Some differences in composition of covering fat,intermuscular fat,and intramuscular fat of meat animals

A method is described for rapid, reproducible extraction of total lipids from adipose and muscle tissues. The distribution of polyunsaturated fatty acids in the depot fats and intramuscular lipids in loin or rib roasts of pork, beef, lamb, and veal has been determined. The phosphatides of the muscle were found to contain a greater amount of polyunsaturated fatty acids than the neutral fats of the intramuscular lipids. American Meat Institute Foundation Journal Paper No. 225.     

Effects of age,sex, and diet upon carcass and liver fatty acid composition of pitman-moore miniature pigs

Fatty acid composition of carcass and liver and proximate analysis of liver were studied in 14–28 day old Pitman-Moore miniature pigs, 26 sow-reared and 30 fed a semisynthetic diet in which the fat was lard. With increasing age, fat of carcass, but not of liver, became significantly more unsaturated. The percentage of palmitic acid (16∶0) and total saturated fatty acids was significantly greater and the percentage of linoleic acid (18∶2) and total unsaturated fatty acids significantly less in carcasses of male than of female pigs. No sex-related differences in proximate or fatty acid composition of the liver were noted. Carcasses of sow-reared pigs contained significantly greater percentages of myristic (14∶0), palmitoleic (16∶1), and linoleic acids and significantly lesser percentages of stearic (18∶0) and oleic (18∶1) acids than did those of pigs fed the semisynthetic diet. Diet-related differences in fatty acid composition of liver closely paralleled those of carcass, although liver contained markedly greater percentages of stearic and arachidonic (20∶4) acids and lesser percentages of palmitoleic and oleic acids than did carcass. Diet-related differences in fatty acid composition of carcass and liver are discussed in relation to the fatty acid composition of dietary fat (sow milk and lard).     

CAST基因多态性与西门塔尔杂交牛胴体和肉质性状的相关性分析

目的分析钙蛋白酶抑制蛋白(Calpastatin,CAST)基因多态性与西门塔尔杂交牛胴体和肉质性状的相关性。方法选取95头西门塔尔杂交牛,采用限制性片段长度多态性聚合酶链反应(Restriction fragment length polymor-phism-polymerase chain reaction,RFLP-PCR)对CAST基因外显子1(Exon1)和外显子5(Exon5)区域的片段的多态性进行检测,并对突变位点与西门塔尔肉牛胴体和肉质性状的相关性进行分析。结果在所分析的片段中,仅引物4扩增的片段(Exon1)存在一个G→C碱基的置换突变(E1 256 g﹥c),为同义突变;该突变位点为RasⅠ酶的自然酶切位点,酶切后存在GG、GC和CC 3种基因型,CC基因型与西门塔尔牛的净肉率性状显著相关(P﹤0.05),而对其他胴体和肉质性状无显著影响。结论 CAST基因Exon1处存在的突变位点与西门塔尔肉牛的净肉率显著相关,因此该位点将有助于筛选与牛肉质相关的辅助选择标记,该基因将为鉴定与肉质相关的功能基因提供参考。     

Influence of different fats in pig feed on fatty acid composition of phospholipids and physical meat quality characteristics

Two feeding experiments (i, ii) were conducted to investigate the influence of different dietary fats on the fatty acid (FA) composition of phospholipids as well as meat quality in pigs. In each experiment 12�4 siblings of Swiss Landrace or Large White breed were allocated to one of four feeding treatments according to sex, breed, and litter and fattened from about 25 to 105 kg liveweight. Pigs were fed a control diet (barley, wheat, soybean meal) or the control diet supplemented with 7% pork fat, 4.95% olive oil or 3.17% soybean oil (i) or 5% of olein or stearin fraction of pork fat or hydrogenated fat (ii). The dietary FA composition was reflected in the FA composition of phospholipids in M. long. dorsi and triceps brachii. However, the unsaturated to saturated ratio was not affected by the dietary intake of polyunsaturated FAs and was only slightly increased by the olive oil supplementation. Trans FAs including conjugated linoleic acid were incorporated into phospholipids only to a small extent. The dietary altered fatty acid composition of phospholipids did not cause any effect on pH, cooking loss, texture, or colour of pork, but meat quality as well as the proportion of saturated FA, arachidonic acid, and n‐3 fatty acids were significantly influenced by genetic effects.     

Buffalo meat composition as affected by different cooking methods

Buffalo meat is considered in Italy as an alternative product for its good nutritional characteristics. The influence of three cooking methods (boiling, grilling and frying) on the chemical and lipid composition of buffalo meat was evaluated. All the treatments reduced the moisture and increased protein, ash and fat content. The increase in fat content was higher after frying due to the incorporation of fat from olive oil. Fried meat had lower saturated fatty acid content due to the incorporation of mono-unsaturated (C18:1) fatty acids from oil. The incorporation of oil fatty acids caused a decrease in conjugated linoleic acid relative content. Moreover, fried meat showed the highest levels of the unhealthy trans fatty acids. Therefore, frying was shown as the worst cooking methods regarding human health. Boiling and grilling increased thiobarbituric acid reactive substances, while frying had no effect on them.     

Effect of omega fatty acid-rich oil blend supplementation on the growth,carcass, meat quality,and gene expression of Barbari goats

This study investigated the effect of supplementing omega fatty acids-rich oil blend, composed of sunflower oil (1.5% and 3.0%), linseed oil (1.5% and 3.0%), and FineXNV1810 (20 g) on the carcass, meat quality, fatty acid profile, and genes (peroxisome proliferator-activated receptor-α, stearoyl-CoA desaturase, acetyl-CoA carboxylase, hydroxy-3-methylglutaryl coenzyme A, and leptin) of Barbari goats. The goat kids (n = 18) were divided into three groups, namely, group A: basal diet; group B: basal diet + oil blend level 1; and group C: basal diet + oil blend level 2, and subjected to the feeding trial for 120 days followed by slaughter and meat quality studies. No treatment effect was recorded in carcass characteristics, pH, water holding capacity, and proximate composition of meat. However, a significant (p < 0.05) treatment effect was observed in cooking loss, lightness, yellowness, and shear force values of meat. There were significant differences (p < 0.05) in linoleic acid, α-linolenic acids, conjugated linoleic acid (CLA), polyunsaturated fatty acids (PUFA), n − 3 and n − 6 PUFA, PUFA/saturated fatty acids and n − 6/n − 3 ratios, and thrombogenic index among groups. An upregulation of the studied genes in the supplemented groups was observed. There were upregulations in the studied genes in the supplemented groups. Practical applications: Goat meat is in great demand the world over, especially in tropical countries, including India, and does not carry any social or religious prohibition. Although goat meat has relatively less fat, consumers express their concern over the presence of undesirable fatty acids. The present study shows that the fatty acid configuration of goat meat can be improved by a dietary supplementation of an oil blend rich in omega fatty acids. The amount of n − 3 PUFA, n − 6 PUFA, and CLA in goat meat was significantly increased due to the dietary oil blend making it healthy for the consumers. Moreover, the dietary oil blend at the studied levels did not significantly affect the growth and meat quality parameters of the goats. Thus, the studied approach can be successfully followed to produce healthier goat meat.     

Study of carcass fats of beef animals. I. The composition of beef brisket fat

Summary The iodine value, titer, and unsaturated fatty acid composition of a number of beef brisket fats have been determined. Beef brisket fats have been found to differ from beef tallows representing composites of fats from other portions of the carcass. The variations are manifested in a higher iodine value, lower titer, lowersaturated fatty acid, and a higher monoethenoid fatty acid composition. The outer brisket fat seems to differ from composite tallows more than the inner brisket fat. This observation, previously unreported, does not apparently conflict with Shorland's designation of beef tallows as “heterolipids.” Journal series number 46 of the American Meat Institute Foundation. Presented at 25th Fall Meeting of the American Oil Chemists' Society, Chicago, Ill., Oct. 8–11, 1951.     

Temperature effects on tocopherol composition in soybeans with genetically improved oil quality

Tocopherol, a natural antioxidant, typically accounts for a small percentage of soybean (Glycine max L. Merr.) oil. Alleles that govern the expression of polyunsaturated fatty acids in soybean germplasm are influenced by temperature. However, little is known about the environmental influences on tocopherol expression. The objective of this study was to assess the influence of temperature on tocopherol composition in soybean germplasm that exhibit homozygous recessive and dominant alleles that govern the predominant ω-6 and ω-3 desaturases. The control cv. Dare and three low-18:3 genotypes (N78-2245, PI-123440, N85-2176) were grown under controlled-temperature environments during reproductive growth. Analysis of crude oil composition at various stages of seed development revealed a strong negative correlation between total tocopherol content and growth temperature. The relative strength of this correlation was greater in the germplasm that exhibited homozygous alleles governing the ω-6 desaturase than those governing the ω-3 desaturase. The decline in total tocopherol with reduced temperature was attributed predominantly to loss of γ-tocopherol. However, γ-tocopherol concentration also was directly related to 18:3 concentration in all genotypes. Thus, low-18:3 oils contained both a lower content and a lower concentration of γ-tocopherol. Although the biochemical basis for this observation is unknown, the antioxidant capacity of γ-tocopherol appeared to be directly associated with changes in oil quality that were mediated more by genetic than by environmental influences on 18:3 concentration. Another aspect of this work showed that low-18:3 soybean varieties should be expected to contain more α-tocopherol, especially when grown under normal commercial production environments. This condition should be regarded as another beneficial aspect of plant breeding approaches to the improvement of soybean oil quality.     

Proximal composition, lipid and cholesterol content of meat from pigs fed peach-palm meal (Bactris gasipaes Kunth) and synthetic lysine

Two experiments were conducted to evaluate the proximal composition, lipids and cholesterol content of meat from pigs fed diets with peach-palm meal (PPM), with or without addition of synthetic lysine (LYS). In experiment 1, 24 pigs were randomly allotted into six treatments with three levels of PPM (0.16 and 32%) and two levels of LYS (0 and 0.27%). In experiment II, 16 finishing pigs were fed with two levels of PPM (0 and 17.50%) and two levels of LYS (0 and 0.27%). At the end of each experiment (42 and 35 d, respectively), pigs were slaughtered and loin samples were obtained to determine crude protein, dry matter, moisture, ash, total lipids, and cholesterol content. In experiment I, pork loin from 16% PPM had more dry matter (26.45 g/100 g) and less moisture (73.49 g/100g) than pork loin from 32% PPM (25.11 y 75.03 g/100g, respectively). Meat samples from pigs without LYS had higher (p < 0.05) content of lipids (2.11 g/100 g) than meat from pigs that consumed LYS (1.72 g/100 g). In experiment II, the proximal, lipids and cholesterol content were similar among treatments. The PPM addition to pig diets did not affect the proximal composition of pork, while LYS addition indicated a reduction of total lipids, which could result as an alternative to obtain leaner meat.     

The effect of dietary fat on the glyceride structure of rat carcass fat

Carcass fats were obtained from weanling rats fed a complete diet for 8 weeks, which consisted of 2% cottonseed oil and 10% of the following fats: (1) corn oil; (2) the fatty acids of corn oil; (3) triricinolein; (4) ricinoleic acid; (5) the hydrogenated fatty acids of castor oil ; and (6) commercial hydrogenated shortening. The fats were subjected to both pancreatic lipase and nonspecific hydrolysis ; the resulting acids converted into methyl esters by conventional methods, and subjected to gas Chromatographie analysis. From these data, the positional distri-bution of the component fatty acids, glyceride types, and isomeric forms were calculated. The results indicated a preferential placement of un-saturated acids in the 2- position of the carcass triglycerides and that the carcass fat composition in terms of unsaturated (U) and saturated (S) fatty acid composition is not greatly influenced by the S and U compositions of the dietary fat. It was found that hydroxy acids or their tri-esters are metabolized much the same as are normal triglycerides and exert no particular in-fluence upon the fat structure of the rat. Some type of relationship between the dietary U and the U₃ in the carcass fat appears to be present. The glycerides of the carcass fats examined here are essentially a random mixture of the major glyceride types, but the isomeric forms (SUS, S SU, USU and UUS) are a definite non-random mixture. Carried out at the Food Res. Div., Armour & Co., and at The Burnsides Research Laboratory under research grant No. EF 225 from the National Institutes of Health, U. S. Public Health Service, and Deparmtent of Health, Education, and Welfare.     

Triglyceride composition of ewe,cow, and goat milk fat

The separation and identification of the components in milk fat, which are mainly triglycerides, is a challenge due to its complex composition. A reverse-phase high-performance liquid chromatography (HPLC) method with gradient elution and light-scattering detection is described in this paper for the triglyceride analysis in ewes’ milk fat. Triglyceride identification was carried out by combining HPLC, gas-liquid chromatography (GLC), and the calculated equivalent carbon numbers of several triglyceride standards. Quantitation of partially resolved peaks in the HPLC chromatogram was accomplished by applying a peak deconvolution program. Forty-four fatty acids were identified by GLC analysis, but only 19 were used for the following prediction of triglyceride molecular species; 181 triglycerides were identified, some of which were grouped at the same peak and needed application of the deconvolution program. Consequently, coefficients of variation were close to or lower than 5%. Moreover, the triglyceride composition of ewe, cow, and goat milk fat were compared by using these methods. These results show that ewe milk fat is richer in short- and medium-chain triglycerides, and cow milk fat is richer in long-chain and unsaturated triglycerides.     

Determination of fat composition

A revolution has taken place in the analysis of fats. Physical methods, both rapid and accurate, have replaced laborious chemical procedures. The timehonored saponification equivalents and iodine values now are calculated from Chromatographic and nuclear magnetic resonance spectroscopic data. Differential migration processes such as countercurrent distribution, liquid-liquid chromatography, and gas chromatography have supplanted the classical distillation and crystallization procedures for analysis and preparation. What have been referred to as “gadgets” are now the stock-in-trade of the analytical lipid chemist. Mass, infrared, ultraviolet, and nuclear magnetic resonance spectrometers are the accepted tools for organic characterization. Recording detectors and computer processing of data reduce the labor of analysis and improve its quantitation. Today’s methodology stands at the verge of specifying fatty acid composition of even so complex lipids as hydrogenated fats in terms of the amounts, the positions, and geometric configurations of its individual component fatty acids. Presented at the AOCS Short Course, East Lansing, Mich., Aug. 29-Sept. 1, 1966. No. Utiliz. Bes. Dev. Div., ARS, USDA.     

Variations in fat content and lipid class composition in ten different mango varieties

The kernels of 10 different mango varieties were extracted. The physico-chemical characteristics and lipid class composition of fats were studied. The fat content of mango kernels grown under the soil and climatic conditions of Bangladesh varied from 7.1% to 10%, depending on the variety. The total lipid extracts were fractionated into lipid classes by a combination of column and thin layer chromatography (TLC). The hydrocarbon and sterol esters varied from 0.3% to 0.7%, triglycerides from 55.6% to 91.5%, partial glycerides from 2.3% to 4% and free sterol from 0.3% to 0.6%. Free fatty acids amounted to 3.0–37% as oleic; glycolipids were 0.6–1.2% and phospholipids 0.11–0.8%. The fatty acid composition of triglyceride (TG) fractions was analyzed by gas liquid chromatography (GLC). Palmitic acid varied from 7.9 molar % to 10.0 molar %, stearic from 38.2% to 40.2%, oleic from 41.1% to 43.8%, linoleic from 6.0% to 7.6%, linolenic from 0.6% to 1.0% and arachidic acid from 1.7% to 2.6%. TLC revealed the presence of lyso-phosphatidylcholine, phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidic acid in the phospholipid fraction.     

Fatty acid composition and glyceride structure of piglet body fat from different sampling sites

Pigs were slaughtered at 16 weeks of age, and fat samples were obtained from outer and inner shoulder, outer and inner loin, and kidney. Fatty acid composition and glyceride type of distribution were determined. Glyceride structure was determined by pancreatic lipase hydrolysis. There were highly significant differences in fatty acid composition between sites. Fatty acids containing less than 18 carbon atoms were preferentially incorporated in the internal positions of the glycerides. The content of saturated fatty acids and fatty acids containing less than 18 carbon atoms at the 2-position of shoulder and loin glycerides was higher than in kidney glycerides. Differences in glyceride types were noted between sites.     

Effects on plasma lipids and fatty acid composition of very low fat diets enriched with fish or kangaroo meat

The effects of very low fat diets (<7% energy) enriched with different sources of long chain (C20 and C22) polyunsaturated fatty acids (PUFA) on plasma lipid levels and plasma fatty acids (PUFA) on plasma lipid levels and plasma fatty acid composition were studied in 13 healthy volunteers. Three diets provided 500 g/day of tropical Australian fish (rich in arachidonic acid and docosahexaenoic acid), southern Australian fish (rich in docosahexaenoic acid) or kangaroo meat (rich in linoleic and arachidonic acids). The fourth diet was vegetarian, similarly low in fat but containing no 20- and 22-carbon PUFA. Subjects ate their normal or usual diets on weeks 1 and 4 and the very low fat diets in weeks 2 and 3. Weighed food intake records were kept, and weeks 2, 3 and 4 were designed to be isoenergetic with week 1. Plasma cholesterol levels fell significantly on all diets within one week. There were reductions in both low density (LDL) and high density lipoprotein (HDL) cholesterol levels, with effects on HDL cholesterol being more consistent. There were no consistent or significant effects on total triglyceride levels despite the high carbohydrate content of the diets. On all diets the percentage of linoleic acid fell in the plasma phospholipid and cholesteryl ester fractions, while the percentage of palmitic acid in the phospholipids and cholesteryl esters and palmitoleic acid in the cholesteryl ester fraction rose on all diets. The percentage of arachidonic acid rose in the phospholipid and cholesteryl esters on the two diets that were good sources of this fatty acid (tropical fish and kangaroo meat). The percentage of docosahexaenoic acid also rose on the two diets that were the richest sources of this fatty acid (the fish diets), and the percentage of eicosapentaenoic acid rose in the phospholipid and cholesteryl esters in proportion to the dietary level of this fatty acid (southern fish > kangaroo > tropical fish). The changes in fatty acid composition were almost completely reversed within seven days of returning to the usual higher fat diets.     

Chemical composition of Creole cattle meat

Proximal composition was determined in meat's Creole cattle (CGBC). For this purpose, four raw cuts of CGBC were analyzed: buttock, flank, loin blade steak, and shoulder blade steak. The mentioned names of the meat cuts come from the National Meat Bureau from the Republic of Argentina. These cuts were taken from an experimental lot of Creole cattle (n = 11) in Jujuy province. Comparisons were made with data extracted from Argentine Table of Food Composition, edited by National Nutrition Institute, Buenos Aires, Argentina (1942). The results show that the level of protein is slightly inferior (in the case of CGBC varies between 18.44 +/- 0.30 and 21.06 +/- 0.11 g/100 g, while in the CTE varies between 20 and 23.8 g/100 g). The content of lipids in the cuts without visible fat is variable (1.06 +/- 0.01 to 2.74 +/- 0.61 g/100 g in the cuts of CGBC and 1.4 to 8.4 for the cuts of CTE). The content of minerals is similar (Fe 2.26 +/- 0.18 to 2.35 +/- 0.23 mg/100 g in CGBC, while in the CTE varies between 3.15 and 3.46 mg/100 g; Phosphorous varies between 142 +/- 10 and 170 +/- 11 mg/100 g in CGBC and 186 to 213 mg/100 g in CTE). These outcomes allow to affirm that the quality of CGBC beef is very similar to CTE beef with regard to principal nutrients.     

Milk fat globules: Fatty acid composition,size and in vivo regulation of fat liquidity

Populations of large and small milk fat globules were isolated and analyzed to determine differences in fatty acid composition. Globule samples were obtained by centrifugation from milks of a herd and of individual animals produced under both pasture and barn feeding. Triacylglycerols of total globule lipids were prepared by thin layer chromatography and analyzed for fatty acid composition by gas chromatography. Using content of the acids in large globules as 100%, small globules contained fewer short-chain acids, −5.9%, less stearic acid, −22.7%, and more oleic acids, +4.6%, mean values for five trials. These differences are consistent with alternative use of short-chain acids or oleic acid converted from stearic acid to maintain liquidity at body temperature of milk fat globules and their precursors, intracellular lipid droplets. Stearyl-CoA desaturase (EC 1.14.99.5), which maintains fluidity of cellular endoplasmic reticulum membrane, is suggested to play a key role in regulating globule fat liquidity. Possible origins of differences between individual globules in fatty acid composition of their triacylglycerols are discussed.     

Contribution of meat fat to dietary arachidonic acid

Arachidonic acid (AA) in the diet can be efficiently absorbed and incorporated into tissue membranes, resulting in an increased production of thromboxane A₂ by platelets and increased ex vivo platelet aggregability. Results from previous studies have shown that AA is concentrated in the membrane phospholipids of lean meats. However, the concentration of AA in the visible fat portion of meats also may be significant despite being ignored in most studies. The aim of this study was to accurately quantitate the AA content of visible fat and the lean portion of beef, lamb, pork, chicken, duck, and turkey. The visible fat of meat contained a significant quantity of AA, ranging from 20 to 180 mg/100 g fat, whereas the AA content of the lean portion of meat was lower, ranging from 30 to 99 mg/100 g lean meat. Beef and lamb meats contained lower levels of AA in both the visible fat and lean portion than that from the other species. The highest level of AA in lean meat was in duck (99 mg/100 g), whereas pork fat had the highest concentration for the visible fats (180 mg/100 g). The lean portions of beef and lamb contained the higher levels of n-3 polyunsaturated fatty acids (PUFA) compared with white meats which were high in AA and low in n-3 PUFA. The present data indicate that the visible meat fat can make a contribution to dietary intake of AA, particularly for consumers with high intakes of fat from pork or poultry meat.     

Biodiesel from extracted fat out of meat and bone meal

Nine non‐halogenated solvents for the extraction of fat from meat and bone meal (MBM) were evaluated by the accelerated solvent method. Yields of about 15% were obtained with all solvents, but n‐hexane was found to be the most suitable extraction solvent, because it is relatively cheap and has a low boiling point. Fat was also extracted from MBM on preparative scale (600 g) by immersion, and the extracted material was analysed for impurities that could affect the subsequent transesterification. The extracted material was converted into fatty acid methyl esters (FAME) via a two‐step process. For further purification, the raw FAME were distilled under reduced pressure. The final product was analysed according to the European specification for biodiesel (EN 14214). Almost all of the values were within the specifications, except the cold‐temperature behaviour and the oxidation stability. All in all, extracted fat from MBM is a potential feedstock for the production of biodiesel.