The activity of free and liposome-encapsulated pediocin AcH was monitored in slurries (25% in dH2O) of beef tallow and beef muscle. Significant loss of pediocin AcH activity was observed within 1.5 min [24-60% recovery of original arbitrary units (AU)] following the addition of 30,000 AU of pediocin per ml slurry. Pediocin activity continued to decrease up to 35 min (14-40% recovery of original AU), but thereafter, pediocin activity did not decrease appreciably. More activity was recovered from tallow-than muscle-based slurries and from heated (100°C, 3 min) slurries compared to unheated slurries. Also, the addition of pediocin AcH to slurries (10,000 AU increments) identified saturation levels of ca. 80,000-90,000 AU for tallow compared to ca. 100,000 AU for muscle. Lastly, the encapsulation of pediocin AcH within phosphatidylcholine liposomes resulted in a 27.5% (heated muscle) and 28.9% (heated tallow) increase in the recovery of pediocin activity compared to otherwise similar slurries containing free pediocin.