Nutritional evaluation of the lipid fraction of Iberian red deer (Cervus elaphus hispanicus) tenderloin

The meat lipid fraction of psoas major muscle from 20 adult (10 males and 10 females) feral Iberian red deer (Cervus elaphus hispanicus) was characterized by quantification of total fat, total cholesterol, vitamin E and fatty acid (FA) composition, including detailed trans octadecenoate isomers and conjugated linoleic acid (CLA) isomeric profile.The total lipid content revealed a very lean meat (0.99 g/100 g of meat), with total cholesterol content averaging 55.6 mg/100 g of muscle. The FA profile displayed a very high PUFA level for ruminant meat (30.2 g/100 g FA). The 18:2 cis-9,trans-11 content was fairly low (0.26% of total FA) compared with other ruminant meats.The comparison of stags and hinds showed more similarities than differences. Nevertheless, hinds displayed superior contents of α-tocopherol and trans MUFA and a better n−6/n−3 ratio than stags.     

Effects of oil and natural or synthetic vitamin E on ruminal and milk fatty acid profiles in cows receiving a high-starch diet

Among trans fatty acids, trans-10,cis-12 CLA has negative effects on cow milk fat production and can affect human health. In high-yielding dairy cows, a shift from the trans-11 to the trans-10 pathway of biohydrogenation (BH) can occur in the rumen of cows receiving high-concentrate diets, especially when the diet is supplemented with unsaturated fat sources. In some but not all experiments, vitamin E has been shown to control this shift. To ascertain the effects of vitamin E on this shift of BH pathway, 2 studies were conducted. The first study explored in vitro the effects of addition of natural (RRR-α-tocopherol acetate) and synthetic (dl-α-tocopherol acetate) vitamin E. Compared with control and synthetic vitamin E, the natural form resulted in a greater trans-10/trans-11 ratio; however, the effect was very low, suggesting that vitamin E was neither a limiting factor for rumen BH nor a modulator of the BH pathway. An in vivo study investigated the effect of natural vitamin E (RRR-α-tocopherol) on this shift and subsequent milk fat depression. Six rumen-fistulated lactating Holstein cows were assigned to a 2 × 2 crossover design. Cows received 20-kg DM of a control diet based on corn silage with 22% of wheat, and after 2 wk of adaptation, the diet was supplemented with 600 g of sunflower oil for 2 more weeks. During the last week of this 4-wk experimental period, cows were divided into 2 groups: an unsupplemented control group and a group receiving 11 g of RRR-α-tocopherol acetate per day. A trans-10 shift of ruminal BH associated with milk fat depression due to oil supplementation of a high-wheat diet was observed, but vitamin E supplementation of dairy cows did not result in a reversal toward a trans-11 BH pathway, and did not restore milk fat content.     

Enrichment of the conjugated linoleic acid content of bovine milk fat by dry fractionation

This study investigated the effect of fat fractionation on the conjugated linoleic acid (cis-9, trans-11-C_18 : 2) content of bovine milk fat. Anhydrous milk fat was fractionated into hard and soft fractions using controlled cooling and agitation. Fractionation of milk fat pre-melted at 60°C using a temperature programme of 33–10°C and a cooling rate of 0.58°C h⁻¹ yielded a soft fraction containing 63.2% more conjugated linoleic acid (2.22 g 100 g⁻¹ FAME), which was also enriched in polyunsaturated fatty acids and vaccenic acid (trans-11-C_18 : 1) compared with the parent fat. Agitation following fractionation was found to have a negative effect on the conjugated linoleic acid content of the soft fraction. Refractionation of the soft fraction did not increase the yield of conjugated linoleic acid. The conjugated linoleic acid and trans fatty acid content of 26 selected food products ranging in milk fat content from 0 to 100% is reported. Conjugated linoleic acid concentrations ranged from 0 to 16.2 mg g⁻¹ fat and were generally lower than the trans fatty acid content which ranged from 0 to 155.7 mg g⁻¹ fat. Spreads containing vegetable oils contained higher trans fatty acid and lower conjugated linoleic acid contents than milk fat-containing products. This study highlights that a milk fat fraction enriched in conjugated linoleic acid may be achieved by dry fractionation.     

Effect of level of linseed on fatty acid composition of muscles and adipose tissues of lambs with emphasis on trans fatty acids

The effects of linseed content in concentrates on the fatty acid (FA) composition of adipose tissues and muscles of lambs were studied in a 2 × 4 design: males (M) vs. females (F) and linseed content (0%, L0, 3%, L3, 6%, L6, 9%, L9). FA proportions were determined both on a DB-wax and on a CP-Sil column in perirenal (PR), dorsal subcutaneous (SC) adipose tissue and in longissusmus dorsi muscle (IM). No effects of linseed contents in the diet on growth performances either in male or female lambs were observed. Linseed supplementation tended to decrease the fatness score. The proportion of linolenic acid increased linearly with the linseed content in the diet, from: 0.6, 0.5, and 0.5% for L0 to 1.9, 1.6, and 1.3% for L9, in PR, SC and IM, respectively. The increase in n − 3 PUFA and in total PUFA was similar to that of linolenic acid. The n − 6:n − 3 ratio decreased from 5.7, 5.3 and 5.8 for L0 to 1.8, 1.7 and 2.7 for L9, in PR, SC and IM, respectively. There was no change in the proportion of docosahexaenoic acid with linseed supplementation. The proportions of C18:1trans-10 and C18:1trans-11 did not vary in PR, SC and IM with linseed supplementation. The total proportion of trans-octadecenoic acid was high in each tissue type and group of lambs. C18:1trans-10 represented about half of the total trans-octadecenoic isomers. With an increase in linolenic acid, most cis- and trans-octadecenoic isomers also increased, but trans-10 and trans-11 isomers did not and cis-9 and cis-11 isomers decreased. With linseed supplementation there was a decrease in the Δ9 desaturase indices in SC.     

Production of conjugated linoleic acid enriched milk and dairy products from cows receiving grass silage supplemented with a cereal-based concentrate containing rapeseed oil

Opportunities for the production of milk and dairy products enriched with cis-9, trans-11 conjugated linoleic acid (CLA) were investigated. Eighteen mid-lactation cows were used in a continuous-design for 7 weeks. During the first week, cows received grass silage ad libitum supplemented with 10 kg per day of a cereal-based concentrate (control) that was replaced with a concentrate containing 50 g kg⁻¹ of rapeseed oil (RO). Changes in milk fatty acid composition were monitored on a weekly basis and milk produced was used to manufacture Edam cheese and butter. Inclusion of RO in the concentrate supplement increased the mean levels of trans-octadecanoic, monounsaturated, CLA and polyunsaturated fatty acid in the milk fat from 1.6, 25.7, 0.46 and 2.8 to 4.3, 35.3, 1.02 and 3.9 g 100 g⁻¹ total fatty acids, respectively. In contrast, the mean level of saturated fatty acids decreased from 71.4 to 60.7 g  100 g⁻¹ total fatty acids. Changes in milk fatty acid composition due to RO occurred within 7 days, with responses reaching a plateau after 21 days. Furthermore, the CLA concentrations in the milk fat from individual cows ranged between 0.37 and 0.65 and 0.43 and 2.06 g 100 g⁻¹ total fatty acids for the control and RO diet, respectively. CLA enriched milk was used successfully to manufacture of Edam cheese and butter with softer textures but with acceptable organoleptic and storage properties. Processing milk into butter or cheese had no effect on the CLA concentrations indicating that enrichment of dairy products is dependent on the content in raw milk fat.     

Effect of tomato by-products in the diet of Comisana sheep on composition and conjugated linoleic acid content of milk fat

To evaluate the effect of supplementing the diet of Comisana sheep with by-products from industrial tomato manufacture on the fat composition and conjugated linoleic acid (CLA) content of milk fat, two groups of 50 ewes each were fed either total mixed ration standard (TMRS) or total mixed ration with added tomato by-products (TMRA). Milk fat composition was determined by high-resolution gas chromatography (HRGC). The milk fat content for the animals fed the TMRA diet increased by 6.41% (P < 0.01) after six weeks, compared with the animals fed the TMRS diet. The CLA content in the milk fat for the group of animals fed the TMRA diet was 19.8% (P < 0.05) higher than for those fed the TMRS diet, and reached 1.33 g 100 g^?1 fat, while the polyunsaturated fatty acid (PUFA) content increased by a 6.43% (P < 0.05) and reached 7.12 g 100 g^?1 fat. The fatty acid composition showed an increase in the amount of polyunsaturated fatty acids. The n ? 3:n ? 6 ratio increased by 13% in the milk from sheep fed with the TMRA diet. These observations were confirmed by triglyceride analysis, which showed a decrease in the amount of short-chain (C₂₈–C₃₂) and medium-chain (C₃₄–C₄₂) triglycerides after six weeks, while the opposite was observed for the long-chain triglycerides (C₄₄–C₅₄).     

Thermal processing of carrots: Lycopene stability and isomerisation with regard to antioxidant potential

The thermal stability of lycopene was evaluated in a carrot cultivar with a high lycopene content (Daucus carota var. Nutri Red) by (a) exposure of carrot homogenates (with/without the addition of oil) to temperatures ranging from 25 to 140 °C; (b) applying convection and microwave vacuum drying to carrot slices. Heating carrot homogenates at temperatures above 100 °C initiated isomerisation of all-trans-lycopene under non-oxidising conditions, as indicated by a significant increase in 9-cis-lycopene. Isomerisation was enhanced at short treatment times, when sunflower oil was added prior to thermal treatment. Independent from an oil supplement, all-trans-lycopene was degraded at temperatures above 70 °C. The ratio of all-trans- to total-cis-isomers changed from 90:10 to 40:60, indicating a higher lycopene bioavailability due to generated cis-isomers. In oil containing carrot homogenates antioxidant properties of the methanol-soluble components raised after heat treatment at 130 °C for 0.5 h. Lycopene remained stable in dried carrots.     

Effects of different forage:concentrate ratios in dairy ewe diets supplemented with sunflower oil on animal performance and milk fatty acid profile

The aim of this study was to evaluate the effect of different forage:concentrate (FC) ratios in dairy ewe diets supplemented with sunflower oil (SO) on animal performance and milk fatty acid (FA) profile, particularly focusing on trans C18:1 FA and conjugated linoleic acid (CLA). Sixty lactating Assaf ewes were randomly assigned to 6 treatments in a 3 × 2 factorial arrangement: 3 FC ratios (30:70, 50:50, and 70:30) and 2 levels of SO addition (0 and 20 g/kg of dry matter). Both the diet FC ratio and SO supplementation affected milk yield, but differences between treatments were small. Although the proportion of concentrate induced limited changes in milk FA profile, dietary SO significantly decreased saturated FA and enhanced total CLA. Furthermore, the incorporation of SO in ewe diets decreased the atherogenicity index value by about 25% and doubled the contents of potentially healthy FA such as trans-11 C18:1 and cis-9,trans-11 CLA. However, the inclusion of SO in a high-concentrate diet (30:70) could switch linoleic acid biohydrogenation pathways, resulting in a significant increase in trans-10 C18:1, trans-9,cis-11 C18:2, and trans-10,cis-12 C18:2 milk fat percentages.     

Rapid method for resveratrol determination by HPLC with electrochemical and UV detections in wines

The study describes an improved version of the reverse-phase-HPLC method. To determine free resveratrol isomers, the method uses isocratic elution and electrochemical detection with the use of a glassy working electrode at a potential of 0.75 V. The effects of important factors – such as the isomerization of standard resveratrol solution in diffused daylight and its dependence on temperature or resveratrol isomerization in wine samples – were investigated. The equilibrium between trans- and cis-isomer was achieved after a 5-h exposure to the daily diffused light and it was not significantly influenced by the temperature (30–60 °C). Linearity was obtained in the concentration range from 0.01 to 10 mg l⁻¹. The detection limit (S/N=3) was 3 μg l⁻¹ for trans-resveratrol and 15 μg l⁻¹ for cis-resveratrol. The trans- and cis-resveratrol were determined in selected Czech red and white wines and in the extract from Vitis vinifera plant. The concentration of trans-resveratrol ranged from 0.7 to 11 mg l⁻¹, that of cis-resveratrol from 0.6 to 5.1 mg l⁻¹.     

Effect of incremental amounts of camelina oil on milk fatty acid composition in lactating cows fed diets based on a mixture of grass and red clover silage and concentrates containing camelina expeller

Camelina is an ancient oilseed crop that produces an oil rich in cis-9,cis-12 18:2 (linoleic acid, LA) and cis-9,cis-12,cis-15 18:3 (α-linolenic acid, ALA); however, reports on the use of camelina oil (CO) for ruminants are limited. The present study investigated the effects of incremental CO supplementation on animal performance, milk fatty acid (FA) composition, and milk sensory quality. Eight Finnish Ayrshire cows (91 d in milk) were used in replicated 4 × 4 Latin squares with 21-d periods. Treatments comprised 4 concentrates (12 kg/d on an air-dry basis) based on cereals and camelina expeller containing 0 (control), 2, 4, or 6% CO on an air-dry basis. Cows were offered a mixture of grass and red clover silage (RCS; 1:1 on a dry matter basis) ad libitum. Incremental CO supplementation linearly decreased silage and total dry matter intake, and linearly increased LA, ALA, and total FA intake. Treatments had no effect on whole-tract apparent organic matter or fiber digestibility and did not have a major influence on rumen fermentation. Supplements of CO quadratically decreased daily milk and lactose yields and linearly decreased milk protein yield and milk taste panel score from 4.2 to 3.6 [on a scale of 1 (poor) to 5 (excellent)], without altering milk fat yield. Inclusion of CO linearly decreased the proportions of saturated FA synthesized de novo (4:0 to 16:0), without altering milk fat 18:0, cis-9 18:1, LA, and ALA concentrations. Milk fat 18:0 was low (<5 g/100 g of FA) across all treatments. Increases in CO linearly decreased the proportions of total saturates from 58 to 45 g/100 g of FA and linearly enriched trans-11 18:1, cis-9,trans-11 18:2, and trans-11,cis-15 18:2 from 5.2, 2.6, and 1.7 to 11, 4.3, and 5.8 g/100 g of FA, respectively. Furthermore, CO quadratically decreased milk fat trans-10 18:1 and linearly decreased trans-10,cis-12 18:2 concentration. Overall, milk FA composition on all treatments suggested that one or more components in camelina seeds may inhibit the complete reduction of 18-carbon unsaturates in the rumen. In conclusion, CO decreased the secretion of saturated FA in milk and increased those of the trans-11 biohydrogenation pathway or their desaturation products. Despite increasing the intake of 18-carbon unsaturated FA, CO had no effect on the secretions of 18:0, cis-9 18:1, LA, or ALA in milk. Concentrates containing camelina expeller and 2% CO could be used for the commercial production of low-saturated milk from grass- and RCS-based diets without major adverse effects on animal performance.     

Temporal changes in milk fatty acid composition during diet-induced milk fat depression in lactating cows

Diet-induced milk fat depression (MFD) in lactating cows has been attributed to alterations in ruminal lipid metabolism leading to the formation of specific fatty acid (FA) biohydrogenation intermediates that directly inhibit milk fat synthesis. However, the mechanisms responsible for decreased lipid synthesis in the mammary gland over time are not well defined. The aim of this study was to evaluate the effect of diet on milk FA composition and milk fat production over time, especially during MFD, and explore the associations between MFD and FA biohydrogenation intermediates in omasal digesta and milk. Four lactating Finnish Ayrshire cows used in a 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments and 35-d experimental periods were fed diets formulated to cause differences in ruminal and mammary lipid metabolism. Treatments consisted of an iso-nitrogenous total mixed ration based on grass silage with a forage to concentrate ratio of 65:35 or 35:65 without added oil, or with sunflower oil at 50 g/kg of diet dry matter. The high-concentrate diet with sunflower oil (HSO) induced a 2-stage drop in milk fat synthesis that was accompanied by specific temporal changes in the milk FA composition. The MFD on HSO was associated especially with trans-10 18:1 and also with trans-9,cis-11 conjugated linoleic acid (CLA) in milk and omasal digesta across all diets and was accompanied by the appearance of trans-10,cis-15 18:2. Trans-10,cis-12 CLA was increased in HSO, but milk fat secretion was not associated with omasal or milk trans-10,cis-12 CLA. The temporal changes in milk fat content and yield and milk FA composition reflect the shift from the predominant ruminal biohydrogenation pathway to an alternative pathway. The ambiguous role of trans-10,cis-12 CLA suggests that trans-10 18:1, trans-9,cis-11 CLA and trans-10,cis-15 18:2 or additional mechanisms contributed to the diet-induced MFD in lactating cows.     

Effectiveness of oils rich in linoleic and linolenic acids to enhance conjugated linoleic acid in milk from dairy cows

Forty Holstein dairy cows were used to determine the effectiveness of linoleic or linolenic-rich oils to enhance C_18:2cis-9, trans-11 conjugated linoleic acid (CLA) and C_18:1trans-11 (vaccenic acid; VA) in milk. The experimental design was a complete randomized design for 9 wk with measurements made during the last 6 wk. Cows were fed a basal diet containing 59% forage (control) or a basal diet supplemented with either 4% soybean oil (SO), 4% flaxseed oil (FO), or 2% soybean oil plus 2% flaxseed oil (SFO) on a dry matter basis. Total fatty acids in the diet were 3.27, 7.47, 7.61, and 7.50 g/100 g in control, SO, FO, and SFO diets, respectively. Feed intake, energy-corrected milk (ECM) yield, and ECM produced/kg of feed intake were similar among treatments. The proportions of VA were increased by 318, 105, and 206% in milk fat from cows in the SO, FO, and SFO groups compared with cows in the control group. Similar increases in C_18:2cis-9, trans-11 CLA were 273, 150, and 183% in SO, FO, and SFO treatments, respectively. Under similar feeding conditions, oils rich in linoleic acid (soybean oil) were more effective in enhancing VA and C_18:2cis-9, trans-11 CLA in milk fat than oils containing linolenic acid (flaxseed oil) in dairy cows fed high-forage diets (59% forage). The effects of mixing linoleic and linolenic acids (50:50) on enhancing VA and C_18:2cis-9, trans-11 CLA were additive, but not greater than when fed separately. Increasing the proportion of healthy fatty acids (VA and CLA) by feeding soybean or flaxseed oil would result in milk with higher nutritive and therapeutic value.     

Conjugated linoleic acid production by immobilized cells of Lactobacillus delbrueckii ssp. bulgaricus and Lactobacillus acidophilus

Lactobacillus delbrueckii ssp. bulgaricus (CCRC14009) and L. acidophilus (CCRC14079), immobilized with chitosan and polyacrylamide, were tested for CLA production. A 10-ml aliquot of L. delbrueckii ssp. bulgaricus cell suspension (3.59 × 10⁷ CFU/ml) was adsorbed to 0.5 g chitosan and polyacrylamide, mixed with 0.2 ml linoleic acid (0.9 g/ml), and incubated at 37 °C for 24 h at pH 5, 6, 7, and 8 for CLA production. CLA levels, produced by immobilized cells of L. delbrueckii ssp. bulgaricus and L. acidophilus with increasing cell counts to 1.08 and 1.28 × 10¹⁰ CFU/ml, respectively, at optimal reaction pHs were evaluated. More CLA was formed at pH 8 of chitosan and pH 7 of polyacrylamide-immobilized L. delbrueckii ssp. bulgaricus cell treatments. Increase in cell count resulted in higher CLA production. The adsorption of L. delbrueckii ssp. bulgaricus cells onto polyacrylamide at pH 7 showed significant improvement in total CLA level. Results demonstrated a potential for enhancing CLA production through immobilization.     

Influence of inclusion of chestnut in the finishing diet on fatty acid profile of dry-cured ham from Celta pig breed

The effect of the inclusion of chestnut in the finishing diet on fatty acid profile of dry-cured Celta ham was studied. Twelve hams of each type (from three different diets: concentrate, mixed and chestnut) were used. Significant differences between treatments (P < 0.001) were found regarding total saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Ham samples from the mixed and chestnut groups had less SFA (35.57% and 35.63%, respectively) with respect to ham samples from the concentrate group (40.33%), while hams from the mixed and chestnut batches showed higher values of MUFA than hams from the concentrate group (50.70 vs. 49.79 vs. 43.85, P < 0.001, respectively). From a nutritional point of view, Celta hams from chestnut diets could be considered as healthier regarding their fatty acid profiles (low n−6/n−3 ratio and high hypocholesterolemic/Hypercholesterolemic ratio). Discriminant analysis selected five variables (C_16:0, C_16:1cis-9, C_20:2, C_20:3n−6 and C_20:4n−6) and calculated two discriminating functions which verifies the presence of chestnut in the finishing diet.     

Combined effects of trans-10,cis-12 conjugated linoleic acid, propionate, and acetate on milk fat yield and composition in dairy cows

Diets inducing milk fat depression (MFD) are known to alter ruminal lipid metabolism, leading to the formation of specific isomers [such as trans-10,cis-12 conjugated linoleic acid (CLA)] that inhibit milk fat synthesis in lactating dairy cows. However, ruminal outflow of these isomers does not fully account for the decreases in milk fat synthesis observed during diet-induced MFD. The high-concentrate diets inducing MFD also induce a greater production of propionate, suggesting a possible inhibition of milk fat by propionate associated with trans-10,cis-12-CLA during MFD. The present experiment aimed to study the combined effects of propionate and trans-10,cis-12-CLA (both inhibitors of milk fat synthesis) on milk fat secretion and the effects of the combination of 2 nutrients with opposite effects (acetate and propionate). Six Holstein cows were used in a 6 × 6 Latin square design with 21-d periods (14 d of nutrient infusion). The treatments were control; ruminal infusion of 1,500 g/d of acetate (A); ruminal infusion of 800 g/d of propionate (P); duodenal infusion of 1.60 g/d of trans-10,cis-12-CLA (CLA); ruminal infusion of 750 g/d of acetate + 400 g/d of propionate (A+P); and duodenal infusion of 1.60 g/d of trans-10,cis-12-CLA + ruminal infusion of 800 g/d of propionate (CLA+P). The amounts of nutrients infused were chosen to induce a similar variation in milk fat content. Treatments A and P decreased dry matter intake. Compared with the control, P and CLA treatments decreased milk fat content and yield by 9% and 15% on average. Treatment A increased milk fat content by 6.5% but did not modify milk fat yield (because of a decrease in milk yield). The effects of A and P, and CLA and P on milk fat and fatty acid percentages and yield were additive (A+P and CLA+P treatments). With a same dose of trans-10,cis-12-CLA, the additional supply of propionate induced a decrease in milk fat 40% higher than that induced by trans-10,cis-12-CLA alone. The milk fatty acid profile obtained with CLA+P was similar to those observed with high-concentrate diets inducing MFD. In conclusion, under our experimental conditions, the effects of the 3 nutrients were additive on mammary lipogenesis, regardless of their separate effects. We also show that propionate could contribute to the milk fat reductions unaccounted for by trans-10,cis-12-CLA during MFD induced by high-concentrate diets.     

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.     

Effects of chestnut tannins on carcass characteristics,meat quality,lipid oxidation and fatty acid composition of rabbits

Seventy two male Bianca Italiana rabbits were used to study the effects of the inclusion (0%, 0.5%, and 1.0%) of a natural extract of chestnut wood (Silvafeed ENC) in the diet on productive traits, carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbit meat. Results showed ENC had no significant effect on live weight, productive traits, hot carcass weight, dressing percentage, skin weight, pH, cooking losses, shear force and colour. The iron content was higher in Longissimus thoracis et lumborum (LTL) muscle of rabbit fed the ENC 1.0% diet than the control group. TBARS average values in the group ENC 0.5% were significantly lower (P < 0.05) than in the control and ENC 1.0% groups. Myristic acid (C14:0; P < 0.01), palmitoleic acid (C16:1 cis-9; P < 0.05) and pentadecanoic acid (C15:0; P < 0.01) contents were lower in LTL muscle of rabbits fed the ENC 1.0% diet, whereas the palmitic acid (C16:0) content was higher (P < 0.05) in the rabbits of this group. Moreover, the rabbits fed with the ENC 0.5% diet had lower (P < 0.01) levels of trans-vaccenic acid (C18:1 trans-11) compared to rabbits fed with the control diet. No significant differences were observed in saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, as well as in PUFA/SFA and n − 6/n − 3 ratios among the groups.     

Biochemical changes throughout the ripening of a traditional Spanish goat cheese variety (Babia-Laciana)

The physico-chemical characteristics, proteolysis (classical nitrogen fractions, caseins and their degradation products and free amino acids), and lipolysis (fat acidity and free fatty acids) were studied throughout the ripening of three batches of Babia-Laciana cheese, a Spanish traditional variety made from raw goats’ milk. The main compositional characteristics of this cheese at the end of the ripening are its high content of total solids (TS) (78.0±2.4 g 100 g⁻¹ of cheese) and fat (61.1±1.2 g 100 g⁻¹ of TS), the presence of residual lactose (1.6±0.8 g 100 g⁻¹ of TS) and its low content of sodium chloride (1.1±0.7 g 100 g⁻¹ of TS) and ash (2.8±0.5 g 100 g⁻¹ of TS). Its pH values (4.44±0.72) are extraordinarily low. The evolution and final values of the different nitrogen fractions show that this cheese undergoes a very slight proteolysis, a fact which was corroborated when the caseins and their degradation products were quantified: β-casein did not undergo any modification throughout ripening, while only 21% of the α_s-caseins were degraded. Free amino acids content increased by a factor of about 7 throughout ripening, resulting in a high content of γ-amino butyric acid and a low content of glutamic acid at the end of the process. Fat acidity increased very slightly, approximately 4.5 times, during ripening, reaching final values of 3.5±2.2 mg KOH g⁻¹ of fat. The total free fatty acids content showed a similar evolution to fat acidity. At the end of the ripening process, the main free fatty acid was C_18:1, followed by C₁₆ and C₁₀.     

Suppressive effect of carotenoid extract of Dunaliella salina alga on production of LPS-stimulated pro-inflammatory mediators in RAW264.7 cells via NF-κB and JNK inactivation

The carotenoid extract from Dunaliella salina was used to evaluate the suppressive effects on lipopolysaccharide (LPS)-induced pro-inflammatory mediators in RAW264.7 cells. The extract composed all-trans forms of α-carotene (28.8 mg/g extract), β-carotene (471.1 mg/g extract), lutein (7.1 mg/g extract) and zeaxanthin (7.2 mg/g extract), 13- or 13′-cis-β-carotene (12.1 mg/g extract), 9- or 9′-cis-α-carotene (19.1 mg/g extract) and 9- or 9′-cis-β-carotene (440.3 mg/g extract) dose-dependently reduced the production of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the secretion of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in LPS-activated RAW264.7 cells. Its attenuation of LPS-induced inflammatory responses was closely related to inhibition of the nuclear NF-κB p50 subunit translocation by blocking inhibitor of κBα (IκB) phosphorylation and degradation correlated with suppressing IκB kinase (IKK) α/β phosphorylation, as well as down-regulation of the c-Jun NH₂-terminal kinase (JNK) activation.     

Effect of abomasal infusions of a mixture of octadecenoic acids on milk fat synthesis in lactating cows

Diets causing milk fat depression (MFD) are known to alter ruminal lipid metabolism leading to the formation of specific biohydrogenation intermediates that exert antilipogenic effects. Several isomers of conjugated linoleic acid (CLA), namely trans-10, cis-12 CLA, cis-10, trans-12 CLA, and trans-9, cis-11 CLA, inhibit mammary lipogenesis in the lactating cow, but ruminal outflow of these biohydrogenation intermediates does not account entirely for the reductions in milk fat synthesis during diet-induced MFD. Milk fat trans-10 18:1 concentrations are consistently increased on diets that cause MFD, suggesting a possible role in the regulation of milk fat secretion. Three rumen-fistulated cows in mid lactation were used in a 3 × 3 Latin square to evaluate the effects of a mixture of 18:1 fatty acid methyl esters (FAME) on milk fat synthesis. Experimental treatments consisted of abomasal infusions of ethanol (control), 6 g/d of trans-10, cis-12 CLA (positive control; CLA), or 247 g/d of a mixture of 18:1 FAME containing (% fatty acids) cis-9 (9.45), cis-12 (3.35), trans-10 (37.3), trans-11 (37.4), and trans-12 (2.66) as major isomers (T181 treatment). Administration of the T181 treatment supplied 92.1 g/d of trans-10 18:1. Infusions were conducted over a 5-d period with a 9-d interval between treatments. Treatments had no effect on dry matter intake, milk yield, or milk protein. Relative to the control, abomasal infusion of T181 and trans-10, cis-12 CLA treatments reduced milk fat secretion by 19.5 and 41.5%, respectively. Even though a direct cause and effect on mammary lipogenesis could not be established, comparisons with published data and considerations of the relative abundance of constituent FAME in treatment T181 implicated trans-10 18:1 as the isomer responsible. In conclusion, current data suggest that trans-10 18:1 potentially exerts antilipogenic effects and may contribute to the reduction in milk fat synthesis during diet-induced MFD in the lactating cow.