86 research outputs found

    Lamb meat colour stability as affected by dietary tannins

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    Twenty-one male Comisana lambs were divided into three groups at 45 days of age and were individually penned for 60 days. Seven lambs were fed a concentrate-based diet (C), seven lambs received the same concentrate with the addiction of tannins from quebracho (Schinopsis lorentzii; T), whereas the remaining animals were fed exclusively fresh vetch (Vicia sativa; H). Colour descriptors (a*, b* and H*) and metmyoglobin (MMb) percentages were measured on minced semimembranosus muscle over 14 days of refrigerated storage in a high oxygen atmosphere. Regardless of dietary treatment, meat redness decreased, while yellowness and hue angle increased (P < 0.001) over storage duration. However, higher a* values, lower b* values and lower H* values were observed in meat from both H- and T-fed animals as compared to meat from C-fed lambs (P = 0.012; P = 0.02; P = 0.003, respectively). Metmyoglobin formation increased over time (P < 0.001), but H diet resulted in lower metmyoglobin percentages than C diet (P = 0.007). We conclude that the inclusion of tannins into the concentrate improved meat colour stability compared to a tannin-free concentrate. Moreover, the protective effect of tannins against meat discolouration was comparable to that obtained by feeding lambs fresh herbage

    Fatty acid composition, shelf-life and eating quality of beef from steers fed corn or wheat dried distillers' grains with solubles in a concentrate supplement to grass silage

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    Thirty-six steers were randomly assigned to one of three dietary treatments fed ad libitum grass silage and concentrate supplements containing either barley/soybean meal (CON), 80% DM corn (CDGS)- or 80% DM wheat (WDGS)-dried distillers' grains with solubles for 124 days pre-slaughter. Chemical and fatty acid composition, shelf-life, and eating quality of longissimus thoracis muscle were determined. Dietary CDGS and WDGS increased the proportion of conjugated linoleic acids (P < 0.05) and tended to increase C18:3n-3 (P = 0.075) and total polyunsaturated fatty acids (P = 0.060) relative to the CON. Feeding diets containing distillers' grains reduced the lipid and colour stability of fresh beef patties stored in modified atmosphere packs (MAP), with CDGS exhibiting an intermediate effect between CON and WDGS. Diet did not negatively influence the texture profile parameters and eating quality attributes of beef stored in MAP. The inclusion of CDGS or WDGS in supplementary concentrates may improve the fatty acid profile but decreased the shelf-life of beef

    Vitamin E is the major contributor to the antioxidant capacity in lambs fed whole dried citrus pulp.

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    The aim of this study was to investigate the effect of dietary whole dried citrus pulp (DCP) on the antioxidant status of lamb tissues. In total, 17 lambs were divided into two groups and fed for 56 days: a barley-based concentrate diet (CON - eight animals), or a concentrate-based diet including 35% DCP to partially replace barley (CIT - nine animals). The CIT diet contained a double concentration of phenolic compounds than the CON diet (7.9 v. 4.0 g/kg dry matter (DM), respectively), but had no effect (P>0.05) on the overall antioxidant capacity of the hydrophilic fraction of blood plasma, liver and muscle. The CIT diet contained clearly more α-tocopherol than the CON diet (45.7 v. 10.3 mg/kg DM), which could explain the higher concentration of α-tocopherol in liver, plasma and muscle (P<0.05). The dietary treatment had no effect on the extent of lipid peroxidation, measured as thiobarbituric acid and reactive substances assay (TBARS values) in the faeces, small intestine, liver, plasma and muscle. Nevertheless, when muscle homogenates were incubated in the presence of Fe3+/ascorbate to induce lipid peroxidation, the muscle from lambs fed DCP displayed lower TBARS values (P<0.01), which negatively correlated with the concentration of α-tocopherol in muscle. These results showed that feeding whole DCP to ruminants increases the antioxidant status of muscle through an increase in the deposition of α-tocopherol

    Effect of different dietary tannin extracts on lamb growth performances and meat oxidative stability: comparison between mimosa, chestnut and tara.

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    Little information is available on the effects of different sources of tannins on ruminant product quality. Nowadays several tannin-rich extracts, produced from different plants, are available and contain tannins belonging to different chemical groups, but most of these have not been used so far as feed supplements. The present study aimed at comparing the effects of feeding three tannin extracts (one containing condensed tannins and two containing hydrolysable tannins) to lambs on growth performances and meat oxidative stability. Comisana male lambs were divided into four groups (n=9 each) and were fed for 75 days: a concentrate-based diet (CON), or CON supplemented with 4% tannin extracts from either mimosa (MI; Acacia mearnsii, De Wild; condensed tannins), chestnut (CH; Castanea sativa, Mill; hydrolysable ellagitannins) or tara (TA; Cesalpinia spinosa, (Molina) Kuntze; hydrolysable gallotannins). Only CH reduced growth rate, final weight, carcass weight and feed intake (P0.05). The TA diet increased (P<0.001) the concentration of γ-tocopherol in muscle and tended to increase that of α-tocopherol (P=0.058). Oxidative stability of raw and cooked meat, or of meat homogenates incubated with pro-oxidants, was not affected by the extracts. These results, compared with those reported in the literature, highlight that some effects of tannins cannot be easily generalized, but may strictly depend on their specific characteristics and on conditions inherent to the basal diet and the metabolic status of the animals

    Adsorption behavior of α-cypermethrin on cork and activated carbon

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    Studies were undertaken to determine the adsorption behavior of α-cypermethrin [R)-α-cyano-3-phenoxybenzyl(1S)-cis- 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, and (S)-α-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2- dimethylcyclopropanecarboxylate] in solutions on granules of cork and activated carbon (GAC). The adsorption studies were carried out using a batch equilibrium technique. A gas chromatograph with an electron capture detector (GC-ECD) was used to analyze α-cypermethrin after solid phase extraction with C18 disks. Physical properties including real density, pore volume, surface area and pore diameter of cork were evaluated by mercury porosimetry. Characterization of cork particles showed variations thereby indicating the highly heterogeneous structure of the material. The average surface area of cork particles was lower than that of GAC. Kinetics adsorption studies allowed the determination of the equilibrium time—24 hours for both cork (1–2 mm and 3–4 mm) and GAC. For the studied α-cypermethrin concentration range, GAC revealed to be a better sorbent. However, adsorption parameters for equilibrium concentrations, obtained through the Langmuir and Freundlich models, showed that granulated cork 1–2 mm have the maximum amount of adsorbed α-cypermethrin (qm) (303 μg/g); followed by GAC (186 μg/g) and cork 3-4 mm (136 μg/g). The standard deviation (SD) values, demonstrate that Freundlich model better describes the α-cypermethrin adsorption phenomena on GAC, while α-cypermethrin adsorption on cork (1-2 mm and 3-4 mm) is better described by the Langmuir. In view of the adsorption results obtained in this study it appears that granulated cork may be a better and a cheaper alternative to GAC for removing α-cypermethrin from water

    Photonic Torque Microscopy of the Nonconservative Force Field for Optically Trapped Silicon Nanowires

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    We measure, by photonic torque microscopy, the nonconservative rotational motion arising from the transverse components of the radiation pressure on optically trapped, ultrathin silicon nanowires. Unlike spherical particles, we find that nonconservative effects have a significant influence on the nanowire dynamics in the trap. We show that the extreme shape of the trapped nanowires yields a transverse component of the radiation pressure that results in an orbital rotation of the nanowire about the trap axis. We study the resulting motion as a function of optical power and nanowire length, discussing its size-scaling behavior. These shape-dependent nonconservative effects have implications for optical force calibration and optomechanics with levitated nonspherical particles

    Detection rate for significant cancer at confirmatory biopsy in men enrolled in Active Surveillance protocol: 20 cores vs 30 cores vs MRI/TRUS fusion prostate biopsy

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    Introduction: The detection rate for significant prostate cancer of extended vs saturation vs mMRI/TRUS fusion biopsy was prospectively evaluated in men enrolled in active surveillance (AS) protocol. Mterials and methods: From May 2013 to September 2016 75 men aged 66 years (median) with very low risk PCa were enrolled in an AS protocol and elegible criteria were: life expectancy greater than 10 years, cT1C, PSA below 10 ng/ml, PSA density &lt; 0.20, 2 &lt; unilateral positive biopsy cores, Gleason score (GS) equal to 6, greatest percentage of cancer (GPC) in a core &lt; 50%. All patients underwent 3.0 Tesla pelvic mpMRI before confirmatory transperineal extended (20 cores) or saturation biopsy (SPBx; 30 cores) combined with mpMRI/TRUS fusion targeted biopsy (4 cores) of suspicious lesions (PI-RADS 3-5). Results: 21/75 (28%) patients were reclassified by SPBx based on upgraded GS ≥ 7; mpMRI lesions PI-RADS 4-5 vs PI-RADS 3-5 diagnosed 9/21 (42.8%) vs 16/21 (76.2%) significant PCa with 2 false positives (6.5%). The detection rate for significant PCa was equal to 76.2% (mpMRI/TRUS fusion biopsy) vs 81% (extended) vs 100% (SPBx) (p = 0.001); mpMRI/TRUS targeted biopsy and extended biopsy missed 5/21 (23.8%) and 4/21 (19%) significant PCa which were found by SPBx (p = 0.001) being characterised by the presence of a single positive core of GS ≥ 7 with GPC &lt; 10%. Conclusions: Although mpMRI improve the diagnosis of clinically significant PCa, SPBx is provided of the best detection rate for PCa in men enrolled in AS protocols who underwent confirmatory biopsy

    Influence of dietary cardoon meal on growth performance and selected meat quality parameters of lambs, and the antioxidant potential of cardoon extract in ovine muscle homogenates

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    Fatty acids and oxidative stability were determined in meat from lambs fed a diet containing 15% dehydrated alfalfa (CON, n = 8) or cardoon meal (CMD, n = 7). Furthermore, the antioxidant activity of a phenolic-rich cardoon meal extract (1.32 GAE mg/ml) was examined in muscle homogenates (0, 0.5, 1, 5% v/w) subjected to iron/ascorbate-induced oxidation. Feeding CMD did not affect lamb performances and carcass traits but reduced (P < 0.05) the vaccenic and rumenic acids and increased stearic acid in muscle. Lipid oxidation was higher in raw meat from the CMD-fed lambs after 7 days of storage (P < 0.05). Feeding CMD did not affect the colour stability of raw meat and the oxidative stability of cooked meat and of muscle homogenates incubated with pro-oxidant catalysts. Adding 5% cardoon extract in muscle homogenates increased (+114.3%; P = 0.03) the total phenolic content and reduced (−77.6%; P < 0.01) lipid oxidation, demonstrating the antioxidant potential of compounds present in cardoon meal

    A novel direct activator of AMPK inhibits prostate cancer growth by blocking lipogenesis

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    5′AMP-activated kinase (AMPK) constitutes a hub for cellular metabolic and growth control, thus representing an ideal therapeutic target for prostate cancers (PCas) characterized by increased lipogenesis and activation of mTORC1 pathway. However, whether AMPK activation itself is sufficient to block cancer cell growth remains to be determined. A small molecule screening was performed and identified MT 63–78, a specific and potent direct AMPK activator. Here, we show that direct activation of AMPK inhibits PCa cell growth in androgen sensitive and castration resistant PCa (CRPC) models, induces mitotic arrest, and apoptosis. In vivo, AMPK activation is sufficient to reduce PCa growth, whereas the allelic loss of its catalytic subunits fosters PCa development. Importantly, despite mTORC1 blockade, the suppression of de novo lipogenesis is the underpinning mechanism responsible for AMPK-mediated PCa growth inhibition, suggesting AMPK as a therapeutic target especially for lipogenesis-driven PCas. Finally, we demonstrate that MT 63–78 enhances the growth inhibitory effect of AR signaling inhibitors MDV3100 and abiraterone. This study thus provides a rationale for their combined use in CRPC treatment

    Quality indices and sensory attributes of beef from steers offered grass silage and a concentrate supplemented with dried citrus pulp

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    peer-reviewedThis study investigated the quality composition, oxidative stability and sensory attributes of beef (longissimus thoracis, LT) from steers offered grass silage and a concentrate supplement in which barley was replaced by 40% and 80% (as-fed basis) of dried citrus pulp (DCP). Dietary treatment did not influence the antioxidant status (α-tocopherol and total phenolic contents) and activities of LT (radical scavenging activity, ferric reducing antioxidant power and iron chelating activity). Feeding DCP significantly increased the proportion of conjugated linoleic acids and polyunsaturated fatty acids in beef. Lipid and colour stability of fresh beef patties stored in modified atmosphere packs (MAP) were unaffected by dietary treatment but feeding 40% DCP reduced (P < .05) lipid oxidation in aerobically-stored cooked beef patties. Beef patties stored in MAP for up to 7 days were assessed by sensory panellists to be juicier for those fed 40% DCP compared to 0% and 80% DCP. Results indicated that substitution of barley with DCP improved the fatty acid profiles of beef without negatively influencing the eating quality of beef.Education, Audiovisual and Culture Executive Agenc
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