Effect of diet and fat content on the functional properties of thawed beef

The effect of animal diet (pasture versus grain) and fat content (1, 15 and 25%) on the functional properties and quality of beef stored for 8 months at -20 °C was determined. After storage, pasture-finished beef had significantly (P<0.001) less malondialdehyde than grain-finished. Grain-finished beef had a more vivid red colour than pasture-finished (P<0.01). The remaining functional properties determined in this study were not affected by diet. Protein solubility, emulsion activity index, and cooked batter torsion strain decreased and hue angle increased with increasing fat content. The solubility of total and sarcoplasmic proteins and cooked batter torsion stress and strain decreased (P<0.001) and hue angle increased (P<0.001) with storage time regardless of diet and fat content. It is concluded that there is not much difference in the functional properties of beef finished on pasture or grain. However, pasture-finished beef is more stable to lipid oxidation than the grain-finished, and hence may be more amenable to further processing.