Effects of encapsulated (e) sodium tripolyphosphate (STP), sodium pyrophosphate (SPP) and various combinations of encapsulated and un-encapsulated (u) forms of these polyphosphates on lipid oxidation in the cooked ground beef during storage (0, 1, 7 d at 4 degrees C) were determined. pH, color, cooking loss (CL), thiobarbituric acid reactive substances (TBARS), lipid hydroperoxide (LPO) and soluble orthophosphate (OP) analysis were conducted. Study results indicated that STP increased pH, whereas SPP decreased pH compared to control (p<0.05). SPP was determined as the most effective polyphosphate type to inhibit lipid oxidation (p<0.05). In addition, the use of eSPP significantly reduced OP content compared to uSPP (p< 0.05). The lowest TBARS and LPO formation were determined in the groups produced with only eSPP or its combinations with uSPP or uSTP or eSTP (p<0.05). Since the group containing a combination of 0.25% eSTP and 0.25% eSPP was found to have lower CL than the other groups produced with only eSPP or its combinations with uSPP or uSTP, this group was suggested as the most appropriate group which can be used in ready to eat meat product processing by the meat industry.