Investigating the Effects of Food Grade Antimicrobial Ingredients on the Microbiota of a Meat Model System
General Material Designation
[Thesis]
First Statement of Responsibility
Dogan, Mehmet
Subsequent Statement of Responsibility
Sindelar, Jeffrey J.
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
The University of Wisconsin - Madison
Date of Publication, Distribution, etc.
2020
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
124
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
Ph.D.
Body granting the degree
The University of Wisconsin - Madison
Text preceding or following the note
2020
SUMMARY OR ABSTRACT
Text of Note
The microbial spoilage of meat is a major problem due to product and economic losses. Therefore, it is important to understand how to address spoilage bacteria to reduce meat and meat product losses. Thus, the objectives of this study were 1) to investigate the antimicrobial effect of organic acids (sodium lactate (SL), sodium diacetate (SD), sodium propionate (SP) and their combinations (SL+SD, SL+SP, SD+SP, SL+SD+SP) on the populations of the lactic acid bacteria (LAB) involved in Ready-to-Eat (RTE) meat spoilage, and 2) to examine how these organic acid salts influence the changes in the spoilage LAB microbiota. Cooked vacuum-packaged deli-style turkey breasts manufactured with the different organic acids were inoculated with five spoilage LAB species (namely Lactococcus lactis, Leuconostoc mesenteroides (bacon and ham isolates), Enterococcus faecium, and Lactobacillus sakei) and stored at 4oC for 42 days. Studies were designed to analyze the effect of organic acids on spoilage LAB population using classical microbiology techniques in the model meat system and using Bioscreen C automated Growth Curve Analysis System in broth. A third study was designed to demonstrate the growth dynamics and microbial community composition changes of inoculated bacterial communities in the model meat system study through the use of 16S rRNA sequencing. Results from microbiological challenge testing revealed the incorporation of SL (SL, SL+SD, SL+SP, SL+SD+SP) in meat formulations extended the lag phase of LAB mixture for up to a week (P< 0.05), whereas SD, SP, and SD+SP, did not provide any antimicrobial effect different from control for 42 days of storage (P > 0.05). In the microbiota analysis, SD did not show any effect on the composition of LAB mixture compared to the control for 35 days, whereas the addition of SL to the SL+SD containing formulation slowed down the changes in the relative abundance of inoculated LAB microbiota for the first 14 days (P < 0.05). Among the LAB species, L. sakei was noted to be competitive and highly adaptive to the environment, being predominant regardless of treatments throughout the 35-day time period. The results demonstrated that the incorporation of SL into formulations satisfactorily impacted microbial spoilage dynamics.