Abstract Glycerin is an organic compound with an alcoholic function and can be esterified into fatty acids to form triglycerides. Due to the increasing availability of glycerin, studies that determine the best level of its inclusion in diets for ruminants are needed. This study evaluated the effects of glycerin supplementation on the proximate composition and fatty acid profile of the longissimus lumborum of heifers fed on Brachiaria brizantha pasture. Thirty-six heifers were distributed in a totally randomized design with four treatments (G0.0 = without glycerin, G4.6 = 4.6% glycerin, G9.3 = 9.3% glycerin and G14.3 = 14.3% glycerin). The addition of glycerin decreased the tetradecanoic and octadecanoic fatty acids but increased the pentadecanoic, heptadecanoic, heptadecenoic, eicosanoic, eicosatetraenoic and docosatetraenoic fatty acids. The saturated (SFA), monounsaturated (MUFA) and omega-3 (n-3) fatty acid concentrations were similar across the diets. However, the polyunsaturated (PUFA) concentrations and the PUFA:MUFA and n-6:n-3 ratios increased with the inclusion of glycerin in the diet. Glycerin levels up to 14.3% (corresponding to a substitution of 50.5% of corn for this byproduct as an energy source) did not alter the proximate composition of the meat but improved the fatty acid profile of the longissimus lumborum muscle and, consequently, increased the meat quality, potentially providing benefits for human health.

Resumen La glicerina es un compuesto orgánico con una función alcohólica que puede esterificarse en ácidos grasos para formar triglicéridos. Debido a su disponibilidad cada vez mayor, se necesitan estudios que indiquen el mejor nivel de inclusión en las dietas para los rumiantes. Este estudio evaluó los efectos de la glicerina sobre la composición próxima y el perfil de ácidos grasos de Longissimus lumborum de novillas suplementadas con pasto de Brachiaria brizantha. Se distribuyeron 36 vaquillas en un diseño totalmente aleatorizado con cuatro tratamientos (G0.0 = sin glicerina, G4.6 = 4,6% de glicerina, G9.3 = 9.3% de glicerina y G14.3 = 14.3% de glicerina). La adición de glicerina disminuyó los ácidos grasos tetradecanoico y octadecanoico, pero aumentó los ácidos grasos pentadecanoico, heptadecanoico, heptadecenoico, eicosanoico, eicosatetraenoico y docosatetraenoico. Las concentraciones de ácidos grasos saturados (SFA), monoinsaturados (MUFA) y omega-3 (n-3) fueron similares en todas las dietas. Sin embargo, las concentraciones de poliinsaturados (PUFA) y los niveles de PUFA: MUFA y n-6: n-3 aumentaron con la inclusión de glicerina en las dietas. Los niveles de glicerina hasta 14.3% (que corresponden a una sustitución del 50.5% de maíz por este subproducto como fuente de energía) no alteraron la composición proximal de la carne pero mejoraron el perfil de ácidos grasos del músculo Longissimus lumborum y, en consecuencia, aumentaron la carne calidad, potencialmente proporcionando beneficios para la salud humana.

The objective of this study was to evaluate the centesimal composition and fatty acids in meat from animals fed diets containing levels of soybean hulls. The experiment was conducted at UESB in Itapetinga-BA, Brazil. Twenty-five confined Santa Inês rams were used. Treatments consisted of different levels of substitution of corn by soybean hulls (0, 25, 50, 75 and 100%) and elephant grass silage as forage. The design was completely randomized. Samples of concentrate and silage were collected to evaluate the fatty acid composition. The experimental period lasted 110 days. After this period, the animals were slaughtered and samples of the longissimus muscle were collected and vacuum-packed for further analysis. The levels of total lipid and protein showed quadratic effect with the increase of soybean hulls in the diet, as the moisture increased linearly with inclusion. There was no effect of treatments on the percentage of ash. The composition of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), PUFA/SFA and omega 6 (n-6) did not change, but increases in n-3 and reduction in the n-6:n-3 ratio were observed when the the amount of soybean hulls in the diet increased. The content of fatty acid conjugated linoleic acid (CLA) ranged from 3.0 to 4.0 g/kg at levels of substitution. The inclusion of soybean hulls in the diet increased CLA, the n-3 and decreased the n-6:n-3 ratio.

Chemical investigation of the leaves of Solanum sordidum Sendtn., Solanaceae, resulted in the isolation and identification of sitosterol, stigmasterol, 3β-O-β-glycopyranosyl stigmasterol, 3β-O-β-glycopyranosyl sitosterol, kaempferol-3-O-α-rhamnopyranosyl-(1-6)-α-glycopyranoside, rutin, and N-trans-feruloyltyramine. The structures of these compounds were established by analysis of 1D and 2D NMR spectrometric data and comparison with data in the literature. The evaluation of antioxidant activity showed an IC50 of 159.5 ppm for the chloroformic fraction and IC50 of 77.5 ppm for the hydromethanolic fraction.