65 research outputs found

    Effect of chestnut and quebracho tannins on fatty acid profile in rumen liquid- and solid-associated bacteria: an in vitro study

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    Tannins are phenolic compounds that interfere with biohydrogenation (BH) of polyunsaturated fatty acids (FAs). The aim of the present in vitro study was to investigate the effects of two different sources of tannins on FA profiles of rumen bacteria, with particular reference to rumenic and vaccenic acid. A control diet (C; composed of 300 g/kg of wheat straw, 132 g/kg of soyabean meal, 96 g/kg of barley meal, 152 g/kg of maize meal, 300 g/kg of maize gluten and 20 g/kg of mineral vitamin premix, all expressed on dry matter (DM)) and four diets, obtained by adding to C two different types of tannins from chestnut (TC) and from quebracho (TQ) at two concentration levels (49 and 82 g/kg DM), were compared. The content of the main unsaturated FAs (C18:1 cis9, C18:1 trans11, C18:2 cis9, cis12 and C18:3 cis9, cis12, cis15) from solid-associated bacteria (SAB) and liquid-associated bacteria (LAB) was affected by the presence of tannins in the diets. In particular, C18:1 trans11 content was significantly increased, especially with TC1, whereas the decreasing of C18:1 cis9 was unaffected, regardless of the presence or the kind of tannins added to feeds. SAB contained higher amounts of intermediates of polyunsaturated FA BH (as C18:1 trans11 and C18:2 cis9, trans11) than LAB that were characterized by a higher amount of C18:0. In the concentration range adopted in this study, the effect of TC and TQ on changes of bacterial FA profile was comparable. Tannins seem to be a good means to modulate the FA profile of rumen bacteria, favouring the accumulation of C18:1 trans11 during in vitro rumen fermentation

    Monobutyrine: a novel feed additive in the diet of broiler chickens

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    Purpose of the present work was to validate the monoglyceride of butyric acid (MB) as an alternative to antibiotics as growth promoters in the diet of broiler chickens. The approach is a kind of prolongation of previous works, in which a blend of mono-, di- and tri-glycerides of butyric acid have been previously tested. The results indicated that MB was very efficient in limiting the mortality of birds challenged with Eimeria spp., but did not appreciably impair the performance of unchallenged birds. In conclusion, the metabolisable energy content of MB appeared comparable with that of soybean oil and MB a reliable coccidiostat

    Influence of milk quality and cheese-making procedure on functional fatty acid transfer in three Italian dairy products: Mozzarella, Raveggiolo and Ricotta

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    Cheese quality traits are affected firstly by milk quality and secondly by processing protocols. The cheese-making procedure plays an important role in the transfer of functional fat components from milk to cheese with important implications on the nutritive value of dairy products. To evaluate the influence of the cheese-making procedure, three fresh Italian cheeses from the same milk bulk, Mozzarella, Raveggiolo and Ricotta were processed and analyzed in terms of fatty acid transfer from milk to dairy products. The fatty acids were transferred with several differences. In particular, C14:0 (P = 0.0011) and C14:1 (P = 0.0007) showed the highest value in Raveggiolo while C16:0 was higher in Raveggiolo and Ricotta (P = 0.0002). Trans-monoene fatty acids have a detrimental effect on human health, however trans C18:1 isomers, from 6 to 10, and trans12 showed no significant differences in transfer from milk to dairy products. In contrast, vaccenic and linoleic acids, which are beneficial fatty acids for human health, were recovered in higher percentages in Raveggiolo than in Mozzarella and Ricotta (P = 0.0188 and P < 0.0001, respectively). The recovery of oleic acid, an antiatherogenic fatty acid, was higher in Ricotta (P < 0.0001). No effect on conjugated linoleic acid was found

    Effect of three species of herbage (Medicago sativa, Lolium multiflorum, Avena sativa) on in vitro ruminal production of conjugated linoleic and vaccenic acids

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    Little information is available about the effect of different forage species on the rumen biohydrogenation process. The aim of the present work is to compare the in vitro production of CLA and C18:1 isomers after incubation of three different herbage species in rumen liquor from sheep. Pasture herbage samples of lucerne (Medicago sativa; MS), ryegrass (Lolium multiflorum; LM) and oats (Avena sativa; AS) were submitted to in vitro fermentation with sheep rumen inoculum. Samples were collected at 2, 4, 6 and 8 hours of fermentation. The fatty acid profile of MS was characterised by 11.62 (g/100 g of lipid extract) of linoleic acid (LA) and 27.08 (g/100 g of lipid extract) of α-linolenic acid (LNA), whereas LA in the other two herbages was 6.60 (g/100 g of lipid extract) and 6.95 (g/100 g of lipid extract) in AS and LM, respectively; LNA was 52.20 (g/100 g of lipid extract) and 54.49 (g/100 g of lipid extract) in AS and LM, respectively. The crude fat content of botanical species was respectively 11.90 (g/100g DM) for AS, and 15.77 (g/100g DM) for LM and 26.17 (g/100g DM) for MS. Rumenic acid (RA, cis-9, trans-11 CLA) was the predominant CLA isomer and the maximum yield was attained with AS after 6 hours of fermentation (0.81 g/100 g of lipid extract); RA concentration remained quite low with the other two herbages. The concentration of the other isomer (trans-10, cis-12 CLA) was always very low; the maximum yield (0.09 g/100 g of lipid extract) was reached after 6 hours with AS. The maximum yield of vaccenic acid (VA, trans-11 C18:1) was reached after 8 hours with MS (2.64 g/100 g of lipid extract). This herbage also produced the highest amount of trans-10 C18:1 at 6 and 8 hours (0.17 g/100 g of lipid extract). AS appeared to have induced the highest amounts of RA relative to the other two forages. The differences in conjugated dienes and C18:1 isomers content during fermentation could be due not only to different amounts of LA or LNA in the herbage, but also to different releasing times of FA from the plant substrate

    Effect of Quebracho tannin extract on soybean and linseed oil biohydrogenation by solid associated bacteria: an in vitro study

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    An in vitro trial was carried out to study the effects of Quebracho tannins extract (QE) on fatty acid profile of rumen solid adherent bac- teria (SAB) during the fermentation of diets supplemented with soybean or linseed oil, as sources of linoleic (LA; 18:2 n-6) and α- linolenic acid (α-LNA; 18:3 n-3), respectively. Two control diets were prepared using a basal mixture of grass hay [760 g/kg on dry matter (DM)], soybean meal (55 g/kg DM), barley meal (130 g/kg DM), vitamin mineral premix (20 g/kg DM) and 35 g/kg DM of soybean (SOC diet) or linseed oil (LOC diet) as lipid supple- ment. Other two diets (SOCT and LOCT) were obtained by integrating SOC and LOC with QE (49 g/kg DM). The results confirmed that Quebracho tannins may be an effective method for reducing in SAB the biohydrogena- tion of LA (17.3 vs 34.5 g/100 g of fatty acid in SOC and SOCT, respectively) and LNA (10.7 vs 21.4 g/100 g of fatty acid in LOC and LOCT, respectively), but not for increasing the rumen accumulation of cis9, trans11 18:2 (0.77 vs 0.32 g/100 g of fatty acid in SOC and SOCT, respec- tively; 0.51 vs 0.43 g/100 g of fatty acid in LOC and LOCT, respectively) and trans11 18:1 (6.15 vs 3.64 g/100 g of fatty acid in SOC and SOCT, respectively; 5.53 vs 4.47 g/100 g of fatty acid in LOC and LOCT, respectively)

    . Nutritional characteristics and quality of eggs from laying hens fed on a diet supplemented with chestnut tannin extract (Castanea sativa Miller)

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    1. The trial was performed with 80 laying hens belonging to two Tuscan autochthonous breeds: 40 birds of the Mugellese breed (MU) and 40 of the White Leghorn breed (WL). 2. The animals were allotted to 4 groups of 20 hens each: two groups were fed on a commercial diet and worked as the control groups (MUC and WLC); the other two groups received the same diet, integrated with 2 g of chestnut tannin extract per kg of diet (MUT and WLT). 3. A sample of 70 eggs were randomly collected and analysed for cholesterol content, fatty acid profile, weight, thickness of shell and colour of yolk. 4. Physical parameters, including yolk colour, and indices of egg quality were not affected by the treatments. 5. The concentration of unsaturated fatty acids increased whereas cholesterol was significantly decreased: -17% in WLT and -9% in MUT. Dietary supplementation with chestnut tannin extract resulted in a modification of lipid composition, toward a more healthy quality of eggs

    Changes in conjugated linoleic acid and C18:1 isomers profile during the ripening of Pecorino Toscano cheese produced with raw milk

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    The aim of the present study was to investigate the evolution of the fatty acid profile, with particular attention to conjugated linoleic acid (CLA) and to C18:1 isomers, during ripening of sheep cheese (Pecorino Toscano cheese) produced with raw milk. After 60 days of ripening the total concentration of C18:1 isomers and that of CLA pool content decreased. In particular, if isomers profile is considered, the percentage of trans11 C18:1, trans10 C18:1 and cis9, trans11 CLA decreased as consequence of biohydrogenation or of double bonds isomerisation, while the concentration of trans10, cis12 CLA increased

    Effect of chestnut tannin extract (Castanea sativa Miller) on the proliferation of Cladosporium cladosporioides on sheep cheese rind during the ripening

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    Strains belonging to the genus Cladosporium can cause black spots on the surface of sheep cheese, making it impossible to sell. Two water solutions of chestnut tannin extract (i) 200 g L-1 (CHE200) and (ii) 400 g L-1 (CHE400), and the chestnut tannin extract powder (CHEP) were tested in a cheese making trial in which 60 cheese units were allotted to 5 experimental groups (each of 12 cheeses: C1, control 1 without any treatment; C2, control 2 treated with a silver ion solution; and cheeses LCHE200, LCHE400, and LCHEP, treated with CHE200, CHE400, and CHEP, respectively). The cheeses were ripened in a room polluted with Cladosporium cladosporioides with the aim to create conditions for the proliferation of this fungus on the cheeses. The results indicated that chestnut tannin extract at a concentration of 200 g L-1 is capable of completely inhibiting C. cladosporioides proliferation, avoiding spoilage of the sheep cheese
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