We studied the effectiveness of partial replacement of glycerol with citric, lactic, malic, and tartaric
acids on the antimicrobial activities of nisin (205 IU/g protein)-incorporated soy protein film against Listeria
monocytogenes, Escherichia coli O157:H7, and Salmonella gaminara. S. gaminara inoculated into 2.6% malic
acid–incorporated films and lactic acid–incorporated films with nisin (5.7 and 3.4 log number colony-forming
units (CFU)/mL, respectively) and without nisin (3.2 and 3.0 log number CFU/mL, respectively) had fewer
survivors than HCl-incorporated film with and without nisin (8.6 and 7.9 log number CFU/mL, respectively).
Malic acid (2.6%)–incorporated soy protein film had the fewest survivors of L. monocytogenes, S. gaminara, and
E. coli O157:H7 (5.5, 3.0, and 6.8 log number CFU/mL, respectively) and has the potential to inhibit a wide
spectrum of microbes in product application.