Commercial Fat Research Articles

Predicting changes in food energy requirements due to genetic changes in growth and body composition of growing ruminants

AbstractIncorporation of food intake into breeding objectives for ruminants is often difficult because the relevant genetic parameters are unavailable. A non-statistical approach to estimating the genetic relationships between food costs and genetic changes in growth and body composition traits was therefore developed.Equations which predict additional food requirements associated with genetic changes in growth and body composition traits are derived from an interspecies growth model. In the growth model, a genotype is mainly described according to its expected mature weights of protein, lipid and a composition trait of interest in the empty body under non-limiting conditions. Other model parameters describe the expected growth of the animal in a specific environment.An example is shown for beef cattle in the United Kingdom, where increases in carcass weight by 1 kg and carcass subcutaneous fat proportion by 0·01 result in increases in food costs by £0·97 and £7·34 respectively for a production system where animals are given an intensive silage/concentrate diet, are slaughtered at 305 kg and have a commercial fat grade 4L. A strong dependence of the results on the type of production system, especially the degree of maturity in protein at slaughter, is demonstrated.The model is easily adapted to other breeds and ruminant species. The approach is recommended for incorporating food intake into breeding objectives for ruminants in situations where reliable estimates of the necessary genetic parameters for a more conventional specification of the breeding objective are unavailable.

Integration of GC/MS Instrumentation into the Undergraduate Laboratory: Separation and Identification of Fatty Acids in Commercial Fats and Oils

A laboratory experiment using a gas chromatography/mass selective detection method has been developed for the isolation, identification, and quantitation of fatty acid content of commercial fats and oils. Results for corn, nutmeg, peanut, and safflower oils are compared with literature values, and the results for corn oil are compared for two different trials of the experiment. In addition, a number of variations on the experiment are suggested including possible extension of the experiment for use in an instrumental analysis course.

Identification of plasma proteins facilitated by enrichment on particulate surfaces: analysis by two-dimensional electrophoresis and N-terminal microsequencing.

Plasma protein adsorption on intravenously injectable drug carriers is regarded as an important factor for the fate of the particles in the body after their administration. Therefore, the plasma protein adsorption patterns on a number of different carrier systems were analyzed in vitro employing two-dimensional electrophoresis (2-DE). The particulate systems presented in this study were polystyrene (PS) model particles, PS nanoparticles surface-modified by adsorption of a surfactant, a commercial fat emulsion, and magnetic iron oxide particles used as contrast agents in magnetic resonance imaging. Most of the spots in the plasma protein adsorption patterns could be identified by matching the resulting 2-DE gels with a reference map of human plasma proteins. Several other proteins that indicated preferentially adsorbed proteins on the surface of the particles investigated have either not been identified on the reference map, or their identity was found to be ambiguous. The relevant proteins are all present in plasma in low abundance. Since these proteins were strongly enriched on the surface of the particles, the resulting spots on the 2-DE gels were successfully identified by N-terminal microsequencing. With this approach, two chains of spots, designated PLS:6 and PLS:8, were determined on a plasma reference map: inter-alpha-trypsin inhibitor family heavy chain-related protein (also named PK-120) and a dimer of fibrinogen gamma, respectively. Plasma gelsolin is presented in a 2-DE adsorption pattern of PS model particles. One of the main proteins adsorbed by droplets of a commercial fat emulsion was identified as apoliprotein H. Moreover, the positions of apolipoproteins apoC-II and apoC-III were also verified on the 2-DE protein map of human plasma. Thus, protein adsorption experiments of the kind presented in this study are increasing our insight into human plasma proteins.

Fat Mimetics in Low‐Fat Cheddar Cheese

ABSTRACTCheeses with 60% reduced fat content were prepared with three commercial fat mimetics. Low‐fat cheeses without added fat mimetics and full‐fat cheeses were prepared as controls. Cheeses were aged 3 months prior to sensory and instrumental evaluation. A low‐fat cheese containing one of the fat mimetics received the highest texture scores from dairy judges and consumer panelists (P≤0.05). The low‐fat control and another cheese with a fat mimetic received higher flavor scores from the trained dairy judges and consumer panelists than the other cheeses containing fat mimetics (P≤0.05). Low‐fat cheeses containing fat mimetics were less rubbery than the low‐fat control cheese (P≤0.05).

Effects of Dietary Fatty Acid Pattern on Melting Point and Composition of Adipose Tissues and Intramuscular Fat of Broiler Carcasses

Soybean oil (SO), rapeseed oil (RO), or two commercial fat products (FP1, FP2) were incorporated at 3.5% levels into four different corn-soybean meal mash broiler diets. Each of the four diets was fed to five replicates (pens) of broiler chickens for 42 d. After slaughtering the birds, samples of the abdominal fat, subcutaneous fat, and fat extracted from the thigh and the breast portion were collected from 16 birds per treatment. The fat samples were analyzed for their fatty acid composition using gas chromatography and the melting point of the abdominal fat was recorded.The results showed that the abdominal and subcutaneous fat had very similar fatty acid patterns and differed significantly from the composition of the fat extracted from breast and thigh. The different dietary treatments caused significant changes in the fatty acid patterns for all analyzed tissues, although the differences were more pronounced for the adipose tissues. Overall, the adipose tissues contained more polyunsaturated and less saturated fatty acids than the fat from the breast and thigh portions. The melting point of the abdominal fat was significantly altered by the use of different dietary fats: RO gave a lower melting point than SO and FP1; the highest values were recorded for FP2.The data presented here indicate that the selection of certain dietary fat sources has a major impact on the composition and the melting point of broiler adipose tissues. The effect on the fatty acid composition of meat portions, however, is limited.

Effects of fats and fatty acids on blood lipids in humans: an overview

Differences in dietary fatty acid structure induce marked differences in lipid and lipoprotein concentrations in plasma from fasting subjects. Under metabolic-ward conditions, replacement of carbohydrates by lauric, myristic, and palmitic acids raise both low-density-lipoprotein (LDL) and high-density-lipoprotein (HDL) cholesterol whereas stearic acid has little effect. Oleic and linoleic acids raise HDL and slightly lower LDL; all fatty acids lower fasting triglycerides when substituted for carbohydrates. Trans monounsaturates lower HDL and raise LDL and lipoprotein(a). The fatty acids in unhydrogenated fish oil potently lower triglycerides, with variable effects on LDL. Of the commercial fats, palm-kernel and coconut oil are the most hypercholesterolemic, followed by butter and palm oil. Replacement of hard fats rich in lauric, myristic, or palmitic acids or trans fatty acids by unsaturated oils will lower LDL, but replacement by carbohydrates will in addition decrease HDL and increase triglycerides. In free-living subjects, high-oil diets could lead to obesity, undoing the favorable effects on HDL and triglycerides.

Structural Studies of Commercial Fat Emulsions Used in Parenteral Nutrition

In this paper, we demonstrate that by employing a combination of sedimentation field‐flow fractionation (sedFFF) and other characterization techniques, such as photon correlation spectroscopy (PCS) and freeze–fracture electron microscopy (EM), it is possible to show that commercial fat emulsions of similar overall chemical compositions not only may exhibit different size distributions but may have different densities as well. A closer look at the density difference between droplet and suspension medium, on the one hand, and the droplet size, on the other, demonstrates that fat emulsions may have structures other than the traditional oil droplet surrounded by a monolayer of surfactant. From our determined and simulated density differences, we propose that these emulsion droplets may have a multilayered surfactant arrangement as well as an inclusion of water vesicles in the oil phase of the emulsion. Freeze‐fracture EM observations provide evidence to confirm the existence of such complex structures. These findings are supported by recent EM work from other laboratories, as well as through chemical verification of elevated water contents in the oil droplets of these emulsions.

Characterization of fat replacers

Effects of commercial fat replacers on rheological properties of emulsions have been studied under a second-order design. The corresponding functions of regression have been calculated to describe the measured effects mathematically. On the basis of a figured three-dimensional plan of response, combinations of variables (fat, fat replacer, water) could be determined showing a similar consistency to the corresponding full-fat foodstuff.

In vitro uptake of polystyrene latex particles and parenteral fat emulsions by human granulocytes

Suspensions of human granulocytes were used to study the in vitro phagocytosis of polystyrene latex particles (1030 nm) as i.v. model drug carriers and of commercial fat emulsions for parenteral nutrition (Lipofundin, Intralipid). Chemiluminescence (CL) was employed to follow the time-dependent uptake of the particle. The total uptake was quantified by the area under the curve of the CL intensity/time profiles and comparitively by a modified fluorimetric assay. The data proved that a linear relationship existed between the AUC of the CL assay and the total mass of internalized polymer. The uptake of fat emulsions could not be followed directly by CL because the CL intensity signal was too weak. Their uptake could be quantified via the impairment of the phagocytic function of granulocytes after pre-incubation with emulsion. The polystyrene particles were used as test colloid. The phagocytic function was reduced up to 50% by 10% fat emulsions.

Diet and Refsum's disease. The determination of phytanic acid and phytol in certain foods and the application of this knowledge to the choice of suitable convenience foods for patients with Refsum's disease

One hundred and fifty‐one foods were analysed for phytanic acid and 57 foods for free phytol. Foods analysed included examples from all major food groups, beverages and confectionery.No significant amount of phytanic acid was found in any food of purely vegetable origin. The sources of phytanic acid in the UK diet were confirmed to be foods derived from ruminant animals and fish. They include beef, lamb and products containing the milk fats of cows, sheep and goats. All fish were found to contain phytanic acid roughly in proportion to their fat content. Domestic and commercial fat blends containing animal fats (chiefly hydrogenated fish oils) and baked goods made from these fats contained phytanic acid: pure vegetable fat blends and foods containing them did not.Free phytol was found in small amounts in a variety of foods but not in sufficient quantity to warrant the exclusion of any one item from the diet of patients with Refsum's disease.

Fatty Acid Analysis, TAG Equivalents as Net Fat Value, and Nutritional Attributes of Commercial Fats and Oils

The fatty acid quantities of 24 commercial fat and oil products in Finland were analyzed by capillary gas chromatography applying relative retention times of fatty acid methyl esters on two channels for identification of fatty acids. An internal standard method (C19:0 methyl ester) with methyl group and empirical fatty acid response corrections was used for quantitation of the fatty acids. GLC on a CF Sil 88 column permitted the determination of trans C16:1, C18:1, C20:1, and C22:1 positional isomers as groups. The net fat contents of fats and oils were calculated as triacylglycerol (TAG) equivalents derived from the fatty acid quantities. Ten nutritional attributes of the fats and oils based on quantitative fatty acid analysis are also presented. A recommendation is given for the use of the 10 fatty acid variables (saturated: total, C < 12, C12-C16, C18; cis-monoenes; all cis-di- and polyenes: total, n-3, n-6; other fatty acids (FAs): total, C18: 1t) as nutritional attributes in evaluation of fats in foods and diets. The fatty acid composition of spreads varied significantly: total saturated from 21 to 69 wt%, cis-monoenes from 17 to 41 wt%, n-6 di- and polyenes from 1.6 to 58 wt%, and n-3 di- and polyenes from 0.3 to 5.2 wt%. The high fraction of saturated C < 12 and C12-C16 is characteristic of butter and coconut fat. The stearic acid content was rather constant. In vegetable oils total saturated varied from 5.9 to 15 wt%, cis-monoenes from 23 to 73 wt%, n-6 di- and polyenes from 11 to 65 wt%, and n-3 di- and polyenes from 0.5 to 11 wt%. There were no saturated C < 12 fatty acids or trans fatty acids. In margarines made only of vegetable oils, other FAs consisted of C18:1t isomers. When fish oil was utilized, C16:1t, C20:1t, and C22:1t isomers were also present. Butter fat containing spreads also had C18:2-conjugated and C18:2ct,tc in addition to C18:1t isomers. In spreads, the content of C18:lt isomers varied from 0 to 17 wt%. Soft margarines had a higher C18:1t content than hard margarines.

Supplemental fat in high-energy rations for lactating cows: effects on intake, digestion, milk yield, and composition

Supplemental fats (SF) have special value in the diets of dairy cows with superior productive ability, because the high energy density of SF allows greater energy consumption and direct transfer of the fatty acids (FA) of the SF to milk fat; this increases metabolic efficiency. Some SF, especially oils with a high degree of unsaturation, disturb ruminal fermentation, decrease fiber digestibility, and lower milk fat test; however, oilseeds (e.g., whole cottonseed) can be fed without observable ruminal inhibition, probably because of a slow release of the oil into ruminal contents. A number of commercial fat supplements are available that have little effect on ruminal fermentation and are highly digestible postruminally. A product of the calcium salts of palm oil fatty acids was shown to have a NE for lactation of more than three times that of corn. As the emphasis in milk pricing formula changes from milk fat to milk protein, there is greater concern regarding the propensity of fat supplements to decrease milk protein (casein) percentage. In two studies, a supplement of ruminally protected lysine and methionine largely prevented the reduction in casein percentage that occurred with feeding SF, indicating that the amino acid profile of undegraded dietary protein is important with regard to preventing the lower casein percentage. Combining fat supplements that are slowly released in the rumen with those that are inert in the rumen will allow maximal use of SF.

Influence of Source and Amount of Dietary Fat on Digestibility in Lactating Cows1,2

Digestibility of commercial fat supplements was determined in two experiments with high (59% of diet DM) forage diets. Experiment 1 was a preliminary trial in which six Jersey cows were in two 3 x 3 Latin squares to evaluate two formulations of calcium soap at two intake levels (500 and 1000 g/d). The two formulations were compared with control (0 supplement) within squares; the squares differed in amount of soap supplemented. Mean apparent digestibilities of fat were not influenced by source or amount of fat supplemented and averaged 82.5, 84.3, and 83.4% for control, 500, and 1000 g/d. In Experiment 2, six Jersey cows were in a 6 x 6 Latin square to compare effects of various commercial fats on digestibility of diet components at 2.85 and 5.7% (DM) added fat. Higher fat decreased digestibility of P and fatty acid Fatty acid intake affected fatty acid digestibility quadratically, and variability among cows increased at higher fatty acid intake. Endogenous fecal fat was 55.9 g/d; apparent digestibility of fat was relatively constant at 80 to 82% between 2 and 5% of diet DM, whereas marginal true digestibility decreased linearly (4.4% units/100g fatty acid consumed). There were no differences among fat sources in fatty acid digestibility. Rumen VFA were not influenced by dietary fat.

Hepatic Uptake of Lipid-Soluble Drugs from Fat Emulsion.

Oil violet in a fat emulsion was taken up into the parenchymal cells of rat liver in vitro. The uptake was greater at 37 degrees C than 25 degrees C or 4 degrees C, and it was increased by addition of postheparin plasma including lipoprotein lipase activity into the reaction medium. The uptake from the emulsion with smaller particles was greater than that from the emulsion with larger particles. The hepatic uptake of 14C-cholesteryl oleate in the emulsion by recirculating perfusion of the liver in situ was also increased by postheparin plasma in the perfusion medium. Its enhancing effect was found for distribution in the parenchymal cells but not in the Kupffer cells. The previous perfusion of Intralipos of the commercial fat emulsion reduced the hepatic uptake of 14C-cholesteryl oleate in the emulsion. The emulsion particle sizes were reduced by postheparin plasma both in vitro and in situ. Consequently, it was suggested that a lipid-soluble compound entrapped in the fat emulsion is taken up into the parenchymal cells by receptor-mediated process via the reduced particle sizes emulsion (remnant), which is a mechanism similar to the dietary fat metabolism.

Short spacings and polymorphic forms of natural and commercial solid fats: A review

Short spacings refer to the cross sectional packing of the hydrocarbon chains. They are independent of chain length. Short spacings are widely used for characterizing the various polymorphic forms. Fats can crystallize into four polymorphic forms, i.e., sub‐α, α, β′ and β. These polymorphic forms differ in their chain packing and thermal stability. The β′ form is also known to exhibit several intermediate polymorphic forms. The nomenclature for the polymorphic forms has generated a great deal of confusion over the years. Several researchers have reported on the polymorphic forms of pure triglycerides. Similar polymorphs have sometimes been described by different names. Currently, the nomenclature proposed by Larsson [Larsson, K.,Acta Chem. Scand. 20:2256 (1966)] is being widely used. Much of the earlier work on polymorphism has been obtained by studying simple purified substances. The listing of short spacings for natural and commercial fats presented in this paper will be beneficial to researchers working in this field.

Effects of intravenous infusions of commercial fat emulsions (Intralipid 10 or 20%) on rat plasma lipoproteins: Phospholipids in excess are the main precursors of lipoprotein-X-like particles

Like most commercial parenteral emulsions, Intralipid ® contains the same amount of phospholipids (12 mg/ml) to stabilize 100 or 200 mg of soybean oil (10 or 20% formula, respectively). By centrifugation, 10 or 20% Intralipid was separated into a supernatant, fat particles containing the bulk of triacylglycerols stabilized by a fraction of phospholipids and an infranatant — called mesophase — consisting mainly of phospholipids used in excess as emulsifier. We observed that the initial triacylglycerol phospholipid ratio of the emulsion ( 100 12 and 200 12 , respectively) determines the size of the triacylglycerol-rich particles (260 and 350 nm) as well as the phospholipid content of the mesophase (6.02 and 4.67 mg/ml). To understand the mechanism of the lipoprotein-X (LPX) accumulation generally reported after intravenous fat infusions, plasma lipid levels and lipoprotein profiles were first compared in the rats after infusion (at a constant rate of 0.5 or 1 ml/h for 43 h) of Intralipid 10 or 20%. For the same intravenous triacylglycerol load (100 mg/h), rats infused with Intralipid 10% at 1 ml/h displayed higher triacylglycerol levels than rats infused with the 20% emulsion at 0.5 ml/h, suggesting that the size of exogenous fat particles modulated the catabolic rate of their triacylglycerols. The plasma levels of LPX varied according to the infusion rate of phospholipids not associated with triacylglycerol-rich particles of the emulsion. Moreover, an apo E and apo B enrichment of plasma and an elevation of the apo B48/apo B100 ratio was always observed after Intralipid infusions. In order to confirm that phospholipids of the mesophase are the main LPX precursors, lipoprotein profiles were then compared in the rats after intravenous infusion, at a constant rate of 1 ml/h, of either the mesophase or a suspension of triacylglycerol-rich particles isolated from Intralipid 20%. As expected, significant LPX amounts were only detected in rats infused with the pure mesophase of the emulsion. It was concluded that products of the lipolysis of exogenous fat particles play only a minor role in the formation of LPX. In fact these abnormal lipoproteins are generated by phospholipids of the mesophase which, like infused liposomes, actively mobilize endogenous free cholesterol. Consequently, in order to be considered as true chylomicron models for safe fat delivery in parenteral nutrition and in order to prevent some detrimental effects on cholesterol metabolism, commercial emulsions should be cleared of phospholipid excess.

Gram-positive bacterial sepsis in rat and tissue lipolytic activity on commercial parenteral fat emulsions

To study the influence of a gram-positive sepsis on the metabolism of circulating lipids, fasted rats were injected with saline (control group) or with a suspension of heat-killed or live Staphylococcus aureus. 18 h later, body temperature was increased, while albuminemia and ketonemia were decreased in the group injected with heat-killed bacteria, as opposed to the control group. Passing from these groups to the group injected with live bacteria, more differences appeared: increase of triglyceridemia and free cholesterolemia; decrease of esterified cholesterol levels and especially of the in vitro activity of diaphragm, heart and adipose tissue lipoprotein lipase and of hepatic lipase. The decrease of lipolytic activities occurred whether they were measured on a fat emulsion containing long-chain or medium- and long-chain triglycerides. The fact that for the latter the activity was always higher than for the former suggests that the host infected with gram-positive bacteria would clear exogenous fat more easily in the case of medium-chain triglycerides.

Hedonic responses and attitudes related to fats used as spreads on bread

Ten commercial fats, spread on bread slices ad libitum, were rated by 119 subjects for their sensory pleasantness. The samples differed in the origin of fat (dairy/vegetable) and fat content (40, 60 or 80%). A questionnaire concerning the consumption and pleasantness by brand name was filled in. Some (76) of the subjects also filled in a questionnaire on attitudes to fats and on health. Dairy fat-based spreads containing 80% fat were rated most pleasant in sensory tests, and also when assessed by brand name. Spreads based on 80% vegetable fat were rated less pleasant, but equally pleasant with some of the 40% and 60% spreads. There was wide variation in pleasantness ratings of 40% fat containing samples. Sensory pleasantness ratings did not correlate with those based on brand names. Ratings of sensory pleasantness were related to habitual consumption of a spread. Attitudes, beliefs and habits partly explained the consumption of certain spreads.

Characterization of animal fats via the GC pattern of fame mixtures obtained by transesterification of the triglycerides

The triglycerides of animal fats from milk, meat or cheese can also be characterized by the gaschromatographic pattern of the fatty acid methylesters (FAME) after conversion by an unsophisticated transesterification procedure. Even from the FAME pattern falsifications of commercial animal fats can be revealed by the fast separation of the FAME using a standard CW 20 M (polyethyleneglycol) capillary column. Characteristic patterns of FAME originating from different animals are shown. The patterns of the FAME from different races of the same animal are very similar, so that the characterisation according to the type of animal is not disturbed.

Influence of phospholipids on ruminal fermentation in vitro and on nutrient digestion and serum lipids in sheep.

Phospholipid supplements were incubated in vitro or fed to sheep to determine how they affected ruminal fermentation, nutrient digestion and serum lipid concentration. In vitro, deoiled soybean lecithin added to hay increased (P less than .05) total VFA concentration but had no effect on fiber digestion in four of five trials. Purified phospholipid (synthetic phosphatidylethanolamine), however, had little effect on in vitro hay fermentation when tested at four levels (0, 10, 20 or 30 mg) in three separate trials. Deoiled soybean lecithin disappeared in vitro at two rates, 12.9 and .66%/h for the fast- and slow-degrading fractions, respectively. Compared with 2.4% corn oil supplements, 5.2% soybean lecithin added to sheep diets (56% concentrate) reduced (P less than .05) energy, fiber and nitrogen digestibilities. Crude lecithin reduced (P less than .05) energy digestibility more than deoiled lecithin. Both types of lecithin increased (P less than .05) serum nonesterified fatty acid concentrations but had no effect on serum glucose, cholesterol or triglyceride concentrations compared with the corn oil diet. In summary, phospholipids had different effects on ruminal fermentation, depending on their source. None had a beneficial effect on fiber digestion. Phospholipids are degraded in the rumen and inhibit digestion in a manner similar to that of the commercial fats and oils.