The objective of this study was to evaluate the effects of sodium lactate/sodium tripolyphosphate pump combinations on the characteristics of pork loins. The product was manufactured to simulate fresh pumped pork loins currently available in the retail market. Paired fresh pork loins (longissimus muscle), pumped to contain 0, 1 or 2% sodium lactate (SL) and/or 0, 0·2 or 0·4% sodium tripolyphosphate (STP) were vacuum packaged and stored at 4°C for 28 days. In pork containing 0·4% STP, samples with 1 or 2% SL had lower pH values than those with 0% SL. Pork containing 1 or 2% SL generally had lower aerobic plate counts than those with 0% SL. Pork with 0·4% STP was darker (lower L* value) and redder (higher a* value) than that with 0 or 0·2% STP. When aerobic plate counts and color characteristics are used as the criteria, the optimum SL/STP combination for solutions used to pump fresh pork loins that are vacuum packaged and held under refrigeration was 1% SL with 0·2% STP.