Influence of dietary linoleic acid on egg fatty acid composition in hens deficient in essential fatty acids

The effect on egg yolk lipids of adding linoleic acid in the form of corn oil to the diet of hens depleted of essential fatty acids over a prolonged period was examined. There was an immediate increase in the amount of linoleate deposited in all yolk lipid fractions. The addition of 8% corn oil resulted in a maximum value of about 20% lineoleic acid in the egg yolk fatty acids being attained over a period of 14 days. This increase in lineoleate deposition was accompanied by a reduction in the level of oleic acid. Minor adjustments in the other egg fatty acids accompanied these major changes.     

摄食不同来源磷脂对大鼠脂质代谢及脑内磷脂脂肪酸组成的影响

研究了摄食不同来源磷脂对大鼠脂质代谢及其脑内磷脂脂肪酸组成的影响。雄性SD大鼠按体重随机分为大豆油对照组(添加9%)、牛乳磷脂组(添加5%)、大豆磷脂组(添加5%)、蛋黄磷脂组(添加5%),喂食3周。检测了血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(FFA)及肝脏TC、TG、磷脂(PL)的含量,并用气相色谱法测定了脑内磷脂脂肪酸的组成变化。结果显示:与大豆油对照组相比,3种磷脂均不同程度提高了大鼠体重、脏器指数,蛋黄磷脂效果显著;3种磷脂不同程度降低了血清TC、TG和FFA含量,牛乳磷脂降低血清FFA显著,大豆磷脂降低血清TC、TG显著,蛋黄磷脂降低FFA显著,大豆磷脂显著提升了血清HDL-C含量;3种磷脂不同程度降低了肝脏TC、TG、PL含量,牛乳磷脂与大豆磷脂降低肝脏TG、TC显著,而蛋黄磷脂降低肝脏TG显著;3种磷脂对脑内磷脂脂肪酸组成的影响各不相同,牛乳磷脂显著提高了脑内磷脂饱和脂肪酸含量,而大豆磷脂和蛋黄磷脂提高了DHA等多不饱和脂肪酸含量。研究表明,3种磷脂均有降血脂、肝脂作用,以大豆磷脂作用尤为明显,大豆磷脂和蛋黄磷脂的益智作用可能优于牛乳磷脂。     

Influence of growth promoting implants on fatty acid composition including conjugated linoleic acid isomers in beef fat

The influence of the growth promoting implants Synovex (SYN), Ralgro (RAL), and Revalor (REV) on the fatty acid profiles of subcutaneous fat, intramuscular fat, and phospholipids of 32 beef steers (eight steers per treatment, and eight controls) was studied. Fatty acid compositions and profiles of conjugated linoleic acid (CLA) isomers were determined by a combination of GC and triple-column Ag⁺-HPLC. Only small differences could be observed between the different treatment groups. The amount of saturated fatty acids relative to monounsaturated fatty acids was increased by all growth promoting implants in subcutaneous fat (P<0.1) and also by SYN in intramuscular fat. RAL led to slightly higher amounts of trans fatty acids in subcutaneous and intramuscular fat (P<0.1). REV-implanted steers showed some significant differences in their profiles of polyunsaturated fatty acids compared to control steers. CLA content and isomeric distribution in subcutaneous fat were affected bySYN, which reduced amounts of total CLA (0.42 mg/g fat vs. 0.53 mg/g in control steers, P<0.001) and decreased the proportions of the primary 18:2 c9t11 isomer (73% of total CLA for SYN vs. 77-78% for all other treatment groups). Slight increases of c9t11 CLA in intramuscular fat were observed in RAL- and REV-implanted steers (P<0.1). Most differences in fatty acid composition observed in this study were probably due to shifts in the storage lipid/membrane lipid ratio.     

The effect of cooking on the fatty acid composition of longissimus muscle from beef heifers fed rations designed to increase the concentration of conjugated linoleic acid in tissue

Longissimus dorsi (LD) muscle from 60 Charolais crossbred heifers, aged for 14 days was used to investigate the effect of cooking on the content of PUFA and CLA fatty acids. Animals were offered a control diet of grass silage and concentrates (CO) or rations designed to enhance the concentration of CLA in tissue, i.e. unsupplemented grazed pasture (G), sunflower-oil supplemented grazing (SFG) or linseed-oil oil supplemented grazing (LSG). The SFG diet was the most effective for increasing the concentration of CLA but also caused the highest n-6/n-3 fatty acid ratio. There were no changes in the relative distribution of fatty acids upon cooking (140°C for 30min) and this procedure can be recommended because it preserves the nutritional value of the meat. It is concluded that irrespective of the change in the fatty acid composition of LD due to alteration in the diet of the cattle, cooking did not cause thermal degradation of PUFA, or thermal degradation or oxidative synthesis of CLA.     

Influence of dietary conjugated linoleic acid on the fatty acid composition and volatile compounds profile of heavy pig loin muscle

This study evaluated the effects of dietary conjugated linoleic acid (CLA) on fatty acid composition, chemical composition and volatile compounds profile of the longissimus dorsi muscle in Italian heavy pigs. The animals (97 kg) were randomly assigned to three diets varying in supplemental CLA (CON = 0 CLA, T1 = 2.5 g CLA kg⁻¹ feed and T2 = 5.0 g CLA kg⁻¹ feed) till the slaughtering at 172 kg. Samples of longissimus dorsi were analysed for chemical composition (moisture, protein and lipid content), fatty acid composition and volatile compounds. No significant differences were observed for proximate chemical composition. Dietary CLA showed limited effects on fatty acid composition of longissimus dorsi, with higher, but not significantly, amounts of saturated fatty acids in the treated groups than in the control group; both the cis‐9, trans‐11 and the trans‐10, cis‐12 isomers of CLA were increased in longissimus dorsi from pigs fed CLA. T1 and T2 pigs had a greater concentration of C16:0 and of C16:1 (P < 0.01) than CON. CLA diets tended to reduce C20:2 (P = 0.077) and C20:4 (P = 0.065) content in longissimus dorsi muscle. Diets containing higher amount of CLA were responsible for increased levels of volatile compounds in meat, but not at a significant level. Copyright © 2005 Society of Chemical Industry     

酶法合成共轭亚油酸型磷脂的研究

在非水相体系中利用固定化脂肪酶为催化剂,将共轭亚油酸酰基转移到磷脂分子中,合成富含共轭亚油酸(CLA)的改性磷脂。选用的三种常用的固定化脂肪酶中Lipozyme RM IM催化效率最高,最佳反应条件为:CLA乙酯与大豆粉末磷脂的摩尔比为4∶1,反应温度45℃。对反应产物中的CLA含量进行检测分析表明,48h后其含量可以达到31.3%。进行分离处理后,检测该产品的理化指标。     

不同脂肪酸组成磷脂对大鼠消化吸收的影响

首先通过在饲料中添加胆固醇和卵黄磷脂,研究了卵黄磷脂对大鼠血清和肝脏脂质水平的影响;其次通过配制含有不同磷脂的高脂乳剂灌胃大鼠,考察了不同磷脂的高脂乳剂对大鼠血清总胆固醇、甘油三酯的影响.结果表明:大豆磷脂、卵黄磷脂和鱿鱼磷脂对甘油三酯的消化吸收具有一定的抑制作用,且鱿鱼磷脂的抑制作用最明显;大豆磷脂和卵黄磷脂可以显著促进胆固醇的消化吸收,而鱿鱼磷脂显著抑制了胆固醇的消化吸收.     

Irradiation effect on fatty acid composition and conjugated linoleic acid isomers in frozen lamb meat

The effect of gamma radiation processing on the lipid content, fatty acid composition and conjugated linoleic acid (CLA) profile in frozen lamb meat was investigated. Samples of longissimus thoracis muscle from lambs fed lucerne basal diets either unsupplemented or supplemented with polyunsaturated vegetable oils were irradiated (7 kGy) and analysed. CLA contents in lamb meat did not affect (P > 0.05) the levels of lipid oxidation induced by the irradiation. No significant differences (P > 0.05) were observed for fatty acid composition, related nutritional indexes (n − 6/n − 3 and PUFA/SFA), as well as for total lipid and CLA contents, between non-irradiated (control) and irradiated meat samples. In contrast, meat irradiation affected the relative proportions of total trans, trans and cis/trans CLA isomers (P < 0.001), in addition to the percentage of some minor individual CLA isomers (t11, t13 and t9, t11, with P < 0.05 and P < 0.001, respectively). The percentage of total cis/trans CLA isomers slightly decreased in irradiated samples, while the relative proportion of total trans, trans isomers slightly increased. This observation may be explained by the higher susceptibility to autoxidation of the cis double bond relative to the trans configuration.     

Influence of early postnatal overnutrition of rats on fatty acid composition of membrane lipids

The influence of early postnatal overnutrition on fatty acid composition of erythrocyte, thrombocyte and liver mitochondria membrane lipids was studied in male rats (3, 6 and 11 months old) reared in small nests (2 pups per dam) in comparison to normally bred rats (12 pups per dam). Independent of age elevated proportions of palmitic and stearic acid at the expense of linoleic and arachidonic acid were found in all membrane lipids investigated in the postnatally overfed animals. These changes are discussed in relation to the enhanced lipogenesis with increased body fat accumulation in this animal model of a dietary induced obesity.     

Effects of conjugated linoleic acid on oxidative stress in rats with sucrose-induced non-alcoholic fatty liver disease

The effect of CLA on hepatic oxidative stress and its relationship with the non-alcoholic fatty liver disease in rats was evaluated. Twenty-one days old Wistar rats were divided in two groups: the control group of six rats, which received a standard diet; and the sucrose group of 12 rats, which was given the same standard diet plus 30% sucrose in the drinking water. After 9 weeks the animals of the sucrose group were divided in two sub-groups of six rats each: the vegetable oil group that was fed 7.5% sunflower oil in the diet, and the CLA group which received 1.5% CLA. After 8 weeks the animals were sacrificed to obtain blood and liver tissue samples. Levels of oxidative stress markers: SOD, GSH, and catalase were measured in serum and liver homogenate and histological analysis was performed to recognize steatosis. Dietary CLA significantly decreased body fat, glutathione peroxidase, and superoxide dismutase in serum and liver. The histological analysis showed that, although CLA consumption was clearly beneficial, it did not entirely prevent sucrose-induced steatosis.     

纯牛奶中18碳TFA及9c,11t-CLA含量的测定研究

为了精确测量出纯牛奶中18碳TFA及9c,11t-CLA的含量,本实验通过毛细管气相色谱法,并采用内标法,对纯牛奶进行了检测,结果显示,纯牛奶中18碳脂肪酸的质量百分比约为35·43%,18碳TFA的质量百分比约为2·27%,而其中C18:1-11t的质量百分比达到1·28%,占所有18碳TFA的一半以上,约为56·36%,同时,牛奶中C18:2-9c,11t的质量百分比只为0·11%,其含量远少于TFA。      

Changes in the fatty acid composition of erythrocyte membranes in patients with chronic alcoholism under the effect of a diet enriched with linoleic acid

The authors have studied the influence of additional introduction into the ration of sunflower oil on fatty-acid composition of erythrocytic membranes in chronic alcoholics. The computerized discriminant analysis has evidenced that additional introduction of sunflower oil into the ration of the patients normalizes the fatty-acid spectrum of erythrocytic membranes. Besides that, enrichment of the ration with linoleic acid improves the parameters characterizing the liver function (bilirubin, alanine aminotransferase of blood serum).     

Oxidation of muscle phospholipids in relation to their fatty acid composition with emphasis on volatile compounds†

The impact of moderate changes of fatty acid (FA) composition of phospholipids (PL) on their oxidative stability and on volatile profiles remains largely unknown. PL of breast muscle of turkeys fed a diet containing 6% tallow, rapeseed oil or soya oil were purified and prepared as liposomes. After 24 h of incubation at 25 °C with iron/ascorbate, oxidation was quantified by measurement of thiobarbituric acid reactive substances (TBA‐RS) and volatile compounds. TBA‐RS level was the lowest (21.4 nmole eq MDA mg⁻¹ PL) in PL from tallow‐fed animals but was not significantly different (P > 0.05) in soya oil (30.9 nmole eq MDA mg⁻¹ PL) and rapeseed oil (30.3 nmole eq MDA mg⁻¹ PL) batches. ANOVA did not clearly distinguish between the three groups according to the quantities of individual volatiles except for Z,E‐2,4‐heptadienal. In contrast, principal component analysis (PCA) performed on standardised quantities of volatile compounds distinguished unambiguously the three groups. Axis 1 was positively correlated with volatile compounds arising from oxidation of n‐6 fatty acids, and negatively with compounds of n‐9 origin. Axis 2 was highly positively correlated with compounds from n‐3 origin. Only a few compounds from each origin (n‐6, n‐3, n‐9) had an atypical behaviour. A weak modification of the FA composition of PL led to concomitant modifications of the quantities of volatile compounds generated through oxidation, which were emphasised by multivariate analysis (PCA). © 1999 Society of Chemical Industry     

The effect of energy-rich and energy-reduced rations with n-alkane yeast portions on the fatty acid composition of selected organ lipids in swine

In 3 test groups (11 pigs in each group) rations with identical fatty acid patterns (except C 17 acids) at high, medium and low-energy levels of the rations were fed. The fatty acid composition of the lipids of liver, heart and brain was analyzed at the end of the experiments. A correlation was found to exist between energy and fatty acid intake and the fatty acid spectrum of the organ lipids. With identical intake of odd-numbered fatty acids, an energy-rich diet leads to a reduction of odd-numbered fatty acids in the heart and liver lipids. A reduced energy concentration causes an increase of odd-numbered fatty acids in liver and heart. Under energy-rich and energy-reduced feeding, C 15 and C 19 acids can be traced in the hepatic lipids. In liver, heart and brain, an energy-rich diet results in increased contents of eicosapentaene and eicosahexaene acid. Under low-energy diet, a reduction of these fatty acids can be found in the brain.     

The composition of the fatty acids and aldehydes of the ethanolamine and choline phospholipids of various meats

The ethanolamine phospholipids of beef, lamb, pork and chicken examined in this study contained over 40% of ethanolamine plasmalogen, whereas fish contained only 13%. The level of choline plasmalogen in choline phospholipids was less than 1% in fish and ranged from 10 to 30% in the other four meats. Palmitaldehyde was the major fatty aldehyde in the choline plasmalogens of beef, lamb, pork and chicken (65–80% of total aldehydes), but was present at lower levels in the ethanolamine plasmalogens. The per cent fatty acid compositions of phosphatidylethanolamine and the corresponding ethanolamine plasmalogen were very similar, being typically low in palmitic acid but very high (56–74%) in polyunsaturated fatty acids. The fatty acids of the choline plasmalogens contained more polyunsaturated fatty acids than the corresponding phosphatidyl cholines, but at lower levels than in the fatty acids of the ethanolamine phospholipids.     

The effect of energy-rich and energy-reduced rations with n-alkane yeast portions on the fatty acid composition of fat stores of swine

In 3 test groups (11 pigs in each group), rations with an identical fatty acid pattern of the fat in the fodder (except C 17 acids) with a high energy level (energy concentrations = 131%), medium energy level (energy concentrations = 100%) and low energy level (energy concentrations 90 or 82%, resp.) were used. In the course of the investigation the fatty acid spectrum was studied by analyzing spinal fat biopsy specimen. An interrelation was found to exist between the energy supply and the fatty acid spectrum in the depot fat. When identical quantities of heptadecenoic and heptadecanoic acids were added to the fodder, a high energy level resulted in a reduced C17 acid content in the spinal fat, whereas a low energy level led to an increased C17 acid content in the spinal fat. Different energy concentrations caused a change in the contents of oleic acid, linoleic acid and linolenic acid in the spinal fat. With changed energy concentrations, the C16 and C18 acid content showed variations compared with the group given standard fodder. The myristin acid content showed almost no change.     

Influence of dietary fish meal on egg fatty acid composition

Changes in the fatty acid composition of egg-yolk fat of hens fed diets with increasing fish meal content are studied by total fatty acid analysis. The fatty acid composition of the major lipid fractions in egg-yolk fat after feeding a high-level fish meal diet was determined by a combination of thin layer chromatography (t.l.c.) and gas-liquid chromatography (g.l.c.) The changes produced show a fatty acid pattern similar to those of the diets themselves. Long-chain polyunsaturated fatty acids are deposited preferentially in the phospholipids, reaching the highest concentration in cephalin and lecithin.     

Influence of methandrostenolone on some aspects of protein metabolism in rats in the context of various protein rations]

Wistar male-rats receiving by mouth dianobol for 10 days and 9 months and fed on rations with different proportions of protein were investigated. Dianobol is shown to produce under definite conditions changes in the intensity of the protein synthesis in the muscle tissue and liver of the test animals and also to raise the activity of tryptophan-peroxidase and of alanine-amintransferase, the protein level in the ration being here of substantial importance. With its long-term administration to rats dianobol displays an androgenic effect on the gonads and the supernumerally genitals without exercising any stimulating action on the weight gain.     

Effect of dietary conjugated linoleic acid in combination with monounsaturated fatty acids on the composition and quality traits of cooked loin

Three levels (0%, 1% and 2%) of a conjugated linoleic acid oil (CLA) were combined with two levels of monounsaturated fatty acids (MUFA) (low – 19% average and high – 39% average) for pig feeding (n = 48, eight animals per treatment). The composition and quality traits (fat content, cooking losses, lipid oxidation, fatty acid profile, volatile profile and sensory analysis) of cooked loin, as affected by dietary CLA, MUFA, and CLA × MUFA interaction were studied. CLA and CLA × MUFA did not affect the intramuscular fat content, cooking losses, lipid oxidation, volatile profile and sensory traits of cooked meat. Therefore, CLA could be supplemented to the pig diet without detriment of the measured quality traits of cooked meat, and regardless of the MUFA level of pig diets. Dietary CLA increased the content of SFA and decreased the level of MUFA of meat, and led to a CLA enrichment, regardless the MUFA level of pig diets, but the content of CLA isomers of fresh meat decreased after the cooking process.