While the full article for this executive summary is currently under peer review, these initial findings are being made available on BeefResearch.org to enable the industry to act on the research, inform the scientific community of ongoing work, and help prevent duplication of research efforts. Once peer review is complete, a link to the published article will be added to this summary.
Cold chain management of boxed beef is critical to maintain product quality and maximize shelf-life performance. A key component of cold chain management is temperature control, which is critical to product quality and safety. Product distribution centers utilize rigid guidelines for acceptable temperatures to receive product in an effort to ensure product quality or safety have not been compromised. It is not uncommon for upstream receiving customers to reject trailer loads when an in-transit air temperature logger is warmer than 4.44 °C for longer than 4 hours. A challenge is, this rejection can occur based off of the transit logger tracking air temperature of a trailer, and not necessarily representative of product temperature. Rejected loads often lead to significant monetary loss and discarded product. Considering the mass of boxed beef packaged in cardboard boxes, stacked tightly on wood pallets, and filling the floor space of a refrigerated truck, it is expected that actual product temperatures would remain unimpacted by warmer air temperatures for some time. The objectives of this research were to evaluate product surface temperature compared to trailer air temperature baseline by using temperature data loggers placed within cases of boxed beef, in a full loaded commercial refrigerated transportation trailer set to a slightly warmer set-point than traditionally expected in boxed beef distribution. Additionally, to determine the beef product quality effects after simulated temperature abuse shipment by conducting a retail shelf-life assessment.
Of note – both phase 1 and phase 2 were completed in entirety over two separate years (early summer 2023, and late summer 2024).
Phase 1: Cases of whole muscle product (bone-in striploin, chuck eye, bone-in ribeye, brisket, inside round, shoulder clod, short ribs, and eye of round) were procured from a commercial beef processing facility and loaded on a commercial refrigerated trailer, standard for distribution of boxed beef, with a set-point of 3.33°C (38 °F). Product was subjected to a multiple day transit (139 hours), simulating realistic transportation time environment, to a distribution center located in the United States. Continuous temperature data logging devices were placed within boxes of product and distributed throughout the trailer, with care being taken to track location of each case and pallet within the trailer. In addition, temperature data loggers were placed at the front and rear of the trailer to capture air temperature during transit.
Phase 2: Cases of whole muscle items (bone-in strip loin, bone-in ribeye, chuck eye, brisket) and ground beef chubs (90/10, 81/19, 80/20) were procured from a commercial beef processing facility. Four cases of each item were procured. One case, selected at random, was identified as the control case. The three remaining cases of each item were designated as test cases to be subjected to a 24h temperature abuse prior to completing shelf-life evaluation. Test cases were placed in a cooler room set at 10°C (50°F) for 24 hours, this simulated product loaded on a warm trailer and subjected to a 24 h transportation process. Temperature data was collected to represent air in the warm trailer (room), and temperatures of products within cases. After spending 24 hours in the abuse cooler product was moved to a traditional holding cooler 0°C (32°F) and evaluated through a case-ready retail shelf-life process mimicking a grocery store process (steaks or roasts cut from whole muscle; patties/pucks cut from chubs of ground beef; placed in foam trays and overwrapped, subjected to retail display case). Shelf-life evaluation included subjective odor and instrumental color through a typical shelf-life display. Significance was set at (p<0.05).
During phase 1, the transportation test, temperature varied by location within the trailer. Furthermore, air temperatures were higher than product temperatures throughout the trailer. There were differences in temperature considering front of truck versus tail of truck, and differences were detected based on location of the box within a pallet (bottom, middle or top). During phase 2, overall, a 24 hour elevated temperature hold did not impact shelf-life performance of whole muscle or ground beef products. The cold product loaded into the stable and slightly abusive, in temperature, cooler, lowered the cooler air temperature during the 24 hours of holding. This finding supports the idea that a mass of full cases of properly chilled beef will maintain chilled temperatures for a period of time even when placed in a warmer environment (such as a warm trailer). This provides extra insurance that a full trailer of properly chilled product can handle some minimal duration of elevated temperatures and an air data logger may not most accurately represent product temperature during this abuse exposure.
In the transportation test, phase 1, air temperatures did not accurately represent product temperatures in a full refrigerated trailer load. Currently, depending on the standard operating procedures (SOP) at a distribution facility, product that is received with a temperature data point ≥4.4°C (40°F) might be rejected and destined for being destroyed, resulting in a significant financial loss and food loss. This work demonstrates that location of a data logger within a refrigerated trailer will impact the temperature recorded (tail versus front of trailer). These results indicate opportunity to revise distribution center receiving temperature restrictions to represent product temperature rather than truck air temperature more appropriately. These data all support understanding that location of placement for a data logger within a refrigerated truck will impact the recorded temperature data points. Overall, a 24-hour temperature abuse simulating a warm trailer (10°C/ 50°F) during the cold holding of ground and whole muscle beef did not negatively impact the retail shelf-life performance. These results indicate that while it is still paramount to ensure product safety and quality are top of mind in cold chain management, there may be some forgiveness opportunity if product is exposed to short term elevated temperatures during distribution. This is especially valuable to the industry during times of elevated environmental temperature or unique circumstances during truck loading or transportation that may result in slightly elevated temperatures for the short duration of transport.
ARMS#010226-07