The number of farmers' markets in United States (U.S.) increased dramatically from 1775 markets in 1994 to 8,476 markets in 2014. However, few studies have investigated consumers' food safety perceptions toward products in farmers' market or their impact on consumers' purchasing behaviors. The objectives of this study were to understand consumers' perception of food safety at farmers' markets and to explore the role of food safety perception on their purchasing fresh produce at a farmers' market. Analysis of covariance was used to investigate food safety perceptions at farmers' market among different demographic groups. In addition, multiple linear regression was used to explore factors including consumers' food safety perception and quality perception on their purchasing at a farmers' market. The results from the ANCOVA indicated that millennial generation consumers perceived better food safety conditions at farmers' markets. The linear regressions indicated quality perception and willingness to support local foods are primary reasons that consumers purchase products at farmers' markets, while food safety perception is not significantly related to purchasing fresh produce. The results imply that consumers generally hold a positive food safety perception that may be in contrast to actual microbial safety of produce obtained from farmers' markets. The results highlight an increasing need for consumer education specifically related to food safety awareness at farmers' markets.

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Aims:  To determine the virulence gene expression of Salmonella Typhimurium in response to sublethal heat stress and determine the adhesion and invasion pattern of heat‐stressed Salmonella in Caco‐2 intestinal epithelial cells. Methods and Results:  Transcriptional profiling was employed to capture the virulence gene response of Salm. Typhimurium at 42°C sublethal heat stress. Data indicated an induction of SPI‐2 and SPI‐5 genes and a repression of SPI‐1‐encoded genes due to heat stress. Gene expression pattern also showed induced transcription of fimbriae genes and genes present within the stress‐associated Rpo regulon. Changes in adhesion and invasion pattern of heat‐stressed Salm. Typhimurium were tested in Caco‐2 cells. Heat‐stressed Salm. Typhimurium showed greater adhesion to Caco‐2 cells compared with nonstressed control cells. Conclusions:  Salmonella Typhimurium exposed to sublethal heat stress responds by altered virulence gene expression, which further enhances the adhesion of bacterial cells to intestinal Caco‐2 cells. Results indicate a role of physiological stress in Salm. Typhimurium in promoting microbial virulence and host cell vulnerability to infection. Significance and Impact of the Study:  Studying the Salmonella virulence genes expression in response to sublethal heat stress is crucial for the understanding of the virulence status of Salmonella in temperature‐abused foods. Results of this study provide information about the gene response and virulence status of Salmonella pathogenicity factors in response to sublethal heat stress towards host cells.

Antimicrobials currently used in the conventional poultry industry include physical, chemical, and biological hurdles. However, there is a need for natural and organic antimicrobials to make the food safe and to retain its natural taste and texture. Potential natural or organic antimicrobials include bacteriophages, bacteriocins, antibody therapy, vaccination, and the use of natural plant compounds such as essential oils. Genomic methods applied to salmonella responses to multiple interventions may offer opportunities to optimize combinations that are the most effective.

Aquaponics is an effective method to practice sustainable agriculture and is gaining popularity in the US; however, the microbial safety of aquaponically grown produce needs to be ascertained. Aquaponics is a unique marriage of fish production and soil-free produce (e.g., leafy greens) production. Fish are raised in fresh water tanks that are connected to water filled beds where fruits and vegetables are grown. The fish bi-products create nutrient-rich water that provides the key elements for the growth of plants and vegetables. The objective of this study was to perform a comparative analysis of the microbial safety and quality of aquaponic lettuce and soil grown lettuce (conventional, bagged, certified organic, and field lettuce). Following this, an intervention study was performed to combat foodborne pathogen surrogates (Salmonella and E. coli), spoilage, and fecal microorganisms using 2.5% acetic acid. The results of the comparative analysis study showed that aquaponically grown lettuce had significantly lower concentration of spoilage and fecal microorganisms compared to in-soil grown lettuce. The intervention study showed that diluted vinegar (2.5% acetic acid) significantly reduced Salmonella, E. coli, coliforms, and spoilage microorganisms on fresh lettuce by 2 to 3 log CFU/g. Irrespective of growing methods (in-soil or soilless), it is crucial to incorporate good agricultural practices to reduce microbial contamination on fresh produce. The intervention employed in this study can be proposed to small farmers and consumers to improve quality and safety of leafy greens.