Ractopamine hydrochloride and immunological castration in pigs. Part 1: fresh belly characteristics for bacon processing and quality

Abstract The effects of ractopamine and immunological castration on belly characteristics, processing yield, physicochemical and sensory quality of bacon were investigated from two crossbred pigs under different conditions of animal production, diet, management and slaughter arranged in factorial design using 2 ractopamine levels (0 and 7.5 ppm) and 3 genders (barrows, immunocastrated and gilts). Before processing, belly firmness, weight, length, width and thickness were measured, and then, bacon processing yield evaluated. After processing, bacon slices were digitally imaged and analyzed for lean meat and fat areas, pH, instrumental color of meat and fat, cooking loss and sensory quality. The ractopamine did not alter belly characteristics, but significantly increased the process yield and decreased cooking loss. Barrows and immunocastrated pigs showed firmer bellies, which could be advantageous for bacon processing and slicing. Barrows presented the highest total area of bacon slices. The results of this study indicate that both techniques ractopamine in the finishing diets and immunocastration of pigs can be combined with no further consequences for belly processing and to bacon quality and with some advantages

Temperature and concentration dependence of density of model liquid foods

Density of binary solutions and combinations of sucrose, glucose, fructose, citric acid, malic acid, pectin, and inorganic salts were measured with an oscillating tube density meter in the temperature range from 10degrees to 60degreesC, at varying concentrations. Density can be predicted with accuracy better than 5 x 10(-5) g cm(-3) using predictive equations obtained by fitting the experimental data. Available literature values agreed well with experimental data. Relations for the excess molar volume of these solutions were derived in terms of mole fraction and temperature. A thermodynamic model for the volumetric analysis of multicomponent aqueous solutions containing electrolyte and non-electrolyte compounds was also proposed. These models can be used for prediction of density of liquid food systems, specially fruit juices and beverages, based on composition and temperature, with high accuracy and without elaborate experimental work

Temperature and concentration dependence of heat capacity of model aqueous solutions

Heat capacities of binary aqueous solutions of different concentrations of sucrose, glucose, fructose, citric acid, malic acid, and inorganic salts were measured with a differential scanning calorimeter in the temperature range from 5degreesC to 65degreesC. Heat capacity increased with increasing water content and increasing temperature. At low concentrations, heat capacity approached that of pure water, with a less pronounced effect of temperature, and similar abnormal behavior of pure water with a minimum around 30degreesC-40degreesC. Literature data, when available agreed relatively well with experimental values. A correction factor, based on the assumption of chemical equilibrium between liquid and gas phase in the Differential Scanning Calorimeter, was proposed to correct for the water evaporation due to temperature rise. Experimental data were fitted to predictive models. Excess molar heat capacity was calculated using the Redlich-Kister equation to represent the deviation from the additive ideal model

Physicochemical and rheological properties of aqueous Tara gum solutions

Commercial Tara gum from three sources was purified by precipitation with isopropanol and evaluated on the structural, physicochemical and rheological properties. FT–IR and NMR techniques were used to determine the molecule structure and monosaccharide composition of Tara gum. The physicochemical properties were determined by intrinsic viscosity measurement using capillary viscosimetry and the rheological properties were determined by rotational viscosimetry. The monosaccharide composition of Tara gum galactomannans showed strong influence of their origin, with a mannose/galactose (Man/Gal) ratio varying between 1.54 and 1.85. Intrinsic viscosity of Tara gum in aqueous solution was influenced by its origin and temperature, and it was well correlated to the sigmoidal model. Hydrochloric acid was found to influence intrinsic viscosity below pH 2, however, combined with temperature treatment (80 ∘C), this limit was increased to pH 4. The rheological behavior at diluted concentrations resulted in shear thickening fluid, with an exponential increase of the consistency coefficient with concentration. Apparent viscosity of semi-diluted and concentrated Tara gum aqueous solutions were modeled by the Cross equation, where zero shear viscosity was influenced by gum concentration and temperature, with different activation energies.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Department of Food Engineering and Technology São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact SciencesDepartment of Food Engineering and Technology São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact SciencesFAPESP: 2017/02808-6CAPES: 88882.195683/2018-0

Effects of ractopamine hydrochloride and immunological castration in pigs. Part 2: belly quality characteristics and fatty acid composition

Abstract The effects of immunocastration and ractopamine in the diet on the belly quality were investigated from two crossbred pigs under different conditions of production, diet, management, and slaughter arranged in factorial design using two levels of addition of ractopamine in the diet, 0 and 7.5 ppm, and three genders (gilts, immunocastrated and barrows). The quality of bellies were analyzed for chemical composition, pH, meat and fat color, backfat thickness and fatty acid profile of the fat. The addition of ractopamine showed no significant influence on pH, color and chemical composition in two crossbred pigs. The immunocastrated had thicker belly backfat compared to the bellies of the gilts. The contents of fatty acids polyunsaturated, linoleic, linoleic, arachidonic, total omega 3 and omega 6 were higher for immunocastrated pigs, as well as presenting values greater than 0.4 for the PUFA:SFA ratio, thus, providing bellies with better nutritional quality. The bellies of the gilts and immunocastrated pigs had higher concentrations of iodine value, indicative of higher unsaturated fat content. The results indicated that the addition of ractopamine and immunocastration had little influence on the quality of bellies as well as in their fatty acid profiles, suggesting the continuity of implementation of these techniques