A Microbiological Comparison of Poultry Products Obtained From Farmers' Markets and Supermarkets in Pennsylvania

Open Access
Scheinberg, Joshua Adam
Graduate Program:
Food Science
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 04, 2012
Committee Members:
  • Catherine Nettles Cutter, Thesis Advisor
  • Stephanie Doores, Thesis Advisor
  • Rama B Radhakrishna, Thesis Advisor
  • Chitrita Debroy, Thesis Advisor
  • Farmers' markets
  • salmonella
  • campylobacter
  • pathogen prevalence
  • poultry
  • needs assessment
  • vendors
  • survey
  • pennsylvania
Abstract: The popularity of farmers’ markets in the United States (U. S.) continues to rise, with an increase from 1,755 in 1994 to 7,175 in 2011. Although farmers’ markets represent a minimal portion of the agricultural market, farmers’ markets have become a significant source of food products for many Americans. Potentially hazardous foods, such as milk, meat, and poultry are popular items sold at farmers’ markets and require specific processing and handling to ensure the safety of the product. Meat and poultry items make up a large portion of potentially hazardous foods sold at farmers’ markets, but only meat products (beef, lamb, pork) are required by federal law to be processed in a USDA-inspected facility. Poultry however, can be grown and processed by individual farmers under exemption status afforded to farmers by the Poultry Products Inspection Act (PPIA). Currently, little to no data have demonstrated the microbiological profile of poultry (chicken or turkey) sold at farmers’ markets and/or compared the findings to conventionally-processed, organic and non-organic poultry sold in supermarkets. Additionally, no study has explored the processing practices, as well as the knowledge and attitudes of poultry vendors in food safety, poultry processing, and regulatory requirements. The purpose of this study was to determine the presence/absence of foodborne pathogens, as well as hygiene indicators, in fresh or frozen whole chicken purchased at farmers’ market and conventionally-processed, organic and non-organic chicken sold in supermarkets. A needs assessment was conducted to evaluate general practices and food safety knowledge and attitudes of poultry vendors at farmers’ markets throughout Pennsylvania. Whole chicken carcasses from farmers’ markets and supermarkets throughout Pennsylvania were obtained and transported back to the Penn State Muscle Foods Laboratory at 4oC until further analysis. Each chicken carcass was rinsed and levels of aerobic plate counts (APC), generic E. coli, and total coliforms were measured. Resulting rinses also were evaluated for presence/absence of Campylobacter spp. and Salmonella spp. following standard culture and confirmation methods. Results demonstrated that 28% (28/100) and 90% (90/100) of whole chicken from farmers’ markets, 20% (10/50) and 28% (14/50) of conventionally-processed organic, and 8.0% (4/50) and 52% (26/50) of non-organic chicken, were positive for Salmonella spp. and Campylobacter spp. respectively. Additionally, among the 90% of Campylobacter spp. positive farmers’ market whole chicken, 67% of rinses were enumerable, with a mean count of 1.6 log10 CFU/ml. The needs assessment survey consisted of a 32-question, paper-based survey that was administered to poultry vendors at their respective farmers’ markets during market hours. The needs assessment consisted of four sections which assessed the processing methods, knowledge, attitudes, and demographics of poultry vendors at farmers’ markets in the areas of poultry processing, food safety, and regulation. The results highlighted that 52% (11/21) of vendors slaughtered and processed their own poultry, while 48% (10/21) had their poultry processed at a separate farm or facility. Among those vendors who knew of their processing conditions, 33% (7/21) processed their poultry outside, 38% (8/21) processed their poultry inside a fixed or dedicated processing area, while the remainder either used a combination of both, or did not know. The majority of vendors appeared to have a good understanding of correct temperature control of poultry during processing. However, more than 50% (11/21) incorrectly answered questions related to pathogens and cross-contamination during processing. Additionally, the attitudinal section revealed that 100% (21/21) of vendors agreed that their poultry was safe and 95% (20/21) of vendors believed their poultry products to be safer than poultry sold in retail supermarkets. 70% (14/20) of vendors recognized that antimicrobial sprays and washes can reduce pathogens on poultry. Interestingly, 25% (5/20) agreed that additional food safety interventions were needed and 33% (7/21) utilized an antimicrobial spray or wash on their poultry before packaging. These data suggest that whole chicken purchased from farmers’ markets in Pennsylvania were more likely to be contaminated with Salmonella spp. and Campylobacter spp., as compared to conventionally-processed poultry sold at supermarkets. The results revealed critical vendor practices and identified important vendor knowledge gaps and attitudes on food safety and poultry processing, while also highlighting the need for training and educational materials for poultry vendors. The data obtained from the vendor needs assessment surveys will aid in the development of future farmers’ market research, as well as generating recommendations, guidelines, fact sheets, and outreach material on food safety issues for vendors selling meat and poultry products at farmers’ markets.