Effect of Eugenol, Vanillin, and ß-Resorcylic Acid on Foodborne Pathogen Survival in Marinated Camel Meat.

The combined inhibitory effect of essential oils (EOs) with meat-based marinades has not been fully studied. Therefore, the present study aimed to gauge the effect of a yogurt-based marinade when individually combined with three EOs, namely eugenol (EU), vanillin (VA), or ß-resorcylic acid (BR) on camel meat cubes inoculated with Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7 during storage. Fresh camel meat cubes of 10 g were inoculated with bacteria and dipped in the mixture of marinade and EO. Overall, the study had six EO treatments (EU 0.5%, EU 1%, VA 0.5%, VA 1%, BR 0.5%, and BR 1%) and two controls (meat without marinade and marinated meat). Treated meat cubes were stored at 4°C or 10°C for 1, 4, and 7 d. Adding only marinade to the camel meat at 10°C decreased the pathogens by 0.8-2.4 log CFU/g. At 10°C, BR decreased L. monocytogenes, E. coli O157:H7, and Salmonella spp. by 2.0, 1.5, and 1.3 log CFU/g, while EU caused a decrease (p < 0.05) of 1.9, 1.2, and 0.9 log CFU/g, respectively. Similarly, VA caused a reduction in these microorganisms of 1.3, 1.1, and 1.0 log CFU/g, respectively (p < 0.05). The combination of marinade and EO resulted in a decrease of the pathogens ranging from 0.9-1.4 and 2.8-3.7 log CFU/g at 4 and 10°C, respectively. The antimicrobial efficacy of EO alone or when combined with marinade was higher at 10°C than at 4°C with all three pathogens at both 0.5% and 1%. Overall, EOs were found to enhance the microbial safety of camel meat. In addition, they are antimicrobials that occur naturally, require a minimum investment, and may prove to be a great asset for marinated camel meat producers.

Inhibition of spoilage bacteria on marinated chicken by essential oils under aerobic and vacuum packaging.

"Chicken tawook" is a marinated boneless chicken entrée consumed in the Middle East. The aim of this study was to determine whether bioactive essential oil (EO) components carvacrol (CA), cinnamaldehyde (CI), and thymol (TH) would delay the growth of microorganisms causing tawook spoilage during aerobic (AP) or vacuum (VP) packed storage. The EOs at 1% and 2% were mixed individually with the marinade. The samples (10 g of chicken cubes with 1.2 g of marinade - with or without EOs) were stored in bags under AP and VP (Geryon® ) for 7 days at 4 ± 1°C and abusive conditions (10 ± 1°C). Two control samples consisting of meat chunks and tawook without EO were used. The microflora numbers were greater at 10°C than at 4°C, and the marinade worked additively with AP against anaerobes, yeast and mold (Y & M) and lactic acid bacteria. It also worked additively with VP against aerobic bacteria recovered as Pseudomonas and the total plate count. EO components were observed to decrease microbial populations by a maximum of 4 to 6 log colony-forming unit (CFU)/g depending on the type of microorganism. The combined mixture of marinade and 2% EO (CA, CI, and TH) resulted in the greatest reductions of all spoilage microorganisms at 10°C under AP on the last day of storage. Overall, VP was more effective (p < 0.05) than AP in controlling microorganisms at both 4 and 10°C. This study provides an affordable and natural alternative for extending product life. PRACTICAL APPLICATION: The use of EOs in marinated chicken (tawook) is expected to help producers reduce spoilage and extend shelf-life of the product when stored at refrigeration temperatures. EOs provide a cheaper alternative and are naturally sourced. Vacuum packaging will increase the shelf-life of marinated chicken tawook and facilitate its storage and transportation.