). We conclude that 1) IV lipids prevent rapid changes occurring in EFAS during PN; 2) 2% is as effective as 4% linoleate in maintaining baseline T/T ratio.

The Effect of Essential Fatty Acid Deficiency on Basal Respiration and Function of Liver Mitochondria in Rats

Rats were fed a diet poor (0.05%) in essential fatty acids (EFA) with hydrogenated coconut oil as fat component, or a control diet containing 4% of the total energy intake in the form of linoleic acid. Effects of dietary EFA deficiency were investigated during a period of 2–30 weeks. Growth retardation becomes significant after 4 weeks of deficiency and attains about 25% when the deficiency is maintained for longer than 12 weeks. Respiration, body weight and age of EFA-deficient rats and controls are in a nonlinear relationship. Basal respiration in relation to the body weight is significantly increased by EFA deficiency; it is unchanged when related to total animals under the employed experimental conditions. Oxidative phosphorylation in isolated liver mitochondria is unaffected by EFA deficiency, i.e., the increased metabolic rate of EFA-deficient rats, related to body weight, cannot be explained from impaired functional integrity of the inner mitochondrial membrane. Respiratory chain enzyme activities in mitochondria from heart and skeletal muscle and specific amounts of mitochondria in these tissues are unchanged by EFA deficiency.

Utilization of arachidonic and linoleic acids by cultured human endothelial cells.

When cultured human umbilical vein endothelial cells are supplemented with linoleic acid, the arachidonic acid content of the cellular phospholipids is reduced approximately 35%. Most of the fatty acid compositional change occurs during the first 24 h. One factor responsible for this effect is the inability of the endothelial cells to convert appreciable amounts of linoleic to arachidonic acid, due to a fatty acid delta 6-desaturase deficiency. By contrast, these endothelial cultures contain delta 5- and delta 9-desaturase activity and are able to elongate long-chain polyunsaturated fatty acids. The other factor that contributes to the decrease in arachidonic acid is that high concentrations of linoleic acid reduce the incorporation of arachidonate into cellular phospholipids. Stearic acid, a long-chain saturate, does not produce any reduction, whereas eicosatrienoic acid is an even more effective inhibitor than linoleic acid. In spite of the fact that high concentrations of these polyunsaturates produced inhibition, the endothelial cells were found to efficiently incorporate exogenous arachidonic acid into cellular phospholipids and triglycerides. This may serve to compensate for the inability of these cells to synthesize arachidonic acid from linoleic acid. These findings suggest that the endothelium obtains arachidonic acid from an extracellular source, that this cannot be provided in the form of linoleic acid and, in fact, that high concentrations of linoleic acid actually may interfere with the ability of the endothelium to maintain an adequate supply of intracellular arachidonic acid.

Cystic fibrosis and malnutrition

Cystic fibrosis as a specific disease entity has been known to be associated with malnutrition for almost half a century. The importance of the malnutrition in the disease process remains unknown, as does much information about specific nutritional deficiencies in CF. Supplements for children with CF should include extra energy as fat or carbohydrate, a form of linoleic acid that can be absorbed, hydrolyzed protein, fat-soluble vitamins with vitamins A and E in a water emulsion, vitamin B12, probably B vitamins and vitamin C, and trace minerals. Routine measurements of nutritional status, particularly in children with growth failure, should be made at regular intervals and should include a three-day diet record and a simultaneous 72-hour stool fat determination. If fat malabsorption is not controlled by pancreatic enzymes, the use of antacids or cimetidine should be considered. The true role of nutrition in patients with CF will not be known until the appropriate studies are completed.

The linoleic acid content of seed fats and the isomerism of linoleic acid

The linoleic acid content of a series of seed fats was determined by the thiocyanometric and the tetrabromide-precipitation methods in a search for isomeric linoleic acids. The results indicated the presence of only one form of linoleic acid. The tetrabromide number was shown to be affected by the pronounced solubility of alpha tetrabromostearic acid in the other bromides and in the solid acids, its determination therefore being of only limited value. The thiocyanogen numbers of pure linoleic and linolenic acids were found to be empirical values differing markedly from the theoretical constants, requiring a revision of the accepted equations for the calculation of the per cent concentration of the unsaturated acids in oils and mixed fatty acids.