The experimental obesity by high-fat feeding--a model for evaluation of the biological value of fats

The experimental obesity by high-fat feeding of rats, introduced after weaning, was found to be a suitable model for evaluation of the biological value of nutritional fats with different fatty acid composition: butter (group B), lard (L), partially hydrogenated oil (H), lard + sunflower oil 2:1 (LS). The differences in the fatty acid composition of these regimens affect: the efficiency in creating the model of obesity; the hormonal pattern of blood plasma; some metabolic pathways in liver and adipose tissue (especially in group H); the fatty acid composition of some structural, reserve and transport lipids; some biological tests indicative of membrane's phospholipid and fatty acid composition, i.e. the rate of platelets aggregation. A special attention should be paid to the striking differences in the cellularity and morphogenesis of adipose tissue in group B (hyperplastic obesity) in comparison with all other high-fat groups (hypertrophic obesity), irrespective of the identical energy and protein content of the diets. Thus, the early administration of a diet with butterfat (50% of energy) promoted a model of hyperplastic obesity, while the isocaloric diet with lard + sunflower oil caused a hypertrophic type of obesity. The authors have proved the regenerating capacity of the periepididymal fat pad in adult rats after partial lipectomy. The relative contribution of endogenic and exogenic (nutritional) factors in this process is discussed and the modifications in the cellularity of adipose tissue on these conditions are evaluated.     

UV spectroscopy studies of the oxidation changes in depot and structural lipids in high-fat feeding

The degree of incorporation of conjugated dienes, trienes and tetraenes into reserve (depot fats) and structural liver lipids of rats is studied depending on the type of high-fat feeding (50 energy%): lard, lard + sunflower oil (2:1), butter, hydrogenated sunflower oil. It is found that in adipose tissue there are only conjugated dienes whose concentration is lower than that of lipids of the respective diets and of the liver. Structural lipids are characterized by a high concentration of conjugated tri- and tetraenes. It is established that the fatty acid compositions of the diets and their oxidizability coefficients, respectively, do not correlate with the degree of accumulation of conjugated fatty acid structures in living organisms. The disequilibrated high-fat regimens based on butter and partially hydrogenated sunflower oil create conditions for more intensive incorporation of oxidized fatty acid products into the tissues.     

Oxidation stability and fatty acid composition of selected storage and structural lipids: influence of different high fat diet compositions

The oxidation stability of storage lipids from adipose tissue and of structural lipids from liver was compared to the coefficients of oxidizability of the pure fat used: lard (L); lard + sunflower oil 2:1 (LS); butter (B) and partially hydrogenated oil (H). The oxidation stability of the corresponding high-fat dietary regimens (50 energy-%) was also investigated. The experimental groups L, LS, B and H were compared to the control group (C) fed low-fat laboratory pellet-food. The coefficients of oxidizability were calculated from the fatty-acid composition of the used pure fats. The oxidation stability was performed in condition of accelerated oxidation under kinetic regimen, assaying the peroxide concentration in appropriate time intervals. The coefficients of oxidizability of dietary fats and storage lipids were very similar. This is explained by the fact that the fatty-acid composition of storage lipids reflected that of the corresponding high-fat diets. The oxidation stabilities in storage lipids were markedly lower than these in the respective dietary regimens. The highest oxidation stability in lipids from adipose tissue was found in group B, and the lowest in group LS. Contrarywise, the oxidation stability in liver lipid showed the following declining sequence: C greater than H greater than L greater than LS greater than B. The discrepancies in oxidation stability of the various specimens (pure fats, dietary fats, storage and structural lipids) may be explicated by an intervention of factors with pro- and anti-oxidative action. The large deviations in fatty acid composition in the examined tissues in comparison to the composition of the respective high-fat diets may also play an important role in this respect. These parallel studies on oxidation stability at different levels could improve our possibilities for evaluation of the stability and biological value of fats.     

不同种类高膳食油脂对小鼠血脂、肝脂及尿酸的影响

为了探讨猪油、植物油及其调和油对血脂、肝脂及血尿酸的影响,评估其对特殊人群的健康潜在风险,本文研究以小鼠为模型,模拟居民用油习惯,将50只8周龄雄性C57BL/6J小鼠随机均分为葵花籽油组(SSO)、豆油组(SO)、猪油组(LO)、葵花籽油与猪油调和油组(SSO-L)、豆油与猪油调和油组(SO-L)5组,模拟我国部分人群(5%~10%)日均烹调油脂高摄入水平(95g/d),每组日粮中分别添加10.5%的不同油脂,饲喂8周后采集血液和肝脏组织,检测血清和肝脏指标。结果显示,相比于其他各组,LO组在体脂和血脂方面都有显著或极显著升高(p0.05,p0.01)。而SSO-L组和SO-L组在肝脂方面显著高于对应的SSO组和SO组(p0.05)。同时,SSO-L组和SO-L组的SUA和肝脏XOD水平都显著高于LO组(p0.05)。表明在95 g/d的膳食油脂摄入水平下,猪油会极大增加肥胖和患脂肪肝病的风险。葵花籽油与猪油调和油和豆油与猪油调和油也会通过升高尿酸水平来增大痛风和脂肪肝的患病风险。此外,长期以该水平摄入这两种调和油对肝脏功能也有明显损伤。在该摄入水平下,豆油为较优选择。     

Effect of high-fat cholesterol enriched diets on hypolipemic action of Oenothera paradoxa oil in rats. Part 2. Blood serum and liver fatty acids

The effect of Oenothera paradoxa oil on blood serum and liver fatty acids composition in rats was studied. Rats were fed high-fat diets containing 15% of lard or sunflower oil with or without 0.5% of cholesterol. Soybean protein isolate (27%) was the source of proteins. Intake of Oe. paradoxa oil resulted in increase of levels of gamma-linolenic acid (GLA) and linoleic acid (LA) in blood serum and liver of experimental animals. The effect of Oe. paradoxa oil on blood serum and liver fatty acids composition depended mainly on the type and to the lower degree on the amount of fat in a diet. The addition of cholesterol did not change the influence of examined oil on the composition of fatty acids.     

棕榈油与猪油在组成结构和功能特性上的比较

比较了3种棕榈油和6种猪油产品在理化指标、营养与功能特性指标以及脂肪酸组成及其在甘油三酯Sn-2位上的分布情况,以判断棕榈油对猪油的可替代性.结果表明,棕榈油和猪油的熔点、碘值、酸值、过氧化值等理化指标很接近;棕榈油不含胆固醇,具有比猪油较高的V_E含量和氧化稳定性;在可塑性方面,精炼棕榈油与猪板油相当,而且好于猪杂油和猪膘油,棕榈硬脂与猪骨油相当,棕榈液油与猪皮油相当;虽然棕榈油和猪油的脂肪酸组成具有相似性,猪油的不饱和脂肪酸含量略高于棕榈油的不饱和脂肪酸含量,但是棕榈油的Sn-2位上主要分布不饱和脂肪酸,而猪油的Sn-2位上主要分布饱和脂肪酸,使棕榈油比猪油更加容易消化吸收.     

黄大茶水提物改善高脂小鼠脂肪组织的脂肪酸代谢

目的：探究黄大茶水提物对高脂饮食小鼠脂肪组织脂肪酸代谢的调控机制。方法：将5 周龄雄性C57BL/6小鼠随机分为对照组、高脂饮食组、高脂饮食＋2.5%（终质量分数,下同）黄大茶水提取物组、高脂饮食＋0.5%黄大茶水提取物组。饮食干预处理12 周后,测定小鼠体质量、脂肪组织质量,观察脂肪组织形态,并分析脂肪酸代谢关键基因及蛋白表达量等指标。结果：2.5%黄大茶水提物能高度显著降低高脂小鼠体质量及脂肪组织质量（P＜0.001）;减少脂肪组织的脂质沉积;促进SREBP-1C、FAS、ACC、SCD-1等脂肪酸生成相关基因的表达,促进脂肪酸分解相关基因PGC-1α和CPT-1的表达;不同程度激活腺苷酸活化蛋白激酶（adenosine monophosphate activated protein kinase,AMPK）/乙酰辅酶A羧化酶（acetyl CoA-carboxylase,ACC）通路。结论：2.5%黄大茶水提物饮食干预能显著缓解高脂饮食小鼠肥胖和减少脂质沉积,促进脂肪组织脂肪酸合成和氧化分解代谢,此作用与黄大茶水提物激活AMPK/ACC通路相关。     

Dietary docosahexaenoic acid-rich diacylglycerols ameliorate hepatic steatosis and alter hepatic gene expressions in C57BL/6J-Lep(ob/ob) mice

We examined the effect of docosahexaenoic acid (DHA)-enriched structured lipids-diacylglycerol (SL-DG), which were synthesized using soybean oil (SO) and algae oil (AO), on hepatic lipid metabolism and the mRNA expression of genes involved in hepatic steatosis of C57BL/6J-Lep(ob/ob) compared to the SL-triacylglycerol (TG). The animals were fed a high-fat (10% lard and 10% test oils) and high-cholesterol (0.2% cholesterol) diet for 12 weeks. Mice fed SL-DG showed a lower total white adipose tissue weight and plasma triglyceride concentration than the SO group. Reduction of hepatic triglyceride content in the SL-DG group was related with the suppression of hepatic enzyme activities for fatty acid and triglyceride synthesis along with fecal triglyceride excretion compared to the SL-TG. SL-DG also lowered hepatic cholesterol levels by suppressing cholesterol regulating enzyme activity compared to the SO group. Moreover, SL-DG lowered the mRNA expressions of sterol regulatory element binding protein-1 and its target genes than TG-form oils (SO, AO and SL-TG) in the liver. Thus, the current results suggest that DHA-enriched SL-DG oil used in this study is beneficial for ameliorating hepatic steatosis in obese animal model by improving hepatic fatty acid and cholesterol metabolic enzyme activity and their gene expression.     

冬眠期狗獾油脂肪酸组成分析及安全性动物试验

利用低温提取法从冬眠期狗獾脂肪组织中提取狗獾油,对其脂肪酸组成进行分析并进行安全性动物试验。结果表明:狗獾油脂肪酸主要为不饱和脂肪酸,其中上清液中不饱和脂肪酸含量高达75.3%,沉淀中为65.5%,包括人体所必需的亚麻酸、亚油酸等多不饱和脂肪酸;动物试验发现,狗獾油无急性毒性,对皮肤无刺激性,无过敏反应。分析表明,狗獾油除在传统中医领域用作药物外,还有可能替代猪油成为新的食用动物油。     

几种茶叶提取物对高脂饮食小鼠肥胖的预防作用

目的：对绿茶提取物（green tea extract,GTE）、红茶提取物（black tea extract,BTE）、白茶提取物 （white tea extract,WTE）和白茶茶汤（white tea infusion,WTI）预防肥胖功效进行评价和对比,并对其作用机 制进行研究。方法：分别以寿眉、白琳工夫茶和安吉白茶作为绿茶、红茶和白茶的代表,制备GTE、BTE、WTE 和WTI并喂养C57BL/6J小鼠,同时给予高脂饲料。实验结束后统计体质量、脂肪湿质量,制作肝脏和脂肪组织病 理切片,测定血脂及血清转氨酶水平,实时荧光定量聚合酶链式反应测定小鼠肝脏中脂代谢相关基因表达水平。 结果：GTE和WTE可将高脂饮食引起的体质量增长分别降低22.49%和21.23%,且可显著降低脂肪湿质量和皮下 脂肪细胞直径（P＜0.05）。BTE可将体质量增长降低9.03%,但对小鼠脂肪湿质量和皮下脂肪细胞直径无显著影 响（P＞0.05）。BTE组、WTI组和模型对照组小鼠出现不同程度肝细胞脂肪变性,而GTE和WTE组小鼠肝脏状态 良好。GTE和WTE可在转录水平上改善高脂饮食引起的脂代谢紊乱。结论：本实验所选剂量条件下,GTE、BTE和 WTE对小鼠均无肝毒性和生长抑制作用。GTE和WTE可调节脂代谢相关基因的转录表达水平,增强脂肪酸氧化能 力,抑制脂肪酸合成,从而有效预防小鼠肥胖和脂肪肝的发生。GTE预防肥胖效果略优于WTE（P＞0.05）。BTE 也可预防肥胖发生,但效果不显著。另外,未发现WTI有预防高脂饮食引起的肥胖和脂肪肝发生的效果。     

Enhanced resistance of mice (CBA strain) to infection caused by S. typhimurium depending on the nature of the fat in the diet

Mice received rations containing a mixture of lard with sunflower oil, butter, cooking fat (hydrogenated), fish fat. Hydrogenated fat and fish fat induced a decrease in the portion of polyunsaturated fatty acid omega 6 in lipids of lymphocytes, Peyer's patches, mesenteric lymph nodes and the spleen. At the same time fish fat induced an increase of the portion of polyunsaturated fatty acid omega 3 in lipids studied. A relationship has been noted between the animal survival after intraperitoneal infection with S. Typhimurium and the fatty acid composition in lymphoid tissues. The highest survival rate has been recorded in the groups of animals that received cooking (hydrogenated) fat and fish fat.     

Fatty acid composition of liver and adipose tissue lipids in Wistar rats with fat diet-induced obesity

The influence of dietary fat on the fatty acid composition of liver and adipose tissue lipids was investigated after 4 and 19 weeks of high-fat feeding (50% fat) in comparison to low-fat feeding (3% fat), beginning in the sixth week of age. In rats fed the low-fat diet or an usual pellet diet the fatty pattern of liver triglycerides (TG) was equal to that of adipose tissue, while there were no similarities to the diet. In total liver lipids a constant fatty acid profile was observed, independently of the duration of feeding. High fat feeding results several changes in the fatty acid pattern of liver lipids. While after 4 weeks the fatty acids of liver TG more closely resembled the dietary fatty acids than those of adipose tissue, after 19 weeks of feeding the fatty acid composition of liver TG is comparable with that of adipose tissue. Not all rats fed the high fat diet rendered obese. It could be shown that in rats with higher lipid concentrations in the liver only the fatty acid pattern of liver phospholipids has been altered, while the composition of TG, which are the lipids primarily increased, was not changed.     

Mathematical relationships between the intake of n-6 and n-3 polyunsaturated fatty acids and their contents in adipose tissue of growing pigs

To establish the relationships between the fatty acid composition of adipose tissue in growing pigs and the intake of fatty acids, we performed a feeding trial and did a literature survey. Six groups of pigs were fed diets with variable combinations of corn, linseed and fish oil. After 38 days, biopsies of adipose tissue were analyzed for their contents of linoleic, -linolenic, eicosapentaenoic and docosahexaenoic acid. For the four fatty acids, intake data and adipose tissue levels were also collected from the literature. Linear correlations were computed for the intake of each polyunsaturated fatty acid and its level in adipose tissue, the data set consisting of either the original results only or combined with literature figures. The observed strong correlations between dietary and fat tissue polyunsaturated fatty acids indicate that the fatty acid composition of the diet may be used as an index of the fatty acid composition of the diet, and vice versa. The regression equations presented can be used to steer the fatty acid composition of adipose tissue of growing pigs by the fatty acid composition of their diet.     

Effects of xyloglucan with the partial removal of galactose on plasma lipid concentration

Xyloglucan is a component of the cell walls of higher plants that has been used as a thickener or stabilizer in the food industry in Japan and other Asian countries. Xyloglucan from which side-chain galactose has been partially removed or ‘trimmed’ by β-galactosidase (GXG-TG) shows heat-induced reversible gelation, and reverts to sol upon cooling. Xyloglucan is not digested by human digestive enzymes and acts as a dietary fiber. The effects of xyloglucan from which galactose has been partially removed on plasma lipid concentration in rats was investigated. Male Wistar rats (4 weeks old) were fed a high-fat diet (corn oil or lard) for 28 days (control) and other groups were given a high-fat diet (corn oil or lard) containing GXG-TG (5%, replacing cellulose). GXG-TG significantly reduced total cholesterol, β-lipoprotein, total lipid and phospholipid compared to a high-fat diet with corn oil. GXG-TG significantly reduced total cholesterol, β-lipoprotein, total lipid, phospholipid and adipose tissue weight compared to a high-fat diet with lard. These results indicated that the intake of GXG-TG improves lipid metabolism in rats, similar to that of the intact xyloglucan.     

EFFECT OF DIETARY FATS ON THE FATTY ACID CONTENTS OF CHICKEN ADIPOSE TISSUE

SUMMARY— 150 broiler-type chicks were reared from hatching to 4 wk of age on a low-fat ration before being fed diets containing 10% of either corn oil, lard, beef tallow or hydrogenated coconut oil. Analyses of treatment effects were made at 2 wk intervals until the chicks were 10 wk old. The fatty acid content of extracted total lipids were characteristic of the dietary fats and dietary fatty acid patterns were incorporated into the adipose tissue within 2 wk after the experimental diets were fed. The total lipids when separated into solid fats and liquid oils at room temperature also reflected the fatty acid pattern of the experimental diets. Neutral triglycerides from the adipose tissue contained less linoleic acid and more palmitic and oleic acids than the total lipid fraction. High amounts of palmitic and oleic acids were observed in all of the fractions analyzed. No significant differences were found in total cooking loss, drip loss, taste preference, or TBA values of skin or adipose tissue among the 10 wk old chickens fed different experimental diets.     

ANCM bibliography

Changes in fatty acid profiles of pork loin chops fried in different culinary fats (olive oil, sunflower oil, butter and pig lard) during 10 days of refrigerated storage were studied. Olive oil-fried loin chops (OOLC) were significantly highest in monounsaturated fatty acids (MUFA) and C18:1. Sunflower oil-fried loin chops (SOLC) showed the highest polyunsaturated fatty acid (PUFA) proportions, mainly due to C18:2 contents. Butter-fried loin chops (BTLC) were significantly richer in saturated fatty acids (SFA), such as C12:0, C14:0 and C16:0, while pig lard-fried loin chops (PLLC) contained moderate proportions of SFA, MUFA and PUFA. Fatty acid profiles of neutral lipids (NL), free fatty acids (FFA) and polar lipids (PL) were slightly changed after refrigerated storage. After 10 days of refrigerated storage, differences among samples fried in different culinary fats were maintained or increased. NL from OOLC had the significantly largest percentages of C18:1 and MUFA, while SOLC had the significantly largest percentages of C18:2 and PUFA. The highest percentages of C12:0, C14:0, C16:0 and SFA were characteristic for pork loin chops fried in butter at the end of the storage period. Refrigerated pork loin chops fried in pig lard showed intermediate percentages of SFA, MUFA and PUFA. OOLC had a more desirable nutritional value than other fried pork loin chops after and before the refrigerated storage.     

气相色谱法测定脂肪酸含量判定山茶油纯度

利用气相色谱法,对山茶油掺入大豆油、菜籽油、玉米油和葵花籽油的掺伪油进行脂肪酸组成分析。结果表明:油酸、亚油酸和亚麻酸可作为鉴别山茶油中掺伪大豆油和菜籽油的特征脂肪酸,棕榈酸、油酸和亚油酸可作为鉴别山茶油中掺伪玉米油和葵花籽油的特征脂肪酸;回归预测模型相关系数(R^2)较高(> 0. 99),可分别检出掺伪量4%的大豆油和菜籽油,掺伪量8%的玉米油和葵花籽油,回收率在96. 56%~112. 88%之间。该方法灵敏度高,定量准确,可为掺伪山茶油纯度鉴别及调和山茶油配比的定量分析提供科学依据。     

Feeding feedlot steers fish oil alters the fatty acid composition of adipose and muscle tissue

Sixteen steers (441±31.7kg initial body weight) consumed two high concentrate diets with either 0 or 3% fish oil to determine the impact of fish oil, an omega-3 fatty acid source, on the fatty acid composition of beef carcasses. Collected tissue samples included the Longissimus thoracis from the 6th to 7th rib section, ground 10th to 12th rib, liver, subcutaneous adipose tissue adjacent to the 12th rib, intramuscular adipose tissue in the 6th to 7th rib sections, perirenal adipose tissue, and brisket adipose tissue. Including fish oil in the diet increased most of the saturated fatty acids (P<0.01) and proportions of polyunsaturated fatty acids (P<0.06), and decreased (P<0.01) proportions of monounsaturated fatty acids. Dietary fish oil increased (P<0.01) levels of omega-3 fatty acids in sampled tissues, resulting in lower (P<0.01) omega-6:omega-3 ratios. The weight percentages of C20:5 and C22:6 in tissue may provide the recommended daily allowance for humans. Fish oil may have a role in beef niche marketing if there are no deleterious effects on consumer satisfaction.     

Influence of dietary therapy containing sunflower oil fortified with phospholipids on the lipid metabolism in patients with hypertension and obesity

It was investigated the influence of dietary therapy containing sunflower oil with phospholipids (PL) on the lipid profile of plasma and composition of fatty acids of red blood cells in patients with hypertension and obesity. The results show that after the period of three weeks for each diet the unrefined sunflower oil supplemented with PL (30 gr oil containing 10, 8 gr PL) in diet had more influence on lowering of blood pressure (specially on diastolic BP). This diet reduced serum total cholesterol, low density lipoprotein (LDL), apolipoprotein A 1, apoB and fibrinogen more than the refined sunflower oil diet. This oil presents useful source of polyunsaturated fatty acids and essential PL for diets aimed at prevention of heart disease.     

Composition, stability and acceptability of different vegetable oils used for frying peanuts

The purpose of this work was to determine the chemical stability of vegetable oils in the frying process and the consumer acceptance of fried-salted peanuts prepared in different vegetable oils. Fatty acids composition was determined in sunflower, corn, soybean, peanut and olive oils. A chemical study (free fatty acid and p-anisidine values) of these oils at frying temperature (170 °C) was developed during 96 h. Consumer test of fresh products was performed on fried-salted peanuts prepared in the different oils. Peanut oil and virgin olive oil presented oleic acid as predominant fatty acid (44.8% and 64.2%, respectively), making it more resistant to lipid oxidation at frying temperature than the other refined vegetable oils (sunflower, corn and soybean oils). Virgin olive and peanut oils showed less increment of free fatty acids and p-anisidine value than the other oils along the heating essay. In addition, fried-salted peanuts prepared with refined peanut oil showed higher consumer acceptance than those prepared with other vegetable oils such as sunflower, corn, soybean and olive oils. Peanut oil could be used to fry peanuts obtaining products with higher consumer acceptance and shelf-life, thus preventing loss of their sensory and nutritional quality.