Effect of radio-frequency on heating characteristics of beef homogenate blends

The heating characteristics of different lean-to-fat ratios in ground beef (90/10, 85/15, 80/20, 73/27) was investigated using radio-frequency (RF) heating of ground beef homogenates. A homogenate model system was prepared with ground beef in phosphate buffer (pH 6.0). Homogenate blends were packaged in vacuum bags, immersed in pre-heated water at 10, 25 and 50 °C, and heated in the RF equipment to a target temperature of 60 °C. Beef homogenate blends with more lean and less fat (90/10 and 85/15) heated more rapidly, reaching the target temperature faster than the higher fat composition blends. The RF heating rates of the beef homogenate blends varied with water temperature; higher temperature resulted in rapid RF heating. The RF heating rate at 50 °C was the most rapid in heating all homogenate blends. The instrumental color characteristics for RF heated homogenate blends exhibited lower L* and a* values than uncooked homogenate blends. RF heating resulted in reduced redness and more oxidation of myoglobin (metmyoglobin formation) and lesser oxy- and deoxy-myoglobin redox forms in all beef homogenate blends independent of the initial water temperature. The results present scope to explore short time heating processes which will minimize quality deterioration in RF heated meat products.