Biohydrogenation Products Research Articles

Buffalo meat quality, processing, and marketing: harnessing its benefits and nutraceutical potential

Buffalo meat production is growing in different countries also because buffalo products exhibit some positive characteristics for human health compared to red meats from other species. However, meat quality is also defined by organoleptic aspects. This review aims to highlight the distinctive characteristics of buffalo meat. The principal problems of buffalo meat production are related to the low yield and an abundant layer of subcutaneous fat deposition when the animal is older than 14 months. This last trait, which may seem negative, allows us to carry out prolonged aging time (PAT) without compromising the shelf life and improving meat tenderness, one of the organoleptic characteristic’s consumers desires. Another organoleptic characteristic that guides consumer choice is color. This trait depends mainly on the amount and state of myoglobin, a species- specific sarcoplasmic heme protein, and buffalo presents a different molecule than beef. Furthermore, this bright red molecule in the oxidized state transforms into metmyoglobin or deoxy myoglobin in the absence of oxygen, giving a dark color to the meat, which consumers associate with poor quality from old animals. The presence or absence of oxygen shows advantages and disadvantages by acting on the one hand, on the bright meat color and, on the other, on the oxidation of lipids. The best compromise between the two situations is given by skin packaging, which preserves the meat in an anaerobic environment. Keeping the high nutritional quality over time is imperative to maintain the numerous nutritional properties of buffalo meat. In this regard, buffalo meat presents numerous distinctive characteristics among the different groups of fatty acids. Among the saturated one, the abundance of odd and branched fatty acids compared to the bovine breed should be highlighted; for the unsaturated ones, this meat is characterized by the abundance of biohydrogenation products by rumen bacteria such as trans vaccenic and conjugated linoleic acid (CLA), best known for its anti- carcinogenic properties. In comparison, the endogenous pathway of fatty acid formation through the liver or adipose tissue allows us to enhance the elongation capacity of polyunsaturated n3 fatty acids, vital for human health as precursors of anti-inflammatory prostaglandins. Finally, buffalo meat is an essential source of N- acetylneuraminic sialic acid (Neu5Ac), a nine-carbon molecule located in the terminal ends of glyco-proteins and glycolipids, an essential nutrient for brain development and function. This molecule can also counteract the intestinal absorption of N-glycolyl sialic acid (Neu5Gc) exogenous for humans, abundant in red meat, with high inflammatory action. In addition to being marketed as fresh meat, Buffalo meat can also be transformed into semi-processed or cured products with peculiar characteristics. Lean products could be well integrated into the modern diet, with clear advantages to consumers and breeders. The nutritional and technological potential of buffalo meat is considerable, and it is necessary to communicate this to the consumer, creating an efficient and dynamic market for buffalo meat-based products.

Using canonical correlation analysis to understand the rumen biohydrogenation patterns of linoleic and alpha-linolenic acids in the rumen fluid of bovines

The objective of this study was to determine the multivariate relationship among linoleic acid, alpha-linolenic acid, and their main rumen biohydrogenation (BH) intermediates and products in bovine rumen fluid using canonical correlation analysis (CCA). A dataset consisting of 1177 observations generated by 107 in vitro rumen incubation systems of pure and mixed linoleic acid (18:2-c9, c12) and alpha-linolenic acid (18:3-c9, c12, c15) was gathered. Two canonical variates were defined: A: composed of the nine main BH intermediates and products (18:2-c9, t11; 18:2-t11, c15; 18:1-t11; 18:1-t9; 18:1-t6; 18:1-c11; 18:1-c6; 18:1-c9; 18:0) of 18:2-c9, c12 and 18:3-c9, c12, c15 and B: composed of 18:2-c9, c12 and 18:3-c9, c12, c15. Two canonical functions between A and B with significant canonical correlations (R1=0.990 and R2=0.738; p <0.01) were obtained. However, only the first function was selected for CCA. Exploration of canonical loadings for first function, revealed the following quantitative significance (absolute value) order for fatty acids (FA) within their respective canonical variates: A: 18:0(0.958)>18:1-t9(0.837)>18:1-c11(0.835)>18:1-c6(0.824)>18:1-t11(0.747)>18:1-c9(0.738)>18:1-t6(0.415)>18:2-t11, c15(0.387)> 18:2-c9, t11(0.239); B: 18:2-c9, c12(0.667)>18:3-c9, c12, c15(0.488). The CCA showed that 18:2-c9, c12 has a greater contribution than that of 18:3-c9, c12, c15 on the production of the aforementioned BH intermediates, in which 18:0, as well as the groups of 18:1 cis and trans-FA were mainly affected.

Feeding extruded linseed or soybean and hay free-choice to Rubia Gallega young heifers does not substantially alter health-enhancing fatty acids in meat

Context A common strategy to try and improve the fatty acid (FA) composition of meat and fat from cattle has been to feed protected oil or oilseeds. Aims Concentrate containing 4.5% fat from vegetable oil, extruded linseed or extruded soybean were fed free-choice with hay to Rubia Gallega heifers to examine the effects on meat (Longissimus thoracis (LT)) and subcutaneous fat (SCF) FAcompositions, and effects on meat and carcass quality. A secondary aim was to assess treatment effects on levels of specific desirable FAs in meat and fat. Methods Twenty-four 7-month-old Rubia Gallega heifers were assigned to three experimental diets: control concentrate (with palm oil) or concentrates containing either extruded linseed (LS) or extruded soybeans. Concentrates and hay were fed for 90 days before slaughter at an average age and weight of 300 days and 350 kg, respectively. Key results Minor treatment effects on animal performance, carcass traits and meat quality were noted. Relative to the control concentrate diet, feeding the linseed diet led to a slight increase in α-linolenic acid (18:3n-3) in SCF (P < 0.001), no change in 18:3n-3 in LT, reduced n-6/n-3 ratios in both LT and SCF (LT, P < 0.01; SCF, P < 0.001), and avoided ∑(t6- to t10-)18:1 accumulation in either tissue (LT, P = 0.017; SCF, P < 0.05). Conclusions Although FA improvements when feeding linseed could be viewed as positive for human health, quantitatively, feeding extruded oilseeds and hay free-choice were ineffective at creating rumen conditions needed to substantially enrich n-3 polyunsaturated FAs (PUFA) or desirable biohydrogenation intermediates in LT. Implications To produce high-quality Rubia Gallega meat with meaningful and consistent enrichments of polyunsaturated FAs and beneficial biohydrogenation products will require more efficient methods for ruminal protection of PUFA, and further investigations into the timing and amounts of PUFA-enriched concentrate feeding.

Seasonal variation in fatty acid and triacylglycerol composition of bovine milk fat

The aim of this study was to assess the effects of seasonal variation on the changes of the fatty acid (FA) and triacylglycerol (TAG) composition of bovine milk fat (MF) in a nonseasonal milking system. Weekly milk samples were collected from 14 dairy factories and pooled per week as representative samples of the average Dutch bovine milk. The sample collection started in May 2017 and finished in April 2018, resulting in a total of 52 samples, corresponding to each week of the year. The samples were analyzed for MF content (%) and FA and TAG composition using gas chromatography with flame-ionization detection. The increased intake of C18:3 cis-9,12,15 through grass feeding in spring and summer was associated with major changes in MF FA composition, including reduced proportions of de novo synthesized FA and presence of several rumen biohydrogenation products and conjugated linoleic acid isomers in MF. These changes in seasonal FA composition had an effect on TAG seasonal variation. The TAG seasonal variation showed that all TAG groups were significantly different between months. The low molecular weight and the medium molecular weight TAG groups increased in winter and decreased in summer, whereas the high molecular weight TAG groups increased in summer and decreased in winter. Based on pooled monthly samples, MALDI-TOF-mass spectrometry allowed the analysis of even- and odd-chain TAG species in MF based on their total carbon number and number of double bonds. These analyses indicated saturated TAG species to be greatest in winter, whereas monounsaturated, polyunsaturated, and odd-chain TAG species were greatest in summer. Our study showed that TAG seasonal variation in a nonseasonal milking system is influenced by the variation in FA composition throughout the seasons.

Effects of Increasing Doses of Condensed Tannins Extract from Cistus ladanifer L. on In Vitro Ruminal Fermentation and Biohydrogenation.

Simple SummaryRuminant edible products have been associated with adverse health effects, due to their high saturated fatty acids and low polyunsaturated fatty acids content, resulting from the extensive biohydrogenation conducted by rumen microbiota. Cistus ladanifer condensed tannins were able to change the lamb ruminal biohydrogenation, increasing the beneficial fatty acids production. The aim of this study was to test the effect of increasing doses of C. ladanifer condensed tannins extract (0, 25, 50, 75 and 100 g/kg dry matter) on in vitro rumen fermentation and biohydrogenation. The increasing doses of condensed tannins led to a moderate decrease of volatile fatty acids production, a pronounced depression in microbial odd and branched fatty acids and of dimethyl acetals production, and a minor effect on the biohydrogenation, which indicates that microbial growth was more inhibited than fermentative and biohydrogenation activities. The ability of C. ladanifer condensed tannins extract to modulate the biohydrogenation (BH) was not observed in the present study. However, the results obtained suggest a possible adaptative response of the microbial population to stress stimuli of condensed tannins and lipid supplementation.Cistus ladanifer (rockrose) is a perennial shrub quite abundant in the Mediterranean region, and it is a rich source in secondary compounds such as condensed tannins (CTs). Condensed tannins from C. ladanifer were able to change the ruminal biohydrogenation (BH), increasing the t11–18:1 and c9,t11–18:2 production. However, the adequate conditions of the C. ladanifer CTs used to optimize the production of t11–18:1 and c9,t11–18:2 is not yet known. Thus, we tested the effect of increasing the doses of C. ladanifer CT extract (0, 25, 50, 75 and 100 g/kg dry matter (DM)) on in vitro rumen BH. Five in vitro batch incubations replicates were conducted using an oil supplemented high-concentrate substrate, incubated for 24 h with 6 mL of buffered ruminal fluid. Volatile fatty acids (VFAs) and long chain fatty acids (FA) were analyzed at 0 h and 24 h, and BH of c9–18:1, c9, c12–18:2 and c9, c12, c15–18:3, and BH products yield were computed. Increasing doses of C. ladanifer CTs led to a moderate linear decrease (p < 0.001) of the VFA production (a reduction of 27% with the highest dose compared to control). The disappearance of c9–18:1 and c9,c12–18:2 as well as the production of t11–18:1 and c9, t11:18:2 was not affected by increasing doses of C. ladanifer CTs, and only the disappearance of c9, c12, c15–18:3 suffered a mild linear decrease (a reduction of 24% with the highest dose compared to control). Nevertheless, increasing the C. ladanifer CT dose led to a strong depression of microbial odd and branched fatty acids and of dimethyl acetals production (less than 65% with the highest dose compared to control), which indicates that microbial growth was more inhibited than fermentative and biohydrogenation activities, in a possible adaptative response of microbial population to stress induced to CTs and polyunsaturated fatty acids. The ability of C. ladanifer to modulate the ruminal BH was not verified in the current in vitro experimental conditions, emphasizing the inconsistent BH response to CTs and highlighting the need to continue seeking the optimal conditions for using CTs to improve the fatty acid profile of ruminant fat.

Selenate and selenite affect ruminal metabolism of C18 unsaturated fatty acids and fatty acid composition of lamb tissues

The main aim of our study was to investigate the influence of selenite (SeIV) or selenate (SeVI) added to ovine ruminal fluid with cis9cis12cis15C18:3 (LNA) on contents of fatty acids (FA), especially products of microbial isomerisation of LNA and biohydrogenation (BH) of unsaturated FA in vitro incubated fluids. The second goal of our study was to investigate the effects of SeVI added to a diet containing linseed oil (LO, rich in LNA) on the accumulation of BH products in selected tissues of lambs. Ruminal fluids were incubated in vitro at 39°C under CO2 either alone (the control fluid; RF) or with LNA (1.67 mg/ml), a low (1.33 μg/ml), a high (3.33 μg/ml) dose of Se (as SeIV or SeVI), with a combination of LNA with either a low (1.33 μg/ml) or a high (3.33 μg/ml) dose of Se as SeIV or SeVI. The tubes with incubated fluids were removed after 0, 6, 12, 18 or 24 h of in vitro incubation and then analysed to determine contents of FA. Both the doses of SeIV or SeVI in fluids with LNA revealed no significant effect on the contents of products of LNA isomerisation compared to incubated fluids with LNA. The contents of isomerisation products of LNA in incubated fluids with LNA, irrespective of the presence of SeIV and SeVI, rapidly increased in the fluids incubated for 6 h, followed by a slower rate of disappearance until 24 h. Contents of trans11C18:1 and trans11cis15C18:2 in fluids with LNA, regardless of the presence of both the doses of SeIV or SeVI, increased throughout incubations. The lower dose of SeVI in fluids with LNA increased the capacity of BH to trans11C18:1 in incubated fluids. SeVI added to the lambs’ diet with LO decreased contents of saturated FA (like C18:0) in the liver and musculus longissimus dorsi. LO added to the diets with or without SeVI most effectively increased the level of polyunsaturated FA (PUFA) in the liver, while the higher content of monounsaturated FA was observed in musculus biceps fermoris (MBF) when compared to the control group. The diets with LO, irrespective of the presence of SeVI, reduced the capacity of linoleic acid elongation to cis11cis14C20:2 in the liver and MBF compared to the control lambs. Further studies are required to clarify the effects of SeVI and long-chain PUFA on contents of FA, especially conjugated PUFA, in the ruminal microbiota and tissues of lambs.

Changes in the fatty acid composition of steer subcutaneous fat, including biohydrogenation products, are minimal when finished on combinations of corn and barley grains and silages

Corn production in Western Canada has increased with development of short-season varieties partially offsetting the use of barley as a silage and grain source. The current study evaluated effects of silage and cereal-grain source on subcutaneous fat (SCF) composition of finishing cattle. Steers (465 ± 28.0 kg) were assigned to 24 pens (12 steers per pen) in a 2 × 3 factorial design for an 89 d finishing study. Diets contained corn silage or barley silage at 8% [dry matter (DM)] combined either dry-rolled barley grain (BG; 86% of DM), corn grain (CG; 85% of DM), or an equal blend of BG and CG (85% of DM). Bone-in ribeyes were collected from four steers per pen, and subcutaneous fatty acids were analyzed by gas chromatography. Feeding dry-rolled CG increased dietary fat and 18:2n-6 concentrations, resulting in small increases in 18:2n-6, total n-6 fatty acids, and n-6/n-3 ratios in SCF (P &lt; 0.05). There were no changes in proportions of major trans-18:1 isomers (t10-18:1 or t11-18:1), the main natural isomer of conjugated linoleic acid (cis9,t11–18:2), or n-3 fatty acids. Substitution of dry-rolled CG for BG in finisher diets can, therefore, be done without substantially altering the fatty acid composition of beef fat, including polyunsaturated fatty acid biohydrogenation products.

Partial replacement of rapeseed oil with fish oil, and dietary antioxidants supplementation affects concentrations of biohydrogenation products and conjugated fatty acids in rumen and selected lamb tissues

The purpose of this study was to assess if partial replacement of rapeseed oil (RO) with fish oil (FO) combined with dietary supplementation of various antioxidants (carnosic acid – CA, selenized yeast – SeY and selenate – Se(VI)) influences the profile of biohydrogenation products, intermediates and conjugated fatty acids (CFA) in the rumen content and selected tissues of lambs. Thirty Corriedale male lambs were divided into 5 groups and fed for 35 days isonitrogenous and isoenergetic diets: basal diet enriched with 30 g RO/kg (Group 0 – control), diet enriched with 20 g RO/kg and 10 g FO/kg (Group I) or diets with combined addition of 20 g RO/kg, 10 g FO/kg and antioxidants (Group II supplemented with 1 g CA/kg; Group III with 1 g CA/kg and 0.35 mg/kg Se as SeY; Group IV with 0.35 mg/kg Se as Se(VI)). Applied dietary modification significantly affected the lipid transformation in the rumen. Replacement of RO by FO to the greater extent affected the profile of conjugated than non-conjugated intermediates in all samples. Collateral supplementation of antioxidants acted synergistically with FO in case of CFA content in the rumen content whereas in tissues the impact of antioxidants was antagonistic to FO. Se-compounds influenced CFA amounts in the most potent way, although dependent on their chemical form. Inorganic form (Se(VI)) reduced conjugated biohydrogenation intermediates contents in lamb livers while its organic chemical form (SeY) stimulated deposition of CFA and CD in femoral muscles. Partial replacement of RO by FO resulted in preferential incorporation of CFA isomers into liver and dorsal muscle. A complex insight into PUFA metabolism in the rumen was possible due to consideration of both steps (isomerisation and biohydrogenation) as well as plethora of possible intermediates and arising products (especially conjugated). Our results indicate that isomerisation and biohydrogenation are strongly affected by the Se-compounds. The influenced depended on the chemical form of these compounds: SeY strongly influenced the isomerization of both LA and ALA, whereas inorganic Se modified the biohydrogenation of ALA. So, it can be stated that aside from phytochemicals, Se-compounds have also an ability to modify processes occurring in rumen and thus may lead to favorable modification of FA profile of edible part of ruminant carcass, which is of utmost importance from the consumer point of view.

Combined Short‐Path Distillation and Solvent‐Assisted Crystallization of Beef Fatty Acid Methyl Esters

AbstractSolvent‐assisted crystallization has previously been employed to remove long‐chain saturated fatty acids (≥ 18 carbons) from animal fat to improve its cold temperature biofuel properties. The same technology can be used for removing long‐chain saturated fatty acids (SFA) from animal fats for human consumption, but SFA remaining (i.e., 14:0 and 16:0) are more atherogenic than longer chain SFA. In the present study, an easy and efficient method was developed using short‐path distillation prior to solvent‐assisted crystallization for the more complete removal of SFA from beef tallow, and for the first time reports the distillation and crystallization behavior of polyunsaturated fatty acid biohydrogenation products (PUFA‐BHP). Shorter chain SFA methyl esters (i.e., 14:0 and 16:0) were efficiently removed at 90 °C, 9.3 Pa, with a rotor speed of 70 rpm and either two cycles of distillation at 90 drops/min or three cycles at 110 drops/min. Stearic acid (18:0) was then effectively removed by crystallization at −20 °C using a sample to methanol ratio of 1:10. The remaining fraction enriched with PUFA‐BHP (i.e., rumenic acid, c9,t11‐18:2, and its precursor vaccenic acid, t11‐18:1) have potential use in disease model (i.e., cell culture and animal) studies to help further elucidate their bioactivity and mode of action, and may in the future have functional food or nutraceutical potential.

Anti‐mutagenic Properties of Mono‐ and Dienoic Acid Biohydrogenation Products from Beef Fat

Unsaturated fatty acid biohydrogenation products from beef fat and pure fatty acids were subjected to the Ames Salmonella mutagenicity testing, including monounsaturated fatty acids [MUFA: oleic acid, vaccenic acid, elaidic acid; beef fatty acid fractions rich in trans (t)11/t13-t14-18:1 (t11,13,14-Frac), t10-18:1 (t10-Frac)] and dienoic fatty acids [linoleic acid, conjugated linoleic isomers cis (c)9,t11-18:2 and t10,c12-18:2, and a mixed beef dienoic fatty acid fraction high in c9,t13-/t8,c12/t11c15-18:2 (MD)]. Significantly higher anti-mutagenic effects of oleic acid, vaccenic acid, t11, 13, 14-Frac, and t10-Frac against daunomycin were observed at 2.5mg. All dienoic acids except MD significantly reduced daunomycin mutagenicity at ≥0.25mg. Anti-mutagenicity of oleic and vaccenic acids against 2-aminoanthracene was found at 2.5 and 0.25mg, respectively. All dienoic acids significantly reduced 2-aminoanthracene mutagenicity at ≥0.25mg. Findings of this study show that unsaturated fatty acids, including trans-fatty acids commonly found in beef, can act as strong anti-mutagens.

Lipid Encapsulation Provides Insufficient Total-Tract Digestibility to Achieve an Optimal Transfer Efficiency of Fatty Acids to Milk Fat.

Transfer efficiencies of rumen-protected n-3 fatty acids (FA) to milk are low, thus we hypothesized that rumen-protection technologies allow for biohydrogenation and excretion of n-3 FA. The objectives of this study were to i) investigate the ruminal protection and post-ruminal release of the FA derived from the lipid-encapsulated echium oil (EEO), and ii) assess the bioavailability and metabolism of the EEO-derived FA through measuring the FA content in plasma lipid fractions, feces, and milk. The EEO was tested for rumen stability using the in situ nylon bag technique, then the apparent total-tract digestibility was assessed in vivo using six Holstein dairy cattle. Diets consisted of a control (no EEO); 1.5% of dry matter (DM) as EEO and 1.5% DM as encapsulation matrix; and 3% DM as EEO. The EEO was rumen-stable and had no effect on animal production. EEO-derived FA were incorporated into all plasma lipid fractions, with the highest proportion of n-3 FA observed in cholesterol esters. Fecal excretion of EEO-derived FA ranged from 7–14%. Biohydrogenation products increased in milk, plasma, and feces with EEO supplementation. In conclusion, lipid-encapsulation provides inadequate digestibility to achieve an optimal transfer efficiency of n-3 FA to milk.

Immunogenic inhibition of prominent ruminal bacteria as a means to reduce lipolysis and biohydrogenation activity in vitro

Lipolysis and biohydrogenation in ruminal animals promote the accumulation of saturated fatty acids in their meat and milk. Antibodies were generated against key ruminal lipase contributors Anaerovibrio lipolyticus, Butyrivibrio fibrisolvens, Propionibacterium avidum and acnes. An anti-Pseudomonas lipase antibody was generated to determine if an antibody against a purified protein would be more effective. Each bacterium was cultured and assayed without or with increasing levels of each antibody. Butyrivibrio fibrisolvens H17C also participates in biohydrogenation and therefore the antibody was tested to determine if it could effectively reduce biohydrogenation. Butyrivibrio fibrisolvens was assayed without and with the anti-B. fibrisolvens antibody and linoleic or α-linolenic acid. All antibodies were effective at reducing lipolysis with the anti-Pseudomonas lipase averaging a 78% reduction. The anti-B. fibrisolvens showed a tendency for a reduction (P=0.0713) in biohydrogenation products of α-linolenic acid. Results demonstrate that lipolysis and biohydrogenation can be immunologically inhibited in vitro.

Effects of extracts obtained from Cistus ladanifer L. on in vitro rumen biohydrogenation

Cistus ladanifer (rockrose) is a tanniferous and aromatic shrub abundant in marginal fields of Mediterranean countries that when fed to lambs has been associated with changes in rumen biohydrogenation that led to an increased concentration of vaccenic acid (t11-18:1) in abomasal digesta and meat. It is not clear what type of secondary compounds present in C. ladanifer might be responsible for its effects on rumen biohydrogenation. Thus, we tested the effects of essential oil (EO), dichloromethane extract (DE), total phenolics (TP), non-tannin phenols (NTP) and condensed tannins (CT) fractions on in vitro rumen biohydrogenation. Five in vitro batch incubations replicates were conducted in Hungate tubes containing 60mg of feed substrate (Control), or 60mg of feed substrate plus 6mg of each C. ladanifer extract incubated for 6h with 6mL of buffered ruminal fluid. Volatile fatty acids (VFA) and long chain fatty acids (FA) were analyzed at 0 and 6h and the biohydrogenation of c9-18:1, c9,c12-18:2 and c9,c12,c15-18:3 and the yield of biohydrogenation products were computed. The production of total VFA was not affected by the C. ladanifer extracts and averaged 6.87mmol/L. The disappearance of c9,c12-18:2 and c9,c12,c15-18:3 was higher in CT than in Control and EO (P<0.05). The gain in 18:0 and t11-18:1, relative to initial subtract availability, was higher in CT than in Control and EO (P<0.05). Both CT and DE increased (P<0.05) the c9,t11-18:2 yield, relative to initial subtract availability, compared with Control and EO treatments. The 10-oxo-18:0 was the major oxo FA found and was highest for CT and lowest in EO and DE treatments. The results showed that CT was the most effective fraction of C. ladanifer regarding its effects on rumen biohydrogenation, inducing larger accumulation of t11-18:1, which was achieved not by inhibition of its last reductive biohydrogenation step (i.e. formation of 18:0) but by the promotion of the initial biohydrogenation steps.

Effects of feeding beef fat enriched with polyunsaturated fatty acid biohydrogenation products to pigs

A total of sixteen barrows were randomly assigned to diets containing 5% biohydrogenation product (BHP)-enriched or control beef fat for 7 weeks. On completion of 7 weeks, we found that feeding enriched fat led to deposition of BHP and isomer-specific metabolism of trans-18:1 in adipose tissue. It was also noticed that total and HDL-cholesterol were decreased; however, LDL-cholesterol and triglycerides were not affected.

Beef Fat Enriched with Polyunsaturated Fatty Acid Biohydrogenation Products Improves Insulin Sensitivity Without Altering Dyslipidemia in Insulin Resistant JCR:LA-cp Rats.

The main dietary sources of trans fatty acids are partially hydrogenated vegetable oils (PHVO), and products derived from polyunsaturated fatty acid biohydrogenation (PUFA-BHP) in ruminants. Trans fatty acid intake has historically been associated with negative effects on health, generating an anti-trans fat campaign to reduce their consumption. The profiles and effects on health of PHVO and PUFA-BHP can, however, be quite different. Dairy products naturally enriched with vaccenic and rumenic acids have many purported health benefits, but the putative benefits of beef fat naturally enriched with PUFA-BHP have not been investigated. The objective of the present experiment was to determine the effects of beef peri-renal fat (PRF) with differing enrichments of PUFA-BHP on lipid and insulin metabolism in a rodent model of dyslipidemia and insulin resistance (JCR:LA-cp rat). The results showed that 6weeks of diet supplementation with beef PRF naturally enriched due to flaxseed (FS-PRF) or sunflower-seed (SS-PRF) feeding to cattle significantly improved plasma fasting insulin levels and insulin sensitivity, postprandial insulin levels (only in the FS-PRF) without altering dyslipidemia. Moreover, FS-PRF but not SS-PRF attenuated adipose tissue accumulation. Therefore, enhancing levels of PUFA-BHP in beef PRF with FS feeding may be a useful approach to maximize the health-conferring value of beef-derived fats.

Genetic and environmental relationships of detailed milk fatty acids profile determined by gas chromatography in Brown Swiss cows

The aim of this study was to characterize the profile of 47 fatty acids, including conjugated linoleic acid (CLA), 13 fatty acid groups, and 5 Δ9-desaturation indices in milk samples from Brown Swiss cows. The genetic variation was assessed and the statistical relevance of the genetic background for each trait was evaluated using the Bayes factor test. The additive genetic, herd-date, and residual relationships were also estimated among all single fatty acids and groups of fatty acids. Individual milk samples were collected from 1,158 Italian Brown Swiss cows and a detailed analysis of fat percentages and milk fatty acid compositions was performed by gas chromatography. Bayesian animal models were used for (co)variance components estimation. Exploitable genetic variation was observed for most of the de novo synthesized fatty acids and saturated fatty acids, except for C4:0 and C6:0, whereas long-chain fatty acids and unsaturated fatty acids (including CLA) were mainly influenced by herd-date effects. Herd-date effect explained large portions of the total phenotypic variance for C18:2 cis-9,cis-12 (0.668), C18:3 cis-9,cis-12,cis-15 (0.631), and the biohydrogenation and elongation products of these fatty acids. The desaturation ratios showed higher heritability estimates than the individual fatty acids, except for CLA desaturation index (0.098). Among the medium-chain fatty acids, C12:0 had greater heritability than C14:0 (0.243 vs. 0.097, respectively). Both C14:0 and C16:0 showed negative additive genetic correlations with the main monounsaturated and polyunsaturated fatty acids of milk fat, suggesting that their synthesis in the mammary gland may be influenced by the presence of unsaturated fatty acids. No correlation was observed between C4:0 and the other short-chain fatty acids (except for C6:0), confirming the independence of C4:0 from de novo mammary fatty acid synthesis. Among the genetic correlations dealing with potentially beneficial fatty acids, C18:0 was positively correlated with vaccenic and rumenic acids and negatively with linoleic acid. Finally, fatty acids C6:0 through C14:0 showed relevant correlations due to unknown environmental effects, suggesting the potential existence of genetic variances in micro-environmental sensitivity. This study allowed us to acquire new knowledge about the genetic and the environmental relationships among fatty acids. Likewise, the existence of genetic variation for most of de novo synthetized fatty acids and saturated fatty acids was also observed. Overall, these results provide useful information to combine feeding with genetic selection strategies for obtaining a desirable milk fatty acids profile, depending on the origin of fatty acids in milk.

Fatty acid composition of beef steers as affected by diet and fat depot

Subcutaneous and perirenal fatty acid (FA) profiles were compared in steers fed a control diet (70 : 30 red clover silage (RC) : barley concentrate), a diet with sunflower seed (SS) substituted for barley, and diets with 15% or 30% wheat dried distillers’ grain with solubles (DDGS-15 and DDGS-30) substituted for RC and SS. Perirenal fat (PRF) versus subcutaneous fat (SCF) had greater proportions of total saturated FA (SFA) and branched chain FA (BCFA), and lower proportions of total and major cis -monounsaturated FA ( c -MUFA). Addition of SS to the diet did not change the proportions of total and major c -MUFA and n -6 polyunsaturated FA (PUFA), but led to decreases in the proportions of total and major SFA, BCFA and n -3 PUFA. Progressive substitutions with DDGS led to no further changes in the proportions of total and major SFA and n -3 PUFA, but decreased the proportions of BCFA and c 9-16:1, and increased the proportions of c 9-18:1 and n -6 PUFA. Feeding SS and DDGS-15 diets yielded the largest proportions of total and major t -18:1 ( t 11- and t 13-/ t 14-18:1) isomers in PRF and conjugated lineolic acid (CLA) isomers ( t 7, c 9- and t 9, c 11-18:2) in SCF, but responses were diminished when feeding the DDGS-30 diet. Subcutaneous fat versus PRF from steers fed SS and DGGS diets had larger proportions of non-conjugated 18:2 biohydrogenation products (i.e. atypical dienes) than the control diet. Overall, feeding SS and DDGS-15 diets raised the proportions of t 11- 18:1 in PRF and c 9, t 11-18:2 in SCF, which have potential human health benefits, but feeding DDGS-30 was less effective. Keywords: Beef, rumenic acid, vaccenic acid

The scope for manipulating the polyunsaturated fatty acid content of beef: a review.

Since 1950, links between intake of saturated fatty acids and heart disease have led to recommendations to limit consumption of saturated fatty acid-rich foods, including beef. Over this time, changes in food consumption patterns in several countries including Canada and the USA have not led to improvements in health. Instead, the incidence of obesity, type II diabetes and associated diseases have reached epidemic proportions owing in part to replacement of dietary fat with refined carbohydrates. Despite the content of saturated fatty acids in beef, it is also rich in heart healthy cis-monounsaturated fatty acids, and can be an important source of long-chain omega-3 (n-3) fatty acids in populations where little or no oily fish is consumed. Beef also contains polyunsaturated fatty acid biohydrogenation products, including vaccenic and rumenic acids, which have been shown to have anticarcinogenic and hypolipidemic properties in cell culture and animal models. Beef can be enriched with these beneficial fatty acids through manipulation of beef cattle diets, which is now more important than ever because of increasing public understanding of the relationships between diet and health. The present review examines recommendations for beef in human diets, the need to recognize the complex nature of beef fat, how cattle diets and management can alter the fatty acid composition of beef, and to what extent content claims are currently possible for beef fatty acids.

Effects of different forms and origins of oilseeds on dynamics of ruminal biohydrogenation of long-chain fatty acids invitro.

Dietary unsaturated fatty acids (FA) are intensively hydrogenated in the rumen, resulting in reduced amount of poly-unsaturated fatty acids (PUFA) and accumulation of several biohydrogenation (BH) products. In this study, BH of PUFA originating from different oilseeds (linseed, soya beans, sunflower seed and rapeseed) present in crushed oilseeds or their free oils were assessed in vitro. The assay substrates were incubated in buffered rumen fluid for 0, 6, 12 and 24 h. After incubation, the FA pattern of the incubated samples was analysed using gas chromatography. Biohydrogenation is defined as disappearance of double bonds (DB) calculated from the contents of unsaturated FA. After 24-h incubation, the DB contents of all oilseeds were reduced (p < 0.001) by 40-60%. The reduction was higher (p < 0.001) for the crushed form compared with the oil form. In addition, linseed and sunflower seed known as oilseeds with high contents of linolenic acid C18:3 c9,12,15 (LNA) and linoleic acid C18:2 c9,12 (LA), respectively, showed a higher (p < 0.001) accumulation of the BH intermediates conjugated linoleic acid (CLA, isomer C18:2 c9t11) and vaccenic acid (C18:1 t11) for the crushed form, when compared with the oil. These results suggest an inherent effect of the physical form of the assay oilseeds on in vitro BH. Changes in FA pattern during BH in vitro can be attributed to both source and physical form of the assay oilseeds. However, further investigations are warranted to ensure whether the observed in vitro effects on ruminal BH can be confirmed in vivo.

Isolation of α-linolenic acid biohydrogenation products by combined silver ion solid phase extraction and semi-preparative high performance liquid chromatography.

Polyunsaturated fatty acids typically found in cattle feed include linoleic (LA) and α-linolenic acid (ALA). In the rumen, microbes metabolize these resulting in the formation of biohydrogenation products (BHP), which can be incorporated into meat and milk. Bioactivities of LA-BHP, including conjugated linoleic acid (cis (c) 9,trans (t) 11-18:2 and t10,c12-18:2) and trans fatty acid isomers (t9-, t10- and t11-18:1) have been investigated, but effects of several BHP unique to ALA have not been extensively studied, and most ALA-BHP are not commercially available. The objective of the present research was to develop methods to purify and collect ALA-BHP using silver ion (Ag(+)) chromatography in sufficient quantities to allow for convenient bioactivity testing in cell culture. Fatty acid methyl esters (FAME) were prepared from perirenal adipose tissue from a cow enriched with ALA-BHP by feeding flaxseed. These were applied to Ag(+)-solid phase extraction, and eluted with hexane with increasing quantities of acetone (1, 2, 10, 20%) or acetonitrile (2%) to pre-fractionate FAME based on degree of unsaturation and double bond configuration. Fractions were collected, concentrated and applied to semi-preparative Ag(+)-high performance liquid chromatography (HPLC) for the isolation and collection of purified isomers, which was accomplished using isocratic elutions with hexane containing differing amounts of acetonitrile (from 0.015 to 0.075%). Purified trans-18:1 isomers collected ranged in purity from 88 to 99%. Purity of the ALA-BHP dienes collected, including c9,t13-18:2, t11,c15-18:2 and t10,c15-18:2, exceeded 90%, while purification of other dienes may require the use of other complementary procedures (e.g. reverse phase HPLC).