Effect of slaughter season on fatty acid composition, conjugated linoleic acid isomers and nutritional value of intramuscular fat in Barrosã-PDO veal

This paper describes the influence of slaughter season on lipid content, fatty acid composition, conjugated linoleic acid (CLA) isomeric profile and nutritional value of fat in Barrosã veal from calves reared according to the specifications of the Protected Designation of Origin (PDO). Barrosã purebred calves (n = 27) were raised in a traditional production system and slaughtered in early autumn (October) and late spring (June). Barrosã-PDO veal only presented seasonal differences in the levels of some minor fatty acids and CLA isomers, as well as in the PUFA/SFA ratio. Based on the analysed grass intake indicators, it was shown that veal-PDO has similar values to pasture-fed cattle for both slaughter seasons. From a human nutrition perspective, intramuscular fat in Barrosã-PDO veal has a high nutritional value throughout the year, since CLA contents and the percentages of the c9,t11 isomer are relatively high, and the n − 6/n − 3 ratios are within the recommended values for the human diet.     

Intramuscular lipids of Mertolenga-PDO beef, Mertolenga-PDO veal and “Vitela Tradicional do Montado”-PGI veal

Three quality branded meats (n = 68), “Vitela Tradicional do Montado”-PGI veal, Mertolenga-PDO veal and Mertolenga-PDO beef were analysed for cholesterol (HPLC-UV), α-tocopherol (HPLC-FD), fatty acid composition (GC-FID), including conjugated linoleic acid (CLA) isomeric profile (Ag⁺-HPLC), and nutritional value of lipids. All the meats analysed had similar contents (P > 0.05) of cholesterol, α-tocopherol and intramuscular fat. In contrast, the percentage of 18:0 was lower for PGI veal, and that of 18:1 c9 was higher in PDO veal, whilst the percentage of 18:2 n−6 was higher in PDO beef, relative to other two meats. The content of total CLA and the percentage of its t11,c13 isomer were higher, and the n−6/n−3 ratio was lower, in PDO veal, relative to the other two meats. The data suggested that PGI veal has higher variability for most fatty acids than the other two types of meat. Finally, a discriminant analysis was conducted and the three meat types were well discriminated using the meat fatty acid profile as variables.     

Influence of slaughter season and sex on fatty acid composition, cholesterol and α-tocopherol contents on different muscles of Barrosã-PDO veal

The influence of slaughter season and sex on intramuscular total lipids (ITL) neutral lipid (NL) and phospholipid (PL) compositions, cholesterol and α-tocopherol contents were evaluated in Biceps femoris (Bf), Longissimus dorsi (Ld) and Supraspinatus (Ss) muscles from 92 Barrosã-PDO (Protected Denomination of Origin) calves. ITL content in Bf muscle was affected by slaughter season and sex whereas NL content was only affected by slaughter season. Neither sex nor slaughter season influenced cholesterol and α-tocopherol contents in the muscles under study. Concerning NL composition, sex was an important source of variation on the proportions of total SFA and MUFA in all muscles. Irrespective of the considered muscle, males had higher total SFA but lower total MUFA and MUFA/SFA contents than females. Slaughter season influenced C18:2 cis-9 trans-11 (CLA) content in Bf (P < 0.01) and in Ss muscles (P < 0.05) with calves slaughtered in autumn showing higher values than their counterparts. Total MUFA, n-3 PUFA and n-6/n-3 ratio contents in Ld muscle were also affected by slaughter season. Regarding PL composition, slaughter season × sex interaction affected total SFA, PUFA/SFA and n-6 PUFA contents in Bf and Ss muscles. In addition, this interaction influenced total MUFA (P < 0.05) in Bf muscle and total PUFA (P < 0.01) in Ss muscle. CLA content in PL from Ld was influenced by sex (P < 0.05) and by slaughter season (P < 0.01), with females slaughtered in autumn presenting the highest content. These results clearly indicate that sex and slaughter season are important factors that influence the fatty acid composition of Barrosã-PDO veal.     

Effect of cooking methods on fatty acids,conjugated isomers of linoleic acid and nutritional quality of beef intramuscular fat

The effect of boiling, microwaving and grilling on the composition and nutritional quality of beef intramuscular fat from cattle fed with two diets was investigated. Longissimus lumborum muscle from 15 Alentejano young bulls fed on concentrate or pasture was analyzed. Cooking losses and, consequently, total lipids, increased directly with the cooking time and internal temperature reached by meat (microwaving > boiling > grilling). The major changes in fatty acid composition, which implicated 16 out of 34 fatty acids, resulted in higher percentages in cooked beef of SFA and MUFA and lower proportions of PUFA, relative to raw meat, while conjugated linoleic acid (CLA) isomers revealed a great stability to thermal processes. Heating decreased the PUFA/SFA ratio of meat but did not change its n−6/n−3 index. Thermal procedures induced only slight oxidative changes in meat immediately after treatment but hardly affected the true retention values of its individual fatty acids (72–168%), including CLA isomers (81–128%).     

Simultaneous HPLC quantification of total cholesterol,tocopherols and β-carotene in Barrosã-PDO veal

A simple, rapid and sensitive procedure for the simultaneous determination of total cholesterol, tocopherols and β-carotene in meat is described. The method involves a direct saponification of the meat, a single n-hexane extraction and the analysis of the extracted compounds by normal-phase HPLC, using fluorescence (tocopherols) and UV–Vis photodiode array (cholesterol and β-carotene) detections in tandem. Rates of recovery of spiked meat samples were 93% for cholesterol, 83–86% for (α-, β- and -γ) tocopherols and 89% for β-carotene. Repeatabilities were high (CV < 6%) for all determined compounds, except for δ-tocopherol. This tocopherol, which is not usually present in meat, showed a much lower recovery percentage (73%) and repeatability (12.8%). This methodology was applied for the quantification of total cholesterol, tocopherols and β-carotene in three muscles (longissimus thoracis, longissimus lumborum and semitendinosus) of the Portuguese traditional Barrosã-PDO veal, obtained from autochthonous calves fed extensively during summer (with the least abundant green pastures) and slaughtered in early autumn (October). Barrosã-PDO veal showed median contents of total cholesterol (0.50–0.56 mg/g) and, depending on the analysed muscle, moderate to high contents of α-tocopherol (3.3–3.9 μg/g) and β-carotene (0.07–0.09 μg/g), suggesting an high sensorial and hygienic quality.     

Effects of feeding flaxseed or sunflower-seed in high-forage diets on beef production,quality and fatty acid composition

Yearling steers were fed 70:30 forage:concentrate diets for 205 d, with either grass hay (GH) or red clover silage (RC) as the forage source, and concentrates containing either sunflower-seed (SS) or flaxseed (FS), each providing 5.4% oil to diets. Feeding diets containing SS versus FS significantly improved growth and carcass attributes (P < 0.05), significantly reduced meat off-flavor intensity (P < 0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n − 6 fatty acids (FA, P < 0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P < 0.05). A significant forage × oilseed type interaction (P < 0.05) was found for n − 3 FA, α-linolenic acid, and conjugated linolenic acid, with their greatest intramuscular proportions found when feeding the RC-FS diet. Feeding GH versus RC also significantly improved growth and carcass attributes, sensory tenderness (P < 0.05) and significantly influenced intramuscular FA composition (P < 0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed.     

Fatty acid profile of muscles,liver and mesenteric fat in wild and reared perch (Perca fluviatilis L.)

This study addressed determinations of the fatty acid profile of muscle, liver and mesenteric fat in European perch originating from natural aquifers and from intensive rearing in a closed circuit on an artificial feed mixture. The qualitative composition of fatty acids was identical in both groups of perch, except for 16:4 acid identified exclusively in the reared perch. The study demonstrated equal concentrations of saturated (SFA) and unsaturated (UFA) fatty acids in muscles, liver and mesenteric fat of both groups of perch. The wild fish, however, were characterised by lower concentrations of monoenoic (MUFA) and higher concentrations of polyenoic (PUFA) fatty acids. Analyses also demonstrated similar contents of n − 3 PUFA in muscles and their diversified concentrations in liver and mesenteric fat (higher in the wild fish), as well as a higher content of n − 6 PUFA in all samples. The lower content of MUFA in the wild perch was mainly due to lower concentrations of cis18:1 n − 9 and 20:1 n − 9, whereas the higher content of n − 3 PUFA was due to a higher concentration of DHA, and the higher content of n − 6 PUFA was due to a higher concentration of arachidonic acid (AA). The biggest differences between wild and reared perch were detected for AA. The wild and reared perch were also found to differ in the n − 3/n − 6 ratio (higher in the reared fish) and to have similar values for atherogenic index (AI) (except for liver and mesenteric fat) and thrombogenicity index (TI).     

Enriching the egg yolk in n − 3 fatty acids by feeding hens with diets containing horse fat produced in Uruguay

The present study was conducted to evaluate the ability of horse fat produced in Uruguay, compared with other lipid sources supplemented in the diet of laying hens, to modify the lipid composition and the n − 6/n − 3 fatty acid ratio of the produced eggs. For this purpose, 60 laying hens (Gallus domesticus) were fed for 30 days with five experimental diets (12 hens/diet) containing 3% sunflower oil (SO), rice oil (RO), beef tallow (BT), pressed-fat (PF), obtained by pressing fat from bovine viscera, and horse fat (HF) obtained from horse bone medulla. Throughout the trial, feeding rate, shell index, weight and total lipid contents of eggs, were not affected by the different diets. Feeding on the SO and RO diets significantly increased the amount of linoleic acid of the egg, although it was lower in the RO than in the SO eggs. Diet BT did not affect the saturated fatty acid content of the yolks. The diets with animal fats containing 18:3n − 3 (diets PF and HF), resulted in a significant increase in the n − 3 fatty acid contents of the eggs, through an increase of linolenic (18:3n − 3) and docosahexaenoic acid (DHA, 22:6n − 3) contents. Eggs from hens fed the HF diet showed increased linolenic acid (46 mg/yolk) and DHA (71 mg/yolk, 1.7% of total fatty acids) contents. These levels were obtained after two weeks of feeding. Moreover, the fatty acid profiles of eggs from treatment HF were not significantly affected by thermal treatment of the yolks. In conclusion, the fat from horse bone medulla, as produced in Uruguay, can be considered as a suitable lipid source for diets of laying hens, to modify the nutritional composition of the eggs in n − 3 PUFA content, especially DHA, and consequently, the n − 6/n − 3 fatty acid ratio.     

Characterization of Longissimus thoracis, Semitendinosus and Masseter muscles and relationships with technological quality in pigs. 2. Composition of muscles

The composition of three porcine muscles (Longissimus thoracis: LT, Semitendinosus: ST, Masseter: MS) was characterized and its link with muscle quality was evaluated. The LT muscle had a higher content of tyrosine, tryptophan, and carbohydrates and a lower content of vitamin E and haem iron than the MS muscle, while the ST had similar composition to MS but a lower content of haem iron. Large differences between muscles were observed in relative amounts of most of the major fatty acids. The LT muscle had higher saturated fatty acids (SFA) and n− 6:n− 3 fatty acid ratio, and lower polyunsaturated fatty acids (PUFA), PUFA:SFA ratio, unsaturation index and average fatty acid chain length than the ST and MS muscles. Muscle pH, redness and chroma were positively correlated with vitamin E and unsaturated lipids and negatively correlated with tyrosine, tryptophan, carbohydrates and saturated lipids, whereas muscle lightness and expressible juice showed similar correlations but an opposite sign with these variables.     

Evaluation of lipid oxidation in spaghetti pasta enriched with long chain n−3 polyunsaturated fatty acids under different storage conditions

This study investigated lipid oxidation in spaghetti enriched in long chain n−3 polyunsaturated fatty acids (LC n−3 PUFA) by the addition to semolina of an integrator containing eicosapentaenoic acid and docosahexaenoic acid. Two oxidative parameters were evaluated: peroxide value (PV), to assess primary oxidation and oxidised fatty acids to quantify secondary oxidation products. Functional spaghetti had a shelf life comparable to control pasta. LC n−3 PUFA were not significantly implicated in the onset of oxidation in spaghetti stored under daylight and accelerated oxidation in a laboratory heater. Storage decidedly affected shelf life: PV in functional spaghetti increased from 7.1 to 43.4 meq O₂/kg of fat under light exposure over 12 months, and from 7.1 to 16.2 meq O₂/kg under accelerated ageing at 55 °C for 27 days, reproducing about 18 months at room temperature. Oxidised fatty acids increased in fortified spaghetti from 4.8 to 13.8 g/100 g of fat under light exposure over 12 months and from 4.8 to 7.8 g/100 g of fat at 55 °C in 27 days. The high sensitivity of spectrophotometric and chromatographic analytical methods permitted the evaluation of primary and secondary oxidative derivatives in small amounts of fat.     

Examination of the persistency of milk fatty acid composition responses to fish oil and sunflower oil in the diet of dairy cows

Based on the potential benefits of cis-9, trans-11 conjugated linoleic acid (CLA) for human health, there is a need to develop effective strategies for enhancing milk fat CLA concentrations. Levels of cis-9, trans-11 CLA in milk can be increased by supplements of fish oil (FO) and sunflower oil (SO), but there is considerable variation in the response. Part of this variance may reflect time-dependent ruminal adaptations to high levels of lipid in the diet, which lead to alterations in the formation of specific biohydrogenation intermediates. To test this hypothesis, 16 late lactation Holstein-British Friesian cows were used in a repeated measures randomized block design to examine milk fatty acid composition responses to FO and SO in the diet over a 28-d period. Cows were allocated at random to corn silage-based rations (8 per treatment) containing 0 (control) or 45 g of oil supplement/kg of dry matter consisting (1:2; wt/wt) of FO and SO (FSO), and milk composition was determined on alternate days from d 1. Compared with the control, the FSO diet decreased mean dry matter intake (21.1 vs. 17.9 kg/d), milk fat (47.7 vs. 32.6 g/kg), and protein content (36.1 vs. 33.3 g/kg), but had no effect on milk yield (27.1 vs. 26.4 kg/d). Reductions in milk fat content relative to the FSO diet were associated with increases in milk trans-10 18:1, trans-10, cis-12 CLA, and trans-9, cis-11 CLA concentrations (r² = 0.74, 0.57, and 0.80, respectively). Compared with the control, the FSO diet reduced milk 4:0 to 18:0 and cis 18:1 content and increased trans 18:1, trans 18:2, cis-9, trans-11 CLA, 20:5 n-3, and 22:6 n-3 concentrations. The FSO diet caused a rapid elevation in milk cis-9, trans-11 CLA content, reaching a maximum of 5.37 g/100 g of fatty acids on d 5, but these increases were transient, declining to 2.35 g/100 g of fatty acids by d 15. They remained relatively constant thereafter. Even though concentrations of trans-11 18:1 followed the same pattern of temporal changes as cis-9, trans-11 CLA, the total trans 18:1 content of FSO milk was unchanged because of the concomitant increases in the concentration of other isomers (Δ^4-10 and Δ^12-15), predominantely trans-10 18:1. In conclusion, supplementing diets with FSO enhances milk fat cis-9, trans-11 CLA content, but the high level of enrichment declines because of changes in ruminal biohydrogenation that result in trans-10 replacing trans-11 as the major 18:1 biohydrogenation intermediate formed in the rumen.     

Long chain polyunsaturated fatty acids in smoked Atlantic mackerel and Baltic sprats

Atlantic mackerel and Baltic sprats are rich sources of n − 3 long chain polyunsaturated fatty acids (LC PUFA). Literature data point to an influence of the properties of the raw material, storage conditions, and processing parameters of hot- and cold-smoking on the stability of these acids. The effects of industrial smoking in an automatic smokehouse in controlled, mild conditions at core temperature below 60 °C, as well as of cold storage, on the fatty acids (FA) in mackerel and sprats have been investigated. The FA were determined by gas chromatography (GC) according to the AOCS Ce 1b-89 method, in lipids extracted from the meat of several batches of defrosted and smoked fish early after smoking and during storage at 2 °C for up to 2 weeks. The contents of eicosapentaenoic acid C20:5 n − 3 (EPA) and docosahexaenoic acid C22:6 n − 3 (DHA) in different assortments of smoked mackerel meat were from 50 to 55 and from 67 to 100 mg/g of lipids, respectively while, in hot-smoked sprats, they were from 48 to 68 and from 73 to 128 mg/g of lipids. The results show that the variability of the FA composition of the frozen raw material was larger than the changes induced by smoking or by storage within the period of high quality life of the smoked product.     

Different oilseed supplements alter fatty acid composition of different adipose tissues of adult ewes

Twenty-five mature Small Tail Han ewes were used to investigate the effects of supplemental oilseeds in the diet (sunflower seed, safflower seed, rapeseed, and linseed) on fatty acid composition in different tissues (longissimus lumborum muscle, tail fat, subcutaneous back fat and kidney fat). Averaged over tissue, safflower and sunflower seed was most effective (P < 0.05) in enhancing the concentration of conjugated linoleic acid compared to rapeseed, linseed, and control (1.35% and 1.15% vs. 0.80%, 0.80%, and 0.75%, respectively). Linseed supplemented ewes had lesser n−6/n−3 value (2.48, P < 0.05) compared to sunflower and safflower supplemented ewes (6.12 and 3.90, respectively). Fatty acid composition for most major fatty acids differed among tissues (P < 0.05) but tissue differences varied depending on oilseed supplement (P < 0.05). Proportions of conjugated linoleic acid were greatest in tail fat (1.54% vs. 0.82%, 0.79% and 0.70% for kidney, back, and muscle fat, P < 0.05) as were total unsaturated fatty acids (49.1% vs. 42.4%, 36.7% and 33.4% for muscle, back, and kidney fat, P < 0.05) and tail fat was the most responsive tissue to improvement in fatty acid profile through supplementation. Beneficial fatty acid content of tissues can be increased by oilseed supplementation, but the magnitude of increase varies according to tissue.     

Effect of production system on physical–chemical,antioxidant and fatty acids composition of Longissimus dorsi and Serratus ventralis muscles from Iberian pig

The effect of three production systems of Iberian pigs namely Montanera (free-range system and feeding based on acorns and grass), Recebo (free-range system and nutrition based in combination of acorns, grass and mixed feeds) and Intensive (confinement with mixed feeds) on some quality traits of Longissimus dorsi (LD) and Serratus ventralis (SV) muscles were studied. Muscles from pigs raised in the Montanera system showed significantly higher CIE L^∗, a^∗ and b^∗ values and higher haem pigment content than those from Intensive system. Similarly, muscles from pigs raised in the Montanera system had significantly higher contents of α and γ-tocopherol and phenolic compounds contents and higher lipophilic and hydrophilic activity antioxidant than those from pigs raised in the Intensive system. Fatty acids profiles from Montanera pigs had significantly higher monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids and lower saturated fatty acids (SFA) than those from pigs raised in the Intensive system. In relation to muscle effect, LD showed lower intramuscular fat (IMF), α-tocopherol, phenolic compounds, lipid oxidation and PUFA, but higher MUFA than SV.     

Nutritional composition of the meat of Hereford and Braford steers finished on pastures or in a feedlot in southern Brazil

Chemical and mineral composition and the intramuscular fatty acid (IMF) profile of the Longissimus dorsi muscle (LM) of 60 purebred Hereford, 1/4 Braford and 3/8 Braford steers finished either in a feedlot or on improved pastures of the Pampa biome were evaluated. Pastures were improved with the introduction of Lolium multiflorum, Trifolium repens, and Lotus corniculatus. On average, beef from pasture-fed steers presented higher concentrations of the fatty acids C18:3n − 3 (P < 0.001), C20:3n − 3 (P = 0.035), total n − 3 (P < 0.001) and lower n − 6/n − 3 ratio (P < 0.001) in the IMF, and higher Mg and lower K content in muscle relative to those finished in the feedlot. C12:0 concentration in IMF was higher (P = 0.027) for 3/8 Braford than the purebred Hereford steers, whereas purebred Herefords presented lower C14:1 (P = 0.003) and higher C18:0 (P = 0.022) concentrations than the two Braford groups. The meat composition of purebred Hereford and Braford steers was not substantially different; however, beef produced exclusively on improved pastures presented higher concentration of components that are considered beneficial to human health, such as n − 3 fatty acids, and a lower n − 6/n − 3 ratio.     

Stability of fatty acid composition after thermal,high pressure,and microwave processing of cow milk as affected by polyunsaturated fatty acid concentration

Interest has been increasing to enhance the contents of healthy polyunsaturated fatty acid (PUFA) in milk. However, trans fatty acids and conjugated linoleic acid (CLA) can be altered after thermal processing and high pressures disrupt the milk fat globule membrane, exposing the lipid core and helping its oxidation. The objective of the present research was to study whether processing can alter the fatty acid composition of milk and if these changes are affected by PUFA concentration as previous studies suggest. Two cow milk batches (500 L each), one naturally enriched in PUFA, were processed to obtain pasteurized; high temperature, short time; UHT; high pressure; and microwave pasteurized samples. The detailed fatty acid composition was analyzed with special attention to trans fatty acids and CLA isomers. Results showed that after high temperature, short time processing, total CLA content increased in both milk batches, whereas sterilization resulted in a sigmatropic rearrangement of C18:2 cis-9,trans-11 to C18:2 trans-9,trans-11. The extent of these effects was greater in milks naturally enriched in PUFA.     

Influence of slaughter season and muscle type on fatty acid composition, conjugated linoleic acid isomeric distribution and nutritional quality of intramuscular fat in Arouquesa-PDO veal

The effects of the slaughter season and muscle type on lipid and conjugated linoleic acid (CLA) contents, fatty acid composition and isomeric profile of CLA in Arouquesa veal, from calves reared according to the specifications of the protected designation of origin (PDO), were assessed. Arouquesa purebred calves (n = 31) were raised in a traditional production system, slaughtered in early autumn (October) or late spring (June), and the longissimus dorsi and semitendinosus muscles were sampled for analysis. Arouquesa-PDO veal only showed seasonal differences in the levels of some minor fatty acids (16:1c9, 17:1c9, 18:1t, 18:3n − 3, 20:0 and 22:4n − 6) and CLA isomers (t12,t14, t9,t11 and c11,t13). Furthermore, significant interactions between the slaughter season and muscle type were obtained for several fatty acids and CLA isomers, total lipids and CLA, and the PUFA/SFA ratio. In both seasons, veal-PDO depicts values of pasture-fed cattle. From a human nutritional perspective, veal-PDO in both slaughter seasons has relatively high CLA contents and percentages of the c9,t11 CLA isomer, which is favourable, while the n − 6/n − 3 ratios are within the recommended values for the human diet. In conclusion, the results suggest that intramuscular fat in Arouquesa-PDO veal has high nutritional value throughout the year.     

Nutritional and commercial quality of the striped venus clam, Chamelea gallina, from the Adriatic sea

Nutritional quality parameters (proximate and mineral composition, contents of glycogen, fatty acids, cholesterol, plant sterols, fat-soluble vitamins, carotenes) and ecophysiological and commercial quality indicators (Condition Index, percent content of meat and intervalvar fluid) of the striped venus clam, Chamelea gallina, from the central Adriatic coast of Italy were studied at seasonal intervals over a 1-year period. Contents of protein (8.55–10.7 g/100 g), total lipid (0.73–1.59 g/100 g), glycogen (2.25–4.96 g/100 g) and non-protein nitrogen (0.54–0.78 g/100 g) varied significantly during the year, reaching the highest values in winter, in coincidence with a peak of Condition Index. Gas chromatography of total lipids showed high percentages of n − 3 polyunsaturated fatty acids (33.7–41.9% of total fatty acids), in particular eicosapentaenoic (8.16–20.0% of total fatty acids) and docosahexaenoic acids (12.5–20.3% of total fatty acids) and low levels of total n − 6 polyunsaturated fatty acids (3.61–7.87% of total fatty acids). HPLC analysis of the unsaponifiable lipids showed low levels of cholesterol, the dominant sterol (28.3–34.2 mg/ 100 g), and variable amounts of plant sterols (stigmasterol + campesterol, β-sitosterol, fucosterol + brassicasterol), α-tocopherol and carotenes.     

Meat quality,proximate composition and muscle fatty acid profile of young llamas (Lama glama) supplemented with hay or concentrate during the dry season

Thirty llamas were used to study the effect of a 90 day feed supplementation on meat quality, chemical composition and muscle fatty acid profile. Treatments were: GR = llama on native pasture until slaughter; GR + SH = like GR, but with overnight free access to barley/alfalfa hay; and GR + SC = like GR, but with overnight free access to a wheat bran/sorghum grain concentrate. The supplementation had no effect on postmortem pH and temperature decline in the Longissimus lumborum muscle (LLM), cooking losses nor Warner–Bratzler shear force values (P > 0.05). Meat from GR + SC llama had higher fat content in LLM (P < 0.05) compared to GR and GR + SH llama. Intramuscular fat from GR + SH llama showed higher (P < 0.01) proportions of polyunsaturated fatty acids, higher (P < 0.05) polyunsaturated fatty acids/saturated fatty acids and desirable fatty acids ratio, lower (P < 0.05) omega-6/omega-3 (n − 6/n − 3) ratio, and higher (P < 0.01) conjugated linoleic acid.     

Relationships between intramuscular fat content, selected carcass traits, and fatty acid profile in bulls using a F2-population

The quality and nutritional value of beef is related to the amount of intramuscular fat (IMF) as well as to its fatty acid composition. In this study the relations between the IMF content and the total fatty acid composition, the fatty acids (FA) of triacylglycerols (TG) and the FA of phospholipids (PL) in longissimus muscle of F₂ Charolais × German Holstein crossbred bulls have been analysed. Polyunsaturated fatty acids (PUFA, C18:2n-6; C18:3n-3) and stearic acid (C18:0) are strongly positively correlated to IMF in longissimus muscle at the quantitative level (mg/100 g fresh tissue), but there are negative correlation coefficients for the relative proportion of these fatty acids to IMF. The relationships between IMF and the fatty acid profile of the subfractions TG and PL are lower compared to total muscle fat. Selected carcass fat traits are positively correlated to most of the fatty acids.