Untersuchungen über die Fettverwertung der Regenbogenforelle (Salmo gairdnerii,R.) I: Einsatz von rohem und raffiniertem Sojaöl im Vergleich zu raffiniertem Sonnenblumenöl in einer synthetischen Futtermischung

Investigations of Fat Utilization of the Rainbow Trout (Salmo gairdnerii, R.) I: Use of Raw and Refined Soya Bean Oil in Comparison to Refined Sunflower Oil in a Synthetic Feed Mixture Three vegetable oils (raw soya bean oil, refined soya bean oil and refined sunflower oil) were used as fat components in a synthetic feed mixture (standard diet. These three proved utilization figures of 0.08 and better as well as PER-values of more than 2.50 on an average could be achieved. Between raw and refined soya bean oil no differences were found, whereas sunflower oil showed a somewhat worse utilization.     

Synthese und Eigenschaften gesättigter Trialkylglycerinäther

Synthesis and Properties of Saturated Trialkyl Glycerol Ethers The alkylation of glycerol with alkylbromides yielded even-numbered saturated trialkyl glycerol ethers (1,2,3-trioctyl- to 1,2,3-trihexadecyl glycerol ether). The melting points of these compounds are very similar to those of saturated triglycerides with the same molecular weights. In a subacute compatibility test 10% of tridodecyl glycerol ether (TDG) in standard diet was administered to 20 rats during 13 weeks in comparison to groups obtaining standard diet plus 10% of paraffin oil or only standard diet. The food intake of the TDG group was by about 15% lower than that of the reference group. With the paraffin oil group food intake was higher than with the reference group. The increase in weight of the animals of all three groups did not differ significantly. Incompatibilities as a result of the TDG diet have not been observed. The histomorphological investigations showed slight fatty degeneration of the liver in TDG animals. With animals fed on a paraffin diet this degeneration was much more significant.     

Einfluß von oxidierten Ölen/Fetten sowie α-Tocopherol- und Antioxidantienzulagen auf das Wachstum und die Vitamin E- und A-Gehalte in Geweben von Masthühnerküken

Oxidized Oils/Fats and α-Tocopherol and Antioxidants Increase on Growth and Vitamine E and A Contents in the Tissue of Fat Pullet Chickens Fat contents in mixed food for fat pullet chickens lead to the assumption that the fat will be perished within a very short time whereby negative consequences for the fat soluble vitamines E and A must be expected, too. During three feeding tests with each at 20 groups of 9 animals in each group fresh and oxidized fat (lard, animal mixed fat) or oil (refined soya bean oil) was added to the feed basic mixture at an amount of 10%. Various α-tocopherolacetates (α-TA) increases (0, 25, 50, 75, 100 mg/kg feed) and various synthetic antioxidants (EMQ, BHT, LOXIDAN-TD 100) in combination with 25 or 50 mg α- TA were added to feed mixtures in 3 tests. The determinations of vitamin E and A in blood plasma, in the fat of the subdermal fatty tissue and of the liver took place by high pressure liquid chromatography. The vitamine A content in the livers decreased significantly by the oxidized fats/oils. If the ratios contained antioxidants in addition, statistically secured higher vitamine A data in this organ were found.     

Refining of Roundup Ready® soya bean oil: Effect on the fatty acid,phytosterol and tocopherol profiles

In this study, genetically modified (GM) soya bean seeds with the event known as Roundup Ready® were used for the production of soya bean oil and their fatty acid, phytosterol and tocopherol composition was characterised. Since these compounds can be partially lost during refining, this study also aimed at evaluating the compositional changes along the GM soya bean oil extraction and refining processes carried out industrially. During the refining process of crude soya bean oil, neutralisation was responsible for the major losses on phytosterols (15%). The greatest reduction of tocopherols was also caused by the neutralisation step (20%), while the deodorisation step caused minor losses (9%). Along the refining process, the decreases of total phytosterols and total tocopherols were 20 and 30%, respectively, which are lower than the losses reported in other studies, reflecting the industrial improvements in preserving beneficial health compounds in the refined oil. The results showed that the refined GM soya bean oil presented higher contents of phytosterols (313 mg/100 g) and tocopherols (931 mg/kg) comparing to other reports.     

Zusammenhänge zwischen Fettoxidation und Antioxidantienzulagen im Mischfutter

Relations Between Fat Oxidation and Antioxidative Additives in Mixed Feeding Stuff Storage experiments with various mixtures of feeding stuffs were carried out. The influence of single factors on fat stability in test mixtures should be tested. The type of fat (refined soya bean oil, free fatty acids from soya bean oil raffination) fat content (3, 6, 9%), antioxidants (BHA, TBHQ), amount of anti oxidants (0 - 50 - 100 - 150 mg/kg feeding stuff), storage temperature (4, 14, 24°C) and storage period (6 - 12 - 24 weeks) were varied. The peroxide value (POZ) and the remaining amounts of antioxidants were used as parameters for the determination of the fat oxidation. The test results showed a some what enlarged stability of the fatty acids of soya bean oil raffination compared with refined soya bean oil in presence of anti oxidants. The stabilising effect of TBHQ was higher than that of BHA, but the consumption of antioxidants was lower with BHA than with TBHQ. With increasing amounts of antioxidants the stability of the fat was enlarged. The stability was lowered with rising storage temperature. Increasing storage period gives rise to a considerable increase in oxidation.     

Dimer and Trimer Fatty Acids in Feed Fats Characterized by HPLC-GPC and MS

Commercial feed fats, animal fat distillation residue, bleached earth oil and abused frying fat were fractionated into monomeric and dimeric triglycerides by means of gel permeation chromatography. Upon hydrolysis and methylation the mixtures were analysed by electron impact mass spectrometry using the integrated ion current technique. All samples contained a fraction of dimeric fatty acid methyl ester with molecular ions at m/z 584 , 586, 588 and 590, probably representing a great variety of both cyclic and linear structures. The individual dimers are not separated by this technique but the mass spectra of the multicomponent dimer fractions of all feed fats investigated showed remarkable resemblance. This may indicate that the dimeric fatty acids generated through intermolecular dimerization between two triglycerides are rather similar to those formed through intramolecular dimerization within the triglycerides. In two cases only trimeric fatty acids methyl esters were observed. The actual concentration of dimeric fatty acids was determined by HPLC-GPC to 3.7-13.7%.     

Untersuchungen über die Fettverwertung der Regenbogenforelle (Salmo gairdnerii,R.) VI: Vergleichender Einsatz von 18 unterschiedlichen Futterfetten in einer gereinigten Diät

Investigations about Fat Utilization of the Rainbow Trout (Salmo gairdnerii, R.) VI: Comparative Use of 18 Different Feeding Fats in a Purified Diet In the submitted work the usability of different feeding fats as source of energy in rations for rainbow trouts is reported. In comparison to 10% of sunflower oil in a standard diet the same amount of examined fats (maize germ oil, rice oil, lard, Novitol-30) with a share of less than 3% of essential linolenic acid (18:3, n-3) produced a just so good utilization. Only olive oil with an unbalanced high content of oleic acid decreased significantly. If a share of 6–7% in 18:3, n-3, fatty acids was contained in the feeding fat (rape seed oil poor in erucic acid and rich in erucic acid, raw and refined soya bean oil, refined soya fatty acids) the utilization increased significantly. The best result was achieved by addition of refined soya fatty acids with 15% 18:3, n-3, or red perch oil with a share of 17% 20:5, n-3 and 22:6, n-3. If beef tallow and especially micronized hardened fatty acids were used whose melting point was far beyond 40°C, a significant decrease in utilization was noticed. These fats proved to be less suitable as source of energy in rations for rainbow trouts. The same good characteristics of utilizations as with soya bean oil and rape seed oil were found in case of use of mixed animal fats, though no essential fatty acids were contained. An explanation could not be found. Linseed oil came off badly, though a surplus of essential fatty acids 18:3, n-3 was contained. The high rate of oxidations of the three fold unsaturated linolenic acid and as result a lacking absorption might be the cause.     

Untersuchungen zu Interaktionen zwischen Fetten und Calciumcarbonat bzw. Dicalciumphosphatzusatz bei Verabreichung lipidreicher Rationen an wachsende Schweine

The Interactions between Different Feed Fat Types and Respective Supplements of CaHPO₄·2H₂O and CaCO₃ on Some Nutritional- Physiological Parameters when Feeding Lipid Enriched Rations to Growing Pigs. In four, 3 × 4-factorial digestibility and balance experiments involving in all 48 growing pigs (46 to 60 kg live weight, 4 animals per group), the interactions between four feed fat types (refiend and hardened fish oil 35–37°C; refined coconut fat, poultry oil and soya oil) and three levels of feed calcium and phosphorus (I, II and III) on the apparent digestibility of crude fat, the apparent digestibility of fatty acids, the excretion of fecal soaps, the balances of the elements calcium, phosphorus, magnesium, sodium and potassium as well as the renal and fecal excretion of these minerals was investigated. Per trial 10% by weight of a fat type (fist oil, coconut fat, poultry oil and soya oil) was added to the otherwise identical growers diet. The sole intra-trial difference was the exclusion of a mineral supplement in diet I, the inclusion of 1% by weight of CaHPL₄·2H₂O in diet II and the inclusion of 1% by weight of CaCO₃ in diet III. The fat type constituted the inter-trial variable. Each of the rations fed in the digestibility/balance investigations was fed ot a finishing pig (100 to 110 kg live weight) in the slaughter experiments involving in all 12 hogs. After a 10 day feeding period the 3 pigs per trial were sacrificed, and digesta samples from 5 segments of the gastrointestinaltract (the abomasum, the proximal duodenum, the ileum, the caecum, and the distal rectum) was collected to study the effects of the factors feed-fat-types as well as calcium- and phosphorous levels on the formation of soaps in contents from the alimentary canal. The results of the two trial series were discussed.     

Effect of karawila (Momordica charantia) seed oil on synthesizing the alkyd resins based on soya bean (Glycine max) oil

Air drying long oil alkyd resins of 65% oil length were synthesized from a blend of soya bean (Glycine max) oil and karawila (Momordica charantia) seed oil. Different proportions of karawila seed oil (w/w% 10, 20, 30, 40 and 50) were blended with soya bean oil to examine the effect of karawila seed oil on the drying behavior of alkyds synthesized from soya bean oil. A sharp variation of viscosity is only observed for alkyd resins having more than 40% (w/w) of karawila seed oil. The polyesterification time was reduced and correspondingly the extent of polymerization was also reduced up to 30% (w/w). Significant variation in transesterification time was also observed for 30% (w/w). However, further increase in karawila seed oil above 40% (w/w) had only a marginal effect on the polyesterification reaction. The drying properties of the alkyd resins had been significantly improved with the increase of karawila seed oil up to 30% (w/w) but further increase in karawila seed oil resulted in poor drying characteristics. The film properties (drying time, hardness, adhesion, chemical resistance and gloss) of the alkyd resins were determined. The optimum film properties were recorded for the oil blend with 30% (w/w) karawila seed oil and 70% (w/w) soya bean oil.     

Effects of cold stress on rats fed different levels of docosenoic acids

Male Sprague-Dawley rats, 4 weeks old, were subjected to an ambient temperature of 4 C for periods up to 24 days and fed a synthetic diet containing one of the following oils: peanut oil (PO), rapeseed oil (RO), low erucic acid rapeseed oil (LO), and partially hydrogenated marine oil (HO), each at 20% w/w. A parallel experiment using the same oils was performed at room temperature (23 C). During cold stress, animals on the RO diet showed higher mortality than all other groups; all 20 animals in this group died within 5 days. At room temperature, however, all animals survived. The lipid accumulation in the heart reached its peak in all groups after 3 days and then gradually declined. The accumulation was most pronounced in the RO animals and coincided with the high mortality at 4 C. The fatty acid composition of the cardiac triglycerides reflected that of the diet, while the composition of the cardiac lecithin was only marginally modified.     

Die Veränderungen von Nahrungsfetten bei höheren Temperaturen

Alterations of Edible Fats and Oils at Elevated Temperatures Refining of vegetable fats and oils has no deleterious effect upon their composition as far as desliming, neutralization or bleaching is concerned. However, during deodorization or physical refining small amounts of dimeric triglycerides and of trans fatty acids are formed depending on temperature and duration. The amounts of these by products are insignificant provided that the usual process conditions are applied. In the kitchen the various cooking methods can have quite different effects upon the quality of the fats and oils. Whereas boiling and baking have no effects and short-term shallow frying show only minor changes in quality, deep-fat frying can cause serious alterations especially if the oil is used far too long. Numerous investigations tried to identify these chemical reactions which are predominatly isomerizations as well as polymerization and oxidation reactions. The German Society for Fat Science and Federal Health Authorities in Germany issued recommendations for the assessment of fat deterioration basing on sensory evaluation in combination with some analytical data. Since 60 years and with considerable effort more or less systematic investigations have been performed to answer the question if heated fats are detrimental to human health. Fats and oils were heated under the conditions of good commercial practice and then fed to test animals. In some cases the heated fats were separated into various fractions and these were fed individually. The results of the most significant long-term feeding trials are reported and critically evaluated.     

Significance of soya trypsin inhibitors in nutrition

Although recent evidence clearly indicates that trypsin inhibitors (TI) and low protein digestibility are the major factors responsible for the pancreatic hypertrophic and growth inhibitory effects of raw soybeans, there was uncertainty regarding the biological threshold level of TI at which these biological effects occur. To obtain such data, dehulled defatted flakes (10% dietary protein) containing graded levels of TI were fed to weanling rats for 4 weeks in two feeding trials. Normal pancreas weights were obtained in rats fed samples in which only 54 to 68% of the original TI of raw soya flour was inactivated. In partially toasted flakes with a nitrogen digestibility value of 77%, the average tolerance level of dietary TI activity that did not cause pancreatic hypertrophy was calculated to be 385 mg TI/100 g diet. TI tolerance level at maximum nitrogen digestibility of 85%, which did not significantly lower weight gain and reduce protein efficiencey ratios, was 260 mg TI/100 g diet. Continuous ingestion of high levels of TI (459 mg TI/100 g diet) in a 20% protein diet for 215 days did not inhibit growth nor cause pancreatic hypertrophy when compared to rats fed toasted soya flour diets. Pancreatic hypertrophy that occurs in rats fed raw soya diets containing up to about 1300 mg TI/100 g diet for 35 days was reversed by switching the rats to control diets or to 30% toasted flour. In long-term feeding studies, no pancreatic hypertrophy occurred in rats fed commercial edible-grade soya flour, concentrate, or isolate from time of weaning to adulthood (ca. 300 to 330 days). TI content of the diets ranged from 178 to 310 mg/100 g diet. Microscopic examination of the pancreas revealed no abnormalities. Gross appearances of heart, kidney, spleen and liver were normal. In long-term feeding, vitamin B-12 supplements were needed to provide optimum growth and to maintain body weight. Results of numerous chemical analyses, relatively short-term human tests and long-term animal feeding studies indicate that with proper control of manufacturing processes, soya protein products can be produced that, in mixed diets, have protein nutritional value approaching that of animal protein.     

Dietary n-3 and n-6 PUFA Enhance DHA Incorporation in Retinal Phospholipids Without Affecting PGE<Subscript>1</Subscript> and PGE<Subscript>2</Subscript> Levels

The purpose of this study was to determine whether dietary n-3 and n-6 PUFA may affect retinal PUFA composition and PGE₁ and PGE₂ production. Male Wistar rats were fed for 3 months with diets containing: (1) 10% eicosapentaenoic acid (EPA) and 7% docosahexaenoic acid (DHA), or (2) 10% γ-linolenic acid (GLA), or (3) 10% EPA, 7% DHA and 10% GLA, or (4) a balanced diet deprived of EPA, DHA, and GLA. The fatty acid composition of retinal phospholipids was determined by gas chromatography. Prostaglandin production was measured by enzyme immunoassay. When compared to rats fed the control diet, the retinal levels of DHA were increased in rats fed both diets enriched with n-3 PUFA (EPA + DHA and EPA + DHA + GLA diets) and decreased in those supplemented with n-6 PUFA only (GLA diet). The diet enriched with both n-6 and n-3 PUFA resulted in the greatest increase in retinal DHA. The levels of PGE₁ and PGE₂ were significantly increased in retinal homogenates of rats fed with the GLA-rich diet when compared with those of animals fed the control diet. These higher PGE₁ and PGE₂ levels were not observed in animals fed with EPA + DHA + GLA. In summary, GLA added to EPA + DHA resulted in the highest retinal DHA content but without increasing retinal PGE₂ as seen in animals supplemented with GLA only.     

Dietary n−3 FA modulate long and very long chain FA content, rhodopsin content, and rhodopsin phosphorylation in rat rod outer segment after light exposure

A previous study has shown that the long and very long chain FA (VLCFA) content of the rat retina responds to changes in dietary n−6/n−3 ratio of the fat fed (1). The present study tested whether similar changes in these FA are associated with alterations in rhodopsin content and rhodopsin phosphorylation after light treatment. Weanling rats were fed diets containing 20% (w/w, 40% energy) fat with either high (4.8%, w/w) or low (1.2%, w/w) n−3 FA. After 6 wk of feeding, half of the animals in each group were exposed to light for 48 h at 350 lx or were kept in complete darkness. In the rod outer segment, the high n−3 diet treatment increased the level of 20∶5n−3 and 22∶6n−3 and reduced the levels of 20∶4n−6 and 24∶4n−6 in PC, PE, and PS. After the feeding of a high n−3 FA diet, total n−3 pentaenoic VLCFA from C₂₄ to C₃₄ increased in PC, whereas the n−6 tetra- and pentaenoic VLCFA decreased. No changes occurred in n−3 hexaenoic VLCFA regardless of the level of 22∶6n−3 in the diet. After light exposure, animals fed a high n−3 FA diet showed reduction in 22∶6n−3 as well as in n−6 and n−3 VLCFA in PC. FFA and TG fractions contained increased levels of both 20∶4n−6 and 22∶6n−3 after light exposure. Dark-adapted rhodopsin content and rhodopsin phosphorylation in the rod outer segment of rats fed the low n−3 FA diet were higher than in animals fed a high n−3 FA diet. After light exposure, animals fed the low n−3 FA diet lost more rhodopsin compared to animals fed the high n−3 FA diet, resulting in less phosphorylation of rhodopsin. Results indicate that the FA composition, rhodopsin content, and phosphorylation in visual cells is influenced by the dietary n−3 FA fed as well as by light exposure. The results also imply that 22∶6n−3 may not be the precursor for synthesis of hexaenoic VLCFA.     

Chemical and nutritional studies on the seed oil ofAcacia arabica

The seeds ofAcacia arabica contain 5.2% oil. Physicochemical constants and fatty acid composition of the refined seed oil were determined. The seed oil was rich in linoleic acid (39.2%) and oleic acid (32.8%). Trace quantities of epoxy and hydroxy fatty acids were present in the seed oil. Nutritional evaluation of the refined seed oil was done by rat bioassay with peanut oil as control. The animals fed 10% seed oil showed poor growth performance and low feed efficiency ratio. The digestibility of the seed oil was 90% compared to 94% for peanut oil. The seed oil in the diet of rats for 4 wk did not produce any abnormal serum lipids or histopathological findings.     

Oligopolymer,diglyceride and oxidized triglyceride contents as measures of olive oil quality

The objective of this study was to test the qualities of olive oils of different commercial grades by quantifying oligopolymer compounds by high-performance size-exclusion chromatography (HPSEC). The method required no sample manipulation and was accurate and rapid. The mean level of oligopolymers in refined olive oils was 0.70% and was more than twice as high in refined olive pomace oils. Conversely, edible virgin olive oils had no oligopolymer compounds. HPSEC analyses of polar compounds by silica gel column chromatography also allowed determination of oxidized triglycerides and partial glycerides, which help define levels of oxidative degradation and hydrolysis. Research supported by National Research Council of Italy, Special Project RAISA, Sub-project 4, Paper No. 321.     

Influence of Dietary Fat and Vitamin E on the Lipids in Pork Meat

48 pigs (gilts and barrows) were divided into four groups and fed for three months on diets containing either 3% soya oil or 3% beef tallow, together with α-dl-tocopheryl acetate at either a basal (20 mg/kg feed) or a supplemented (200 mg/kg feed) level. The fatty acid compositions of the longissimus dorsi muscle (m.l.d.) and adipose (backfat) tissue were found to vary with dietary fats and sex. Gilts showed higher contents of polyene fatty acids (PFA) than barrows. The PFAs C20:4ω6, C22:4ω6, C22:5ω3 and C22:6ω3 were not affected by the diet. Levels of α-tocopherol in muscle and adipose tissue were 2.5 to 4.0 times higher in pigs on the supplemented diet compared to pigs on the basal diet. After storage at – 18°C for nine months the muscle tissues were subjected to iron-induced lipid peroxidation. Supplementation of the feed with α-tocopheryl acetate improved the oxidative stability of the muscle. The influences of dietary fat and sex on lipid peroxidation were reduced by supplemental α-tocopheryl acetate. Muscle tissue from the basal-diet/soya-oil group was more susceptible to lipid oxidation than muscle tissue from the basal-diet/beef-tallow group.     

Anwendung der Gelpermeationschromatographie auf die Untersuchung thermisch-oxydativ belasteter Fette

The Application of Gel Permeation Chromatography to the Investigation of Thermal-Oxidatively Treated Oils Principle and apparatus used in gel permeation chromatography (GPC) are given along with methods for the determination of dimeric, trimeric and higher oligomeric triglycerides in frying fats that are subjected to extreme thermal oxidation. Separation of a frying fat into monomeric and oligomeric triglycerides by means of preparative GPC followed by analyses of their products of saponification revealed that dimeric fatty acids occur only in the fraction of oligomeric triglycerides. Accordingly, the dimerization reaction in the presence of atmospheric oxygen consists entirely of an intermolecular reaction. Under various conditions (at 240°C in the presence of air, at 240°C under argon, and under partial exposure to both light and air) all the oligomerization reactions obey the reaction law of the first order, although their rates are different. In the investigation of animal fats by GPC tallow and butter were found to contain none, whereas the fat in cheese, chicken and lard were found to contain upto 1% dimeric triglycerides.     

High‐fat diet based on trienantin has no adverse metabolic effects in rats

The present study was designed to evaluate the metabolic effects of a high‐fat diet based on trienantin, an uncommon medium‐odd‐chain triacylglycerol. Male Wistar rats (33.37 ± 5.69 g) (n = 3×10) were maintained for 6 weeks on a control diet (7 g soya oil/100 g) or a high‐fat diet based on trienantin (40 g margarine, 4 g soya oil and 25.79 g trienantin/100 g), or a high‐fat diet based on soya oil (40 g margarine and 29.79 g soya oil/100 g). The serum lipid profile, hepatic function and injury markers, and renal function and injury markers were determined. Samples of liver, stomach, kidney and small intestine were collected for histological analysis. The animals fed the high‐fat diet based on trienantin exhibited a lower body weight gain in relation to the control group, between the second and fifth week of the experiment. There were no differences amongst the biochemical markers of the three groups (p ≥0.05). Lipid infiltration of the hepatocytes was detected in a similar manner in all groups (p ≥0.05). These data demonstrate that the high‐fat diet based on trienantin did not promote adverse metabolic effects under the conditions of this study. This could serve as a reference parameter in the evaluation of the safety of its therapeutic application.     

Kurzfristige Fütterungsversuche mit Methylestern dimerer Fettsäuren

Short-Time Feeding Tests with Methyl Esters of Dimeric Fatty Acids Fatty acid methyl esters ex safflower oil were polymerised at high temperature and separated by distillation. Feeding experiments with rats at a level of up to 50 cal-% in the food showed the highest degree in growth retardation with those fractions which contained esters of dimeric fatty acids. Esters of dimeric fatty acids of well defined structure, were fed to mice per os to determine acute toxicity. With the compounds applied the toxicity was far higher than 20 ml/kg body weight. After feeding radiocarbon labelled dimeric fatty acid esters, it could be shown that a high percentage of the material fed was excreted. However, a small amount is metabolised since ¹⁴CO₂ was observed in the exhaled air, and radioactive monomeric fatty acids were found in the body fat. Finally a small amount of the labelled dimeric fatty acids fed to the rats was recovered from the body fat indicating direct incorporation.