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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #347047
Research Project: Characterization and Mitigation of Bacterial Pathogens in the Fresh Produce Production and Processing Continuum

Location: Environmental Microbial & Food Safety Laboratory

Title: Minimizing pathogen growth and quality deterioration of packaged leafy greens by maintaining optimum temperature in refrigerated display cases with doors

Author
item DE FRIAS, ATILIO - University Of Maryland
item Luo, Yaguang - Sunny
item Zhou, Bin
item Turner, Ellen
item Millner, Patricia
item Nou, Xiangwu

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/14/2018
Publication Date: 5/15/2018
Citation: De Frias, A.J., Luo, Y., Zhou, B., Turner, E.R., Millner, P.D., Nou, X. 2018. Minimizing pathogen growth and quality deterioration of packaged leafy greens by maintaining optimum temperature in refrigerated display cases with doors. Food Control. 92:488-495.

Interpretive Summary: Packaged fresh-cut leafy greens are often displayed in open refrigerated cases at the retail level to provide unobstructed customer access. However, the infiltration of ambient air into these open cases could result in temperatures exceeding the US Food Code requirement of 5 °C or below. At USDA-ARS, scientists demonstrated that retrofitting open refrigerated display cases with glass doors reduced temperature abuse, minimized product quality deterioration and food safety risks, and reduced operational energy cost. These findings can help the retail industry to develop cost-effective approaches to support compliance with US Food Code and to maintain produce quality and safety.

Technical Abstract: Retail display of packaged fresh-cut leafy greens is a critical stage of cold chain management and is prone to temperature abuse when produce is displayed in open cases, due to infiltration of ambient air into the case. Previous studies demonstrated that retrofitting open display cases with doors is the most effective solution to bring produce temperatures into compliance with FDA Food Code (< 5 ºC), retain product quality longer, and reduce operational energy costs. In this study, we evaluated changes in quality attributes and populations of inoculated bacterial pathogens (Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes) in packaged baby spinach, chopped romaine, and lettuce mix displayed in a refrigerated case retrofitted with doors. All products displayed in the case with doors maintained high freshness and attractiveness after 3-day display, and the quality was comparable to that of products stored at a constant temperature in a 4 ºC cold room. No substantial changes in pathogen populations were observed during the display period. These results demonstrate that retrofitting display cases with doors is a practical means of reducing temperature abuse and damage for fresh-cut products.