Plant extracts and essential oils at concentrations acceptable to a sensory panel inactivate salmonella typhimurium dt104 in ground pork

Authors: CHEN, CYNTHIA - University Of Arizona; MARCHELLO, JOHN - University Of Arizona; Friedman, Mendel; RAVISHANKAR, SADHANA - University Of Arizona

Submitted to: Food and Nutrition Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/23/2021
Publication Date: 2/26/2021
Citation: Chen, C.H., Marchello, J., Friedman, M., Ravishankar, S. 2021. Plant extracts and essential oils at concentrations acceptable to a sensory panel inactivate salmonella typhimurium dt104 in ground pork. Food and Nutrition Sciences. 12(2):162-175. https://doi.org/10.4236/fns.2021.122014.
DOI: https://doi.org/10.4236/fns.2021.122014

Interpretive Summary: Salmonella Typhimurium DT104 is one of the major foodborne pathogens that is known for its resistance to multiple antibiotics. Humans can be infected by Salmonella via consumption of contaminated food such as pork sausage, as indicated by two epidemiological studies in Germany that reported that consumption of raw pork products is the major risk factor in sporadic Salmonella infections of both adults and children. A potential method of inhibiting pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. While the addition of antimicrobials may improve microbiological safety, it may simultaneously adversely affect the sensory characteristics of the meat. To help overcome this aspect, the objective of this study was to define the appropriate concentrations of cinnamon and oregano essential oils and of apple and olive extracts that are acceptable to consumers when added to ground pork. Sensory characteristics (color, aroma, taste, acceptability) of laboratory produced ground pork inoculated with Salmonella bacteria were adversely affected by added high concentration of the plant antimicrobials. The results also show that for a ground pork product to be acceptable by consumers, the maximum amount of the cinnamon and oregano oils should not exceed by 0.5%, and of apple and olive extracts by 3%. This study shows how it is possible to discover the proper balance between desirable antimicrobial effects of plant compounds and the concurrent ability to maintain food sensory qualities of a food. The methodology and results might be of interest to FSIS.

Technical Abstract: A potential method to inhibit pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. Because these antimicrobials may also adversely affect the sensory characteristics of the meat, the objectives of this study were to define the appropriate concentrations of olive extract (OE), apple extract (AE), oregano oil (OO), and cinnamon oil (CO) added to ground pork that are acceptable to a sensory panel. Antimicrobial activities were determined against two initial inoculum levels (107 and 105 CFU/ml) of Salmonella Typhimurium DT104 in inoculated ground pork. Sensory tests showed that acceptable concentrations of oregano and cinnamon oils and were 0.5% and of olive and apple extracts 3%, respectively. Salmonella inoculated ground pork samples with added antimicrobials were then stored at 4°C up to 7 days. Survivors were enumerated at day 0, 3, 5, and 7. Added 0.5% cinnamon oil and olive extract at 3% induced a 1.0 and a 0.9 log reduction at day 7. At 3%, the olive extract showed a 1.06 log maximum reduction from the lower initial inoculum of 104 CFU/g. Pork samples containing oregano oil and apple extract did not show a significant reduction compared to the control without the additives. The results indicate that cinnamon oils and the olive extract can potentially be applied at consumer-acceptable concentrations against low levels of Salmonella Typhimurium DT104 in ground pork.