Inhibition of Campylobacter jejuni on fresh chicken breasts by kappa-carrageenan/chitosan-based coatings containing allyl isothiocyanate or deodorized oriental mustard extract

摘要

Campylobacter species are common bacterial pathogens associated with human gastroenteritis worldwide. The objectives of this study were to determine the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of ally! isothiocyanate (AITC) against 4 Campylobacter jejuni strains in Mueller-Hinton (MH) broth at 4, 21, 37 and 42 degrees C and to screen the C. jejuni strains for their ability to degrade sinigrin (which forms AITC) in pH 7.0 MH broth at 35 degrees C for 21 d. Also evaluated was the antimicrobial activity of an edible 0.2% kappa-carrageenan/2% chitosan-based coating containing AITC or deodorized oriental mustard extract against a 4 strain C. jejuni cocktail (6.2 log(10) CFU/g) on vacuum-packaged fresh chicken breasts during 4 degrees C storage. MIC values of AITC were 0.63 to 1.25 ppm and 2.5 to 5 ppm against tested strains at 37 and 42 degrees C, respectively. However, the MBC was 2.5 and 5 ppm at 37 and 42 degrees C, respectively, and increased to a range of 40 to 160 ppm at 4 degrees C. kappa-Carrageenan/chitosan-based coatings containing 50 or 100 mu l/g AITC reduced viable C. jejuni to undetectable levels on chicken breast after 5 d at 4 degrees C, while 25 mu l/g AITC or 200 to 300 mg/g mustard extract in coatings reduced C. jejuni numbers by 1.75 to 2.78 log(10) CFU/g more than control coatings without antimicrobial. Both oriental mustard extract (50 to 300 mg/g) and AITC (>= 25 mu l/g) reduced aerobic bacteria by 1.72 to 2.75 log(10) CFU/g and lactic acid bacteria (LAB) by 0.94 to 336 log(10) CFU/g by 21 d compared to the control coating. kappa-Carrageenan/chitosan coatings containing 50 mu l/g AITC or >= 300 mg/g oriental mustard showed excellent potential to control C jejuni viability on raw chicken