This study investigated the effect of mixing and grinding, tempering, addition of sodium chloride and sodium tripolyphosphate and processing under a nitrogen atmosphere on the color of restructured beef steaks initially and at I-month intervals for 3 months of frozen storage. Mixing and grinding and manufacture under a nitrogen atmosphere had the greatest detrimental effect on the extent of discoloration initially; this was probably due to low oxygen concentration. Tempering and the addition of sodium chloride without sodium tripolyphosphate produced the most rapid increase in rate of discoloration during frozen storage. Tripolyphosphate partially counteracted the detrimental effect of sodium chloride, however, this effect did not appear to be due to the higher pH produced by the phosphate or the chelating ability of the phosphate. Surface discoloration and overall color were highly correlated with surface metmyoglobin (r= -0.87) and overall metmyoglobin (r= -0.94).

Ten muscles and muscle groups were excised from each of eight typical (average yield grade 2.99) and eight lean (average yield grade 1.73) steer carcasses and analyzed to determine differences between carcass types. Lean carcasses (raw basis) were higher (PcO.05) in moisture and protein and lower (PcO.05) in fat, cholesterol and calories in comparison to typical carcasses. Typical carcasses (cooked basis) were higher (PcO.05) in fat and caloric content than lean carcasses. No differences (P>O.O5) were found between carcass types (cooked basis) for moisture, protein, cholesterol, dry matter cholesterol, cooking loss or shear force value. Semitendinosus muscles from typical carcasses were rated higher (PcO.05) for juiciness and tenderness than from lean carcasses. Differences (PcO.05) were found among muscles for all traits measured.

Effects of isolated soy protein (ISP), frozen, textured isolated soy protein (FTISP), soybean oil (SO), and hydrogenated soybean oil (HSO) addition on chemical, color, sensory, and microbial stability of lean (>90%) ground beef patties (LGBP) were evaluated. Soy oil was incorporated as an emulsion (SE). Nine treatments, including two all beef controls (20 and 10% fat), were formulated to contain combinations of SE, HSO and FTISP. Sensory panelists found LGBP with 25% FTISP (10% fat from beef) to have as intense beef flavor (P>0.05) as all beef controls. Lipid oxidation and pigment discoloration rates were slowed by fat adjustment to 10% with SO and/or HSO. Soy had no effect (P>0.05) on microbial stability.

Low-fat pattics containing water, carrageenan, encapsulated salt and hydrolyzed vegetable protein (carrageenan-based pattics) with 0, 1, 2 or 3% potassium lactate were compared to low-fat all-beef patties with no additives. Carragcenan-based patties had enhanced (PcO.05) scnsory properties (juiciness, tenderness, mealiness and beef flavor intcnsity) compared to all-beef patties. The bacterial populations of lowfat, carragcenan-based patties did not differ (PcO.05) from low-fat all-beef patties. Bacterial growth in low-fat, carrageenan-based patties was reduced through the use of 2 or 3% potassium lactate with no dclctcrious effects on the sensory properties of the low-fat, ground beef. However, low-fat, carrageenan-based patties underwent greater (PcO.5) discoloration and lipid oxidation during aerobic refrigerated storage than all-beef patties.