Left: Ag and Biosystems Engineer, Ajit K. Mahapatra, measures the temperature of meat in a low-voltage current electrolyte system for controlling microorganisms in food. Right: Petrifilms showing bacterial colonies.
Strategies that reduce food-borne pathogens in the animal prior to processing for meat could reduce incidences of human exposure to these organisms. The gastrointestinal tracts of sheep and goats are natural reservoirs of E. coli. Fecal shedding in live animals is correlated with carcass contamination. Lambs are often fed a finishing grain-based ration in order to improve productivity. However, meat goats are predominantly fed a roughage diet until slaughter. Shedding of E. coli by ruminants is influenced by the diet and therefore dietary changes in food animals during the days prior to slaughter may reduce fecal shedding of bacteria.
Pre-harvest dietary management will serve as a cost-effective decontamination strategy in small ruminant production systems, particularly for goat processing enterprises, since most of the goat processors in the southern states operate with moderate resources and limited technology. Research conducted at FVSU include manipulating pre-harvest feed deprivation time, diet (concentrate vs. roughage), and diet change from hay to concentrate. Pre-harvest management methodologies can be implemented with virtually no additional operational costs to the farmers. These management methods are also expected to enhance marketability and profitability by improving the shelf life of carcasses and products.
FVSU researchers are also studying other cost-effective pathogen reduction strategies that can be adopted by small and very small processing facilities. Our goal is to determine and compare the microbiological characteristics of spray washing live goats and goat carcasses with ozonated water, electrolyzed oxidizing water, or salt water, as well as to determine the effects of such treatments on subsequent meat quality characteristics. Scientists are also conducting feasibility and economic cost-benefit analyses of introducing these technologies into goat slaughter establishments and meat processing facilities as strategies to inactivate foodborne microorganisms.
In FVSU’s food engineering laboratories, researchers are working on finding novel methods to kill pathogens without using heat. Using non-thermal methods for destroying pathogens allows us to decontaminate food without damaging the products. The food industry wants to ensure the safety of its products while maintaining quality. FVSU scientists applied low voltage electric current to meat samples contaminated with E. coli, covered with a thin film of table salt solution. Exposure of contaminated meat to electric current destabilized bacterial cell membranes, and with sufficient current intensity and duration of treatment, cell membranes were irreversibly damaged, important cellular compounds leaked out, and the E. coli organisms were killed. The low voltage current reduced E. coli by 98.9% in 16 minutes. Further research is required to see how this technology can be implemented in commercial operations such as meat processing plants.
FVSU is a part of the 1890 ARD (Association of Research Directors) Consortium entitled “Prevention of Microbial Foodborne Outbreaks: Food Safety Research, Teaching and Outreach Program for 1890-Land Grant Universities". The objectives of the research project are to:
- Develop and evaluate effective methods of intervention of foodborne microbial contamination on targeted foods (meat and dairy, organic foods and fresh produce)
- Develop and evaluate methods of detection and monitoring of foodborne pathogens in targeted foods
- Evaluate food quality, regulatory compliance, economic feasibility, and sustainability of intervention and detection methods
The consortium includes researchers from FVSU, North Carolina A&T, Delaware State, Florida A&M, Langston, Tuskegee, University of Arkansas at Pine Bluff, University of Maryland at Eastern Shore, Virginia State, Alabama A&M, and Lincoln University.