Performance of Cold Chains for Chesapeake Bay Farmed Oysters and Modeled Growth of Vibrio parahaemolyticus

Abstract

Temperature-controlled supply chains (cold chains) require an unbroken chain of refrigeration to maintain product quality and safety. This study investigated cold chains for farmed oysters raised in the Chesapeake Bay, one of the largest shellfish-growing regions in the United States, and sold live to the half-shell market in surrounding states. Temperature sensors were used in boxes of oysters from February to September 2017, which generated 5,250 h of temperature data. Thirty-nine businesses participated in the temperature sensor study, and 26 of those businesses participated in interviews to further understand how cold chains function. Internal oyster temperatures were measured above 50°F (10°C) for over 1 h in 19% (7 of 36) of shipments, which is a temperature that exceeds National Shellfish Sanitation Program criteria. The highest internal oyster temperature recorded in any shipment was 54.5°F (12.5°C). Some parts of the cold chain had difficulty maintaining storage temperatures below 45°F (7.2°C) in warmer months when Vibrio control plans were in effect. We modeled the effects of temperature on Vibrio parahaemolyticus. The model predicted moderate bacterial growth before oysters were under temperature control, but cold chains prevented further bacterial growth and provided a moderate drop-off in V. parahaemolyticus abundance.

Combination of Direct Viable Count and Fluorescent In Situ Hybridization (DVC-FISH) as a Potential Method for Identifying Viable Vibrio parahaemolyticus in Oysters and Mussels

“…Numerous cases of gastroenteritis caused by V. parahaemolyticus have been detected and isolated in Spain, Greece, Britain, Denmark and other countries in Europe over the years [ 72 , 73 ]. Love et al [ 74 ] demonstrated that the cold chain was effective in reducing the risk of V. parahaemolyticus in seafood by modeling the effects of temperature on the growth of this bacterium in oysters. Moderate bacterial growth was detected in oysters that had not entered the cold chain, while bacterial growth stopped once they were under refrigeration.…”

Managing the risk of Vibrio parahaemolyticus infections associated with oyster consumption: A review

“…Some parts of the cold chain in the study by Love, Lane, et al. (2019) could not maintain temperatures less than 7.28 °C, particularly during the warmer months when Vibrio control plans were in effect. Consequently, the internal temperature of oysters in the cold chain reached 12.5 °C, which is conducive for the multiplication of V. parahaemolyticus (Fernandez‐Piquer et al., 2011; Parveen et al., 2013).…”

“…Love, Lane, et al. (2019) investigated the performance of cold chains for the Chesapeake Bay farmed oysters in the United States and reported that 19% of shipments had temperatures higher than 10 °C (50 °F) for longer than 1 hr, which exceeded the recommendation of the National Shellfish Sanitation Program (NSSP) in the United States. In another study by Love, Kuehl, et al.…”

“…Love, Lane, et al. (2019) demonstrated that climatic variations affected the performance of the cold chain of oysters in the United States. Some parts of the cold chain in the study by Love, Lane, et al.…”

“…Collectively, these findings suggest that maintaining the temperature in the cold chain of oysters from harvest or production to consumption remains difficult (Love, Kuehl, et al., 2019; Love, Lane, et al., 2019; Madigan, 2007). Temperature abuse that may occur during processing, transportation, or storage can allow V. parahaemolyticus to grow to dangerously high concentrations in oysters.…”