Cooked Product Temperature and Curing Ingredients Affect Properties of Irradiated Frankfurters

Frankfurters (9.07-kg batches) were conventionally made in which three replications of the following treatment combinations were used (a) curing ingredients: 0 or 50 ppm of sodium nitrite, 75 ppm of sodium nitrite-25 ppm of sodium nitrate, or 50 ppm of sodium nitrite-25 ppm of sodium nitrate, (b) seasoning: dry soluble or equivalent ground spice, (c) cooked product temperatures of 65.5 or 76.6 C and (d) radiation processing levels of either 0, 0.8 or 3.2 megarads. Regardless of curing ingredient combinations or levels of irradiation, lowering internal cooked product temperatures (65.5 vs. 76.6 C) improved internal color, off-odor, off-flavor, moistness and overall desirability scores of frankfurters. Use of a dry soluble seasoning in comparison to an equivalent natural ground spice seasoning had no effect on sensory, chemical or palatability traits of irradiated frankfurters. Although not significant, frankfurters made without nitrite (0-NO₂₎ compared to those made with 75 NO₂-25 NO_3, had greater process shrinkage values and were significantly less desirable in visual color, off-flavor and overall palatability. External and internal color scores of frankfurters made with NO₂ and NO₃ combinations were less intensely pink, with an increase in irradiation from 0 to 0.8 to 3.2 megarads. Sensory traits (off-flavor, off-odor, texture and overall palatability) were less desirable in those frankfurters irradiated at 3.2 megarads as compared to those irradiated at 0.8 megarads. Both levels of irradiation produced less desirable frankfurters than the non-irradiated controls (0 megarads). Improvements in sensory properties of irradiated frankfurters may be accomplished by use of at least 50 ppm of NO₂ and cooking to a final internal product temperature of 65.5 C.