Marinade with thyme and orange oils reduces Salmonella Enteritidis and Campylobacter coli on inoculated broiler breast fillets and whole wings

Abstract

Essential oils have been reported to possess antimicrobial properties and therefore have potential usage as natural antimicrobials in food. In a previous study, thyme orange essential oil combination (TOC) used at the 0.5% level as a dip application on chicken cut-up parts had a significant antibacterial effect against Salmonella and Campylobacter. A study was designed to evaluate the effect of salt-phosphate marinade solution containing 0.5% TOC to 1) reduce Salmonella Enteritidis and Campylobacter coli numbers on broiler breast fillets and whole wings marinated by vacuum tumbling, and 2) reduce cross-contamination of both pathogens between inoculated and uninoculated parts during marination. A total of 52 skinless breast fillets and 52 whole wings were used for the 2 replications. For each replication, each cut-up part was randomly assigned to 1 of 5 groups: treatment 1: uninoculated parts marinated without TOC; treatment 2: inoculated parts marinated without TOC; treatment 3: uninoculated parts marinated with TOC; treatment 4: inoculated parts marinated with TOC; and control: nonmarinated inoculated parts. Samples were dipped in an inoculum containing a mixture of Salmonella Enteritidis and C. coli. The treatment samples were marinated by vacuum tumbling. All samples were immediately evaluated to determine Salmonella Enteritidis and C. coli numbers. Results indicated that TOC at the 0.5% level in the marinade solution applied by vacuum tumbling significantly reduced (P < 0.05) numbers of viable Salmonella Enteritidis by 2.6 and 2.3 log cfu/mL on broiler breast fillets and C. coli by 3.6 and 3.1 log cfu/mL on whole wings. Cross-contamination was observed as the uninoculated chicken parts marinated with inoculated parts were positive. However, the number of bacterial cells recovered from the TOC treated samples were significantly lower (P < 0.05) than the numbers recovered from the untreated samples. Marination with a salt phosphate formulation containing 0.5% TOC successfully reduced Salmonella and Campylobacter numbers on poultry products.