Abstract

Single acid (acetic acid, lactic acid, propionic acid and phosphoric acid) and acid complex solutions at the ratio 1:1 or 2:1 at pH 3 were investigated their antimicrobial activities against three selected foodborne pathogens (Escherichia coli, Salmonella typhi and Staphylococcus aureus). The influences of the deacetylation degrees (DD) (80% and 95%), concentrations (500, 1000, and 2000 μg/mL) and contact time (10, 20, 30, 40, 50 and 60 min) on the antimicrobial activity of chitosan against three bacteria were also studied. The better condition of chitosan and acid complex solutions were selected to use as sanitizers sprayed on the broiler carcass surfaces (breast and thigh) to determined their antimicrobial activities. The results showed that acid complex solutions with the ratio 2:1 had the better inhibiting efficiency against pathogens than the single acid and acid complex solutions at the ratio 1:1. The antimicrobial activity of chitosan against bacteria significantly increased as the contact time and chitosan concentrations increased. Acetic acid＋lactic acid or acetic acid＋propionic acid (2:1) were dissolved with/without chitosan solution (1000 μg/mL with DD 95 %) and sprayed on the broiler carcass surfaces against pathogens. The results displayed that acetic acid + lactic acid sprayed with chitosan significantly reduced S. aureus, E. coli and S. typhi counts on the surface of the breast (2.73, 2.84 and 2.71 log CFU/cm2, respectively) and the thigh (2.56, 2.85and 2.43 log CFU/cm2, respectively). Conclusion, acid complex solutions mixed with chitosan can be used to avoid the deterioration of slaughtered meat quality.

Key words: Foodborne pathogens, chitosan, organic acid, sanitizer, broiler carcass.