The objectives were to investigate the ability of a two-factor central composite rotatable design (CCRD), using cooking temperature (CT) and endpoint temperature (ET) as independent variables, to predict selected chemical, physical and sensory meat quality characteristics considered important by the industry, researcher and consumer alike. Response surface analysis (RSA) was used simultaneously to evaluate the nature of the responses obtained, with 13 CT-ET combinations for the various species being evaluated. A contour plot-response surface graphics program ("SURCON") was developed at Oregon State University during this research and applied to the evaluation of the data. Evaluation of the nature of the response surfaces formed a major part of the thesis. Fresh pork loin roasts, frozen lamb loin roasts, turkey halves (breast and thigh meat), and control (conventionally processed) and treated (prerigor, pressurized) semitendinous beef blocks were used for heat treatments. For pork, the dependent variables of heating rate (°C/min); evaporation loss (%); cooking time (min); total moisture (%); total nitrogen and "remaining" protein fraction (dry weight basis); chromaticity coordinate, z; and sensory panel juiciness, were significant and the CCRD was successful. For lamb, the dependent variables of heating rates (°C/g; °C/min); total cooking, drip and evaporation loss (%); cooking time (min); total moisture (%); expressible moisture index; total nitrogen (wet weight basis); chromaticity coordinate, x and z; saturation index and sensory panel doneness and color were significant. For turkeys, the dependent variables of heating rates (°C/g, °C/min, °C/g/min), total cooking and evaporation loss (%), cooking time (min), total nitrogen, low ionic strength and "remaining" protein fraction (dry weight basis) and non-protein nitrogen extract (wet weight basis), and sensory panel thigh juiciness were significant and the CCRD was successful in its ability to predict significant dependent variables. The CCRD and RSA of pre-rigor pressurized beef beef were affected differently by CT-ET combinations than control processed beef. / Graduation date: 1985

No description available.

No description available.

Three experiments, two with pigs and one with Atlantic salmon, (<I>Salmo salar</I>) were carried out to investigate the effects of dietary supplementation with α-tocopheryl acetate (ATA) on quality of pig and salmon tissues. In Experiment 1, 32 pigs were individually fed either of two dietary fat sources: 0.5:0.5 <I>w/w</I> coconut oil/lard (59 g/kg finisher diet) or rapeseed oil (100 g/kg finisher diet) (as contained in full-fat rapeseed {FFR}), with or without supplementary ATA at 200 mg/kg diet. In Experiment 2, 24 pigs were individually fed either a diet which contained mixtures of vegetable oil (59 g/kg diet) (having a high level of palm oil) or rapeseed oil diet as in Experiment 1. The rapeseed oil diets were supplemented with 0, 200 and 500 mg ATA/kg diet. In Experiment 3, a commercial diet with high lipid content (290 g/kg diet) and 250 mg ATA/kg diet was supplemented with 0, 400 and 700 mg ATA/kg diet. Diets were fed to 54 salmon. Tissue samples were stored at 4°C and/or -20°C for different periods. Spectral data on tissue samples were collected with an NIRSystems 6500 scanning monochromator. Salmon and pig tissues, and pig muscle subcellular fractions (microsomal and mitochondrial) were analysed for fatty acid composition, α-tocopherol (AT) content and oxidative stability (by thiobarbituric acid test). In both pigs and salmon, muscle drip loss was measured, and the colour score and carotenoid content of salmon fillets were determined. Data presented in this study indicate that pig tissues respond positively to increased dietary supply of unsaturated fatty acids (UFA). Pig tissue UFA and n-3 fatty acid contents were increased, and n-6/n-3 fatty acid ratio was decreased by feeding diets containing FFR. There was only a slight influence of dietary fatty acids on fatty acid composition of the subcellular membranes. AT concentration was higher in the mitochondrial fraction than the microsomal fraction. The mitochondrial fraction lipids had a higher content of UFA than those of the mcirosomal fraction. Supplemental dietary ATA increased the AT content of both pig and salmon tissues.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript. / Digitized by Kansas Correctional Industries

No description available.

No description available.

Thesis (Ph.D. Physiology)) -- University of Limpopo, 1995 / Refer to document