POST-HARVEST FOOD SAFETY
• Thermal treatment of pecans
Despite being low in water activity, treenuts such as Pecans are prone to microbial contamination on the farm. Our field studies indicated the prevalence of bacterial pathogens such as Salmonella, E. coli O157:H7 and Listeria monocytogenes on pecans. This necessitates efficient post-harvest intervention to ensure microbiological safety of pecans. Studies were in progress using thermal treatments such as hot water and steam as a “kill-step” to achieve a 5 log reduction of bacteria and the effect of these interventions of quality and consumer acceptability.
• Effect of residual sanitizer on fresh produce
After sanitizer treatment of produce commodities, there will be still a chance of cross-contamination during post treatment steps including storage, handling and packaging. Studies were conducted to investigate the effect of residual sanitizers (Cl2, ClO2, Lactic acid, Acetic acid, etc.) on the survival and the attachment of E. coli O157: H7 and L. monocytogenes on the spinach surface. The findings of this research would be helpful to understand how the cross contaminating pathogens behave on the produce surface in the presence of residual sanitizers.
• Sprout safety
Sprouted seeds have been associated with several outbreaks of human illness. Because the seeds and beans need warm and humid conditions to sprout and grow, the sprouting condition is an ideal for the growth of pathogenic bacteria. Studies were conducted to evaluate the efficacy of sequential hot water and peroxyacetic acid (PAA) treatment in inactivating Salmonella on alfalfa, radish or clover seeds intended for sprout production. Further, the role of sprouting process on the growth of generic E. coli on alfalfa seeds and the efficacy of sequential aqueous chlorine dioxide treatment in eliminating the generic E. coli during sprouting were also investigated.
• Chlorine Dioxide Treatment of sweet potatoes, strawberries, and blueberries
Two forms of chlorine dioxide are used to reduce the bacterial load of pathogen inoculated Louisiana specialty crops. Sweet potatoes are treated with aqueous chlorine dioxide and strawberries and blueberries are treated with gaseous chlorine dioxide. Data from this research will be used to train Louisiana farmers in science driven produce safety treatments to remain economically competitive in light of FSMA’s Produce Safety Rule.