Physico‐chemical composition,fractionated glycerides and fatty acid profile of chicken skin fat

Skin is one of the several co‐products of chicken meat industries, considered as waste, being rarely utilized or underutilized. Brazil is the world leader in chicken exports (3.6 million tons) and the third largest producer with 10.9 million tons, from which 440 000 ton/year are residues. This work aimes at characterizing chicken skin fat (CSF), comparing it with soybean oil, a well‐known and abundant compound, evaluating the physico‐chemical composition, fractionated glycerides and fatty acid profile, searching for CSF use in interesterification reactions. For that, determination of peroxide and p‐anisidine values, as well as thiobarbituric acid, iodine, saponification, acidity, unsaponified matter and refraction indexes were accomplished, besides the glycerides fractionation, followed by FAME derivatization and identification by GC. The nutritional quality indexes were calculated from the lipid profile. CSF showed satisfactory quality due to low acidity (0.65 g oleic acid/100 g), peroxide (2.14 meq/kg), p‐anisidine (0.70 absorbance units/g) values, besides presenting high proportion of MUFA (40%). However, due to CSF low hypocholesterolemic/hypercholesterolemic value (HH = 2.72), it may be difficult to use it for nutritional purposes the way it is found, once it tends to increase cholesterol. CSF it is a promising residue for different purposes including interesterification reactions and biodiesel production.     

Optimization of the ETBE (ethyl tert-butyl ether) production process

The synthesis of ETBE (ethyl tert-butyl ether) from the reaction of ethanol with isobutene is an exothermic reaction of equilibrium. To increase the conversion of isobutene requires operating the reaction system at low temperatures and with excess ethanol in order to displace the equilibrium towards the products. ETBE and ethanol form an azeotropic mixture which hinders the recycling of nonreacted ethanol in the process. The purpose of this work is to optimize the synthesis of ETBE eliminating the introduction of water into the system to break the ETBE/Ethanol azeotrope. The production process model proposed here eliminates the recycling of ethanol and suggests the use of the azeotropic mixture (ETBE/Ethanol) in the formulation of gasolines. The direct use of the azeotrope in the formulation of automotive gasolines reduces the implementation and production costs of ETBE.     

Analysis of volatile compounds in some typical Brazilian fruits and juices by SPME-GC method

This paper describes the analysis of volatile organic compounds (VOC) in typical Brazilian fruit and fruit juices by a solid-phase microextraction (SPME) method using a capillary gas chromatography system with flame ionization detection and mass spectrometry (GC-MS). A SPME holder with a 100-µm polydimethilsiloxane fibre coating was utilized. The optimal conditions were desorption at 220°C for 1 min, absorption at 50°C for 20 min and 4.00 ml of sample in the headspace vial. The method gave good precision and showed a linear response. More than 100 VOC were identified in the fruit and juices studied by GC-MS. The method was employed to quantify ethanol, naphthalene and benzoic acid in four different species of Brazilian fruit and their juices.     

Biohydrogenation intermediates are differentially deposited between polar and neutral intramuscular lipids of lambs

The deposition of C₁₈ fatty acids (FA), especially in rumen biohydrogenation intermediates, was studied using 36 lambs fed four diets with graded proportions of sunflower oil (SO) and linseed oil (LO). Lambs were fed one of four diets consisting on dehydrated lucerne with either: 6% SO, 4% SO plus 2% LO, 2% SO plus 4% LO and 6% LO. The profile of C₁₈ FA was greatly affected by replacement of SO with LO in both lipid fractions. In PL, oil replacement led to an extensive substitution of 18:2n‐6 with 18:3n‐3 and cis‐9 18:1, resulting in a fairly constant degree of unsaturation of C₁₈ FA in membrane PL. C₁₈ FA were differentially incorporated in NL and PL. Cis‐isomers like cis‐11; cis‐12; cis‐15 18:1 and cis‐12, cis‐15 18:2 were preferentially incorporated in PL with the exception of cis‐9, cis‐15 18:2. Trans C₁₈ FA, including CLA isomers, were preferentially incorporated in NL with the exception of cis‐11, trans‐13 18:2. The preferential deposition of biohydrogenation derived trans C₁₈ FA, including CLA isomers in NL, suggests that their potential to change membrane FA composition and structure is low.     

Use of calcitriol to maintain postpartum blood calcium and improve immune function in dairy cows

Our objectives were to determine the effects of an injectable formulation of calcitriol on mineral metabolism and immune function in postpartum Holstein cows that received an acidogenic diet prepartum to minimize hypocalcemia. In experiment 1, cows within 6 h of calving received calcitriol (0, 200, or 300 μg) to determine the dose needed to increase plasma concentrations of Ca; 300 μg was sufficient to sustain Ca for at least 3 d. In experiment 2, multiparous cows were assigned randomly to receive only vehicle (control, n = 25) or 300 μg of calcitriol (n = 25) subcutaneously within the first 6 h after calving. Blood was sampled before treatment and 12 h later, then daily until 15 d in milk (DIM), and analyzed for concentrations of ionized Ca (iCa), total Ca (tCa), total Mg (tMg), and total P (tP), metabolites, and hormones. Urine was sampled in the first 7 DIM and analyzed for concentrations of tCa, tMg, and creatinine. Neutrophil function was evaluated in the first week postpartum. Dry matter intake and production performance were evaluated for the first 36 DIM. Calcitriol administration increased concentrations of calcitriol in plasma within 12 h of application from 51 to 427 pg/mL, which returned to baseline within 5 d. Concentrations of iCa and tCa increased 24 h after treatment with calcitriol. Concentrations of iCa (control = 1.08 vs. calcitriol = 1.20 mM), tCa (control = 2.23 vs. calcitriol = 2.33 mM), and tP (control = 1.47 vs. calcitriol = 1.81 mM) remained elevated in cows treated with calcitriol until 3, 5, and 7 DIM, respectively, whereas concentration of tMg (control = 0.76 vs. calcitriol = 0.67 mM) was less in calcitriol cows than control cows until 3 DIM. Concentrations of parathyroid hormone decreased in calcitriol cows compared with control cows (control = 441 vs. calcitriol = 336 pg/mL). Calcitriol tended to increase plasma concentrations of β-hydroxybutyrate and serotonin, but concentrations of glucose, nonesterified fatty acids, and C-telopeptide of type I collagen in plasma did not differ between treatments. Cows treated with calcitriol excreted more urinary tCa (control = 0.5 vs. calcitriol = 2.1 g/d) and tMg (control = 4.5 vs. calcitriol = 5.0 g/d) in the first 7 and 2 DIM, respectively, than control cows. Compared with control, calcitriol improved the proportion of neutrophils with oxidative burst (control = 31.9 vs. calcitriol = 40.6%), mean fluorescence intensity for oxidative burst (control = 90,900 vs. calcitriol = 99,746), and mean fluorescence intensity for phagocytosis (control = 23,887 vs. calcitriol = 28,080). Dry matter intake, yields of milk, and milk components did not differ between treatments. Administration of 300 μg of calcitriol at calving was safe and effective in increasing blood concentration of iCa and plasma concentrations of calcitriol, tCa, and tP for the first 6 d after treatment, and improved measures of innate immune function in early-lactation Holstein cows.