ABSTRACTBeef infraspinatus roasts were used to determine the effects of phosphate injection and acetic acid treatment on precooked microwave‐reheated beef roasts. Treatments consisted of roasts pumped 10% of their weight with water, water containing 4.75% tripolyphosphate, water containing 4.75% tripolyphosphate and 10% NaCl, and roasts with no added water. After cooking, roasts were halved, and one half of each roast was dipped in 3% acetic acid before vacuum‐packaged, refrigerated storage. Results showed roasts that contained both salt and phosphate had the lowest cooking losses, TBA numbers, Warner‐Bratzler Shear values, and were rated by sensory panelists as the most palatable. Treatment with acetic acid significantly (P<0.05) lowered bacterial counts without adversely affecting sensory qualities of the precooked microwave‐reheated beef