Microbiological Quality and Safety of Fresh Produce and an Assessment of Post-harvest Practice of Vendors at West Virginia and Kentucky Farmers’ Markets

Introduction: Fresh produce sold at farmers’ markets (FMs, <$500,000 annually) raises food safety concerns due to their exemption of Food Safety Modernization Act. No information is available regarding microbial quality/safety of produce at West Virginia- and Kentucky-FMs.

Purpose: This study aims to evaluate the microbiological quality/safety of 5 different fresh produce from WV- and KY-FMs, and assess the post-harvest practices of vendors at Morgantown-WV-FM.

Methods: A total of 212 produce samples including tomatoes (64 samples, 13 vendors), green peppers (54 samples, 11 vendors), cucumbers (35 samples, 5 vendors), cantaloupes (16 samples, 2 vendors) and spinaches (43 samples, 8 vendors) were randomly purchased from two Morgantown-WV-FMs and one Bowling Green-KY-FM during fall 2015. Buffered-peptone-water (BPW) processed samples were analyzed for the aerobic-plate-counts (APCs), total-coliform-counts (TCCs), and yeast/molds population on petrifilms, and were secondly-enriched in Rappaport-Vassiliadis (Salmonella enterica spp.) and UVM broth (Listeria spp.) followed by streak-plating onto XLD (Salmonella enterica spp.) and Modified-Oxford agar (Listeria spp). Presumptive Salmonella and Listeria colonies were confirmed by API20E-kit+qPCR (Salmonella-InvA gene) and Listeria12L-kit+multiplex-PCR, respectively. A follow-up survey (20 questions) was conducted to assess the post-harvest practices of 28 vendors at Morgantown-WV-FM. Data (3 repeats/10-20 samples/repeat) were analyzed using the ANOVA and Chi-Square test of SAS.

Results: Among 212 samples, APCs, TCCs, and yeast/molds were 3.72-5.63, 3.67-5.47, and 3.07-4.13 log CFU/g, respectively, and spinach significantly contained the highest (P<0.05) population of APCs, TCCs, and yeast/molds. Salmonella enterica spp. was detected on 10.9% (7/64) of tomatoes, 18.5% (10/54) of peppers, 56.3% (9/16) of cantaloupes, and 18.6% (8/43) of spinach. Only 3.78% (8/212) of samples were confirmed for Listeria spp., and 50% (4/8) were identified as L. monocytogenes. Survey showed that 74% (20/27) venders washing produce with only 9% (2/23) using sanitizers/antimicrobials, and 50% (7/14) did not refresh sanitizers.

Significance: Results showed Salmonella and Listeria present on fresh produce at local FMs, and indicated that developing post-harvest protocols to control foodborne pathogens and developing Good Agriculture Practices training material/courses are important for FM vendors.